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Guo, Zhiling. "Torsional Stiffness of Corrugated Paperboard." Miami University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=miami1477434308012406.
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Steed, William T. "Torsional Stiffness Measuring Machine (TSMM) and Automated Frame Design Tools." University of Cincinnati / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1273168255.
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Assaye, Abb. "Torsional Stiffness Calculation of CFRP Hybrid Chassis using Finite Element Method : Development of calculation methodology of Formula Student CFRP Chassis." Thesis, Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-79065.
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Composite sandwich structures are being used in the automotive and aerospace industries at an increasing rate due to their high strength and stiffness per unit weight. Many teams in the world’s largest engineering competition for students, Formula Student, have embraced these types of structures and are using them in their chassis with the intent of increasing the torsional stiffness per unit weight. The Formula Student team at Karlstad University, Clear River Racing, has since 2017 successfully built three carbon fiber based sandwich structure chassis. A big challenge when designing this type of chassis is the lack of strategy regarding torsional stiffness simulations. Thus, the goal of this thesis project was to provide the organization with a set of accurate yet relatively simple methods of modelling and simulating the torsional stiffness of the chassis. The first step in achieving the goal of the thesis was the implementation of simplifications to the material model. These simplifications were mainly targeted towards the aluminum honeycomb core. In order to cut computational times and reduce complexity, a continuum model with orthotropic material properties was used instead of the intricate cellular structure of the core. To validate the accuracy of this simplification, the in-plane elastic modulus of the core was simulated in the finite element software Abaqus. The stiffness obtained through simulations was 0.44 % larger than the theoretical value. The conclusion was therefore made that the orthotropic continuum model was an accurate and effective representation of the core. Furthermore, simplifications regarding the adhesive film in the core-carbon fiber interfaces were made by using constraints in Abaqus instead of modelling the adhesive films as individual parts. To validate this simplification and the overall material model for the sandwich structure, a three-point bend test was simulated in Abaqus and conducted physically. The stiffness for the sandwich panel obtained through physical testing was 2.4 % larger than the simulated stiffness. The conclusion was made that the simplifications in the material modelling did not affect the accuracy in a significant way. Finally, the torsional stiffness of the 2020 CFRP chassis was found to be 12409.75 Nm/degree. In addition to evaluating previously mentioned simplifications, this thesis also serves as a comprehensive guide on how the modelling of the chassis and how the three-point bend test can take place in regards to boundary conditions, coordinate system assignments and layup definitions.
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Judd, Clinton T. "LATERAL-TORSIONAL VIBRATION OF A SIDE-LOADED ROTOR WITH ASYMMETRIC SHAFT STIFFNESS." DigitalCommons@CalPoly, 2010. https://digitalcommons.calpoly.edu/theses/288.
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Using energy equations a four degrees of freedom analytical model is developed for a two-disk rotor with shaft stiffness asymmetry. A radial constant force is applied to the outboard disk to emphasize the effects of gravity or aerodynamic side loading. Special emphasis is placed on characterizing the lateral and torsional vibration trends associated with shaft asymmetry which may be used to identify failing shafts in operational rotor systems. Simulation reveals distinct patterns in lateral and torsional response, with strong dependencies on the magnitude of the side load, magnitude of the asymmetry and proximity of the lateral and torsional natural frequencies. Notable interaction is also observed between the lateral and torsional response. Lateral response peaks are found to correlate to torsional response peaks under some conditions. An experiment is performed to compare the response of a real system with the simulated model.
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Villasenor, Aguilar Jose Maria. "Lateral-Torsional Buckling Instability Caused by Individuals Walking on Wood Composite I-Joists." Diss., Virginia Tech, 2013. http://hdl.handle.net/10919/19212.
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Recent research has shown that a significant number of the falls from elevation occur when laborers are working on unfinished structures. Workers walking on wood I-joists on roofs and floors are prone to fall hazards. Wood I-joists have been replacing dimension lumber for many floor systems and a substantial number of roof systems in light-frame construction. Wood I-joists are designed to resist axial stresses on the flanges and shear stresses on the web while minimizing material used. However, wood I-joists have poor resistance to applied lateral and torsional loads and are susceptible to lateral-torsional buckling instability. Workers walking on unbraced or partially braced wood I-joists can induce axial and lateral forces as well as twist. Experimental testing demonstrated that workers cause lateral-torsional buckling instability in wood I-joists. However, no research was found related to the lateral-torsional buckling instability induced by individuals walking on the wood I-joists. Furthermore, no research was found considering the effects of the supported end conditions and partial bracing in the lateral-torsional buckling instability of wood I-joists.The goal of this research was to derive mathematical models to predict the dynamic lateral-torsional buckling instability of wood composite I-joists loaded by individuals walking considering different supported end conditions and bracing system configurations. The dynamic lateral-torsional buckling instability was analyzed by linearly combining the static lateral-torsional buckling instability with the lateral bending motion of the wood I-joists. Mathematical models were derived to calculate the static critical loads for the simply supported end condition and four wood I-joist hanger supported end conditions. Additionally, mathematical models were derived to calculate the dynamic maximum lateral displacements and positions of the individual walking on the wood I-joists for the same five different supported end conditions. Three different lean-on bracing systems were investigated, non-bracing, one-bracing, and two-bracing systems. Mathematical models were derived to calculate the amount of constraint due to the lean-on bracing system. The derived mathematical models were validated by comparison to data from testing for all supported end conditions and bracing systems.
The predicted critical loads using the static buckling theoretical models for the non-bracing system and the static buckling theoretical models combined with the bracing theoretical models for the simply and hanger supported end conditions agreed well with the critical loads obtained from testing for the two wood I-joist sizes investigated. The predicted maximum lateral displacements and individual positions using the bending motion theoretical models for the simply and hanger supported end conditions agreed well with the corresponding maximum lateral displacements and individual positions obtained from testing for both wood I-joist sizes. Results showed that; a) the supported end condition influenced the critical loads, maximum lateral displacements and individual positions, b) the bracing system increased the critical loads and reduced the maximum lateral displacements, c) the critical load increased as the load position displaced away from the wood I-joist mid-span, d) the critical load reduced as the initial lateral displacement of the wood I-joist increased and e) the wood I-joist mid-span was the critical point in the dynamic lateral-torsional buckling instability.
Ph. D.
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Adriaenssens, Sigrid Maria Louis. "Stressed spline structures." Thesis, University of Bath, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.341171.
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This thesis concerns stressed spline structures. A spline is defined as `an initially straight member with identical second moment of area about any axis perpendicular to its centroidal axis, bent into a spatial curve'. An analytical proof is presented to show that the spline's torsional stiffness is of no importance in its analysis (provided construction details do not introduce any torsional moment). This paramount proof allows the formulation of a spline analysis that relies solely on three translational degrees of freedom (3DOF) per node. Applying this 3DOF analysis to unstrained curves and battened or hoop supported membranes is approximate since the bending stiffness would correspond to one direction only. A series of four test cases validates the proposed 3DOF analysis. The analysis is first applied to a laterally loaded spline ring, where solution convergence and the effect of unequal length segment modelling are investigated. Most significantly, this test case demonstrates that the spline ring has a greater out-of-plane stiffness than a pre-bent ring. This feature lies at the basis of spline stressed membranes - the spline has superior out-of-plane stiffness under the action of forces applied by the membrane. The second and third test cases -- buckling of elastica and of a shallow sinusoidal arch -- clearly demonstrate that the 3DOF analysis is much faster, more accurate, and produces results closer to the analytical values compared with a 6DOF analysis. The fourth test case proves the efficiency of the 3DOF analysis through investigating buckling behaviour and loads of four circular arches under radial loading. As the torsional stiffness does not enter the 3DOF analysis, the stiffness of a spline constructed of spliced segments is identical to that of a continuous spline. In order to demonstrate their feasibility, five medium span (161n-32m) Glass Fibre Reinforced Plastic (GFRP) and one large span (57nt) steel tensegrity stressed spline membranes are designed, form-found and analysed under realistic loading conditions. These design studies show firstly that the spline and membrane stresses occurring under loading are within acceptable material limits and secondly that buckling occurs at values much higher than those encountered in reality. This thesis has demonstrated that engineered stressed spline structures, for which the development of a 3DOF was essential, have great design potential.
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Herrmann, Manuel. "Torsional Stiffness and Natural Frequency Analysis of a Formula SAE Vehicle Carbon Fiber Reinforced Polymer Chassis using Finite Element Analysis." DigitalCommons@CalPoly, 2016. https://digitalcommons.calpoly.edu/theses/1692.
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Finite element is used to predict the torsional stiffness and natural frequency response of a FSAE vehicle hybrid chassis, utilizing a carbon fiber reinforced polymer sandwich structure monocoque and a tubular steel spaceframe. To accurately model the stiffness response of the sandwich structure, a series of material tests for different fiber types has been performed and the material properties have been validated by modeling a simple three-point-bend test panel and comparing the results with a physical test. The torsional stiffness model of the chassis was validated with a physical test, too. The stiffness prediction matches the test results within 6%. The model was then used to model the natural frequency response by adding and adjusting the materials’ densities in order to match physical mass properties. A hypothesis is made to explain the failure of the engine mounts under the dynamic response of the frame.
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Hu, Ye. "Lateral Torsional Buckling of Wooden Beams with Mid-Span Lateral Bracing." Thesis, Université d'Ottawa / University of Ottawa, 2016. http://hdl.handle.net/10393/35076.
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An analytical and numerical investigation is conducted for the lateral torsional buckling analysis of wooden beam with a mid-span lateral brace subjected to symmetrically distributed loading. Two models are developed; one for the case of a rigid brace and another one for the case of a flexible brace. The analytical solutions are based on the principle of stationary potential energy and a Fourier expansion of the buckling displacement fields and bending moments. The validity of both models are verified against 3D finite element analyses in ABAQUS. Where applicable, verifications were also conducted against available solutions from previous studies. Parametric studies were conducted to investigate the effect of geometric and material parameters on the critical moments. The results indicate the presence of two separate groups of potential buckling modes, symmetric and anti-symmetric, with fundamentally different behavioural characteristics. The governing buckling mode is shown to depend on the bracing height, load height and lateral brace stiffness. The study shows that beyond a certain threshold bracing height, the critical moment is governed by the antisymmetric mode of buckling. Also, above a certain optimum bracing stiffness, no increase is observed in the critical moments. The models developed are used to construct a comprehensive database of parametric investigations which are then employed for developing simplified equations for determining the threshold heights, associated critical moments, and optimum stiffness.
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Fraser, Samuel. "A method of using computer simulation to assess the functional performance of football boots." Thesis, Loughborough University, 2015. https://dspace.lboro.ac.uk/2134/17733.
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This thesis details the development of Finite Element Analysis (FEA) techniques to simulate assembly and functional performance of football boots within a virtual environment. With a highly competitive market and seasonal changes in boot design common, the current design process can require numerous iterations, each adding time and cost to the development cycle. Using a reliable model allows evaluation of novel design concepts without the necessity to manufacture physical prototypes, and thus has potential financial benefits as well as reducing development time. A modelling approach was developed to construct a three dimensional boot model using FEA techniques, simulating the assembly of representative boot constituent parts based on manufacturing patterns, geometries and materials. Comparison between the modelled and physical boots demonstrated good agreement. Assessment of physical boot manufacture enabled the validation of the simulated assembly techniques, with digital image correlation hardware and software used to provide experimental measurements of the surface deformation. Good agreement was reported, demonstrating the predictive capabilities of FEA. Extensive review of literature provided applicable loading conditions of the boot during game play, with bending and torsional stiffness identified as important parameters. Boundary conditions associated with the foot during these movements provided a platform from which mechanical tests were used and developed to quantify boot function. Modelling techniques were developed and applied to the assembled FEA boot model, simulating the loading conditions to verify the validity when compared with experimental measurements. Bending and torsional stiffness extracted from the model were compared with the physical equivalent, demonstrating good predictive capabilities. The model was able to represent bending stiffness of the physical equivalent within 5.6% of an accepted boot range up to 20°, with torsional stiffness represented within the accepted range between 10° inversion to 7.5° eversion, corresponding to a large proportion of match play. Two case studies proved the applicability of the FEA techniques to simulate assembly and determine mechanical functionality virtually through a combination of automated modelling methods and a bespoke framework, demonstrating how it could be implemented within the industrial design process.
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Kumar, Naren. "Investigation of drive-train dynamics of mechanical transmissions incorporating cycloidal drives." Thesis, Queensland University of Technology, 2015. https://eprints.qut.edu.au/84752/8/Naren%20Kumar%20Thesis.pdf.
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Cycloidal drives are compact, high-ratio gear transmission systems used in a wide range of mechanical applications from conveyor drives to articulated robots. This research hypothesises that these drives can be successfully applied in dynamic loading situations and thereby focuses on the understanding of differences between static and dynamic loading conditions where load varies with time. New methods of studying the behaviour of these drives under static and dynamic loading circumstances were developed, leading to novel understanding and knowledge. A new model was developed to facilitate research and development on Cycloidal drives with potential benefits for manufacturing, robotics and mechanical-process-industries worldwide.
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Nation, Cory A. "The "45 Degree Rule" and its Impact on Strength and Stiffness of a Shaft Subjected to a Torsional Load." University of Dayton / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1417442309.
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Mende, Milan. "Konstrukční návrh kompozitního chassis Formule Student." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2021. http://www.nusl.cz/ntk/nusl-449785.
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The Master’s thesis deals with the design and production of a composite chassis of the new formula Dragon X. The carbon prepreg used for manufacturing of the monocoque was to be operated at high temperatures. Therefore, this thesis deals with the application of composites structures in the high temperature environment. The thesis addresses the torsional stiffness problematics and it was not only physically tested, but also simulated by FEM analysis and the results were compared.
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Haratek, Marek. "Měření charakteristiky torzních stabilizátorů náprav vozidel." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2021. http://www.nusl.cz/ntk/nusl-445162.
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This diploma thesis deals with the measurement of the torsion stabilizer characteristics. The beginning of the thesis explains the function of a torsion stabilizer in a vehicle and introduces various technical options of stabilization. Next part is focused on computational simulation of representative stabilizers. Next parts are devoted to proposition of measuring device for torsion stabilizers in the laboratory and execution of the experiment. In the final part multibody model is created to demonstrate achieved results.
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Pasha, Hasan G. "Estimation of Static Stiffnesses from Free Boundary Dynamic (FRF) Measurements." University of Cincinnati / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1416569956.
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Kudr, Jan. "Zařízení pro měření torzní tuhosti karoserie." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2013. http://www.nusl.cz/ntk/nusl-230964.
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Those theses describe torsional stiffness car chassis. Here is write short knowledge about various type of measuring, explain impact torsional stiffness on car handling. Target of this theses is work out structural proposal of device for measuring torsional stiffness car chassis, suitable method of measuring, calculate measurement mistake and provisional cost calculation.
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Dubský, Jiří. "Experimentální vozidlo pro testování pohonných jednotek." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2011. http://www.nusl.cz/ntk/nusl-229706.
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The goal of this diploma thesis is to design a frame for an experimental vehicle. The primary object is to design a conception and layot of a drive unit. The frame design is followed by a creation of a model for an analysis. The model will serve for torsional stiffness computing using FEM analysis software. After evaluation of results additional chanhges of the design may take place. A vehicle will serve for testing combustion engines of the same conception and thus it is not intended to run on public roads.
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Santoso, Junius. "Toward Deployable Origami Continuum Robot: Sensing, Planning, and Actuation." Digital WPI, 2019. https://digitalcommons.wpi.edu/etd-dissertations/582.
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Continuum manipulators which are robot limbs inspired by trunks, snakes, and tentacles, represent a promising field in robotic manipulation research. They are well known for their compliance, as they can conform to the shape of objects they interact with. Furthermore, they also benefit from improved dexterity and reduced weight compared to traditional rigid manipulators. The current state of the art continuum robots typically consists of a bulky pneumatic or tendon-driven actuation system at the base, hindering their scalability. Additionally, they tend to sag due to their own weight and are weak in the torsional direction, limiting their performance under external load. This work presents an origami-inspired cable-driven continuum manipulator module that offers low-cost, light-weight, and is inherently safe for human-robot interaction. This dissertation includes contributions in the design of the modular and torsionally strong continuum robot, the motion planning and control of the system, and finally the embedded sensing to close the loop providing robust feedback.
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Hajdušek, Zdeněk. "Baja SAE Vehicle Design." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2012. http://www.nusl.cz/ntk/nusl-230209.
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This master’s thesis describes the design of the Baja SAE vehicle according to the applicable rules. In the beginning is the work focused on search competing vehicles and subsequently on design the first Baja SAE vehicle in the Czech republic. This thesis is systematically divided into chapters according process to the vehicle design. The main part of a master's thesis is design of axle kinematics in software Adams and frame design. The model was designed in Catia V5. The frame was analysed of torsional stiffness and stress in software ANSYS.
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Chalupa, Pavel. "Analýza torzní tuhosti upravené varianty rámu vozidla Formule Student." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2010. http://www.nusl.cz/ntk/nusl-228970.
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Pavel Chalupa Torsional Stifness Analysis of Formula Student Frame Modification DW, IAE, 2010, 66 str., 66 obr. This thesis is concerned with a calculation analysis of a frame construction for Formula Student. The Base design of this construction is modeled in computer program ProEngineer. In next step the model is transfered to calculation software Ansys. The analysis is made by finite element method in torion and bend there. The calculation of torsional stiffness is made of resultant values. Finally, the results are compared with previous frame versions.
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Ratiborský, Pavel. "Konstrukční návrh trubkového rámu Formule Student." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2014. http://www.nusl.cz/ntk/nusl-231389.
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This thesis deals with the design of the tubular frame for the Formula Student car competition. The first part is a brief introduction to the competition and used variants of frames. The main part starts with a list of restrictions by the rules and other necessary installation components. The central part is devoted to the draft modifications and their assessment in terms of torsional stiffness by FEM analysis. The final section presents the resulting frame design with respect to the required properties. The work is concluded final evaluation.
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Malchárek, Miroslav. "Měření torzní tuhosti vozidla s využitím 3D scanneru." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2014. http://www.nusl.cz/ntk/nusl-231528.
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This thesis deals with the measurement of the torsional stiffness of the frame using Tritop system. There is described development of the frame due to the complexity of torsional stiffness. Further there is outlined a brief overview of the types of measurement and the effect of torsional stiffness on the driving behavior of the vehicle. The aim of the work is to develop a method for measuring torsional stiffness of the vehicle Formula Student and from the results of repeated measurements to assess the accuracy and repeatability of measurements.
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Slimařík, Dušan. "Návrh nové evoluce trubkového rámu vozidla Formule Student." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2012. http://www.nusl.cz/ntk/nusl-230250.
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Design of new evolution steel welded tubular frame specified for Formula Student series is the main goal of this thesis. In the first instance, type of frame designs is described. Next part of thesis is devote to rules, which must be respected in designing of new evolution of tubular frame. In main part, construction design and calculations of torsional stiffness using MKP analysis are mentioned. Interesting point of this work is located at penultimate part, which deals with preparation of tubular frame production. This is integral part of the construction process at all. Thesis ends with project summary.
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Trněný, Pavel. "Rám formulového vozu s návrhem upevňovacích prvků karosérie." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2013. http://www.nusl.cz/ntk/nusl-230919.
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This masters thesis concernes with design of formula student frame. Part of masters thesis is to a overview of possible solutions. The main criterion in frame design is final torsional stiffness. Another part of frame design is too solution of suspension attachement to frame. In next part of masters thesis is solved bodywork design and it´s fastening to frame. Final part has few informations about frame manufacturing.
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Petro, Pavol. "Torzní tuhost rámu vozidla Formule Student." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2016. http://www.nusl.cz/ntk/nusl-254361.
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The master´s thesis is focused on chassis design of Formula Student car. It´s describes not only design of frame but also mounting of suspension components like arms, rockers and dampers. During whole design process was using finite elements method calculations, to achieve determined value of torsional stiffness and prevent local deformation of frame structure during drive. Value of torsional stiffness is also verificated by measurement and in last chapter is described influence of torsional stiffness on vehicle dynamics.
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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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Krkoška, Kamil. "Optimalizace konstrukce rámu vozidla Formule Student." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2010. http://www.nusl.cz/ntk/nusl-229053.
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The goal of this diploma thesis was to create optimalizated frame design for Formula Student/SAE. Basic requirements were, that new design must meet the newest Formula Student/SAE rules and other various requirements. In the thesis are built up an overview of most important rules and also an overview of previous frame designs. Next are described design process of the new frame and its stress analysis in FEM software. Main attention is given to analysis of torsional stiffness. The results of analysis are compared to previous frame designs and to parameters of Formula Ford. There are also given recommendations and other possibilities for further frame design development.
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Jurnečka, Ladislav. "Torzní tuhost rámu Formule Student." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2014. http://www.nusl.cz/ntk/nusl-231527.
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Diploma thesis deals with detection of torsional stiffness with using photogrammetric equipment TRITOP device and subsequent comparison with created computational model in FEM software. Measurement and calculations were accomplished according to tutorials, which are the most effective and giving the most accurate results. Next the optional method of measurement of torsional stiffness in practice is formed for future formula series called Dragon. The reasons of different results and suggestion of optimalization are sum up in the end of the thesis.
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Garami, Boris. "Dynamický model harmonické převodovky." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2016. http://www.nusl.cz/ntk/nusl-254390.
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This thesis deals with the design of a dynamic model of a harmonic drive. It includes a theoretical study aimed at the analysis of the harmonic drive gearing principle and its nonlinear properties. The first part of the practical section deals with the analytical calculation of the nondeformed geometry of the Flexspline. Based on these results, several simulations in ANSYS are created to identify torsional characteristics of a harmonic drive. These simulation models are further enhanced by the analysis of clearance, backlash and inaccuracies and their impact on torsional properties. By using MATLAB /Simulink, several dynamic submodels are created representing the individual characteristics of nonlinearities in harmonic drives. Furthermore, a comprehensive dynamic model is created of the mechatronic system which is describing all nonlinearities and kinematic error of the transmission. The dynamic model is also experimentally verified based on its damping properties.
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Vargas, Vinicius Athaydes de. "Efeitos da flexibilidade estrutural em simulações de dinâmica lateral de veículo de transporte de carga." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2011. http://hdl.handle.net/10183/34760.
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Este trabalho apresenta uma análise multicorpos de combinação veicular de carga com chassi de semirreboque flexível, para avaliação de dinâmica lateral. O contexto é dado por um breve panorama do transporte rodoviário de cargas no Brasil. No intuito de melhorar seus produtos, os fabricantes de implementos rodoviários têm utilizado metodologias de desenvolvimento baseadas em simulação virtual. Nessas circunstâncias, análises dinâmicas são realizadas, geralmente levando-se em conta a hipótese de corpos rígidos (não deformáveis). Subjetivamente, é sabido que a inclusão da flexibilidade em um modelo numérico o aproxima do fenômeno real, mas são raros os trabalhos que analisam quantitativamente essa diferença. Assim, neste estudo é proposta uma abordagem para consideração da flexibilidade estrutural do chassi de um semirreboque em simulações de tráfego. Procede-se a discretização do quadro do implemento em elementos finitos, para realização de análise de vibração livre, na qual são determinados os modos (autovetores) e as frequências naturais (autovalores) da estrutura. Utilizando metodologia de superposição modal, os modos de vibração são classificados para compor, por combinação linear, a flexibilidade da estrutura nas análises dinâmicas em ferramenta comercial de MBS (sistemas multicorpos). São realizadas, então, simulações de manobras representativas da dinâmica lateral de combinações veiculares, com ênfase à estabilidade em rolagem. Os efeitos globais da inserção de flexibilidade modal no chassi do semirreboque são avaliados por meio de métricas específicas, baseadas em normas ISO de dinâmica lateral para veículos pesados. Os resultados das simulações, apresentados em forma gráfica e tabelas, mostram a grande influência da flexibilidade estrutural do chassi no desempenho dinâmico da combinação veicular analisada. Grandezas relevantes como aceleração lateral (no domínio do tempo e da frequência), ângulo de rolagem e força atuante nos pneus, além de fenômenos físicos como a transferência lateral de carga em curvas, são fortemente afetados pela flexibilidade do quadro. Agrega-se ao trabalho desenvolvido uma forma simplificada de equacionar analiticamente a rolagem de um semirreboque flexível. É realizada também uma análise de sensibilidade da rigidez torcional do chassi quanto ao número de travessas.This work presents a lateral dynamics multibody analysis of a heavy articulated vehicle with a flexible frame for the semi-trailer. The context is given by a short perspective of the load carrying transportation scenery in Brazil. In order to build better products, the trailer manufacturers have been using development methodologies based on virtual simulation. In these circumstances, dynamic analyses are carried out, considering the hypothesis of rigid (non-deformable) bodies. Subjectively, it is known that the inclusion of flexibility in a numerical model brings it closer to reality, but very few studies work on giving numbers to this difference. Thus, this study presents an approach for taking into account the frame structural flexibility of a semi-trailer in traffic simulations. The frame of the semi-trailer is represented by a finite element model, and a free vibration analysis of this structure is carried out. The mode shapes (eigenvectors) and natural frequencies (eigenvalues) are determined. With a mode superposition method, the vibration modes are classified, for the purpose of building the structural flexibility (by linear combination) of the chassis in the dynamic analyses of the MBS software. Typical maneuvers of lateral dynamics are simulated, testing the roll stability of the combined vehicle model. The global effects for considering the mode flexibility in the semitrailer frame are evaluated through specific metrics, based on ISO standards for heavy vehicles lateral dynamics. The strong influence of the frame structural flexibility, when analyzing the articulated vehicle transient behavior, is showed by simulation results, which are presented in graphics and tables. Important measurements, such as lateral acceleration (in time and frequency domains), roll angle and vertical force on tires, besides physical phenomenon like lateral load transfer, are significantly modified by the flexibility of the frame. A simplified approach for writing the analytical equations of the flexible semi-trailer roll dynamics is added to the study. A torsional stiffness sensitivity analysis is also performed, regarding the number of transversal members in the semi-trailer chassis.
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Přikryl, Karel. "Návrh dálničniho osobního vozidla na elektrický pohon." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2011. http://www.nusl.cz/ntk/nusl-229675.
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This thesis deals with design concept of the electric car. At first, vehicle dynamics was solved in program MathCad. The components were selected from the obtained results. This was followed by a proposal layout design and vehicles main dimensions design. The frame was created in program ProEngineer, and then imported into ANSYS. Simulation of torsional rigidity was made in ANSYS by FEM.
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Hajer, Václav. "Konstrukční uspořádání zadní části rámu vozidla Formule Student." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2011. http://www.nusl.cz/ntk/nusl-229851.
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This diploma thesis deals with description of the design of the rear of the vehicle structure of Formula Student processed by using a 3D CAD system. Formula have to fulfill all requirements Formula Student rules. The requirements and rules are given by building of engine and other considered engine components. The final version of the design of the rear part is assembled with the supplied front and the computational model is created to simulate the torsional stiffness of the FEM system. Another analysis model is created for a foreign supplied frame construction. Both of these frames are in terms of torsional stiffness evaluated and mutually compared. There are also mentioned selected Formula Student rules and overview of the formula frames and their overview.
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Děrda, Martin. "Návrh rámu vozidla Formule Student." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2017. http://www.nusl.cz/ntk/nusl-318534.
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This diploma thesis focuses on proposing construction and manufacture plans of a hybrid frame chassis consisting of a tubular space frame and a monocoque made of composite materials. Next, it discusses the simulation of the chassis via FEM analysis and also measuring of its torsional stiffness. In the final part of the thesis, the frame is compared to its older predecessor, which is made solely of a tubular space frame, and its advantages and disadvantages are evaluated.
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Straka, Martin. "Koncepční návrh sportovního dvousedadlového vozu." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2010. http://www.nusl.cz/ntk/nusl-229055.
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is diploma thesis deals with design concept of two-seater sports car with the main focus on chassis torsional stiffness and axle kinematics. The main idea started with some paper sketches which were later transferred to the 3D model with all the main parts (engine, differential, driver etc.) using CATIA V5 design program. Then the torsional stiffness was counted using FEM software ANSYS 12.0. Finally the axis geometry during bump/rebump movement of the wheel was simulated in MBS system ADAMS 2007.
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Ondák, Lukáš. "Alternativní rám Formule Student vyhovující požadavkům mezinárodních pravidel." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2014. http://www.nusl.cz/ntk/nusl-231356.
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This master thesis describes design of frame construction of Formula Student car. The objective was to reduce weight and increase the torsional stiffness against to last version of the car. Next objective was to prove advantages of alternative frame. This had been achieved by gradual transformation of standard design of frame to alternative with the usage of FSAE alternative frame rules. The weight was reduced by 20% and torsional stiffness was increased by 34% thanks to FEM simulation and sophisticated changes of alternative frame design.
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Hlaváč, František. "Návrh řízení formulového vozidla s použitím kardanových kloubů." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2019. http://www.nusl.cz/ntk/nusl-400874.
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The aim of this master thesis is the construction of a steering system for Formula Student monopost. The main part of the thesis is the design and analysis of steering column using universal joints. The thesis also contains design and analysis of steering rack together with experimental measurement of steering column torsional stiffness. An important part of the thesis is also a calculation of steering forces.
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Ericsson, Luis Gustavo Sigward. "Estudo da influência da rigidez do quadro na dirigibilidade de um veículo de competição Fórmula SAE em ambiente multicorpos." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/18/18149/tde-21082009-105817/.
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O objetivo deste trabalho é estudar a influência da rigidez do quadro na dirigibilidade de um veículo de competição fórmula SAE (protótipo E2-M, da equipe EESC-USP) em ambiente multicorpos com o software Adams/Car. Um modelo contendo os subsistemas de suspensão, direção, pneumático, powertrain, barra estabilizadora e quadro foi construído em ambiente multicorpos com componentes modelados como corpos rígidos. Posteriormente foram elaborados três modelos de quadros flexíveis com diferentes valores de rigidez torcional para substituir o quadro rígido. Estes foram obtidos através da análise modal com o auxílio do método dos elementos finitos. Para comparação da dinâmica lateral dos modelos, típicas manobras do estudo de dirigibilidade foram consideradas tais como rampsteer, step-steer e single lane change. Os resultados obtidos foram de aceleração lateral e velocidade de guinada. Pelas condições avaliadas, pode-se concluir que a rigidez torcional de um quadro para o protótipo E2-M pode estar entre 700 e 1500 N.m/o. Essa variação de rigidez representou 5 kg de massa no quadro. Porém deve-se fazer uma avaliação modal com a massa suspensa calibrada para verificar se não existe acoplamento de modos e freqüências com outros subsistemas.This dissertation is intended to study the influence of frame stiffness in handling of a Formula SAE vehicle (E2-M prototype from EESC-USP Formula SAE team) in multibody with Adams/Car software. A model containing the subsystems of suspension, steering, tires, powertrain, frame and stabilizing bar was built considering rigid bodies. Subsequently, three models of flexible frames were developed with different values of torsional stiffness to replace the rigid frame. They were obtained through modal analysis with the aid of finite element method. For the handling investigation, maneuvers such as ramp-steer, step-steer and single lane change were considered. The results evaluated were lateral acceleration and yaw velocity. According to results, the torsional stiffness for the E2-M prototype can be between 700 and 1500 Nm/o. But an eigenvalue analyses is also necessary to verify if there is no coupling of modes of the calibrated sprung mass with other subsystems.
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Žídek, Tomáš. "Aplikace sendvičové konstrukce na formulový vůz." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2016. http://www.nusl.cz/ntk/nusl-254214.
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The master thesis describes application of a sandwich construction for Formula Student car. It will replace the current tubular space frame according to FSAE rules. The introduction is focused on the information of international Formula Student competition, including TU Brno Racing Team. Then there are important rules for the construction of frames and composite monocoques. For the selected production technology are found strength properties of face sheets made of carbon and hybrid fibres. Another part of thesis deals with the design of the sandwich panel using analytical calculation to determine the bending stiffness. On the basis of these proposals are made three-point bending and shear tests. Using of FEM simulation is detected torsional stiffness of the tubular space frame and the monocoque concept from the proposed sandwich panels. The conclusion is devoted to a summary of the important information and possible monocoque manufacturing process.
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Young, Alexander. "Validating Automotive Frame Torsion Stiffness Measurement Techniques." University of Cincinnati / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1470672143.
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Balázs, Ivan. "Klopení tenkostěnných ocelových nosníků s vazbami vybočení z roviny ohybu." Doctoral thesis, Vysoké učení technické v Brně. Fakulta stavební, 2017. http://www.nusl.cz/ntk/nusl-371784.
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The doctoral thesis focuses on problem of stability of steel thin-walled beams with lateral and torsional restraints along the spans. Theoretical background of lateral-torsional buckling of an ideal beam with and without restraints preventing out-of-plane buckling is briefly described. In the following chapters the problem of stabilization of steel thin-walled beams by planar members is dealt with. The state of the art in this field is summarized and some open questions are identified. The research in this field could bring new findings about actual behavior of these structural systems. The rate of stabilization can be quantified using values of shear and rotational stiffness provided to a thin-walled member by a planar member. In the frame of the thesis the problem of torsional restraint given to steel cold-formed members by sandwich panels under load is discussed. In case of the uplift load applied on the sandwich panels the torsional restraint should be verified by experimental analysis. To contribute to this field, experimental verification of rotational stiffness provided to steel cold-formed beams by sandwich panels was proposed and performed. Torsional restraint under no external load as well as under uplift load applied on the panels was investigated. The purpose was to obtain the values of the rotational stiffness provided by planar members. The performed tests indicate significant and practically applicable rate of the torsional restraint even in case of the uplift load on the surfaces of the panels. Utilization of the values of the rotational stiffness might result in more economical, effective and reliable structural design. Selected problems were investigated using numerical modeling in a finite element method based software.
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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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Mirjalili, Vahid. "Modelling the structural efficiency of cross-sections in limited torsion stiffness design." Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=99780.
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Most of the current optimization techniques for the design of light-weight structures are unable to generate structural alternatives at the concept stage of design. This research tackles the challenge of developing an optimization method for the early stage of design. The main goal is to propose a procedure to optimize material and shape of stiff shafts in torsion.Recently introduced for bending stiffness design, shape transformers are presented in this thesis for optimizing the design of shafts in torsion. Shape transformers are geometric parameters defined to classify shapes and to model structural efficiency. The study of shape transformers are centered on concept selection in structural design. These factors are used to formulate indices of material and shape selection for minimum mass design. An advantage of the method of shape transformers is that the contribution of the shape can be decoupled from the contribution of the size of a cross-section. This feature gives the designer insight into the effects that scaling, shape, as well as material have on the overall structural performance.
Similar to the index for bending, the performance index for torsion stiffness design is a function of the relative scaling of two cross-sections. The thesis examines analytically and graphically the impact of scaling on the torsional efficiency of alternative cross-sections. The resulting maps assist the selection of the best material and shape for cross-sections subjected to dimensional constraints. It is shown that shape transformers for torsion, unlike those for bending, are generally function of the scaling direction.
The efficiency maps ease the visual contrast among the efficiency of open-walled cross-sections and that of close-walled cross-sections. As expected, the maps show the relative inefficiency of the former compared to the latter. They can also set the validity range of thin- and thick-walled theory in torsion stiffness design. The analytical results are validated with the numerical data obtained from ANSYS to guarantee the consistency of the models. The thesis concludes with three case studies that demonstrate the method.
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Hubáček, Jan. "Rám malosériového sportovního automobilu." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2011. http://www.nusl.cz/ntk/nusl-229646.
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This master´s thesis deals with the design, calculation and verification of sports car frame. Empahasis was placed on meet standards for homologation. Work on diploma project was produced by the design program INVENTOR 2010 and then calculated in ANSYS 12. The last step was optimization and comparison.
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Janiš, Libor. "Deformační měření s využitím zařízení Tritop." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2009. http://www.nusl.cz/ntk/nusl-228727.
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This work deal with, suggestion of measuring procedure of deformation modulus of system Tritop and his application on real instances. Also the measuring procedure of torsional stiffness of vehicle body is designed, and the models of frames including attachment of a car are elaborated, where the measuring of torsional stiffness will be done on.
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Kilic, Mehmet. "Design And Development Of A Mechanically Adjustable Linear Torsion Spring Using Cams." Master's thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/3/12610960/index.pdf.
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Linear springs with variable stiffnesses find some key roles in robotic applications. They are implemented into robotic devices for two main reasons, to increase energy efficiency of walking-running robots and prosthesis, and to get safe human-robot interaction at industrial robots. Being inspired from the human actuation system, a mathematical method to get mechanically adjustable linear springs is noted in the literatureantagonistically working two quadratic springs method. But the proposed solution requires two non-linear springs with quadratic spring characteristics and they are not readily available. Several solutions have been noted in the literature for the acquisition of such non-linear springs. At this thesis work, the solution is realized with a string wrapping around cam mechanism. Two different prototypes were designed and constructed and the second one was physically tested to validate the linear spring behavior. The results displayed good linear spring characteristics with different levels of adjustable spring stiffness. Beside the antagonistically working two quadratic springs method, three novel methods to get mechanically adjustable linear springs are introduced at this thesis. They are based on using hanging weights, an exponential characteristic spring and a linear translation spring respectively. The real prototypes were not manufactured but sample designs using string wrapping around cam mechanisms are made.
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Macháček, Tomáš. "Návrh stabilizátoru automobilu." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2013. http://www.nusl.cz/ntk/nusl-230471.
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Tato diplomová práce je zaměřená na stabilizátory u podvozku aut. První část popisuje všeobecné znalosti vlivu naklonění karosérie na jizdní vlastnosti auta a možnosti konstrukčních řešení používaných v praxi. Dále jsou v této části uvedeny nevýhody použití stabilizátoru a jejich náhrady. Nasledující téma se zaměřuje na soutěž Formule Student a její všeobecná pravidla. Hlavní částí této práce je analýza stabilizátoru Formule Ford, na kterou v poslední části této práce navazuje analýza předního a zadního stabilizátoru Formule Student. Byly vytvořené kompletní MBS modely pro přední a zadní zavěšení včetně stabilizátoru. Díky těmto modelům bylo možné provést výpočty klopných tuhostí a pevnostní výpočty. Z těchto výpočtů bylo možné určit vhodné nastavení stabilizátoru. Všechny modely mohou být dále použitelné pro analýzu jízdních vlastností příslušného vozidla.
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Derner, Petr. "Měření zkrutné tuhosti karosérie s využitím fotogrammetrického zařízení TRITOP." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2009. http://www.nusl.cz/ntk/nusl-228710.
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This master's thesis deals with measurement of torsional rigidity of a vehicle body with the application of TRITOP optical measuring system. The measurement was made in dynamic test-room of Škoda Auto a.s. together with a methodology used by this company. In the light of the objective comparison of both measuring methods and their accuracy, the optimal method of measurment and evaluation was made.
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Krasula, Jan. "Návrh stabilizátoru automobilu." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2011. http://www.nusl.cz/ntk/nusl-229936.
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This master’s thesis is focused on a design of the formula student’s anti-roll bar. The beginning of the thesis is devoted to the introduction of the anti-roll bar function and the explanation of its effect on a vehicle including the analysis of various constructions. Second part deals with the Formula Student competition. There is the analysis of the formula Ford’s anti-roll bar as a starting point for our own design. In the section which deals with the anti-roll bar design several alternatives are designed, the stress analysis of components are made and multi body system models are developed for final solutions. These models serve for further analyses of driving characteristics of the vehicle.
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Geara, Fadi. "Contribution à l'étude de la torsion des poutres en voiles minces et des poutres à profil dissymétrique." Châtenay-Malabry, Ecole centrale de Paris, 1998. http://www.theses.fr/1998ECAP0598.
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Cette recherche est une contribution à l'étude de la torsion des poutres en voiles minces ouverts et des poutres à sections transversales non symétriques. En effet, dans le cas des poutres en voiles minces ouverts, on a développé la statique de la torsion suivant la théorie de Vlassov, c'est-à-dire en tenant compte du gauchissement qui accompagne en général la torsion, et ses effets sur les éléments de structure. Notre travail commence par la résolution de l'équation différentielle de la torsion gênée pour diverses conditions aux limites et différents chargements. Des exemples numériques ont concrétisé l'importance de la prise en compte du gauchissement dans le cas des éléments minces. L'étude a été complétée par la formulation de la poutre continue soumise à la torsion et par une étude numérique comparative avec la méthode des éléments finis en utilisant une modélisation en éléments coques et montrant la concordance entre les deux méthodes. D'autre part, dans le cas des poutres a profil dissymétrique, le centre de torsion n'est pas en général confondu avec le centre de gravité. Notre travail était de prendre en compte cette excentricité et d'introduire son effet dans la matrice de rigidité d'un élément de poutre droite, ainsi que ses effets sur les sollicitations et les déplacements des éléments de structure. L'étude a été complétée par plusieurs exemples schématisant l'intérêt de l'utilisation de la matrice de rigidité modifiée.
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Křepela, Jan. "Dynamické vlastnosti osy C pro multifunkční soustružnické centrum." Doctoral thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2011. http://www.nusl.cz/ntk/nusl-233982.
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his Disertation thesis involves the creating of the simulation model of the C axis drive over mentioned machine and them verification on the prototype of this machine. C axis is controlled with position feedback. Simulation model was created before the realisation of the machine prototype for the preliminary identification of the dynamic behaviours in the working cycles and them opportunity of the realisation this conception. C axis is constructed with worm gear and is controlled with help of Master-Slave drive. This torque drive eliminates the production backlash in the worm gear. The multifunction turning center, where is used this C axis, is determinate for heavy duty roughing cutting of the forged peaces, where is problem with dynamic stability of the cutting process. Simulation model includes the problems with multi-body mass system, friction on the worm gear, self locking, damping on the worm gear and the optimization of the parametrs for many regulators. Simulation model was verified on the prototype of the machine. Achieved results bring the new knowledge, which are used for simulation complicated machine nodes and this knowledge is used for research and developing of the similar mechatronics system.
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Lin, Hung-tao, and 林泓道. "Provided Torsional Brace Stiffness of Solid RC Slab to Steel Beams." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/ett2y3.
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碩士國立臺灣科技大學
營建工程系
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Generally the steel beams is bonded to RC slab by using shear studs when we use the solid RC slab as torsional bracing.This connection is not completely rigid so the real effective stiffness will be represented by considering the joint stiffness between beams and slab. In this research,14 specimens with 7 different types of connection were tested under Monotonic load to investigate the joint stiffness. It shows more effective way to improve the joint stiffness by using stiffned equipment of joint. On the other hand, when we use the solid RC slab as the torsional brace of steel beams,the flexural stiffness of RC slab is the torsional bracig stiffness.However RC slab has cracking issue,we can only estimate the flexural stiffness reasonably through the experiments. In this research,4 specimens with 2 different types were tested under Monotonic load to investigate the flexural stiffness of RC slab. From the test result, the strength and the stiffness after craking of RC slab would be improved once we use the stiffned equipment of joint.