Dissertations / Theses: 'Effective Moment of Inertia'

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Warmoth, Francis James. "Floor Vibrations: Girder Effective Moment of Inertia and Cost Study." Thesis, Virginia Tech, 2002. http://hdl.handle.net/10919/41005.

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Studies on the effective moment of inertia of girders that support concrete slabs using joist seats as the horizontal shear connections, and a cost efficiency analysis comparing composite and non-composite floor systems that meet vibrations design standards, were conducted. The first study was undertaken because over-prediction of girder effective moment of inertia was the suspected cause of several recent vibration problems in floors supported by widely spaced LH-series joists. Eight purpose-built floors of the type in question were subjected to experimental tests of girder effective moment of inertia and girder frequency. Frequencies were tested for two live loading cases. Three separate test configurations were made with each floor by changing the seat-to-girder connections between bolted, welded, and reinforced. In the study, 1) the accuracy of the current design practice is assessed, 2) a new relationship was proposed, and 3) suggestions for finite element modeling are made. In recent years, composite construction has been used to improve cost efficiency by reducing structural weight and in some cases by reducing story height. However, vibration problems are a design consideration in composite floors because lighter floors tend to be more lively. It is not clear if cost savings can be made with composite construction if vibrations are considered in the design. To compare the cost of composite and non-composite floors that satisfy AISC/CISC Design Guide criterion for walking excitation, four typical size bays were analyzed using commercial design software that finds the least expensive member configuration for a given bay size. All acceptable bay configurations of member sizes and spacing were evaluated for least non-composite and composite costs, then these results were compared. The findings show that composite construction can be more economical when initial dead load deflections do not control the design.
Master of Science

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Wickline, Joseph Edward. "A Study Of Effective Moment of Inertia Models for Full-Scale Reinforced Concrete T-Beams Subjected to a Tandem-Axle Load Configuration." Thesis, Virginia Tech, 2002. http://hdl.handle.net/10919/35754.

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This thesis is a product of the U.S. Army Corp of Engineer's desire to develop a more accurate procedure for estimating the load capacity of an in-service T-beam bridge. A bridge type that is a stumbling block for U.S. Army field engineers due to the unknown amount and placement of the flexural reinforcement in the T-beam girder cross-sections. Personnel from the U.S. Army Corp of Engineer's Waterways Experiment Station in cooperation with personnel from Virginia Tech conceived a procedure that is potentially more accurate, can be quickly executed in the field, and is relatively easy to use by field engineers. In general, the procedure provides a method for transition between the quantity of flexural reinforcement in a reinforced concrete T-beam and the member's actual moment of inertia. Specifically, the goal of this thesis is to evaluate the accuracy of selected, effective moment of inertia models as a component in the proposed analysis procedure. The accuracy of the selected models is evaluated with test data generated from a testing program detailed herein, which load tested full-scale reinforced concrete T-beams. The test specimens were subjected to a closely-spaced, tandem-axle load configuration, a load configuration typical of military equipment.
Master of Science

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Banibayat, Pouya. "Experimental Investigation of the Mechanical and Creep Rupture Properties of Basalt Fiber Reinforced Polymer (BFRP) Bars." University of Akron / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=akron1323229543.

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Alvarez, Guevara Kervin Alexander, and Chumpitaz Marco Fabricio Medina. "Análisis de la influencia de las secciones agrietadas en la respuesta a una solicitud sísmica en edificios regulares e irregulares multifamiliares de 5, 10 y 15 pisos en la ciudad de Lima." Bachelor's thesis, Universidad Peruana de Ciencias Aplicadas (UPC), 2020. http://hdl.handle.net/10757/653473.

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Esta investigación aborda la real influencia que tiene el agrietamiento de los elementos estructurales en la reducción de rigidez cuando se produce un evento sísmico. Para ello, en primer lugar, describió la realidad problemática, los antecedentes y generalidades previos acerca del tema para determinar qué tipo de edificación utilizar. En segundo lugar, el marco teórico expuso un conjunto de conceptos fundamentales necesarios para entender el agrietamiento del concreto, la obtención de la inercia efectiva, la irregularidad de edificaciones y se dio un repaso sobre las consideraciones de normas extranjeras. En tercer lugar, se determinó trabajar con 6 planos de viviendas multifamiliares, de los cuales 3 fueron estructuras regulares y 3 fueron irregulares. Asimismo, se subdividió las estructuras en alturas de 5, 10 y 15 pisos, ya que son el tipo de edificación que más se construyen en Lima. Después se halló los parámetros geográficos, de uso y geométricos a partir de la Norma E-030, para luego realizar el análisis sísmico lineal (estático y dinámico). Luego, se realizó los diagramas de momento – curvatura (vigas, columnas y placas), para que, a partir de ellos, obtener un factor de reducción de la inercia bruta y realizar un nuevo análisis sísmico considerando este valor como efecto del agrietamiento. Finalmente, se realizó un análisis comparativo entre los resultados obtenidos de acuerdo a la altura en edificaciones regulares e irregulares.
This research addresses the real influence of the cracking of structural elements in the reduction of rigidity when a seismic event occurs. To do this, first, he described the problematic reality, the background and previous generalities about the topic to determine what type of building to use. Secondly, the theoretical framework exposed a set of fundamental concepts necessary to understand the cracking of concrete, the obtaining of effective inertia, the irregularity of buildings and a review of the considerations of foreign standards. In the third place, it was determined to work with 6 multifamily housing plans, of which 3 were regular structures and 3 were irregular. Likewise, the structures were subdivided into heights of 5, 10 and 15 floors, since they are the type of building that is most constructed in Lima. Afterwards, the geographic, use and geometrical parameters were found from the E-030 standard, to then perform the linear seismic analysis (static and dynamic). Then, the moment diagrams - curvature (beams, columns and plates) were made, so that from them, obtain a reduction factor of the gross inertia and perform a new seismic analysis considering this value as an effect of cracking. Finally, a comparative analysis was made between the results obtained according to the height in regular and irregular buildings.
Tesis

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Samsvik, Jonas, and Adam Norén. "Framtagning av spännviddstabell för ribbdäcksbjälklag." Thesis, Högskolan Dalarna, Byggteknik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:du-30449.

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Examensarbetets syfte är att finna en beräkningsgång för ribbdäcksbjälklag så att en spännviddstabell kan skapas. Ett ribbdäcksbjälklag består av stående limträbalkar med en liggande KL-träskiva ovan som fungerar som golv. I detta examenarbete är KL-träskivan 2,4 meter bred och vilar på två limträbalkar. Full samverkan mellan de olika materialen råder. Idag finns det några aktörer på marknaden som levererar liknande typer av bjälklag men det finns ingen beräkningsgång preciserad i Eurokod. Förstudien till examensarbetet har visat på att tillvägagångssättet för att lösa den mest problematiska beräkningen har varit densamma för de företagen vi har kollat på. Svårigheten är att beräkna den effektiva bredden för tvärsnittet. Det finns även olika standarder som gäller för hur stor nedböjningen får vara för ett bjälklag. I examensarbetet utförs beräkningar för att uppfylla de krav som gäller i Sverige samt de krav som gäller i Österrike. Detta görs för att dalamissivträ misstänker att kraven på de österrikiska bjälklagen är högre ställda med avseende på svikt, de vill kunna erbjuda ett styvare bjälklag. I tabellen ska dimensioner anges för att respektive krav ska uppfyllas. De österrikiska kraven har visat sig vara hårdare ställda jämfört med de svenska och kommer därför att kräva en balk av större dimension i de lägre lastfallen. I fallen med större laster kommer balkdimensionerna mellan de olika lastfallen inte att skilja sig. Där har det visast sig att branddimensioneringen varit helt dimensionerande. Tabellen ska vara ett hjälpmedel för företaget Dala massivträ att lättare nå ut till beställare. Beräkningsgången har gjorts i Mathcad, där okända parametrar har lösts ut och beräknats fram. Vissa parametrar har varit fasta utifrån Dala massivträs önskemål, så som KL-träskivans tjocklek och ingående komponenters materialegenskaper. När beräkningarna har gjorts har de kontrollerats så att momentkapacitet och tvärkraftskapacitet är tillräcklig i respektive last fall och spännvidd. Nedböjningen har kontrollerats liksom branddimensioneringen. Har bjälklaget inte uppfyllt hållfastighetsdimensionering eller kraven för svenskstandard alternativt österrikiskstandard har en högre dimension valts på limträbalken. Limträbalk har valts utifrån Setra trävarors standardsortiment. Resultatet av beräkningarna har förts in i en spännviddstabell som byggts upp för att enkelt kunna välja balk utifrån tänkt last fall. Beräknings exempel finns redovisat i en bilaga där ett lastfall och en spännvidd redovisas. Resultatet leder till att varje spännvidd och lastfall får två dimensioner, en för att klara svensk standard och en för att klara österrikiskstandard. I diskussionen diskuteras eventuella felkällor, effekten av tätare placering med limträbalkar och orsaken till en differens i jämförelsen mellan Mathcad och Calculatis. Även resultatet i spännviddstabellen diskuteras.
The purpose of the degree project is to find a calculation path for ribbed deck joists so that a span width table can be created. A ribbed deck joists consists of standing glulam beams with a lying cross laminated timber slab above which functions as a floor. In this thesis, the cross laminated timber board is 2.4 meters wide and rests on two glulam beams. Full cooperation between the different materials prevails. Today, there are some players in the market that deliver these types of floor but there is no calculation rate specified in Eurocode. The preliminary study for the degree project has shown that the approach to solving the most problematic calculation has been the same for the companies we have looked at. The difficulty is to calculate the effective width of the cross section. There are also different standards that apply to how large the deflection may be for a beam. In the thesis work, calculations are performed to meet the requirements that apply in Sweden and the requirements that apply in Austria. Dimensions must be specified in the table for fulfilling the respective requirements. The Austrian requirements have proved to be harder compared to the Swedish ones and will therefore require a beam of greater dimension in the lower load cases. In case with the larger loads, the beam dimensions between the different loads will not differ because it has been shown that the fire has been dimensional. The table should be a tool for the company Dala massivträ to reach the customer more easily. The calculation path has been made in Mathcad, where unknown parameters has been solved and calculated. Some parameters have been fixed based on Dala massivträ´s wishes, such as the thickness of the cross laminated timber board and the material properties of the component parts. Once the calculations have been made, they have been checked so that torque capacity and transverse power capacity are sufficient in the respective load cases and span. The deflection has been checked as well as the fire dimensioning. The flooring has not fulfilled the dimensioning or the requirements for Swedish standard alt. Austrian standard has a higher dimension selected on the glulam beam. Glulam beam has been selected based on Setra's wood products standard range. The result of the calculations has been entered into a span table which has been built up in order to be able to easily select the beam from outside the intended load case. The calculation example is presented in an annex where a load case and a span are reported. The result is that each span and load fall get two dimensions, one to meet the Swedish standard and one to cope with the Austrian standard. In the discussion, is discussed possible sources of error, the effect of denser placement with glulam beams and the cause of a difference in the comparison between Mathcad and Calculatis. The result in the span table is also discussed.

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Koh, Meng hock. "Fission-barriers and energy spectra of odd-mass actinide nuclei in self-consistent mean-field calculations." Thesis, Bordeaux, 2015. http://www.theses.fr/2015BORD0208/document.

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Alors qu’il existe de nombreux calculs microscopiques de barrières de fission pour des noyaux composés pair-pairs, il n’y a cependant que relativement peu de tels calculs pour des noyaux de masse impaire. Ceci est dû aux complications induites par la brisure de la symétric de reversement du sens du temps au niveau du champ moyen qui est engendrée par la présence d’un nucleon non apparié. Pour éviter cette difficulté, des calculs existants pour des noyaux de masse impaire ont tout simplement négligé ces effets de brisure de la symétrie de reversement du sens du temps.Dans ce travail, on se donne pour but d’améliorer la description des barrières de fission, aussi bien que des propriétés spectroscopiques du niveau fondamental et de l’état isomérique de fission,pour quelques isotopes de masse impaire dans la région des actinides en prenant en compte de tels effets. Ceci a été réalisé dans le cadre du formalisme de Skyrme–Hartree–Fock plus BCS avec blocking en adaptant ce formalisme à la brisure de la symétrie considérée. L’interaction résiduelle d’appariement a été approchée par une force de séniorité dont les paramètres ont été ajustés pour reproduire les différences de masse pair-impair de quelques noyaux de la région des actinides.Les énergies des têtes de bande rotationnelle de basse énergie ont été calculées dans le cadre du modèle unifié de Bohr-Mottelson pour quatre noyaux bien déformés (235U, 239Pu, 237Np, 241Am)produisant un bon accord qualitatif avec les données pour les noyaux impairs en neutrons. L’accord significativement moins bon obtenu pour les noyaux impairs en protons pourrait résulter de l’usage de l’approximation de Slater pour l’interaction d’échange de Coulomb. Les énergies de déformation de deux noyaux impairs en neutrons (235U, 239Pu) ont été calculées pour quelques configurations de particule individuelle, jusqu’après la barrières de fission externe. La symétrie axiale a été imposée tandis que la brisure de la symétrie droite-gauche (ou de parité intrinsèque) a été permise dans la région de la seconde barrière. Les hauteurs des barrières de fission pour ces noyaux impairs dépendent significativement des configurations de particule individuelle. Un accord qualitatif avec les données disponibles pour les hauteurs de barrières des noyaux impairs considérés et leurs voisins pair-pairs a été généralement obtenu
While there have been numerous microscopic calculations on fission barriers of even-even compoundnuclei, there are however, relatively few such work dedicated to odd-mass nuclei. This is dueto the complications posed by the breaking of the time-reversal symmetry at the mean-field leveldue to the presence of an unpaired nucleon. In order to circumvent this difficulty, previous fission barriercalculations of odd-mass nuclei have been performed by neglecting the effect of time-reversalsymmetry breaking. This work aims to improve on the description of fission barriers as well asthe spectroscopic properties of ground and fission-isomeric state, of some odd-mass actinide nucleiby taking the effect of time-reversal symmetry breaking into account. This has been perfomedwithin a Skyrme-Hartree-Fock-plus-BCS framework with blocking, where the BCS formalism hasbeen adapted to accomodate this symmetry breaking. The Skyrme nucleon-nucleon effective forcehas been used with various sets of parameters (SIII, SkM*, SLy5*). The residual pairing interactionhas been approximated by seniority forces whose neutron and proton parameters have beenfitted to reproduce the odd-even mass differences of some actinide nuclei. The low-lying rotationalband-head energies evaluated within the Bohr-Mottelson unified model have been determined forfour well-deformed odd-nuclei (235U, 239Pu, 237Np, 241Am) yielding a good qualitative agreementto the data for odd-neutron nuclei. The agreement was significantly less good for the odd-protonnuclei, possibly due to the use of the Slater approximation for the exchange Coulomb interaction.The deformation energies of two odd-neutron nuclei (235U and 239Pu) have been calculated forsome single-particle configurations up to a point beyond the outer fission-barrier. Axial symmetrynuclear shape has been assumed while a breaking of the left-right (or intrinsic parity) symmetryhas been allowed around the outer fission-barrier. The fission-barrier heights of such odd-neutronnuclei depend significantly on the particle configurations. A special attention has been paid tothe very important rotational correction to deformation energies. In particular, the correction ofthe moment of inertia calculated from the usual Belyaev expression was considered. Overall, aqualitative agreement with available data on fission-barrier heights for the considered odd-neutronnuclei and their even neighbours has been obtained

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Schorah, David J. "The effect of moment of inertia on the speed of swung implements." Thesis, Sheffield Hallam University, 2015. http://shura.shu.ac.uk/20803/.

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The maximum swing speed of an implement is an important performance parameter in many sports. It is understood that moment of inertia (MOI) has an effect upon the swing speed of an implement and numerous studies have found a similar rate of swing speed decay (n). These studies considered different movements which suggested that skill was less important than physique to the relationship between swing speed and MOI. The aim of this project was to quantify this relationship and to determine whether the physical characteristics of a participant can be used to predict their swing speed performance. A series of eight visually identical rods with varied MOI were swung in a heavily restricted, maximal motion and trials were recorded with a motion capture system. The results found that swing speed decreased as MOI increased. It was also found that if n was assumed to be constant, the maximum work done by a participant was strongly and significantly related to their swing speed. The relationship between work done and swing speed was used to create a model to predict swing speed for an implement with a specific MOI. This model was validated for a new set of participants performing the same restricted motion and all measured data fell within the confidence intervals of the predictions. The ecological validity of the model was tested in an analysis of the swing speed of tennis groundstrokes. An impact model was used to analyse the effect of changing MOI on ball speed. It was discovered that there is an optimum MOI that produces a maximum ball speed and that this optimum MOI is dependent upon n. This makes the customisation of equipment a realistic possibility. A simple method for measuring n in a non-laboratory environment is proposed that will enable the customisation process to take place.

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Pearce, Steven James. "Core-mantle interactions resulting from sudden changes in the Earth's moment of inertia." Diss., The University of Arizona, 1995. http://hdl.handle.net/10150/187267.

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The effect of sudden changes in the Earth's moment of inertia on the hydromagnetic state of the core is studied. Rapid changes in georotation, due to ice age transgression and regression, are described as varying boundary conditions in an axisymmetric Earth model containing both viscous and electromagnetic coupling. The deterministic equations describing the limit of rapid rotation are employed in conjunction with restricted 2-D predictive magneto-fluid equations. A kinematic description is devised for both buoyancy driven mass motions and the regeneration of the poloidal magnetic field. A pseudo-spectral method is used to solve the incompressible magneto-fluid equations. The variables are collocated in radius using Chebyshev polynomials and the pseudospectral evaluations in colatitude are done using associated Legendre polynomials. Time dependence and magnetic diffusion are controlled by a modified second order semi-implicit Runge Kutta scheme. Deterministic steady state solutions were found in full agreement with Hollerbach and Jones (1993a,b; 1995). Steady state boundary layers, arising from differential motion of the outer core boundaries, were found to induce significant departures for both α²- and αω-dynamo steady state configurations. The hydromagnetic communication time of the core, determined the predictive magneto-fluid equations, is found to be consistent with the deterministic calculations. 'Within the context of this model, it is concluded that a causal connection is plausible between geomagnetic transients and significant changes in the Earth's moment of inertia.

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Rücker, Jan. "Měření hmotnostních parametrů vozidel." Master's thesis, Vysoké učení technické v Brně. Ústav soudního inženýrství, 2012. http://www.nusl.cz/ntk/nusl-232657.

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This thesis is the first part deals with methods of determining weight parameters of vehicles. By measuring the position of center of gravity and inertia measurements. In the second part focuses on the measurement of gravity position in a selected group of vehicles Škoda and their comparison between vehicles and comparison with simulation programs PCcrach and Virtual crach.

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Xu, Tongyi. "Design and Analysis of a Shock Absorber with a Variable Moment of Inertia Flywheel for Passive Vehicle Suspension." Thèse, Université d'Ottawa / University of Ottawa, 2013. http://hdl.handle.net/10393/26293.

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Conventional vehicle suspensions consist of a spring and a damper, while mass is rarely used. A mass, if properly used, can also create a damping-like effect. However, a mass has only one terminal which makes it difficult to be incorporated into a suspension. In order to use a mass to achieve the damping-like effect, a two-terminal mass (TTM) has to be designed. However, most of the reported TTMs are of fixed moment of inertia (TTM-CMI), which limits the further improvement of the suspension performance and responsiveness to changes in environment and driving conditions. In this study, a TTM-based vibration absorber with variable moment of inertia (TTM-VMI) is proposed. The main component of the proposed TTM absorber contains a hydraulic-driven flywheel with sliders. The moment of inertia changes with the positions of the sliders in response to the driving conditions. The performance of the proposed TTM-VMI absorber has been analyzed via dynamics modeling and simulation and further examined by experiments. The analysis results indicate that the TTM-VMI absorber outperforms the TTM-CMI design in terms of body displacement; and ride comfort, tire grip and suspension deflection for zero and impulse inputs with comparable performance for sinusoidal input.

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Dvořák, Karel. "Měření setrvačných charakteristik těles pro účely matematického modelování dynamiky vozidel." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2008. http://www.nusl.cz/ntk/nusl-227970.

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The aim of the diploma thesis is to create a concept of methods that can be used for measurement of important mechanical inertia properties of bodies -- the coordinates of center of gravity and the the moment of inertia tensor, in case we don't have 3D model of these bodies. The thesis divides this problem into several sub-problems and suggests the solutions for each of them. Required equipment was created and measurement was carried out. At the end the measured values are compared with the teoretical ones and accuracy of this method is determined.

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Blad, Marika, and Balog Alexander Tynnerstål. "Design of Eccentric Double Amplitude Vibration Drum Roller Shaft with Improved Mass Moment of Inertia : Product Development of Compaction Equipment." Thesis, Blekinge Tekniska Högskola, Institutionen för maskinteknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-19643.

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Road construction is important to make transports safe and sustainable. To compact asphalt an amount of energy needs to be conducted into the material either by static pressure or dynamic vibrations. An asphalt-roller compact the material and increases its load-bearing capacity. An eccentric shaft that generates vibrations is attached inside the roller drums. The shaft has two modes, varying between high eccentricity with slower pulses and low eccentricity with faster pulses. The study has been performed with the purpose to decrease the mass moment of inertia by redesigning the present eccentric shaft and verifying the new concepts with linear and non-linear FEM simulations. The new models were to have the same functional properties as the present eccentric shaft. The current cross-section of the shaft was changed to a cross-section of a circle in the periphery. This was done by adding all features in new geometry to a simple shaft base and creating an analysis chain. To create the new lengthwise design brainstorming was used to generate ideas. The ideas were then sorted by using a Pugh matrix. CAD was used to model the concepts with the desired eccentric properties. Simulation in FEM software was used to acquire information about the behaviors during operation. Academic validation and useful information have been gathered by doing a literature review. Two resulting concepts with properties fulfilling the prevailing restrictions. The circular cross-section in the periphery was adapted and the eccentric properties were kept. The simulation results from FEM software ended satisfactorily within limits for both execution in steel and ductile iron. For both concepts the mass moment of inertia was minimized, with 40.5 % in steel and in ductile iron with 42.0 % and 42.6 %. An analysis chain has been performed showing that a cross-section with a circular geometry is optimal when the intention is to minimize the mass moment of inertia. It is possible to minimize the mass moment of inertia without negatively affecting the eccentric properties. The lengthwise design of a shaft with eccentric properties has been studied and simulated. Two concepts with varied lengthwise designs have been created with conserved eccentric properties and significantly decreased mass moment of inertia. The concepts can compose a good basis to continue investigating the lengthwise design which hopefully ends in a manufacturable eccentric shaft that contributes to environmental asphalt construction with low energy usage.
Tillverkning av vägar är viktigt för att transporter ska kunna utföras på ett säkert och hållbart sätt. För att packa asfalt behövs en mängd energi överföras till materialet genom statiskt tryck eller dynamiska vibrationer. En asfaltsvält packar materialet och ökar dess belastningsförmåga. En excentrisk axel som genererar vibrationer sitter inuti trummorna på välten. Denna axel har två lägen som varierar mellan att ha hög excentricitet med lägre puls samt låg excentricitet med högre puls. Studien har genomförts med syftet att minska den nuvarande excenteraxelns masströghetsmoment genom att designa om den samt verifiera nya koncept med linjära och icke-linjära FEM beräkningar. De nya modellerna skulle behålla samma funktionella egenskaper som den nuvarande excenteraxeln. Det nuvarande tvärsnittet i XY-planet ändrades till en cirkel i rotationsaxlens periferi, genom att lägga till alla funktioner med nya tvärsnitt på en enkel axelbas i en analyskedja. En ny design i längsled påbörjades med brainstorming för att generera nya idéer. Idéerna sorterades sedan med hjälp av en Pugh-matris. Koncepten modellerades sedan med önskade excentriska egenskaper i CAD. FEM-mjukvara användes för att simulera koncepten och samla information om beteenden under körning. Akademisk validering och användbar information samlades in i en litteraturstudie. Arbetet resulterade i två koncept med egenskaper som uppfyllde rådande krav. Det cirkulära tvärsnittet i periferin behölls och likaså de excentriska egenskaperna. FEM resultaten visade sig hamna tillfredsställande under gränserna med materialen stål och segjärn. För båda koncepten minskade masströghetsmomentet varav 40.5 % i stål och 42.0 % respektive 42.6 % i segjärn. En analyskedja har genomförts som visat att ett tvärsnitt av en cirkel i periferi är optimalt med intentionen att minska masströghetsmomentet. Det är möjligt att minska masströghetsmomentet utan att påverka de excentriska egenskaperna negativt. Designen längs med en axel med excentriska egenskaper har studerats och simulerat. Två koncept med varierad design har modellerats, koncepten har behållna excentriska egenskaper och betydligt minskat masströghetsmoment. Koncepten kan utgöra gott underlag för fortsatt undersökning av designen i längdled. Förhoppningsvis kan det i sin tur resultera i en tillverkningsbar excentrisk axel som bidrar till miljövänligare asfaltskonstruktion med låg energiåtgång.

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Bataineh, Anas. "Analysis and design of tall concrete buildings : an investigation regarding the use of cracked versus un-cracked moment of inertia." FIU Digital Commons, 2004. http://digitalcommons.fiu.edu/etd/1431.

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A debate is currently prevalent among the structural engineers regarding the use of cracked versus un-cracked moment of inertia of the structural elements in analyzing and designing tall concrete buildings. (The basic definition of a tall building, according to the Journal of Structural Design of Tall Buildings Vol. 13. No. 5, 2004 is a structure that is equal to or greater than 160 feet in height, or 6 stories or greater.) The controversy is the result of differing interpretations of certain ACI (American Concrete Institute) code provisions. The issue is whether designers should use cracked moment of inertia in order to estimate lateral deflection and whether the computed lateral deflection should be used to carry out subsequent second-order analysis (analysis considering the effect of first order lateral deflections on bending moment and shear stresses). On one hand, bending moments and shear forces estimated based on un-cracked moment of inertia of the sections may result in conservative designs by overestimating moments and shears. On the other hand, lateral deflections may be underestimated due to the same analyses resulting in unsafe designs.

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Hou, Xian. "Detections of seven faint g-ray pulsars and constraints on neutron star moments of inertia with the Fermi-LAT." Phd thesis, Université Sciences et Technologies - Bordeaux I, 2013. http://tel.archives-ouvertes.fr/tel-01058049.

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Le Large Area Telescope (LAT) à bord du satellite Fermi, lancé le 11 Juin 2008, est sensible au rayonnement gamma de20 MeV à plus de 300 GeV. 148 pulsars gamma à ce jour ont été détectés avec le Fermi-LAT, dont 117 sont détaillés dansle Deuxième Catalogue de Pulsars gamma de Fermi (2PC). Les pulsars forment la plus grande classe de sources au GeVdans la Voie Lactée. Les études de pulsars gamma apportent des contraintes importantes sur les modèles d'émission gamma etpermettent des percées dans notre compréhension des pulsars.Cette thèse présente des détections de sept pulsars gamma faibles déjà connus en radio, dont quatre jeunes ou d'âgesmoyens et trois millisecondes (MSP). L'analyse spectrale et la caractérisation des courbes de lumiére sont décriteset comparées à la population de 2PC. Ces détections ont l'intérêt particulier de sonder et d'étendre l'espace desparamètres de la population actuelle. Elles illustrent la distorsion inhérente dans 2PC et marquent la transition de lapremière phase (pulsars brillants) à la seconde phase (pulsars faibles) d'opération de Fermi. Le développement desmodèles théoriques et un recensement complet de la population galactique des étoiles à neutrons bénéficieront de plusde détections de pulsars faibles dans les années à venir.Certains pulsars gamma dans 2PC manifestant de grande efficacité gamma sont étudiés dans cette thèse. L'examen desdifférents paramètres qui influencent l'efficacité conduit à quelques candidats pour lesquels un plus grand momentd'inertie est nécessaire afin de résoudre le paradoxe de grande efficacité. Les observations de Fermi en rayons gamma ontl'air à apporter des contraintes indépendantes sur le moment d'inertie et les équations d'état des étoiles à neutrons.

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Shekar, Sadahalli Arjun. "ADAPTIVE CONTROL DESIGN FOR QUADROTORS." OpenSIUC, 2017. https://opensiuc.lib.siu.edu/dissertations/1472.

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Unmanned Aerial Vehicles (UAV) control has become a very important point of scientific study. The control design challenges of a UAV make it one of the most researched areas in modern control applications. This thesis specifically chooses the Quadrotor as the UAV platform. Considering the quadrotor has 4 rotors and 6 degrees of freedom, it is an underactuated system and is dynamically unstable that has to be stabilized by a suitable control algorithm in order to operate autonomously. This thesis focuses on the quaternion representation of the quadrotor system dynamics and develops an adaptive control for its trajectory tracking problem. The control design uses the certainty equivalence principle where adaptive tracking controls are designed separately for each of the translational and rotational subsystems. With this approach, the success of the outer loop translational control relies on the fast convergence of the inner loop rotational control in order to guarantee the system’s stability while achieving the tracking objective. For the translational subsystem in the outer loop, a modified geometric control technique is considered with an adaptive component for the estimation of the uncertain mass of the quadrotor. For the rotational subsystem in the inner loop a backstepping based control design is adopted due to its systematic design and intuitive approach. An adaptive component is further integrated with it to estimate the integrated components of the uncertain Moment of Inertia matrix and other constant parameters in the system dynamics to guarantee the stability of the inner loop system while achieving the tracking objective. Furthermore, a complete backstepping control design methodology is presented which overcomes the issues of certainty equivalence principle where the inner loop needs to execute significantly faster than the outer loop to stabilize the system.

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Mereghetti, Emanuele. "Application of Effective Field Theories to Problems in Nuclear and Hadronic Physics." Diss., The University of Arizona, 2011. http://hdl.handle.net/10150/202538.

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The Effective Field Theory formalism is applied to the study of problems in hadronic and nuclear physics. We develop a framework to study the exclusive two-body decays of bottomonium into two charmed mesons and apply it to study the decays of the C-even bottomonia. Using a sequence of effective field theories, we take advantage of the separation between the scales contributing to the decay processes, 2m(b) ≫ m(c) ≫∧(QCD). We prove that, at leading order in the EFT power counting, the decay rate factorizes into the convolution of two perturbative matching coefficients and three non-perturbative matrix elements, one for each hadron. We calculate the relations between the decay rate and non-perturbative bottomonium and D-meson matrix elements at leading order, with next-to-leading log resummation. The phenomenological implications of these relations are discussed. At lower energies, we use Chiral Perturbation Theory and nuclear EFTs to set up a framework for the study of time reversal (T) symmetry in one- and few-nucleon problems. We consider T violation from the QCD θ term and from all the possible dimension 6 operators, expressed in terms of light quarks, gluons and photons, that can be added to the Standard Model Lagrangian. We construct the low energy chiral Lagrangian stemming from different TV sources, and derive the implications for the nucleon Electric Dipole Form Factor and the deuteron T violating electromagnetic Form Factors. Finally, with an eye to applications to nuclei with A ≥ 2, we construct the T violating nucleon-nucleon potential from different sources of T violation.

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17

Grác, David. "Měření momentů setrvačnosti vozidla." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2014. http://www.nusl.cz/ntk/nusl-231201.

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This diploma thesis is concerned with selecting the appropriate method for determining the moment of inertia to the vertical, lateral and longitudinal axis through the centre of gravity of the vehicle. Using the special mechanical device, constructed on IAE was carried out repeated measurements of known mass properties in each axis. With the aid of obtained data was calculated measurement error. To compare the resulting values was created MBS model.

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Toman, Josef. "Zařízení pro měření výškové polohy těžiště vozidla." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2014. http://www.nusl.cz/ntk/nusl-231246.

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This diploma thesis deals with measurement of vehicle centre of gravity height position. In the first part is created summary of methods used for measuring centre of gravity position and moment of inertia of the vehicle. In the other parts are designed and analyzed two dynamics method of measuring centre of gravity height position. This thesis presents analysis of the errors of the proposed methods, results of measurements and design of the construct adjustments device for measuring of the moments of inertia enabling its used for measuring centre of gravity height position. Some components are through analyse of tension.

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Lanči, Jaroslav. "Návrh zařízení pro měření tenzoru setrvačnosti vozidla." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2012. http://www.nusl.cz/ntk/nusl-230309.

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The aim of this thesis was to design a device allowing to measure the moments of inertia of a motor vehicle around several intersecting axes. Next, a three dimensional model of the proposed device was created in programme Pro/ENGINEER. Stress analysis of individual components was performed using the finite element method (FEM) in programme ANSYS.

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Neužil, Ondřej. "Řízení orientace družice - laboratorní úloha." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2018. http://www.nusl.cz/ntk/nusl-377016.

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This diploma thesis is about the basics of satellite systems, about their sorting, usage and technologies. An important part is the description of the principles controlling and stabilization of the small experimental CubeSat type satellites. The main point is the proposition and construction of the laboratory model of the CubeSat type satellite that should simulate the chosen methods of controlling and stabilization in laboratory conditions. The thesis describes the construction of the electronic parts of the model, the controlling software of the satellite’s processor and user software for easy controlling by PC.

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Votava, Ondřej. "Návrh oběžného kola radiální turbíny se sníženým momentem setrvačnosti." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2020. http://www.nusl.cz/ntk/nusl-432805.

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This master’s thesis deals with topological optimization of the impeller of a radial turbocharger turbine. It focuses on reducing the moment of inertia with unchanged aerodynamic properties. The optimization was carried out using CFD, thermal and structural analysis. The computational modeling was performed using the finite element analysis in ANSYS. The work proposes models of the impeller with the topological modification of the internal structure. Based on the values of moment of inertia, the stress and the strain the most suitable model was selected.

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Fikry, Abdullah M. "Development of a model to estimate the effective second moment of area of one-way reinforced concrete flexural elements." Thesis, University of Liverpool, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.245757.

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23

Cajazeiras, LÃcio Laertti Rios. "O centro de massa e aplicaÃÃes Ã geometria." Universidade Federal do CearÃ, 2016. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=17269.

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Muitas sÃo as ferramentas desenvolvidas para a resoluÃÃo de problemas de Geometria Euclidiana. O presente estudo apresenta uma ferramenta baseada no conceito fÃsico de centro de massa, proporcionando o desenvolvimento de habilidades necessÃrias na resoluÃÃo de problemas geomÃtricos, principalmente em relaÃÃo Ãs questÃes apresentadas em OlimpÃadas de MatemÃticas, tanto no Ensino Fundamental como no Ensino MÃdio.
There are many tools developed for solving Euclidean Geometry problems. This study presents a tool based on the physical concept of center of mass, allowing the development of the skills needed to solve geometric problems, especially the ones presented in Mathematics Olympiads, both in Elementary School and in High School.

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24

Nilsson, Albin, and Johan Fallström. "Framtagning av konceptsmodell för mekanisk avskiljning av feltryckta wellpappark." Thesis, Örebro universitet, Institutionen för naturvetenskap och teknik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-92814.

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This thesis was made for EMBA Machinery AB and includes a product development process with the result of a concept model. EMBA is a company that develops and manufactures machines for the global corrugated board industry and wants to extend their solutions with a system that automatically removes the misprinted corrugated boards. The idea is to incorporate the system with the already existing processing flow and should be combined with the existing video system that validate the print quality. The concept model is a concept of the mechanical parts needed for the solution and can be used as a foundation for further work towards a product for the market. To produce this concept model methods for divergent problem solving were used. Several concept solutions were created and evaluated with the purpose of finding the best one. This concept was then developed further into a 3D-model of all the interlocking machine- and construction elements, whom in detail demonstrates the removal of misprinted boards. Calculations, which included determining moment of inertia and an acceleration curve, were also done based on data from this model with the intent of testing the plausibility of the solution and to offer a theoretical foundation on which to base further work with this concept.
Det här examensarbetet utfördes åt EMBA Machinery AB och innefattar en produktutvecklingsprocess med slutresultat i en konceptmodell. Företaget utvecklar och tillverkar i dag maskiner för den globala wellpapp-industrin och önskar nu komplettera sitt utbud med ett system som automatiskt sorterar bort wellpappark som erhållit felaktigt grafiskt tryck. Detta är tänkt att kunna inkorporeras i deras befintliga processeringsflöde och skall kombineras med befintlig videoteknik för validering av det grafiska trycket. Konceptmodellen som tas fram är således en potentiell lösning av de mekaniska delar som samverkar i sållningen av feltryckta ark och är tänkt som en grund för vidare arbete att ta fram en marknadsfärdig produkt. I processen att ta fram denna konceptmodell tillämpades metoder för divergent problemlösning där flera lösningskoncept genererades och värderades i syfte att hitta det bästa. Detta koncept utvecklades sedan till en mer detaljerad representation av lösningen i form av en 3D-modell av de samverkande maskin- och konstruktionselementen, vilken i detalj demonstrerar hur det valda konceptet löser sållningen av feltryckta ark. Beräkningar, vilka innefattade framtagning av tröghetsmoment och accelerationskurva, utfördes även med data från denna modell i syfte att testa lösningens rimlighet och att erbjuda en teoretisk grund att jobba vidare med i fortsatt arbete av konceptet.

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Jadrný, Jan. "Výpočtový model vyvažovací jednotky řadového pětiválcového motoru v multi-body systému." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2008. http://www.nusl.cz/ntk/nusl-228008.

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The diploma thesis deals with a calculation and a construction concept of a balancing unit of a strait five cylinder combustion engine. The thesis contains the calculation and the construction concept of the balancing shafts. Also the concept of the calculation model of a driving mechanism with the balancing unit in MSC Adams – Engine is included.

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Zhang, Runtong. "Measurement of effective diffusivity : chromatographic method (pellets & monoliths)." Thesis, University of Bath, 2013. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.608352.

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This thesis aims to find out the effective diffusivity (Deff) of a porous material – γ-alumina, using an unsteady state method with two inert gases at ambient condition with no reactions. For porous materials, Deff is important because it determines the amount of reactants that transfers to the surface of pores. When Deff is known, the apparent tortuosity factor of γ-alumina is calculated using the parallel pore model. The apparent tortuosity factor is important because: (a) it can be used to back-calculate Deff at reacting conditions; (b) once Deff with reactions is known, the Thiele modulus can be calculated and hence the global reaction rate can be found; (c) apparent tortuosity factor is also important for modelling purposes (e.g. modelling a packed-bed column or a catalytic combustion reactor packed with porous γ-alumina in various shapes and monoliths). Experimental measurements were performed to determine the effective diffusivity of a binary pair of non-reacting gases (He in N2, and N2 in He) in spherical γ-alumina pellets (1 mm diameter), and in γ-alumina washcoated monoliths (washcoat thickness 20 to 60 µm, on 400 cpsi (cells per square inch) cordierite support). The method used is based on the chromatographic technique, where a gas flows through a tube, which is packed with the sample to be tested. A pulse of tracer gas is injected (e.g. using sample loops: 0.1, 0.2, 0.5 ml) and by using an on-line mass spectrometer the response in the outlet of the packed bed is monitored over time. For the spherical pellets, the tube i.d. = 13.8 mm and the packed bed depths were 200 and 400 mm. For monoliths the tube i.d. = 7 mm and the packed lengths were 500 and 1000 mm. When the chromatographic technique was applied to the monoliths, it was observed that experimental errors can be significant, and it is very difficult to interpret the data. However, the technique worked well with the spherical pellets, and the effective diffusivity of He in N2 was 0.75 – 1.38 × 10-7 m2 s-1, and for N2 in He was 1.81 – 3.10 × 10-7 m2 s-1. Using the parallel pore model to back-calculate the apparent tortuosity factor, then a value between 5 to 9.5 was found for the pellets.

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Říha, Stanislav. "Viskózní tlumič torzních kmitů plynového vidlicového šestnáctiválce." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2010. http://www.nusl.cz/ntk/nusl-229308.

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Master’s thesis with title Viscous torsional vibration damper of a gas v-sixteen engine deals with torsion vibrafon of the crankshaft and chance how to eliminated it. First part of diploma thesis containes calculation of torsion vibrafon without damper. In second part is added damper. In the end of this thesis is equaiont made of both parts.

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28

Eicholtz, Matthew R. "Design and analysis of an inertial properties measurement device for manual wheelchairs." Thesis, Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/34677.

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The dynamics of rigid body motion are dependent on the inertial properties of the body - that is, the mass and moment of inertia. For complex systems, it may be necessary to derive these results empirically. Such is the case for manual wheelchairs, which can be modeled as a rigid body frame connected to four wheels. While 3D modeling software is capable of estimating inertial parameters, modeling inaccuracies and ill-defined material properties may introduce significant errors in this estimation technique and necessitate experimental measurements. To that end, this thesis discusses the design of a device called the iMachine that empirically determines the mass, location of the center of mass, and moment of inertia about the vertical (yaw) axis passing through the center of mass of the wheelchair. The iMachine is a spring-loaded rotating platform that freely oscillates about an axis passing through its center due to an initial angular velocity. The mass and location of the center of mass can be determined using a static analysis of a triangular configuration of load cells. An optical encoder records the dynamic angular displacement of the platform, and the natural frequency of free vibration is calculated using several techniques. Finally, the moment of inertia is determined from the natural frequency of the system. In this thesis, test results are presented for the calibration of the load cells and spring rate. In addition, objects with known mass properties were tested and comparisons are made between the analytical and empirical inertia results. In general, the mass measurement of the test object had greater than 99% accuracy. The average relative error for the x and y-coordinates of the center of mass was 0.891% and 1.99%, respectively. For the moment of inertia, a relationship was established between relative error and the ratio of the test object inertia to the inertia of the system. The results suggest that 95% accuracy can be achieved if the test object accounts for at least 25% of the total inertia of the system. Finally, the moment of inertia of a manual wheelchair is determined using the device (I = 1.213 kg-m²), and conclusions are made regarding the reliability and validity of results. The results of this project will feed into energy calculations for the Anatomical Model Propulsion System (AMPS), a wheelchair-propelling robot used to measure the mechanical efficiency of manual wheelchairs.

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Parchański, Martin. "Pětiválcový řadový vznětový motor." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2010. http://www.nusl.cz/ntk/nusl-229101.

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The purpose of this thesis is design of in-line a five-cylinder diesel engine arrangement with given main parameters, power train design, balancing centrifugal and inertia moments and calculation of torsion vibrations. The proposed engine must be based on four-cylinder diesel Zetor engine.

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30

Akmaluddin. "Experimental study of beam deflection to improve a model for the effective second moment of area of one-way reinforced concrete elements." Thesis, University of Liverpool, 2004. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.400197.

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31

Hanych, Jaroslav. "Konstrukční návrh zařízení pro měření výškové polohy těžiště vozidla." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2018. http://www.nusl.cz/ntk/nusl-378015.

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This master's thesis deals with problems connected with measuring vehicle centre of gravity height. The research part summarizes generally known methods of measuring vehicle centre of gravity and moments of inertia. Essential part of this thesis is the design of a device for measuring the centre of gravity height of a road vehicle on a principle of measuring a period of oscillation. The height position of the platform of the device is adjustable through hydraulic cylinders. A stress-strain analysis of the design was executed through a combination of analytical methods and a finite element method. The process of measurement was described and an equation for determination of centre of gravity height was deduced. Error of measurement was estimated based on the knowledge of partial errors of measured values.

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Fracarolli, Juliana Aparecida 1984. "Utilização do biospeckle laser na avaliação do potencial germinativo de sementes de ipê-roxo (Tabebuia heptaphylla) (Vellozo) Toledo." [s.n.], 2011. http://repositorio.unicamp.br/jspui/handle/REPOSIP/256884.

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Orientadores: Inacio Maria Dal Fabbro, Leila Martins
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agrícola
Made available in DSpace on 2018-08-17T22:21:55Z (GMT). No. of bitstreams: 1 Fracarolli_JulianaAparecida_M.pdf: 1740641 bytes, checksum: 3b58affa12601dc23d779d12bd0a1f66 (MD5) Previous issue date: 2011
Resumo: O ipê-roxo (Tabebuia heptaphylla (Vellozo) Toledo) é uma espécie de alto valor econômico, ornamental e medicinal, pertencente à família Bignoniaceae, cuja multiplicação ocorre prioritariamente por sementes. Há considerável necessidade de estudos sobre o desempenho fisiológico das unidades de dispersão dessa e de outras espécies florestais. O objetivo desse trabalho foi avaliar a potencialidade do biospeckle, técnica baseada no fenômeno óptico de interferência, como ferramenta de caracterização do potencial germinativo das sementes de ipê-roxo. A quantificação do biospeckle foi expressa através do cálculo do Momento de Inércia (MI). Foram utilizados laser vermelho (632 nm de comprimento de onda) e 10 mW de potência, câmera filmadora digital e computador. Foram realizados cinco experimentos, a saber: (1) Avaliação de danos térmicos em sementes através do biospeckle; (2) Avaliação da interferência do tegumento na sensibilidade do biospeckle; (3) Diferenciação entre sementes germinadas e não germinadas através do biospeckle; (4) Determinação da faixa de umidade das sementes para a melhor interação entre o laser e a semente para o biospeckle; (5) Avaliação de sementes de ipê-roxo submetidas ao envelhecimento acelerado através do biospeckle. Para os experimentos 1, 2, 3 e 4 as sementes foram hidratadas até atingirem grau de umidade de 69%, divididas em quatro sub-amostras sendo que duas delas foram submetidas ao congelamento. Em seguida as sub-amostras foram separadas em 5 níveis de umidade (28, 35, 54, 63, 69%) e iluminadas com laser. Nesses ensaios foram planejados quatro tratamentos: (1) sementes sem tegumento; (2) sementes com tegumento; (3) sementes sem tegumento submetidas a congelamento a 0°C e (4) sementes com tegumento submetidas ao congelamento a 0°C. Os resultados permitem afirmar que é possível diferenciar as sementes que sofreram dano térmico daquelas que não sofreram através do biospeckle. A presença do tegumento interfere na sensibilidade do biospeckle. É possível diferenciar as sementes viáveis das inviáveis através do biospeckle. Do experimento 4 obteve-se uma correlação positiva entre os valores de MI e de umidade das sementes. Verificou-se também que a faixa de teor de água para a melhor interação entre o laser e a semente de ipê-roxo está entre 28 e 54%. Esta faixa de umidade das sementes foi utilizada como referência para o experimento 5. No experimento 5 as sementes foram submetidas ao envelhecimento acelerado (42°C e umidade relativa do ar de 100 % durante 24, 48, 72, 96 e 120 horas) e avaliadas através da técnica do biospeckle e teste de germinação. Obteve-se que é possível detectar a redução de viabilidade e vigor das sementes de T. heptaphylla ocasionada pelo envelhecimento acelerado. Dessa forma, o biospeckle é uma técnica que vem sendo desenvolvida e apresenta-se como uma ferramenta possível para avaliar o potencial germinativo das sementes de ipê-roxo
Abstract: Ipê-roxo (Tabebuia heptaphylla (Vellozo) Toledo) is considered of very important economical, ornamental, as well as medicinal value which is included in the Bignoniaceae botanical family which multiplication is quite solely carried by seeds. Forest dispersion elements, i.e., the seeds, deserve a deep understanding of their physiological performance. The objective of this research work was to evaluate a biospeckle method potential in testing seed viability, which is based on the laser interferometry. The biospeckle phenomenon quantification was carried by means of the Moment of Inertia (MI) which formula resembles its mechanical counterpart. The equipment employed in the experimental setup included a 632 nm red diode laser of 10mW, a digital movie camera as well as a PC. The five tests carried were (1) thermal damage evaluation on seeds, (2) biospeckle sensitivity to the tegument interference, (3) differentiation between non germinated and germinated seeds evaluation by the biospeckle, (4) determination of the best seed moisture content to laser interaction and (5) evaluation of accelerated aging ipê-roxo seeds through the biospeckle. In tests 1, 2, 3 and 4 seeds were hydrated to the value of 69% and divided into four sub samples from which two of them were forwarded to freezing. Following the four sub samples were separated into five moisture level groups (28, 35, 54, 63, 69%) and exposed to the laser. Four treatments have been imposed to the experimental tests, named (1) seeds without teguments, (2) seeds with tegument, (3) frozen at 0° C seeds without teguments and (4) frozen at 0° C seeds with teguments. Results from biospeckle tests confirm the possibility of differentiating seeds with thermal damage from those without thermal damage. When the tegument is covering the seed, the sensitivity of biospeckle is affected.?It's possible to differentiate viable seeds from non viable seeds using biospeckle technique. From test (4) it is obtained a positive correlation between MI and seeds moisture content. It was also verified that seed moisture content between 28% and 54% showed better interaction with laser. That moisture content range was adopted for the test (5). Seeds were submitted to accelerated aging process in the test (5) (42°C and 100% of relative humidity for 24, 48, 72, 96 and 120 hours) following by biospeckle evaluation and germination tests. It was concluded that viability reduction of T. heptaphylla as generated by accelerated aging can be detected by the biospeckle test. Thus, the biospeckle is a technique that has been developed and is presented as a possible tool to assess the germination potential of ipê-roxo seeds
Mestrado
Maquinas Agricolas
Mestre em Engenharia Agrícola

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Drozdek, Lukáš. "Silikonový tlumič torzních kmitů řadového šestiválcového vznětového motoru." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2008. http://www.nusl.cz/ntk/nusl-228281.

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This thesis "Silicone damper of a six-cylinder in-line diesel engine " is focused on the proposal of alternative using of silicone damper for the a six-cylinder in-line diesel engine, which is made for tractors and other industrial aplications. The aim of this thesis is to count the oscilation of crankshaft by the help of appropriate dynamic model, then to propose such a basic parameters of silicone damper, which absorbes torsion blip crankshaft to acceptable value. The next part of my thesis is proposal of the constructive implementation of fixation the silicone damper on the free part of crankshaft. The last part of my thesis is comparing and evaluating the oscilation of crankshaft without a dumper and with a new propsal of the silicone damper.

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Karlovets, Ekaterina. "Spectroscopie d'absorption à très haute sensitivité de différents isotopologues du dioxyde de carbone." Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENY027/document.

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Le travail présenté porte sur l'analyse et l'interprétation théorique du spectre d'absorption du dioxyde de carbone dans le proche infrarouge: spectroscopie d'absorption ultrasensible et modélisation théorique des positions et intensités des raies d'absorption. Ce travail vise à affiner et étendre l'ensemble des paramètres des opérateurs effectifs nécessaires à la génération des listes de raies pour les bases de données spectroscopiques. Les résultats obtenus peuvent être divisés en trois parties.Dans la première partie, nous avons établi les équations relatives aux paramètres q0 J, qJ, q2J and q3J-types des éléments de matrice de l'opérateur moment dipolaire effectif en fonction des dérivées du moment dipolaire et des constantes de force obtenues par transformation de contact pour les isotopologues: 16O12C18O, 16O12C17O, 16O13C18O, 16O13C17O, 17O12C18O. En utilisant ces équations et les relations isotopiques obtenues pour les constantes moléculaires, des calculs numériques nous ont permis de dériver les paramètres effectifs du moment dipolaire des séries de transitions ∆P= 0, 2, 4, 6 et 8, pour les six isotopologues asymétriques ci-dessus. La comparaison des paramètres rapportés dans la littérature et obtenus dans ce travail a été effectuée et discutée.La deuxième partie est consacrée à l'analyse du spectre d'absorption du dioxyde de carbone hautement enrichi en 18O, enregistré avec une très grande sensibilité par spectroscopie CW-Cavity Ring Down Spectroscopy entre 5851 et 6990 cm-1 (1.71-1.43 µm). Au total, 19526 transitions appartenant à onze isotopologues (12C16O2, 13C16O2, 16O12C18O, 16O12C17O, 16O13C18O, 16O13C17O, 12C18O2, 17O12C18O, 12C17O2, 13C18O2 et 17O13C18O) ont été attribuées sur la base des prévisions du modèle de l'Hamiltonien effectif. Toutes les bandes identifiées correspondent aux séries de transitions ∆P= 8, 9 et 10, où P=2V1+V2+3V3 est le nombre de polyade (V1,V2,V3 sont les nombres quantiques vibrationnels). Les intensités des transitions les plus faibles sont de l'ordre de 2×10-29 cm/molécule. Les paramètres spectroscopiques précis de 211 bandes appartenant à neuf isotopologues ont été calculés. Au total, neuf perturbations de résonance de la structure rotationnelle de l'état supérieur ont été observées et identifiées pour les isotopologues 16O12C18O, 12C18O2, 13C18O2, 16O13C18O, 16O12C17O et 17O12C18O. Un nouvel ensemble de paramètres du Hamiltonien effectif a été obtenu par un ajustement global de nos données et de l'ensemble des données de la littérature. En utilisant une approche similaire, les ajustements globaux des intensités obtenues pour les transitions des séries ∆P= 8, 9 and 10 ont permis d'obtenir l'ensemble de paramètres effectifs du moment dipolaire.Dans la troisième partie, nous présentons l'analyse du spectre CW-CRDS du dioxyde de carbone naturel entre 7909 et 8370 cm-1 (1.26-1.19 µm). Au total, 3425 transitions appartenant à 61 bandes de six isotopologues - 12C16O2, 13C16O2, 16O12C18O, 16O12C17O, 16O13C18O et 16O13C17O- ont été attribuées. Dans la région spectrale étudiée, toutes les bandes appartiennent à la série ∆P=11. Les paramètres spectroscopiques précis des états supérieurs de 57 bandes ont été obtenus à partir d'un ajustement des positions mesurées (rms typiques des écarts de l'ordre de 0.6×10-3 cm-1). Les ajustements globaux des intensités obtenues ont permis de déterminer les paramètres effectifs du moment dipolaire de la série ∆P=11 des six isotopologues étudiés.Les résultats obtenus ont eu un grand impact sur la modélisation globale des spectres de du dioxyde de carbone. Ils ont permis d'affiner et d'étendre les mesures existantes et d'améliorer considérablement les paramètres de l'Hamiltonien et moment dipolaire effectifs. Les résultats obtenus ont d'ores et déjà été intégrés dans les bases de données spectroscopiques de CO2 les plus couramment utilisées (HITRAN, GEISA, CDSD)
This thesis is devoted to the investigation of the high resolution near infrared spectra of carbon dioxide and includes experimental measurements and theoretical modeling of line positions and intensities and refinement and extension of the set of effective operator parameters. The obtained results can be divided by three parts:In the first part, we present the equations for the q0 J, qJ, q2J and q3J-types parameters of the matrix elements of the effective dipole-moment operator in terms of the dipole-moment derivatives and force field constants derived by means of contact transformation method for the following carbon dioxide isotopologues: 16O12C18O, 16O12C17O, 16O13C18O, 16O13C17O, 17O12C18O and 17O13C18O. Using these equations and the obtained isotopic relations for the molecular constants, we derived the effective dipole-moment parameters for the ∆P= 0, 2, 4, 6 and 8 series of transitions of the six above asymmetric carbon dioxide isotopologues (P=2V1+V2+3V3 is the polyad number where V1,V2 and V3 are the vibrational quantum numbers). The comparison of the parameters reported in the literature and obtained in this work is performed and discussed.The second part is devoted to the analysis of the room temperature absorption spectrum of highly 18O enriched carbon dioxide recorded by very high sensitivity CW-Cavity Ring Down Spectroscopy between 5851 and 6990 cm-1 (1.71-1.43 µm ). Overall, 19526 transitions belonging to eleven isotopologues (12C16O2, 13C16O2, 16O12C18O, 16O12C17O, 16O13C18O, 16O13C17O, 12C18O2, 17O12C18O, 12C17O2, 13C18O2 and 17O13C18O) were assigned on the basis of the predictions of the effective Hamiltonian model. Line intensities of the weakest transitions are on the order of 2×10-29 cm/molecule. The line positions were determined with accuracy better than 1×10-3 cm-1 while the absolute line intensities are reported with an uncertainty better than 10%. All the identified bands correspond to the ∆P= 8, 9 and 10 series of transitions. The accurate spectroscopic parameters for a total of 211 bands belonging to nine isotopologues were derived. Nine resonance perturbations of the upper state rotational structure were identified for 16O12C18O, 12C18O2, 13C18O2, 16O13C18O, 16O12C17O and 17O12C18O isotopologues. New sets of Hamiltonian parameters have been obtained by the global modeling of the line positions within the effective Hamiltonian approach. Using a similar approach, the global fits of the obtained intensity values of the ∆P= 8, 9 and 10 series of transitions were used to derive the corresponding set of effective dipole moment parameters.In the third part, we report the analysis of the absorption spectrum of natural carbon dioxide by high sensitivity CW-Cavity Ring Down spectroscopy between 7909 and 8370 cm-1 (1.26-1.19 µm). Overall, 3425 transitions belonging to 61 bands of 12C16O2, 13C16O2, 16O12C18O, 16O12C17O, 16O13C18O and 16O13C17O were assigned. In the studied spectral region, all bands correspond to ∆P= 11 series of transitions. The accurate spectroscopic parameters of the upper states of 57 bands were derived from a fit of the measured line positions (typical rms deviations of about 0.6×10-3 cm-1). The global fits of the obtained intensity values of the ∆P= 11 series of transitions were used to determine the corresponding set of effective dipole moment parameters of the six studied isotopologues.The large set of new observations obtained in this thesis has an important impact on the global modeling of high resolution spectra of carbon dioxide. It has allowed refining and extending the sets of effective dipole moment and effective Hamiltonian parameters. The obtained results have allowed improving importantly the quality of the line positions and intensities in the most currently used spectroscopic databases of carbon dioxide (HITRAN, GEISA, CDSD)

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Schulze, Sören. "Bewegungsdesign unter Berücksichtigung des reduzierten Massenträgheitsmoments." Universitätsbibliothek Chemnitz, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-206894.

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Das Bewegungsdesign stellt einen wichtigen Aspekt beim Betrieb von ungleichmäßig übersetzenden Mechanismen dar. Durch Minimierung von Bewegungsparametern wie der Geschwindigkeit und Beschleunigung ist die Verringerung von Schwingungsamplituden sowie Bauteildeformationen infolge kinetostatischer Kräfte erzielbar. Weiterhin kann hierdurch der Verlauf des Antriebsmoments des Motors beeinflusst werden. Das reduzierte Massenträgheitsmoment J(φ) eines nichtlinear übersetzenden Mechanismus ist stellungsabhängig definiert durch die generalisierte Koordinate φ. Daher stellt die Minimierung von Beschleunigung und Geschwindigkeit mittels konstanter Grenzen über den gesamten Antriebsbereich eine Vereinfachung dar, welche die stellungsabhängige Trägheit außer Acht lässt. Der Beitrag stellt eine Möglichkeit zur Generierung der Grenzwerte für die Beschleunigung und Geschwindigkeit aus den Verläufen des reduzierten Massenträgheitsmoments J(φ) sowie dessen Ableitung nach der generalisierten Koordinate J‘(φ) vor. Die ermittelten Ober- und Untergrenzen dienen als Parameter für einen Optimierungsalgorithmus. Dieser nutzt den Ansatz der harmonischen Synthese um mit Hilfe der linearen Programmierung die Bewegungsfunktion zu generieren. Für einen Mechanismus mit einem Freiheitsgrad wird mittels eines herkömmlichen Ansatzes und mit dem neu vorgestellten Verfahren das optimale Bewegungsgesetz ermittelt. Mittels einer Mehrkörpersimulation werden neben Geschwindigkeit und Beschleunigung auch das resultierende Antriebsmoment und der Energiebedarf bilanziert.

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Štěpánek, Tomáš. "Měření polohy těžiště vozidla." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2008. http://www.nusl.cz/ntk/nusl-228353.

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This diploma thesis is devoted to problems of measurement centre of gravity position. At the beginning diploma thesis is created summary of methods to measuring moment of inertia and position measuring of centre of gravity of vehicle. Proposal is in-process on the basis method weighing on oblique position. And measurement is possible in Institute of automotive engineering in Brno. Is proposed measuring platform and preparative for obstruct changes of centre of gravity position at measuring. Measuring procedure is described and is derived formula toward calculation position of gravity centre of vehicle. To troubleshooting parts of platform are elaborate solidity calculations. In final parts diploma thesis are mentioned results from these measurements. Drawing documentation of platform and programme for calculation of centre of gravity of vehicle is enclosed in diploma thesis.

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Yu, Zitian. "Integrated Estimation and Motion Control for Electric Vehicles." The Ohio State University, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=osu1531778655719369.

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Kubica, Petr. "Zařízení pro měření výškové polohy těžiště vozidla." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2015. http://www.nusl.cz/ntk/nusl-232123.

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This diploma thesis deals the with measurment of the centre of gravity height position of a road vehicle and its issues. The introduction of this thesis focuses on the determining of the position of the center of gravity and the moment of inertia of a road vehicle. The next part is about creationing of a construction plan and its verification. The thesis contains a sensitivity analysis of this device including its results. The end of the thesis informs about the executed measurment in a laboratory and about recommendations for next measurments.

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Isildak, Murat. "Use Of Helical Wire Core Truss Members In Space Structures." Master's thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/12610553/index.pdf.

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In an effort to achieve lighter and more economical space structures, a new patented steel composite member has been suggested and used in the construction of some steel roof structures. This special element has a sandwich construction composed of some strips of steel plates placed longitudinally along a helical wire core. The function of the helical core is to transfer the shear between the flange plates and increase the sectional inertia of the resulting composite member by keeping the flange plates at a desired distance from each other. Because of the lack of research, design engineers usually treat such elements as a solid member as if it has a full shear transfer between the flanges. However, a detailed analysis shows that this is not a valid assumption and leads to very unsafe results. In this context, the purpose of this study is to investigate the behavior of such members under axial compression and determine their effective sectional flexural rigidity by taking into account the shear deformations. This study applies an analytical investigation to a specific form of such elements with four flange plates placed symmetrically around a helical wire core. Five independent parameters of such a member are selected for this purpose. These are the spiral core and core wire diameters, the pitch of the spiral core, and the flange plate dimensions. Elements with varying combinations of the selected parameters are first analyzed in detail by finite element method, and some design charts are generated for the determination of the effective sectional properties to be used in the structural analysis and the buckling loads. For this purpose, an alternative closed-form approximate analytical solution is also suggested.

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Horký, Karel. "Návrh setrvačníku jednovzpěrného čelisťového drtiče." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2019. http://www.nusl.cz/ntk/nusl-400467.

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Diploma thesis deals with design of a flywheel and a belt pulley of single toggle jaw crusher DCJ 900x600. The first part is dedicated to overview of the methods for calculation of a size of flywheels for working machines. The second part is focused on calculation of a size of the flywheel. The third part treats the constructional design of the flywheel. In the last two parts there is elaborated analysis of a changing size of the flywheel depended on increasing the working rotation speed and change of coefficient .

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Galásek, Martin. "Pryžový tlumič torzních kmitů čtyřválcového vznětového motoru." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2018. http://www.nusl.cz/ntk/nusl-377464.

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The diploma thesis ‚Rubber Torsional Vibration Damper Of a Four-Cylinder Diesel Engine‘ covers all the development phases related to a design of a rubber damper for a specified engine. The individual phases of it are discussed in details throughout the thesis. At first, the construction plan of a crankshaft is given. The computational checks for torsional vibrations and forced torsional vibration are performed then. With regards to it there might be derived the basic parameters and dimensions of a rubber torsional vibration damper. The knowledge of them enables to prepare the constructional plan of a rubber torsional vibration damper. By using this damper construction plan the torsional displacements (deviations) and forced vibrations are calculated. Finally, a mechanical and thermal stress test of this damper is performed and a crankshaft production drawing is produced.

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Linke, Mats, and Tobias Saarela. "EFFEKTEN AV VIKTMANIPULERAD UTRUSTNING PÅ DRAGSKOTTSHASTIGHET OCH GREPPSTYRKA I INNEBANDY : EN SEX VECKORS STUDIE PÅ MANLIGA 17-ÅRIGA INNEBANDYSPELARE." Thesis, Högskolan i Halmstad, Biomekanik och biomedicin, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-15290.

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Innebandy är en växande idrott, som framför allt utövas i Sverige, Finland och Schweiz, men där väldigt lite forskning ännu finns publicerad. Tidigare studier inom ishockey och baseboll har visat att träning med viktmanipulerad utrustning förbättrat bland annat greppstyrka och svinghastigheten av slagträ i baseboll. Annan forskning har visat på att det är en förbättring i det neuromuskulära samspelet snarare än ökad muskelmassa som förbättrat prestationen vid dynamisk motståndsträning. Skotthastigheten anses vara en viktig faktor inom innebandy för prestationen och eftersom det inom baseboll har visats att viktmanipulerad utrustning kan förbättra svinghastigheten så vore det intressant att se om samma resultat kan uppnås inom innebandy. Syftet med studien var att undersöka effekten av innebandyträning med en viktmanipulerad innebandyklubba med avseende på dragskottshastighet och greppstyrka hos manliga innebandyspelare samt undersöka korrelationen mellan dragskottshastighet och greppstyrka. Även testpersonernas subjektiva uppfattning av träningen med den viktmanipuleradeutrustningen undersöktes. Testgruppen bestod av 13 stycken 17-åriga manliga innebandyspelare. Under en sex veckors period genomförde testpersonerna 30 minuter av sin vanliga innebandyträning med den viktmanipulerade klubban (40 gram tyngre) tre gånger i veckan. Dragskotten filmades med en höghastighetskamera (Casio Exilim EX-FH25) med 250 fps och analyserades sedan i Dartfish för att mäta hastigheten. För att fastställa greppstyrkan användes en handdynamometer (Jamar – Baseline Hydraulic Hand Dynamometer). Träningen resulterade i en signifikant skillnad hos testpersonernas greppstyrka i den nedre handen på klubban (p<0,05). Däremot hittades ingen signifikant skillnad för den övre handens greppstyrka eller dragskottshastigheten. Studien visade heller inte på någon korrelation mellan dragskottshastighet och greppstyrka hos testpersonerna. Testpersonerna hade olika åsikter kring hur den extra tyngden påverkade innebandytekniken.De funna resultaten indikerar att träning med viktmanipulerad utrustning i innebandy signifikant förbättrar spelarnas greppstyrka i den nedre handen. Den ökade kraftutvecklingen kan eventuellt förklaras av ett ökat neuromuskulärt samspel. Studien ger en ökad förståelse för hur dynamisk motståndsträning kan implementeras i den dagliga innebandyträningen, vilket kan tillämpas vid planeringen av träningsprogram.
Floorball is a sport with increasing number of participants, which has not been studied extensively according to the literature. Previous studies on ice hockey and baseball have shown that training with weight manipulated equipment improved grip strength and swing speed. Other research has shown that the increased performance with dynamic resistance training rather occurs from the improvements in the neuromuscular facilitation than an increase in muscle mass. In floorball shooting velocity is considered to be an important factor of the performance. Since it has been shown in baseball that training with weight manipulated equipment can improve the bat velocity, it would be interesting to see if the same results can be found in floorball. The purpose of this study was to investigate the effect of grip strength and drag shot velocity in floorball training with a weight manipulated floorball stick. The study also investigated the relationship between grip strength and drag shot velocity. The test subjects’ subjective perception about the training method was also investigated. Thirteen 17-year-old male floorball players participated in the study. During a six weeks period the subjects used the weight manipulated equipment during 30 minutes, three times per week during their regular team practice. 40 grams lead tape was attached to the player's equipment to increase the resistance. The drag shots were filmed with a high speed camera (Casio Exilim EX-FH25) at 250 fps. The drag shot velocity was analyzed in Dartfish. To assess grip strength a hand dynamometer (Jamar - Baseline Hydraulic Hand Dynamometer)was used. The training resulted in a significant increase for the subjects’ grip strength in the lower hand on the stick (p <0,05). The study found no significant difference for the upper hand grip strength or drag shot velocity. No correlation between drag shot velocity and handgripstrength among the subjects were found. Conclusion: The results found in this study indicate that training with weight manipulated equipment can significantly improve the player’s lower hand grip strength. The results can eventually be explained by more effective fiber recruitment in the muscles. Studying floorball can contribute to increase the interest in research on floorball and increase the understanding for how dynamic resistance training can be incorporated in daily floorball practice.

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Kumar, Prashant. "Investigation of Kelvin-like solid foams for potential engineering applications : an attractive set of geometrical and thermo-hydraulic properties." Thesis, Aix-Marseille, 2014. http://www.theses.fr/2014AIXM4730/document.

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Les mousses à cellules ouvertes ont diverses applications industrielles, par exemple pour des échangeurs de chaleur, des réacteurs structurés, la filtration, la catalyse, récepteurs solaires volumétriques en raison de leurs propriétés uniques telles qu'une importante porosité et une surface spécifique élevée. Pour déterminer théoriquement la surface spécifique géométrique et les relations entre les paramètres géométriques de mousses, une corrélation mathématique généralisée a été développée. A cet effet, la géométrie de la tetrakaidecahedron a été utilisé et différentes formes de sections transversales de brins de structures en mousse ont été pris en compte de façon explicite. La corrélation dérivée pour prédire les propriétés géométriques peut facilement être étendue à des formes différentes. Des simulations numériques 3-D à l'échelle des pores ont été réalisées pour étudier la perte de charge et la conductivité effective thermique. L'écoulement du fluide à travers la mousse à cellule ouverte a été réalisé dans trois régimes différents: les régimes de Darcy, transitoire et inertiel. L'importance des propriétés géométriques sur les caractéristiques d'écoulement de fluide et leurs inclusions dans les corrélations proposées pour prédire la perte de charge est discutée. La question « Les paramètres d'Ergun peuvent-ils avoir des valeurs numériques constantes ou non ? » est discutée. Trois différentes corrélations étaient dérivées pour prédire la conductivité thermique effective à la fois isotrope et anisotrope des mousses. Les paramètres géométriques de la matrice de mousse étaient introduits dans les corrélations pour prédire la conductivité thermique effective
Open cell foams have diverse industrial applications e.g. heat exchangers, structured reactors, filtration due to their unique properties such as high porosity and high specific surface area. In order to theoretically determine the geometric specific surface area and relationships between geometrical parameters of isotropic open cell foams, a generalized mathematical correlation was developed. For this purpose the tetrakaidecahedron geometry was used and different shapes of strut cross-sections of foam structures were taken explicitly into account. The derived correlation to predict geometrical properties can be easily extended to different strut shapes. 3-D numerical simulations at pore scale were performed to study the pressure drop characteristics and effective thermal conductivity. Fluid flow through open cell foam was performed in three different regimes: Darcy regime, transition regime and inertia regime. Importance of geometrical properties on fluid flow characteristics and their inclusion in the proposed correlations for predicting pressure drop is discussed. "Can Ergun parameters have constant numerical values or not" is also extensively discussed. Three different correlations were derived to predict the effective thermal conductivity for both, isotropic and anisotropic open cell foams. Geometrical parameters of foam matrix were introduced in the correlations to predict effective thermal conductivity

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44

Henry, Kevin Claude. "Soft Surface Roll Mechanics Parameters for Light Vehicle Rollover Accident Reconstruction." BYU ScholarsArchive, 2007. https://scholarsarchive.byu.edu/etd/1436.

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Light vehicle rollover accidents on soft surfaces can be modeled assuming constant drag with linear motion equations and other engineering principles. The concept of using segment average results to evaluate roll mechanics parameters throughout a roll sequence, and specifically, segment duration to evaluate vehicle trajectory between ground impacts is developed. The trajectory model is presented, explained and compared to values obtained by analyzing digital video of rollover crash tests. Detailed film analysis procedures are developed to obtain data from rollover crash tests that are not otherwise documented. Elevation of the center of gravity of vehicles is obtained where instrumentation does not explicitly yield this data. Instantaneous center of gravity elevation data throughout a roll sequence provides the opportunity to calculate descend distances as a vehicle travels from one ground contact to another. This data is used to quantify severity of ground impacts as a vehicle interact with the ground throughout a roll sequence. Segment average analysis is a reasonable method for determining general roll mechanics parameters. Because of the chaotic nature of rollover accidents, the range of effective drag factors for a given roll surface may be quite large. Choosing an average of typical drag factors is a reasonable approach for a first-order approximation although certain parameters may be predicted less accurately than if actual values were known. The trajectory results demonstrate the influence of drag factor descent height calculations. Typical constant drag factors tend to overestimate descent height early in a roll sequence and underestimate descent height later in the sequence. The trajectory model is a useful tool to aid in understanding rollover mechanics although a rolling vehicle may be in contact with the ground for a significant fraction of a roll segment. The model should not be used at locations in roll sequences where there are extremes in translational center of gravity decelerations. These extremes include the segments immediately following overturn where there are large angular accelerations and large differences between the tangential velocity of the vehicle perimeter and the translational velocity of the center of gravity, as well as segments that include vehicle impacts with irregular topography.

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45

Souza, Marcelo Kehl de. "Laser scanner terrestre: uma ferramenta eficaz para medidas de estruturas geológicas em afloramentos." Universidade do Vale do Rio dos Sinos, 2012. http://www.repositorio.jesuita.org.br/handle/UNISINOS/4461.

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Submitted by Maicon Juliano Schmidt (maicons) on 2015-07-15T16:40:07Z No. of bitstreams: 1 Marcelo Kehl de Souza.pdf: 8811133 bytes, checksum: 60e926db27cbf5fa1c6577c32be6adfa (MD5)
Made available in DSpace on 2015-07-15T16:40:07Z (GMT). No. of bitstreams: 1 Marcelo Kehl de Souza.pdf: 8811133 bytes, checksum: 60e926db27cbf5fa1c6577c32be6adfa (MD5) Previous issue date: 2012-01-31
CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
FAPERGS - Fundação de Amparo à Pesquisa do Estado do Rio Grande do Sul
Petrobras - Petróleo Brasileiro S. A.
PROSUP - Programa de Suporte à Pós-Gradução de Instituições de Ensino Particulares
Este estudo desenvolveu um método para a obtenção da orientação espacial de estruturas geológicas planares com a utilização da técnica Light Detection and Ranging (LIDAR), especificamente com o Laser Scanner Terrestre. A área de estudo localiza-se na Incopel- pedreira de basalto, no município de Estância Velha, estado do Rio Grande do Sul. O estudo cobriu levantamento de campo com as determinações das atitudes de planos utilizando bússola e clinômetro e o imageamento digital utilizando a técnica LIDAR. Três métodos foram utilizados para computar os planos selecionados na nuvem de pontos, sendo eles: Três pontos, Regressão Planar e Momento de Inércia. A eficiência dos métodos utilizados foi avaliada pelos métodos tradicionais de medidas (bússola e clinômetro). O método de Três Pontos é simples e fácil para computar a orientação de planos, contudo, não possui ferramentas de análise de qualidade. O método de Regressão Planar é efetivo para medir a orientação de planos e possui ferramenta de análise de grau de ajuste ao plano calculado. O método de Análise de Momento de Inércia, além de apresentar menores diferenças em relação aos métodos tradicionais, apresenta análise de grau de ajuste e análise da confiabilidade com relação aos planos computados, provando ser uma ferramenta eficiente para o processamento da orientação de planos a partir de pontos. Palavras-chave: LIDAR. Formação Serra Geral. Orientação de fraturas. Três Pontos. Análise de Momento de Inércia. Regressão Planar.
This study aimed to build a model to survey geological planar structures geometries by using Light Detection and Ranging (LIDAR) technique, specifically with the Terrestrial Laser Scanner. The area chosen for the survey and application of the proposed method is located at Incopel basalt quarry, in the town of Estância Velha, State of Rio Grande do Sul. The study covered a field survey with the determinations of planes attitude using compass and clinometer and digital images using LIDAR. Three methods were used to compute the selected planes in the point cloud, namely: Three Points, Planar Regression, and Moment of Inertia analysis. The methods were evaluated and compared to traditional methods of measurement (compass and clinometer). The Three Point method is quick and simple to measure planar geological structures orientation; however, it does not have any tool for quality analysis. The Planar Regression method proves to be effective in calculating the orientation of planes and features a tool for analyzing the degree of fit to the calculated plane. The Moment of Inertia presents minor measurement differences compared to traditional methods, and provides degree of fit and reliability analysis to the calculated plane, proving to be an efficient tool for processing the orientation of planes from points.

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LANDULFO, EDUARDO. "Estados de alto spin e inversao por assinatura no Brsup78." reponame:Repositório Institucional do IPEN, 1997. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10673.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
FAPESP:96/01220-7

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47

Nilsson, Lucas. "Estimation of Ship Properties for Energy Efficient Automation." Thesis, Linköpings universitet, Reglerteknik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-133557.

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One method to increase efficiency, robustness and accuracy of automatic control, is to introduce mathematical models of the system in question to increase performance. With these models, it is possible to predict the behavior of the system, which enables control according to the predictions. The problem here is that if these models do not describe the dynamics of the system well enough, this method could fail to increase performance. To address this problem, one idea is to estimate the dynamics of the system during operation, using methods for system identification, signal processing and sensor fusion. In this thesis, the possibilities of estimating a ship's dynamics during operation have been investigated. The mathematical model describing the dynamics of the ship is a graybox model, which is based on the physical and mechanical relations. This model's properties are therefore described by physical quantities such as mass and moment of inertia, all of which are unknown. This means that, when estimating the model, these physical properties will be estimated. For a systematic approach, first a simulation environment with a 4-degrees-of-freedom ship model has been developed. This environment has been used for validation of system identification methods. A model of a podded propulsion system has also been derived and validated. The methods for estimating the properties of the ship have been analyzed using the data collected from the simulations. For system identification and estimation of ship properties, the influence of measurement noise and potential of detecting a change in dynamics has been analyzed. This has been done through Monte Carlo simulations of the estimation method with different noise realizations in the simulations, to analyze how the measurement noise affects the variance and bias for the estimates. The results show that variance and bias vary a lot between the parameters and that even a small change in dynamics is visible in some parameter estimates when only ten minutes of data have been used. A method based on cumulative summation (CUSUM) has been proposed and validated to analyze if such a method could yield fast and effective detection of system deviations. The results show that the method is rather effective a with robust detection of changes in the dynamics after about four minutes of data collection. Finally, the methods have been validated on data collected on a real ship to analyze the potential of the methods under actual circumstances. The results show that the particular data is not appropriate for this kind of application along with some additional problems that can yield impaired results.
Genom att inkludera matematiska modeller som beskriver ett systems dynamik i styrningsalgoritmer, kan man åstadkomma en automatisk styrning med förbättrad effektivitet, robusthet och noggrannhet. Med dessa modeller går det att förutsäga beteendet hos systemet och därmed öppnas också möjligheten att använda sig av detta i styrningen. Problemet är att om dessa modeller inte beskriver systemets dynamik tillräckligt bra kan prestandan istället sänkas genom dessa metoder. Den här sortens problem kan man lösa genom att aktivt skatta systemets dynamik under körning, med hjälp av metoder för systemidentifiering, signalbehandling och sensorfusion. I denna exjobbsrapport har möjligheterna att skatta ett skepps girdynamik undersökts. Den matematiska modell som beskriver skeppets dynamik är en grålådemodell som baserar sig på fysikaliska och mekaniska samband. Denna modells egenskaper beskrivs därför av fysikaliska storheter så som massa, tröghetsmoment och tyngdpunkt, vilka alla är okända. Detta innebär att vid modellskattning skattas dessa fysikaliska storheter, vilka kan vara av stort intresse. En simuleringsmiljö med en skeppsmodell med fyra frihetsgrader har skapats och använts för att validera metoder för systemidentifiering. En modell av ett roterbart framdrivningssystem har också härletts och inkluderats i simuleringsmodellen. Vid systemidentifiering och skattning av skeppets egenskaper har dels inverkan av mätbrus analyserats samt även möjligheter till att detektera skillnader i dynamik. Detta har gjorts med Monte Carlo-simuleringar av skattningsmetoden med olika brusrealiseringar för att analysera hur mätbrus påverkar variansen och metodfelet hos skattningarna. Resultaten visar att vissa parametrar skattas med större noggrannhet och hos dessa kan därmed en förändring i dynamik identifieras när endast tio minuter av data har använts. En metod baserad på kumulativ summering av residualer har formulerats och validerats, detta för att undersöka om en sådan metod kan ge snabb och effektiv detektion av systemförändringar. Resultat visar på robusthet i att detektera skillnader i dynamik efter ungefär fyra minuter av datainsamling. Slutligen har metoderna validerats på data insamlad på ett riktigt skepp för att undersöka potentialen under verkliga omständigheter. Resultaten visar att just denna data inte är lämplig för denna applikation samt några problem som kan leda till försämrade resultat.

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48

Mojžíšek, Dominik. "Dynamická analýza koleje." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2018. http://www.nusl.cz/ntk/nusl-372123.

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The diploma thesis deals with descriptions of vehicle - track dynamic interface. There are described basic analytical models of railway track. The numerical models are created by using finite element methods with moving load simulated axle of rail vehicle. The aim of thesis is to create the model which most accurately describes the dynamic phenomena in the track. The results from models are compared with data obtained by measuring in the track. Next aim of thesis is to determine dependency of rail cross-sectional characteristics on equivalent rail head wear and then on rail deflection.

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49

Yen-ChiehNing and 寧彥傑. "Design of micropolar metamaterials with negative effective mass moment of inertia." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/37nz4n.

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50

Kara, Ilker F., and Ashraf F. Ashour. "Flexural performance of FRP reinforced concrete beams." 2012. http://hdl.handle.net/10454/7629.

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yes
A numerical method for estimating the curvature, deflection and moment capacity of FRP reinforced concrete beams is developed. Force equilibrium and strain compatibility equations for a beam section divided into a number of segments are numerically solved due to the non-linear behaviour of concrete. The deflection is then obtained from the flexural rigidity at mid-span section using the deflection formula for various load cases. A proposed modification to the mid-span flexural rigidity is also introduced to account for the experimentally observed wide cracks over the intermediate support of continuous FRP reinforced concrete beams. Comparisons with experimental results show that the proposed numerical technique can accurately predict moment capacity, curvature and deflection of FRP reinforced concrete beams. The ACI-440.1R-06 equations reasonably predicted the moment capacity of FRP reinforced concrete beams but progressively underestimated the deflection of continuous ones. On the other hand, the proposed modified formula including a correction factor for the beam flexural rigidity reasonably predicted deflections of continuous FRP reinforced concrete beams. It was also shown that a large increase in FRP reinforcement slightly increases the moment capacity of FRP over-reinforced concrete beams but greatly reduces the defection after first cracking.

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Dissertations / Theses on the topic 'Effective Moment of Inertia'

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