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Dissertations / Theses on the topic 'Brake application'
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1
Ripley, Ian, and ian ripley@qr com au. "An Investigation of Brake Application Delays in Australian Train Brake Systems." Central Queensland University. Engineering, 2005. http://library-resources.cqu.edu.au./thesis/adt-QCQU/public/adt-QCQU20060720.100110.
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An investigation of brake application delays in Australian train brake systems
began with a literature review of pneumatic train braking systems. Data located in the
review gave examples of brake application delays of pre 1990 designs from the U.K.,
India and North America. Information on application delays on later Australian designs
was scarce. Reading of literature has shown a difference between the Australian and
North American control valves in the way the propagation of the pressure reduction rate
in the brake pipe is maintained. Control valves of the North American style allow the
brake pipe air to be connected for a short time to a small cavity or quick service volume
of each valve. The quick service volume is then released to atmosphere. The action of
exhausting a small amount of air from the brake pipe helps to ensure a propagation of an
adequate pressure reduction rate as it travels to the next valve. Australian control valves
rely on the ratio of the volume of brake pipe between control valves and the size of the
quick service volume or bulb to ensure the propagation of an adequate pressure
reduction as it travels to the next valve. The air in a bulb of an Australian valve is not
expelled to atmosphere until a brake release is made.
The research explored possible reductions in application delays by utilizing an
experimental pipe test rack that included 4 control valves and 120 meters of brake pipe.
Experiments with different configurations of exhaust orifices or chokes, valves and
branch pipe lengths that supplied the valves gave a record acquired by data acquisition
of the timing of each valve and the local pressure drop from a valve or each valve for
comparison.
Experiments with exhaust chokes that gave a reduction drop rate in the brake pipe
that approached the minimum required to operate a control valve resulted in instability
of the application operation of the control valve. The quick service volume of different
sizes was included in the experiments to give comparisons in the propagation of the
pressure reduction toward the end of a long train. Further increases into the size of the
bulb of a control valve to enhance the propagation features toward the end of a long
train are discussed. The branch pipe with different diameters from 12 mm to 20 mm and
lengths from 160 mm to 800 mm when fitted to an adaptor pipe bracket were
investigated and results show that larger diameters gave larger gulps in the brake pipe.
Other components that were studied included the pipe bracket that is fitted on some
control valves. The pipe bracket and isolation cock was found to add 282 mm of
additional length to the air path and while not changing the operation of the valve, the
results showed a smaller drop in local pressure in the brake pipe to assist the pressure
reduction rate than shown in valves without pipe brackets.
2
Jahajeeah, N. "Application of numerical modelling in SSM automotive brake calliper castings." Journal for New Generation Sciences, Vol 4, Issue 1: Central University of Technology, Free State, Bloemfontein, 2006. http://hdl.handle.net/11462/491.
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Published ArticleNumerical modelling has successfully been used as an efficient tool to convert a gravity cast brake calliper to a thixocasting process. The thixo-module of Procast has been used for the modelling process to obtain optimum processing parameters. Results from interrupted shot castings show excellent correlation with the fluid dynamics and flow pattern of the model. The level and location of porosity revealed by non-destructive X-rays and microscopic analyses showed good correlation with the model prediction.
3
Avraam, More. "MR-fluid brake design and its application to a portable muscular device." Doctoral thesis, Universite Libre de Bruxelles, 2009. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210235.
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Many devices are available on the market for the evaluation and rehabilitation of patients suffering from muscular disorders. Most of them are small, low-cost, passive devices based on the use of springs and resistive elements and exhibit very limited (or even not any) evaluation capabilities; extended muscular force evaluation is only possible on stationary, expensive, multi-purpose devices, available only in hospitals, which offer many exercise modes (e.g. isokinetic mode) that are not available on other devices.The objective of this thesis is to make the functionalities currently only implemented on bulky multi-purpose devices available at a lower cost and in a portable fashion, enabling their use by a large number of independent practitioners and patients, even at home (tele-medecine applications).
In order to achieve this goal, a portable rehabilitation device, using a magneto-rheological fluid brake as actuator, has been designed. This particular technology was selected for its high level of compactness, simple mechanical design, high controllability, smooth and safe operation. The first part of this thesis is devoted to the design of MR-fluid brakes and their experimental validation. The second part is dedicated to the design of the rehabilitation device and the comparison of its performances with a commercial multi-purpose device (CYBEX).
Doctorat en Sciences de l'ingénieur
info:eu-repo/semantics/nonPublished
4
Moody, David. "Application Pressure for an Electronic Brake System : Estimation and Implementation of a Recursive Filter." Thesis, Uppsala University, Department of Information Technology, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-111173.
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Scania CV AB is one of the major heavy truck manufacturers in the world. Many of their trucks use a brake system that is electronic where the driver demands retardation and the brake power is generated pneumatically. The objective of this thesis is to re-search if it is possible to determine the pressure at which the brakes start giving a retard-ing force, the application pressure, for the Electronic Brake System (EBS) and if a pre-dictive estimation of the application pressure can be implemented.
Three different ways of determining the application pressure are presented in the thesis and a signal processing method where the mean of pre-braking acceleration is used for change detection gives the most reliable results. This method is then implemented in a recursive filter where a predictive estimation of the application pressure is developed. Due to the lack of precision in the signals the estimation does not give a result that can be used and until this is solved by Scania it is difficult to see how a good way of pre-dicting the application pressure can be developed.
5
Fu, Ping Rong Kimberly. "Study and development of novel composite materials for the application of car brake rotor." Thesis, Curtin University, 2014. http://hdl.handle.net/20.500.11937/2321.
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From experimental study of properties including density, tensile strength, Young’s modulus, fracture toughness for both aluminium alloy reinforced with silicon carbide and aluminium alloy reinforced with alumina representing metal matrix composites, and measurements of compressive strength for the above composites and alumina and aluminium titanate based ceramics as functionally graded materials, together with estimated thermal conductivity and specific heat capacity, show promising results for the use of these materials for car brake rotor.
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Yuen, Dick Kwan Kenneth. "Brake disc life prediction for material evaluation and selection : the application of finite element and fatigue analysis to the prediction of crack initiation in brake discs during operation." Thesis, University of Bradford, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.363977.
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Helin, Alva. "A Framework for Assessment of and Advancement Towards Sustainable Circular Economy : An application on automotive brake calipers." Thesis, KTH, Hållbar utveckling, miljövetenskap och teknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-280486.
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The current use of natural resources within the industry generally constitutes of linear systems of raw material extraction to waste formation. However, an increased awareness of sustainability issues has resulted in engagements to try to minimise the impacts on the environment that these linear systems impose. Circular Economy is a concept for a strategy that strives towards closing loops of material in society, and therefore reduce the need of raw material extraction and waste formation. Although Cir- cular Economy strives towards increasing the sustainability of a system, recent research has shown that circularity of material does not necessarily have to lower the environmental impact. Therefore there is a need for a method that can assess circularity from a holistic perspective to ensure the contribution of the Circular Economy strategy to a more sustainable society. The aim of the study is to create a framework that accounts for both conventional circular economy indicators and environmental impacts, and that helps set a strategy for companies to transform towards sustainable Circular Economy. The findings of the performed literature study resulted in the gathering of the most used assessment tools for assessment of circular economy in previous studies: Material Flow Analysis, Cumulative En- ergy Demand and Life Cycle Assessment. This set of tools is used to identify hot spots of impact of a product throughout the product lifetime and to set a strategy toward better practices of manufacturing companies. The study gives an example of practical implementation of the framework on a case study of brake caliper remanufacturing at Autoexperten, a chain of franchise concept garages owned by the parent company KGK. A Material Flow Assessment and a Life Cycle Assessment is performed on a scenario modeled to represent the current state of the case of remanufacturing at Autoexperten, and an alternative scenario that do not include the practice of remanufacturing. The results of the performed assessments concluded that the current state scenario is the most preferable alternative regarding energy use, material use and environmental impact. Therefore, the main recommendation in regards to business strategies for Autoexperten and KGK is to continue the practice of remanufacturing.Dagens användning av naturresurser inom industrin utgörs i allmänhet av linjära system från utvinning av råmaterial till produktionen av avfall. En ökad medvetenhet om hållbarhetsfrågor har dock resulterat i engagemang för att försöka minimera den miljöpåverkan som dessa linjära system skapar. Cirkulär ekonomi är ett koncept för en strategi som strävar efter att cirkulera flöden av material i samhället och därmed minska behovet av råmaterialutvinning och avfallsbildning. Även om den cirkulära ekonomin strävar efter att öka hållbarheten inom ett system har ny forskning visat att cirkularet av material inte nödvändigtvis behöver minska miljöpåverkan inom ett system. Därför har det skapats ett behov av en metod som kan undersöka cirkuläritet från ett holistiskt perspektiv för att säkerställa att den cirkulära ekonomin verkligen bidrar till ett mer hållbart samhälle. Syftet med studien är att skapa ett ramverk som undersöker både konventionella indikatorer av cirkulär ekonomi och miljöpåverkan, och som också skapar en strategi för företag för att uppå hållbar cirkulär ekonomi. Resultatet av en litteraturstudie genererade en uppsättning av de mest använda utvärderingsverktygen för analys av cirkulär ekonomi bland tidigare studier: Materialflödesanalys, kumulativt energibehov och livscykelanalys. Den här uppsättningen av verktyg används i studien för att identifiera processer med speciellt hög påverkan i en produkts livscykel och för att skapa en strategi för bättre prestanda av tillverkande företag. Studien ger ett exempel på en praktisk implementering av ramverket på en fallstudie av renovering av bromsok på Autoexperten, en kedja med franchisekonceptgarage som ägs av moderbolaget KGK. En materialflödesanalys och en livscykelanalys utförs i studien på ett scenario som modelleras för att representera det rådande omständigheterna för renovering av bromsok hos Autoexperten, och ett alternativt scenario som inte inkluderar renovering av bromsok. Slutsatsen som kunde dras av resultaten av materialflödesanalysen och livscykelanalysen var att scenariot med de rådande omständigheterna för renovering av bromsok är det som är mest fördelaktigt vad gäller energianvändning, materialanvändning och miljöpåverkan. Därför är den huvudsakliga rekommendationen för skapandet av en affärsstrategi för Autoexperten och KGK att fortsätta med renoveringen av bromsok.
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Vermot, Des Roches Guillaume. "Frequency and time simulation of squeal instabilities. Application to the design of industrial automotive brakes." Phd thesis, Ecole Centrale Paris, 2011. http://tel.archives-ouvertes.fr/tel-00594224.
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Brake squeal is a common noise problem encountered in the automotive industry. Higherfriction coefficients and weight reduction recently led to higher vibration levels in the audiblefrequency range. This quality issue becomes economic due to penalties imposed to the brakesupplier although no robust design method exists. The industrial practice thus relies on costlyprototyping and adjustment phases. The evolution of computational power allows computationof large mechanical assemblies, but non-linear time simulations generally remain out of reach.In this context, the thesis objective is to provide numerical tools for squeal resolution at earlydesign stages.Parameterized reduction methods are developed, using system real modes as Rayleigh-Ritzvectors, and allow very compact reduced models with exact real modes. The proposed ComponentMode Tuning method uses the components free/free modes as explicit degrees of freedom.This allows very quick sensitivity computation and reanalyzes of an assembly as function oflocal component-wise parameters. Non-linear time simulations are made possible through twoingredients. A modified non-linear implicit Newmark scheme and a fixed Jacobian are adaptedfor contact vibrations. The brake is reduced keeping a superelement with exact real modes anda local non-linear finite element model in the vicinity of the pad/disc interaction.A set of design tools is illustrated for a full industrial brake model. First, instant stabilitycomputations and complex mode trajectories are studied. Modal interactions and non-linearphenomena inside the limit cycles are thus well understood. Time/frequency correlations areperformed using transient modal identification and space-time decomposition. A time domainmodal damping model is also shown to be very useful. The modification of a critical componentfor squeal resolution is finally tested and validated.
9
Vermot, des Roches Guillaume. "Frequency and time simulation of squeal instabilities. Application to the design of industrial automotive brakes." Thesis, Châtenay-Malabry, Ecole centrale de Paris, 2011. http://www.theses.fr/2011ECAP0009/document.
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Le crissement de frein est une nuisance sonore classique dans l’automobile. L’augmentationdes coefficients de friction et la réduction de la masse mènent aujourd’hui à de hauts niveauxvibratoires dans les fréquences auditives, et ces problèmes de qualité se traduisent par des pénalités économiques aux équipementiers, bien qu’il n’existe pas de méthode robuste de conception.La pratique industrielle repose donc sur de coûteuses phases de prototypage et d’ajustement.L’évolution de la puissance de calcul permet le calcul de grands assemblages mécaniques mais lesétudes vibratoires non-linéaires restent généralement hors de portée. Dans ce contexte, l’objectifde la thèse est de fournir, dès les phases de conception, des outils de conception numérique d’aideà la résolution du crissement.Une méthode de réduction paramétrée utilisant comme base de Rayleigh-Ritz les modes réelsdu système assemblé permet la génération de modèles réduits très compacts, avec modes réelsexacts. La méthode proposée d’ajustement des modes de composants utilise les modes libresde composants comme degrés de liberté explicites. L’étude des sensibilités et la réanalyse d’unassemblage en fonction de modifications à l’échelle d’un composant deviennent possibles. Lesétudes temporelles non-linéaires sont rendues possibles par deux développements. Un schémade Newmark non-linéaire modifié et un Jacobien fixe adapté aux vibrations de contact sontintroduits. Le frein est réduit en un superélément avec modes réels exacts et une zone nonréduite au niveau du contact.Un ensemble d’outils de conception est illustré sur un modèle industriel de frein. La stabilitéinstantanée et les trajectoires de modes complexes sont étudiées. Les interactions modales et lesphénomènes non-linéaires au sein des cycles limites sont alors mieux compris. Des corrélationstemps/fréquence sont obtenues par l’identification modale instantanée et une décompositionespace-temps. La grande utilité d’un modèle temporel d’amortissement modal est illustrée.Enfin, la modification d’un composant critique au crissement est testée et validéeBrake squeal is a common noise problem encountered in the automotive industry. Higherfriction coefficients and weight reduction recently led to higher vibration levels in the audiblefrequency range. This quality issue becomes economic due to penalties imposed to the brakesupplier although no robust design method exists. The industrial practice thus relies on costlyprototyping and adjustment phases. The evolution of computational power allows computationof large mechanical assemblies, but non-linear time simulations generally remain out of reach.In this context, the thesis objective is to provide numerical tools for squeal resolution at earlydesign stages.Parameterized reduction methods are developed, using system real modes as Rayleigh-Ritzvectors, and allow very compact reduced models with exact real modes. The proposed ComponentMode Tuning method uses the components free/free modes as explicit degrees of freedom.This allows very quick sensitivity computation and reanalyzes of an assembly as function oflocal component-wise parameters. Non-linear time simulations are made possible through twoingredients. A modified non-linear implicit Newmark scheme and a fixed Jacobian are adaptedfor contact vibrations. The brake is reduced keeping a superelement with exact real modes anda local non-linear finite element model in the vicinity of the pad/disc interaction.A set of design tools is illustrated for a full industrial brake model. First, instant stabilitycomputations and complex mode trajectories are studied. Modal interactions and non-linearphenomena inside the limit cycles are thus well understood. Time/frequency correlations areperformed using transient modal identification and space-time decomposition. A time domainmodal damping model is also shown to be very useful. The modification of a critical componentfor squeal resolution is finally tested and validated
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Desai, Chetan Prabhakar. "An experimental and numerical investigation of natural convection in open ended annuli and its application to the cooling of an aircraft brake assembly /." The Ohio State University, 1995. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487863429091573.
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Gay, Sebastien Emmanuel. "Contactless magnetic brake for automotive applications." [College Station, Tex. : Texas A&M University, 2005. http://hdl.handle.net/1969.1/ETD-TAMU-1005.
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Hung, L. Y. "Applications of brane configurations." Thesis, University of Cambridge, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.604787.
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Chapter 3 reviews anomalies in field theories and the anomaly inflow mechanism in space-filling intersecting brane configurations. We review and discuss dynamics at the intersection domain of the I1 system (whose intersection domain is (1 + 1)-dimensional). We also present a supergravity solution of intersecting D7-branes over (5 + 1) dimensions i.e. the I5 system, and discuss their connections to the conifold in F-theory. Chapter 4 is concerned with the study of entropies of small black holes in IIB string theory, in the presence of higher derivative corrections. In chapter 5 we study D-brane inflation in the warped throat, where a D3-brane open-string modulus plays the role of the inflation. We review the computation of non-perturbative corrections to the inflation potential from holomorphically-embedded stacks of D7-branes, and derive explicit expressions for the case of two non-intersecting sets of Kuperstein embedded D7’s. We present explicit models that satisfies angular stability, and demonstrate how models with an inflation scale exceeding that of SUSY breaking are constructed.
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Lantto, Emil. "Integrated brake in hydraulic motor for winch applications." Thesis, Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-71298.
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The company named Bosch Rexroth, previously Hägglunds drives, in Mellansel, Sweden develops, produces and sells radial piston hydraulic motors for industrial use, some are used to drive winches. The winch application mostly needs a brake to function as a parking brake and emergency brake. The company offers brakes that are installed as external assemblies. This thesis work is done to finding brake concept solutions that requires less space and doesn’t add as much to weight and cost and that could be better integrated in the application. The steps to achieve this includes evaluating the needs, generating new brake concepts, refining these, evaluating the concepts found, refining the best concept and finally presenting the result. The brake concept found to be the best of the set generated is a slightly altered drum brake that, as an example, is integrated into the winch drum and has the potential to have a shorter response time than concepts used today.
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Rockström, Ivar. "Simulation of road slope with brake applications on horizontal ground." Thesis, Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-79867.
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During some operations the brake system on a truck is exposed to severe stress and hightemperatures. To ensure function and safety during these operations, Scania test thebrake system both test rigs and in actual trucks around the world. There are tests thatare regulated by law that the truck manufacture must pass to be allowed to sell its vehicleand there are Scania internal tests to validate performance and quality. One of thoseinternal Scania tests is a severe test with extreme temperatures, called the Rossfeld-test,performed at the Rossfeld slope in the German Alps. The idea is that the truck rolls downthe slope only accelerated by the downhill force where the wheel brakes will be appliedwhen the vehicle speed passes 35 km/h and released when going slower than 25 km/h,this is repeated until the end of the slope. No auxiliary brakes are used. The objective of this thesis is to investigate the possibility of using a Scania truck as a testbench to perform a simulation of a truck rolling down a descent. And by this investigatethe possibility of recreating a wheel brake test as the Rossfeld-test on a horizontal roadby using the engine as the source of acceleration instead of the gravity. In this thesis a model was developed in Matlab/Simulink which through the CAN-busnetwork in the truck could request engine torque and brake pressure. Given the roadtopography of the actual German slope, the corresponding downhill force was calculatedand requested of the engine and brake pressure was applied when the truck passed 35km/h and released again when reaching 25 km/h. The model was verified against roll-tests performed in known slopes with three, eightand sixteen percent gradient. Results from simulations with the truck showed a biggerinconsistency with respect to acceleration and gear selection when requesting a low torqueas with the simulation of a 3% slope. This was not the case when requesting a highertorque as when simulating a 8% or 16% slope. The results showed that at a highertorque request the acceleration was more consistent but the truck was still acceleratingslower than the corresponding roll-test and an extra twelve percent of torque was addedto mimic the acceleration of the roll-test. The first 3000 m of the Rossfeld-slope wassimulated by driving in a circle and the temperature measurements catches the differencesin temperature build up as in the result from a real Rossfeld-test performed in the Germanalp. This shows there is a potential in this type of simulation.
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Corradi, Grégoire. "Approches numérique et expérimentale pour des structures à interfaces frottantes : Application au crissement de frein." Thesis, Lyon, 2019. http://www.theses.fr/2019LYSEC044.
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Les systèmes de freins sont parfois sujets au crissement qui sont des vibrations auto-entretenues induites par le frottement et caractérisées par un contenu fréquentiel formé de raies à hautes fréquences supérieures à 1kHz. Ces vibrations et bruits intenses sont une source de gêne pour les usagers automobile, un problème de santé publique pour les riverains de gares lors du freinage de TGV et peuvent amener à l'endommagement du train d'atterrissage sur les avions.Afin de comprendre ce phénomène et pour le reproduire numériquement, une stratégie complète d'étude est développée. Elle se base sur l'observation expérimentale d'essais de crissement sur un banc d'essais qui permet de formuler des hypothèses de modélisation. Ces dernières sont un guide pour la construction d'un modèle numérique de frein simple. Une méthode de Double Synthèse Modale est appliquée au modèle afin d'en réduire la taille et de permettre des simulation numériques en temps raisonnable et ne nécessitant pas trop de ressources informatiques.La démarche numérique qui suit commence classiquement par une analyse de stabilité par la méthode CEA où les valeurs propres du modèle linéarisé autour de la position d'équilibre glissante sont évaluées. Puis une intégration temporelle est effectuée dans les cas détectés comme instables afin de calculer les niveaux de vibrations. L'étude se termine par une estimation du champ acoustique rayonné par la structure complète.Dans chacune des phases de l'analyse numérique, des outils spécifiques sont utilisés pour comparer le modèle de référence aux modèles obtenus par les deux étapes de réduction. Un critère d'erreur sur les valeurs propres et un critère de MAC sont utilisés pour l'analyse de stabilité. Pour l'étude temporelle, les allures des signaux sont comparées, ainsi que leurs cycles limites et leurs spectrogrammes. Les participations des modes instables sont également calculées pour observer le régime transitoire. En ce qui concerne la partie acoustique, les signaux sont comparés dans un premier temps de façon qualitative pour observer les différences entre les champs émis en fonction des différentes tailles de bases de réduction. Puis un outil basé sur une décomposition en 2D par wavelet des motifs acoustiques est introduit et appliqué pour estimer de façon quantitative les convergences des champs rayonnésBrake systems are sometimes prone to squeal noise, which is due to friction-induced self-sustained vibrations, characterized by a set of frequencies above 1kHz. Those vibrations and resulting noises are a source of perturbations for car occupants, which can be nowadays considered as a health issue.This thesis deals with a global strategy to better understand this phenomenon from an experimental point of view and to propose the prediction of squeal noise by numerical approaches. Moreover, experimental observations of squeal occurrences are analyzed to lead to assumptions about the modelisation of numerical finite element models for squeal prediction. A Double Modal Synthesis is also applied to reduce the size of the discrete finite element model of brake system and to save computational time and ressources. The proposed numerical approach starts with a stability analysis with the classical CEA method. Then the determination of nonlinear self-excited vibrations are performed for the unstable cases detected via the CEA method. Finally the acoustic field emitted by the brake system is computed to predict squeal noise.Specific tools are applied for each computational step to assess the efficiency of reduced model versus the reference model: criteria based on the mean error on eigenvalues and the Modal Assurance Criterion analysis (MAC) are used for the stability analysis; comparisons of the limit cycles, spectrograms and the modal contributions of unstable modes are undertaken for the transient responses; patterns of the acoustic intensity are computed on several observations surfaces and a decomposition based on the theory of 2D wavelets is introduced and applied to assess the convergence of patterns
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Popescu, Costin Schwarz John H. "Branes, brane actions and applications to field theory /." Diss., Pasadena, Calif. : California Institute of Technology, 2001. http://resolver.caltech.edu/CaltechETD:etd-12082006-104418.
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Leatherbarrow, Andrew. "Development of carbon fibre reinforced carbon-silicon carbide composites for advanced friction brake applications." Thesis, Loughborough University, 2011. https://dspace.lboro.ac.uk/2134/8403.
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In the present study, different origins of recycled carbon fibre and carbon are evaluated against virgin-based alternatives as cost-effective constituents inside carbon fibre/carbon-silicon carbide (Cf/C-SiC) composites. These include: recycled, end-of-life or reclaimed carbon fibre and pyrolytic carbon (pyC), which are investigated inside these composites for potential friction materials to replace or extend the life of current high-end automotive, industrial and aircraft brake discs. The literature review begins by investigating the differences and implications of the applications on the requirements of the carbon fibre inside the composite and documents past and current progress made. The constituents that comprise these composites were investigated and the manufacture routes were reported in terms of their advantages and disadvantages. A three-step process was identified as the most costeffective and promising route to manufacture these new Cf/C-SiC composites with suitably high mechanical properties: 1). Polymer infiltration (PI) and hot pressing (HP) to create a carbon fibre reinforced plastic (CFRP), 2). Pyrolysis to convert the CFRP into a porous Cf/C composite, 3). Liquid silicon infiltration (LSI) to introduce the silicon carbide (SiC) matrix. Beyond this, the aims, feasibility and current progress of recycling carbon fibres were documented. It was found that current recycling technologies are in their infancy, in both academia and industry, although great commercial potential is recognised. Investigations herein revealed the capability to mechanically recycle carbon fibres from waste carbon fibre pre-pregs and CFRP spars, re-use end-of-life carbon fibre pre-pregs and reclaim carbon fibre from existing CFRP spars using pyrolysis. Testing and analysis were split into two stages: firstly, how the pre-preg architecture changes during pyrolysis and secondly, the resulting Cf/C-SiC composites: microstructural evolution after LSI; physical, mechanical and micro-mechanical properties; frictional performance. Pyrolysis of end-of-life pre-pregs revealed no significant difference in comparison to virgin carbon fibre pre-pregs. Instead, any differences were attributed to the: fibre orientation, preform architecture and resin carbon yield. Testing revealed that end-of-life pre-pregs and reclaimed CFRP's were suitable for pyrolysis and further processing toward Cf/C-SiC composites. In addition, the architecture could be either customised or inherited from the original. Physical and mechanical property testing revealed that Cf/C-SiC composites incorporating recycled, end-of-life and re-claimed carbon fibre could achieve comparable densities, open porosities and flexural strengths compared to similarly processed virgin Cf/C-SiC composites. Microstructural examination by optical and electron microscopy revealed that the hierarchy order of the developed microstructure inside these composites by LSI was the same irrespective of the carbon fibre or carbon format. Combined TEM and XRD investigations indicated that the generated SiC and silicon belonged to the same polytypes regardless of the carbon format and that the most likely type was facecentered cubic (FCC) β 3C-SiC and cubic silicon respectively. Small-scale dyno in a disc-on-pad configuration revealed that a Cf/C-SiC composite comprising end-of-life fibre could achieve the required mechanical strength to perform dyno testing and that the surface topography had a significant influence on the coefficient of friction (COF), COF stability and wear rate.
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Ko, Sheng-Lan. "Chiral 2-form actions and their applications to M5-brane(s)." Thesis, Durham University, 2015. http://etheses.dur.ac.uk/11110/.
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We study the symmetry and dynamics of M5-branes as well as chiral p-forms in this thesis. In the first part, we propose a model describing the gauge sector of multiple M5-branes. The model has modified six-dimensional Lorentz symmetry and its double dimensional reduction gives 5D Yang-Mills theory with higher derivative corrections. The non-abelian self-dual string solutions to this model are presented. In the second part of the thesis, we propose an alternative new action for the single M5-brane. The six-dimentional worldvolume space is covariantly split into 3+3. The relation of the new action to the conventional PST action as well as to the M2- brane action are studied. Finally, we briefly discuss the attempt to formulate the M5-brane action in a 2+4 splitting of worldvolume space and some duality properties and issues of chiral p-form actions.
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Rowles, Jr Michael R. Jr. "Modeling brake specific fuel consumption to support exploration of doubly fed electric machines in naval engineering applications." Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/104294.
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Thesis: Nav. E., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2016.Thesis: S.M. in Naval Architecture and Marine Engineering, Massachusetts Institute of Technology, Department of Mechanical Engineering, 2016.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages [71a]-[71b]).
The dynamic operational nature of naval power and propulsion requires Ship Design and Program Managers to design and select prime movers using a much more complex speed profile rather than typical of commercial vessels. The inherently reduces the overall efficiency of the plant as operated in comparison to its potential. The fuel consumption of prime movers is a multi-variable function of power demand and rotational speed. Mechanically coupled power and propulsion arrangements constrain this two degree of freedom relationship by removing the independence of the speed parameter. Fixed frequency power generation requires a constant prime mover speed that has a narrow power band for optimal fuel consumption. Likewise, geared propulsion arrangements restrict the prime mover's speed to a dependence on the combined propulsor thrust-hull resistance performance which generally follows a cubic function. Optimal fuel consumption, however, involves matching the load's efficiency performance to that of the prime mover. This requires the rotational speed of the prime mover to be an independent variable with the freedom to adjust to the lowest specific fuel consumption for the demanded power. Variable frequency drive (VFD) concepts offer relief of this constraint but at a cost in the form of increased power conversion and control support system footprints. The ever increasing and complex demands for electrical power increases the motivation and interest in innovative technologies that improving current design concepts. Incorporating doubly fed electric machines (DFEM) into the power and propulsion design architecture enables the efficiency results of a VFD system but with a smaller conversion and control support footprint. The Navy has invested resources into research and development of several electric power and propulsion technologies enabling deployment of VFD systems on a handful of ship classes. The wind power generation industry has matured many aspects of DFEM technology. Leveraging this experience into naval engineering applications could help facilitate additional platform types and sizes to benefit from the operational advantages of integrated electrical architectures. Applying DFEM concepts to naval engineering requires a horizontal transfer of the body of knowledge. Researchers in the field of DFEM technology need to gain a better understanding of the intricacies of integrating a marine vessel's engineering plant with the vessel's designed purpose. New methods of analysis tailored specifically to marine power and propulsion require development for the technology to be properly assessed. This study outlines the various issues challenging ship designers and explains the manner in which DFEM research can be continued in naval engineering. Finally a method of examining a prime mover's fuel consumption is developed to provide a three-dimensional "fuel map" surface relationship of power-to-speed-to-fuel consumption. This thesis will serve as a building block supporting further DFEM power and propulsion concept analysis.
by Michael R. Rowles, Jr.
Nav. E.
S.M. in Naval Architecture and Marine Engineering
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Hartz, Jason Michael. "The Plow That Broke the Plains: An Application of Functional Americanism in Music." Ohio University / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1289337896.
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Callender, Chad M. "Refractory metal to nickel-based alloy joining technologies for high temperature applications." Auburn, Ala., 2006. http://repo.lib.auburn.edu/2006%20Summer/Theses/CALLENDER_CHAD_35.pdf.
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Keflas, Petros. "Brave : an OR-parallel logic language and its application to search problems in artificial intelligence." Thesis, University of Essex, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.290744.
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Stiffler, Kory M. "A walk through superstring theory with an application to Yang-Mills theory: k-strings and D-branes as gauge/gravity dual objects." Diss., University of Iowa, 2010. https://ir.uiowa.edu/etd/744.
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Superstring theory is one current, promising attempt at unifying gravity with the other three known forces: the electromagnetic force, and the weak and strong nuclear forces. Though this is still a work in progress, much effort has been put forth toward this goal. A set of specific tools which are used are gauge/gravity dualities. This thesis consists of a specific implementation of gauge/gravity dualities to describe k-strings of strongly coupled gauge theories as objects dual to Dpbranes embedded in confining supergravity backgrounds from low energy superstring field theory.
Along with superstring theory, k-strings are also commonly investigated with lattice gauge theory and Hamiltonian methods. A k$string is a colorless combination of quark-anti-quark source pairs, between which a color flux tube develops. The two most notable terms of the k-string energy are, for large quark anti-quark separation L, the tension term, proportional to L, and the Coulombic 1/L correction, known as the Luscher term.
This thesis provides an overview of superstring theories and how gauge/gravity dualities emerge from them. It shows in detail how these dualities can be used for the specific problem of calculating the k-string energy in 2+1 and 3+1 space-time dimensions as the energy of Dp-branes in the dual gravitational theory. A detailed review of k-string tension calculations is given where good agreement is found with lattice gauge theory and Hamiltonian methods. In reviewing the k-string tension, we also touch on how different representations of k-strings can be described with Dp-branes through gauge/gravity dualities. The main result of this thesis is how the Luscher term is found to emerge from the energy calculation of Dp-branes. In 2+1 space-time dimensions, we have Luscher term data to compare with from lattice gauge theory, where we find good agreement.
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Neelakantan, Vijay Anand. "Modeling, design, testing and control of a two-stage actuation mechanism using piezoelectric actuators for automotive applications." Connect to resource, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1127236489.
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Thesis (Ph. D.)--Ohio State University, 2005.Title from first page of PDF file. Document formatted into pages; contains xvii, 213 p.; also includes graphics (some col.). Includes bibliographical references (p. 206-213). Available online via OhioLINK's ETD Center
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Langlois, Karine. "Contribution à la modélisation du genou arthrosique. Application à l’étude d’une orthèse de décharge." Thesis, Paris, ENSAM, 2016. http://www.theses.fr/2016ENAM0074/document.
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Le projet se situe dans le contexte de la gonarthrose fémoro-tibiale, et plus spécifiquement de son traitement par orthèse de décharge. Du fait de la cinématique particulière de l’orthèse testée, un protocole spécifique a été mis en place dans le but d’approfondir les mécanismes d’actions de cette orthèse. Ce protocole s’est appuyé sur des outils d’investigation utilisés dans la routine clinique (système EOS® et Vicon®). Seize sujets symptomatiques ont participé à l’étude. Les objectifs principaux étaient de valider et d’utiliser des méthodes de personnalisation des modèles, support de la biomécanique, dans ce contexte spécifique, afin d’améliorer la précision de la quantification des paramètres cinématiques et dynamiques. En effet, l’état de l’art démontre que l’indicateur dynamique couramment utilisé dans l’étude de la gonarthrose, le moment articulaire externe d’adduction, souffre de résultats controversés. Les objectifs secondaires étaient de caractériser la pathologie à l’aide des indicateurs calculés ainsi que d’approfondir le mécanisme d’action de l’orthèse de décharge. Ainsi, deux méthodes principales ont été investiguées. La première porte sur l’analyse séquentielle cinématique de l’articulation fémoro-tibiale en utilisant le système EOS®. Cette analyse nécessite une étape de recalage d’objet 3D sur des vues 2D biplanaires. La fiabilité de ce recalage manuel a été quantifiée en évaluant, d’une part, la précision de la méthode grâce à des données in vitro et, d’autre part, la répétabilité de la méthode grâce à la participation de 3 opérateurs et de 6 sujets asymptomatiques dont les acquisitions ont permis d’obtenir des vues du genou dans plusieurs positions (extension et flexion 20°, 40°et 90°). La seconde méthode consiste en la fusion de données issues de deux environnements (EOS® et Vicon®) de façon à quantifier les moments articulaires externes dans le genou en définissant le point auquel sont calculés ces moments à partir du modèle 3D du fémur. Ce modèle étant recalé dans l’environnement Vicon® par l’intermédiaire des marqueurs externes détectables dans les acquisitions EOS® et Vicon®. Les résultats principaux concernent :1/ la fiabilité du recalage des modèles 3D des os sur des vues 2D de l’ordre de 0,3° et 1,6 mm dans le plan sagittal de 2,1° et 1,8mm dans le plan transversal ; 2/ la quantification d’angles positionnels 3D du fémur et du tibia des membres inférieurs symptomatiques montrant que la surface articulaire tibiale (plateaux tibiaux) tend à demeurer horizontale contrairement à l’inclinaison plus marquée du fémur ; 3/ une variation des moments articulaires externes en fonction de l’intégration ou non d’un modèle interne pour le calcul de ce paramètre ; 4/ la quantification de la cinématique séquentielle de l’orthèse et du genou. La fiabilité des méthodes développées dans ce travail a été estimée ouvrant la voie à leurs applications et à leurs développements en clinique.Mots clés : gonarthrose fémoro-tibiale ; orthèse ; analyse séquentielle ; recalageThe context is the knee osteoarthritis and its treatment via an unloading brace. As the evaluated brace has specific kinematics, a dedicated protocol was set up using clinical routine tools (EOS® and Vicon®). Sixteen symptomatic subjects participated to this study. The main objective was to validate and to use personalization methods of the biomechanical models to improve the accuracy kinematics and kinetics parameter computation in this specific context. Indeed, the state of the art highlights that the dynamic indicator, currently used in knee osteoarthritis studies, the external adduction joint moment is controversial. The secondary objectives were both the characterization of the pathology using indicators obtained on the acquired data and the in-depth study of the mechanical action of the unloading brace evaluated in this study. Thus, two main methods were investigated. The first one is the sequential analysis of the knee kinematics using EOS® system. This analysis required a registration step of a 3D object on 2D biplanar views. The manual registration reliability was quantified by evaluating both the method accuracy with in-vitro data and the method repeatability thanks to the participation of 3 operators and 6 asymptomatic subjects allowing the acquisition of knee images in several positions (extension and 20°, 40°, and 90° flexion). The second method consists in the fusion of data obtained in the two acquisitions environments (EOS® and Vicon®), to obtain the external knee joint moment in order to define the point where the moment is computed from the femur 3D model. This model is registered in the Vicon® environment through external markers visible in both the EOS® and Vicon® acquisitions. The main results relate to: 1/the reliability of the registration of the bone 3D model on 2D views estimated at about 0,3° and 1,6 mm in the sagittal plane and about 2,1° and 1,8 mm in the transverse plane ; 2/ the quantification of the angular relative position of the shank and tibia of the symptomatic lower limbs, showing the tibial plateau horizontality opposed to the femur emphasized inclination ; 3/ external joint moment variation according to the computation method (with or without internal model included) ; 4/ brace and knee sequential kinematic quantification. As the reliability of the methods developed in this study was estimated, further developments and clinical applications and development could now be explored using these methods.Keywords : knee osteoarthritis; brace, sequential analysis; registration
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Neelakantan, Vijay. "Modeling, design, testing and control of a two-stage actuation mechanism using piezoelectric actuators for automotive applications." The Ohio State University, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=osu1127236489.
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Fernández, Daniel (Fernández Moreno). "New Applications of the Gauge/Gravity Duality." Doctoral thesis, Universitat de Barcelona, 2013. http://hdl.handle.net/10803/119603.
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The purpose of this thesis is to put forth and present a series of new applications of the gauge/string duality to areas of high energy physics and condensed matter physics. The contributions showcased in this thesis amount to the ever growing recollection of evidence that supports the duality, which has already become a broad and extensive field of its own.
Most of the work contained in this thesis addresses the study of the quark gluon plasma, a state of matter that might allow to be approximated by simple gravitational descriptions and is, at the same time, accessible by experiment. This constitutes a great advantage, since it gives the possibility of testing the qualitative predictions that can be derived from the calculations in holography, like the ones presented in this thesis. One of them is that a heavy quark moving suficiently fast through a quark-gluon plasma may lose energy by Cherenkov-radiating mesons. Special emphasis is given to the fact that this effect takes place in all strongly coupled, large-Nc plasmas with a gravity dual. Phenomenological implications for heavy-ion collision experiments are also discussed.
On the other hand, an extensive use is made of a IIB supergravity solution dual to a spatially anisotropic finite-temperature N = 4 super Yang-Mills plasma. Motivation comes from the fact that the quark gluon plasma created in heavy-ion collisions is anisotropic. The analysis focuses on three important observables of the plasma: Firstly, the drag force experienced by a massive quark propagating through the plasma is considered. The results show a generic misalignment of the gluon cloud trailing behind the quark, the quark velocity and the drag force itself whenever anisotropy is taken into account. Secondly, a study of the jet quenching parameter of the plasma is presented for arbitrary orientations and arbitrary values of the anisotropy. Perhaps surprisingly, the anisotropic value can be larger or smaller than the isotropic one, and moreover, this depends on whether the comparison is made at equal temperatures or at equal entropy densities. Finally, the screening length for quarkonium mesons in the anisotropic plasma is computed. The most important result is that not only can the temperature cause the dissociation of mesons, but anisotropy itself, even at zero temperature, may be responsible for it.
Lastly, the duality is applied to the holographic description of anisotropic p-wave super- fluids, and a gravitational model is used to perform a complete analysis of their transport phenomena in the superfluid phase. The thermoelectric, piezoelectric and exoelectric effects are thoroughly studied. The results reproduce characteristic features of both superfluids and superconductors. In particular, the viscosities of the fluid deviate from the universal value, as is expected in an anisotropic condensed phase. An additional viscosity coeficient, associated to the difference in normal stresses and not previously considered in the holographic context, is also computed.El propósito de esta tesis es presentar una serie de nuevas aplicaciones de la dualidad gauge/gravedad a áreas de la física de altas energías y de la materia condensada. La mencionada dualidad se ha convertido en un amplio y extenso campo, y las contribuciones resaltadas en esta tesis se unen a la creciente recopilación de evidencia que la apoya. La mayoría del trabajo realizado se refiere al estudio del plasma de quarks y gluones, un estado de la materia que podría permitir ser aproximado por simples descripciones gravitatorias y que es, al mismo tiempo, accesible experimentalmente. Esto daría la posibilidad de poner a prueba las predicciones cualitativas que se derivan de cálculos holográficos como los contenidos en esta tesis. Uno de ellos recoge la predicción de que un quark pesado moviéndose lo suficientemente rápido a través del plasma de quarks y gluones podría perder energía por radiación Cherenkov de mesones. Un énfasis especial se da al hecho de que este efecto tiene lugar en todos los plasmas fuertemente acoplados en el límite de gran N(c), siempre y cuando tengan un dual de gravedad. Por otra parte, se hace un extenso uso de una solución de supergravedad IIB dual a un plasma de N = 4 súper Yang-Mills anisotrópico a temperatura finita. La motivación viene del hecho de que el plasma de quarks y gluones creado en colisiones de iones pesados es anisotrópico. El análisis se centra en tres observables importantes del plasma: La fuerza de arrastre experimentada por un quark masivo que se propaga en el plasma, el parámetro de jet quenching para direcciones y valores de la anisotropía arbitrarios, y la longitud de apantallamiento de mesones de quarkonium en el plasma anisotrópico. Finalmente, se aplica la dualidad a la descripción holográfica de superufluídos de onda p. Se usa un modelo gravitatorio para realizar un análisis completo de sus fenómenos de transporte en la fase superufluídica. Los efectos termoeléctrico, piezoeléctrico y exoeléctrico se estudian en detalle. Los resultados reproducen características típicas tanto de superufluídos como de superconductores. También se calcula un coeficiente de viscosidad adicional, asociado a la diferencia de esfuerzos normales y no considerado previamente en el contexto holográfico.
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Andolfsson, L. Thomas G. [Verfasser], Rolf [Gutachter] Bracke, and Jörg [Gutachter] Renner. "Thermal properties of rocks : a periodic solution of thermal diffusion and its application to the presssure dependency of thermal properties / L. Thomas G. Andolfsson ; Gutachter: Rolf Bracke, Jörg Renner ; Fakultät für Geowissenschaften." Bochum : Ruhr-Universität Bochum, 2019. http://d-nb.info/1180027833/34.
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(9830255), Ian Ripley. "An investigation of brake application delays in Australian train brake systems." Thesis, 2004. https://figshare.com/articles/thesis/An_investigation_of_brake_application_delays_in_Australian_train_brake_systems/13422623.
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An investigation of brake application delays in Australian train brake systems began with a literature review of pneumatic train braking systems. Data located in the review gave examples of brake application delays of pre 1990 designs from the U.K., India and North America. Information on application delays on later Australian designs was scarce. Reading of literature has shown a difference between the Australian and North American control valves in the way the propagation of the pressure reduction rate in the brake pipe is maintained. Control valves of the North American style allow the brake pipe air to be connected for a short time to a small cavity or quick service volume of each valve. The quick service volume is then released to atmosphere. The action of exhausting a small amount of air from the brake pipe helps to ensure a propagation of an adequate pressure reduction rate as it travels to the next valve. Australian control valves rely on the ratio of the volume of brake pipe between control valves and the size of the quick service volume or bulb to ensure the propagation of an adequate pressure reduction as it travels to the next valve. The air in a bulb of an Australian valve is not expelled to atmosphere until a brake release is made. The research explored possible reductions in application delays by utilizing an experimental pipe test rack that included 4 control valves and 120 meters of brake pipe. Experiments with different configurations of exhaust orifices or chokes, valves and branch pipe lengths that supplied the valves gave a record acquired by data acquisition of the timing of each valve and the local pressure drop from a valve or each valve for comparison. Experiments with exhaust chokes that gave a reduction drop rate in the brake pipe that approached the minimum required to operate a control valve resulted in instability of the application operation of the control valve. The quick service volume of different sizes was included in the experiments to give comparisons in the propagation of the pressure reduction toward the end of a long train. Further increases into the size of the bulb of a control valve to enhance the propagation features toward the end of a long train are discussed. The branch pipe with different diameters from 12 mm to 20 mm and lengths from 160 mm to 800 mm when fitted to an adaptor pipe bracket were investigated and results show that larger diameters gave larger gulps in the brake pipe. Other components that were studied included the pipe bracket that is fitted on some control valves. The pipe bracket and isolation cock was found to add 282 mm of additional length to the air path and while not changing the operation of the valve, the results showed a smaller drop in local pressure in the brake pipe to assist the pressure reduction rate than shown in valves without pipe brackets.
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Gbadeyan, Oluwatoyin Joseph. "Low friction hybrid nanocomposite material for brake pad application." Thesis, 2017. http://hdl.handle.net/10321/2666.
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Submitted in fulfillment of the requirements for the degree of Master in Engineering: Mechanical Engineering, Durban University of Technology, Durban, South Africa, 2017.Despite the huge improvements made in the development of vehicle brake pad materials, problems such long stopping distances, noise pollution, and heat dissipation still continue to persist. In this regard, a novel polymer-based hybrid nanocomposite brake pad (HC) has been developed. Here, a combination of carbon-based materials, including those at a nanoscale, was used to produce the brake pad. The coefficient of friction, wear rate, noise level, and interfacial temperature was investigated and compared with that of a commercial brake pad material (CR). It was found that the brake pad performance varied with the formulation of each pad. Hybrid nanocomposite brake pads material exhibited superior performance in most tests when compared to the commercial brake pad. They exhibited a 65% lower wear rate, 55% lower noise level, 90% shorter stopping distance, and 71 % lower interfacial temperature than the commercial brake pad (CR). Furthermore, mechanical properties such as hardness, compressive strength, shear strength, and impact resistance were also evaluated. The material exhibited a 376% higher shear strength, 100% improved compressive strength, 77% greater modulus and 100% higher impact strength than the commercial brake pad. The hardness of both brake pads material was statistically comparable. Additionally, the thermal stability, degradation, water and oil absorption behaviour were measured. It was found that HC brake pad material exhibited a 100% lower water absorption and 80% oil absorption rate. The brake pads also exhibited a thermal stability within the brake pad standard maximum working temperature of 300 -400 0C. The superior performance of hybrid nanocomposite brake pad material observed was due to synergism between the carbon-carbon additives and uniform dispersion of carbon fiber as shown in Figure 4.16. Scanning electron microscopy study was subsequently performed on fracture and worn surfaces of the brake pads. The micrographs show changes in the structural formation after the incorporation of carbon based fillers. It also shows the smooth structure and uniform dispersion of the carbon fiber. The smooth surface of the worn brake pad is an indicative of a harder structure. No ploughing or score marks were evident. Hence, it was deduced that the reinforced had superior mechanical and tribological properties. These improved properties are suggestive of materials that may be successfully used for brake pad application.
M
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Lin, Chien-Hen, and 林建亨. "Application of Electric Brake System for an Electric Vehicle." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/w8gxp2.
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碩士國立臺北科技大學
車輛工程系所
93
An electric vehicle is driven by electric motors. It has following three remarkable advantages in driving and braking: (1) Motor’s response is fast and torque generation is accurate, (2) Motors can be installed and controlled in 2 or 4 wheels separately, and (3) Motor torque can be precisely known by current measurement. These advantages enable us easily to design (1) High performance antilock braking systems, and (2) Accurate estimation of road surface condition. This research proposes an electric brake system for an electric vehicle which has in-wheel motors. The electric vehicle has no hydraulic brake in the brake system. The brake system with an electric circuit will switch the ultracapacitors to be in charge, in discharge, in parallel or in series to tune the brake torque. During the earlier period of the braking operation or in sufficient regenerative brake torque condition, the generated electric energy will charge to the ultracapacitors. During the later period of the braking operation or in insufficient regenerative brake torque condition, the ultracapacitors will discharge to the motor which generates opposite torque to brake the wheel. Because regenerative braking torque can be more precisely known than hydraulic brake torque, vehicle velocity is estimated using the wheel dynamic. A sliding mode observer is designed to estimate the friction force and the slip velocity from a wheel speed sensor and a motor current sensor. A sliding mode controller is designed to achieve wheel slip control. The control input is motor applied voltage which can be from the battery or the ultracapacitors. A dynamic vehicle model will be established in Matlab/Simulink to simulate and verify the performance of the proposed wheel slip control and the optimum capacitance and number of ultracapacitors.
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Lee, Yi-Hsien, and 李宜賢. "The Application of Composite Material on Motorcycle Brake Lever." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/gj5j89.
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碩士國立臺北科技大學
車輛工程系
106
This research with ideal was came from a concept as Value Analysis & Value Engineering to take advantage of plastic material PA (Nylon, Polyamide) mixed with GF (Glass fiber) to be a composite material for replaces metal lever on motorcycle brake master cylinder. The benefit of composite material for motorcycle brake master cylinder lever will be getting lighter and cheaper than metal lever to saving production cost as an achievement. In order to getting better study on analysis with smoothly, we will build a 3D model in first to review the style with model if workable on radial hand brake of motorcycle and then use CAE software as FEA and Mold-flow Analysis to take an advanced in feasibility study on tooling design for eliminate the potential defective injection and unnecessary wrong way of hand brake lever designing。 In order to check hand brake lever design if workable with feasibility study, we will create a simple tool and inject the prototype sample to validate the hand brake lever strength if reaching actual requirement with satisfy performance on motorcycle according to JASO standard (Japanese Automotive Standards Organization). The JASO is also a popular test specification who complied by the most of motorcycle manufactories. This test specification is also equated to FMVSS Standard (Federal Motor Vehicle Safety Standards) in the United States (U.S.) or SAE standard (Society of Automotive Engineers)。
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Su, Geng Yi, and 蘇耿毅. "Application of the Brake by Wire Systemfor Adaptive Cruise Control System." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/19665576843676941884.
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碩士大葉大學
車輛工程學系碩士班
96
This study established the integration technology and methodology for vehicle Adaptive Cruise Control (ACC) active brake control subsystems. Experimental data including the brake pedal position and force, master and slave cylinder pressure and travel were incorporated to build and to validate the active brake system dynamic model developed by object oriented software Matlab/Simulink®. The brake system dynamic simulation model was integrated to the vehicle longitudinal dynamic program to calculate the vehicle deceleration response to the active brake and driver brake command. The slave cylinder brake pressure from each wheel simulated and measured can then be used to calculate the resulting brake force and the corresponding vehicle deceleration which can be later validated. The developed vehicle dynamic model considered the variation of brake force of the front and rear wheels in ACC vehicle. Since the ACC system requires vehicle follow the preceding vehicle with a safe distance on either straight line or turning drive condition, the active brake and radar signal must integrated to assure their performance can satisfy the requirement of ISO 15622 ACC system standard. This integration methodology can reduce the time and expanse for establishing the research and development capacity for ACC system and active brake controller thus increase the vehicle safety and reliability.
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(9847868), Zuoyan Zhang. "Effect of traction/brake torque on the dynamics of wagons." Thesis, 2008. https://figshare.com/articles/thesis/Effect_of_traction_brake_torque_on_the_dynamics_of_wagons/13465325.
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"Braking and traction torques are not explicitly considered in most of the wagon dynamics simulation packages, as their primary focus is to provide a platform for long distance route simulations with near real-time scenarios which demands fast solution algorithms. These packages consider the braking scenarios through the definition of speed profile as a priori. It is commonly acknowledged that the speed profile is affected by tribological and geometric parameters at the wheel-rail interface as well as the characteristics of brake application. Hence it’s prudent to evaluate the speed profile based on input torque due to traction/ brake forces; this research has considered such an approach and developed the program that can simulate the longitudinal behaviour of railway wagon dynamics during braking and traction. Consequently, this program enables to simulate wheelset locking and wagon yaw, roll, pitch in a natural way."--Abstract.
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TSENG, JHIH-JIAN, and 曾建誌. "The Design Analysis of the New Wedge Brake in Application Using Magnetorheological Fluid." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/98214598761719670412.
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碩士國立臺灣科技大學
機械工程系
96
Magnetorheological Fluid (MRF) is a suspension fluid constructed of scattering polarizable solid granule in isolated solvents. Under the influence of outside magnetic field, its inner structure and viscosity properties have a wonderful change. As the process is speedy (in milliseconds), reversible, easily control and continuously adjustable, its applications in many fields such as industry. The application of Wedge is very extensive in the daily life; its advantage can get the result of saving effort. Since the yield-stress of MRF can be changed fast and adjusted through magnetic field and add the wedge type reducible brake of a brake device exerts and space-saving advantage, in this property can be utilized in the car’s brake, that the brake force would linear and steady to output and the car would stop by the maximum deceleration to shorten the brake distance and to keep the driving safety. Computer simulation of a domestic Honda Civic car as an example, in the speed (50- 100km/h) with the brake systematic comparison of general ABS, the brake device can be reduced by nearly 50% of distance o and brake time by MR add wedge type. As the same conditions stated above, in different cars (Honda, Yulon) analyses under speed 100km/h, all can reach the greatest deceleration rapidly (2G) to reduce brake time, it is obvious MR adds the wedge type that a brake device can really improve safety of brake.
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林劍鳴. "Study of The Application of Fuzzy Control Theory on Differential Brake Steer System." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/94280727941548110617.
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碩士國立屏東科技大學
機械工程技術研究所
86
This project is to study the application of fuzzy control theory on differential brake steer system. The purpose of a differential brake steer system is that when a vehicle deviates from road direction, it applies different braking force on left and right wheels to generate a countering torque, and consedquently, to correct the direction of the vehicle. This research uses a two degree of freedom bicycle model to simulate the dynamics of a vehicle. The dynamics model also contains brake system dynamics, which features ABS (anti - skid braking system) system with the characteristics of saturation. In the project, classical PID control and fuzzy control theories are used to design the differential brake steer control system. The performances are compared. The inputs to the system are: (1) lateral deviation of the vehicle gravity center from the road center, (2) changing rate of the deviation, and the outputs from the controllers are the braking forces at each tire. The PID controller design is based on two D. O. F. model. The gains of the controller is tuned according to the required performance of the system. For the fuzzy controller, fuzzy theorem is used to develop appropriate fuzzy matrix to adjust parameters to improve the transient and steady - state behaviors. Beside the inputs stated above, predicted deviation of the vehicle future path from road profile is also used in fuzzy controller to see its contribution. In this research, effects of different factors on the performances of the system are investigated. These factors include: (1) steering wheel deviation, (2) heading angles deviation of the vehicle, and (3) lateral deviation of the vehicle. The results of the simulations reveal that the steering can be corrected by the system successfully, under permissible safety range.
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Yang, Cheng-Che, and 楊承哲. "Application to Vehicle Brake System using Adaptive Sliding Mode Control with Fuzzy Composition." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/58591022736675080569.
Full textAbstract:
碩士國立屏東科技大學
車輛工程系碩士班
93
This thesis addresses the problem of controlling a vehicle motion system by continuously adjusting the brake torque. In order to satisfy these specifications, firstly a deceleration trajectory must be planned, before the controller desired. At braking process, the vehicle velocity and deceleration will track the trajectory. An full-order model which consists of the vehicle motion subsystem, wheel dynamics, and servo hydraulic dynamics is under consideration. There are two kinds of design scenarios proposed in this thesis. In the first type of scenario is to design the controllers separately according to two dynamic conditions which are arising from different values of slip ratio. Then these two separately designed controllers are incorporated based on fuzzy concept. For the second controller design, besides, the different dynamic models stemming from different road conditions are first merged using TSK model approximation method. On the basis of the developed model, an adaptive sliding model control scheme is then proposed. After the mechanical part of the full-order system is achieved. The controller for hydraulic counterpart is finally fimished by adopting adaptive control approach. Lyapunov functions for the two types of control are proposed to guarantee the asymptotical stability of the vehicle motion systems. To demonstrate the validity of the design, several simulations are also performed and discussed.
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Cho, Yu Chuan, and 卓玉娟. "Application of Finite Element Methods for the Analysis of Automotive Disc Brake Caliper." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/22198024091895460350.
Full textAbstract:
碩士國立中興大學
土木工程學系
92
The research utilizes the concept of reverse engineering and the finite element theory, together with the existing CAD software, to develop a procedure for product design. That is, although the design rules of the original product is unknown, it is still possible to understand the characteristics and design criteria of the product with currently manufacturing drawing and the application of finite element analysis. Suggestions and improvement for the future product can also be provided based on this approach to make design projects faster with current CAD software. The objective of this research is to develop the finite element analysis capability and procedures, in order to simulate the mechanism of the disc brake system, and provide suggestions for further improvement based on the reverse engineering approach. In this study, we applied the FEA simulation to the CM99 disc brake caliper with the commercial package ─ ANSYS, and attempted to understand the mechanical property of the main components. The displacement and von Mises stress were calculated. With such information, we can understand different needs of strength and stiffness for each component and possibly the original design concept behind the CM99 disc brake caliper. Further study of the simulation results also provide suggestion for product improvement by modifying geometry of the caliper for the purposes of weight reduction or strength enhancement. The analysis result showed that the designed strength of the anchor in the current model is so conservative that it is possible to reduce the material used. The shape of the pad should be similar to a circle to reduce the unbalanced wearing. Also, the stiffness of the pad back plates can be increased to decrease reducing bending deformation. Furthermore, the stiffness of the bushings are suggested to be increased, but should still be able to absorb the external shock and vibration. The distance between the two pins can also be increased to achieve larger inertial moment and provide larger reacting force. Finally, this research has shown the possibilities and feasibilities of improving the existing product with finite element analysis techniques, even when the original design rules are unknown.
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"A method for systems design using precedence relationships : an application to automotive brake systems." Sloan School of Management, Massachusetts Institute of Technology, 1990. http://hdl.handle.net/1721.1/2324.
Full text
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Chang, Chun-fu, and 張鈞富. "The Design Analysis of the Heavy Artillery Brake In Application of the Magnetorheological Fluid." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/atma34.
Full textAbstract:
碩士國立臺灣科技大學
機械工程系
94
Magnetorhological fluid（or simply“MR”fluid）is a kind of intellectual materials that the mechanical properties can be rapidly changed by the application of magnetic field and is easily controlled. The application of magnetorheological fluid in heavy artillery reduce the breech force after firing. For example, equation of motion is derived from the analyticl system of the M2 155mm cannon, than design a new type brake. It is equal to the original system according to basic operating modes for MR fluid devices. Compare the difference between MR system and original system while under the influence of the magnetic field. The analysis results show that MR system in magnetic field can be used to reduce the breech force, displacement, speed and acceleration effectively. Designed artillery to different functions has the advantage of damping-changed and damping-adjusted under different speeds of shooting. If magnetorheological fluid is adopted, breech force can be reduce, and the efficiency recoil can be improved.
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Karakoc, Kerem. "Modeling and design optimization of electromechanical brake actuator using eddy currents." Thesis, 2012. http://hdl.handle.net/1828/4289.
Full textAbstract:
A novel electromechanical brake (EMB) based on the eddy current principle is proposed for application in electrical vehicles. The proposed solution is a feasible replacement for the current conventional hydraulic brake (CHB) systems. Unlike CHBs eddy current brakes (ECBs) use eddy currents and their interaction with an externally applied magnetic field to generate braking torque. Due to their pure electrically controllable and contact free nature, ECBs have multiple advantages over the current CHB systems, such as faster response, reduced weight and number of components, ease of implementing various controllers (e.g., anti-lock braking), and reduced noise levels. However, the torque generated by a typical ECB at low speeds is insufficient to effectively and completely stop a moving vehicle. Therefore, an ECB is commonly used as an assistive brake to the CHB system in heavy vehicles, i.e. trains and trucks In order to overcome this shortcoming, the use of AC magnetic fields is proposed to realize a stand-alone ECB system in which sufficient braking torque can be generated at low speeds. To this end, eddy currents are modeled analytically using the governing Maxwell’s equations with the consideration of time varying field application. The analytical model was validated using finite element analysis. Results show that the braking torque increases with the application of a time varying field.
Various forms of time varying fields have been studied. It was found that the
frequency-modulated applied field in triangular waveform results in the highest braking torque. Next, the design was optimized to maximize the braking torque and an optimum configuration was obtained using multiple pole projection areas (PPAs). Optimization results show that the braking torque significantly increases with the introduction of additional PPAs to the configuration, and the braking torque generation for an optimum four-PPA ECB configuration exceeds the braking requirements for current passenger
vehicles.
For control purposes, a dynamic model for a novel stand-alone ECB system using AC fields for automotive applications has been successfully designed and evaluated. Also, a model-based predictive controller has been developed for the optimum ECB
configuration. Finally an experimental test-bed has been designed for experimentation of both DC and AC field application on ECB.Graduate
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Popescu, Costin Radu. "Branes, brane actions and applications to field theory." Thesis, 2001. https://thesis.library.caltech.edu/4867/1/Popescu_c_2001.pdf.
Full textAbstract:
This thesis describes the construction of supersymmetric world-volume actions for various kinds of extended objects that appear in string theory, the so-called p-branes, D-branes and M-branes. We also present an application of branes to computing the spectrum of a conformal field theory in the context of the AdS-CFT correspondence.
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Fan, Kai-Huan, and 范凱煥. "Development and Application of Scoliosis Brace Skin Pressure Sensing System." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/x3zqmc.
Full textAbstract:
碩士國立臺北科技大學
機械工程系機電整合碩士班
106
This study integrates the pressure sensor module to develop the backrest pressure measurement system. At present, the backrest pressure measurement system has integrated pressure sensing, providing the information that the patient usually wears combined with the monitoring pressure to adjust the backrest tightness. The patient can be informed of the wear correction information by the measurement system. In this study, a pressure sensor is used to sense the waist pressure distribution of the back frame, and a simple correction mechanism is proposed to replace the traditional problem that the weight must be corrected by using the weight correction, and the problem that the traditional back frame pressure can only measure the pressure at a single point is studied. As a result, the pressure sensor measures the interface pressure. For the subject, the sensor has a high linear correlation. The correlation coefficient is as high as 0.9 or more. The maximum error of the sensor accuracy is 5.5%. The minimum error is 0%, and in the final clinical trial, it is verified that the sensors contralateral curved backrest skin pressure measurement system can be practically applied.
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Chen, Hong-Jia, and 陳宏嘉. "The application of Buckling Inhibited Brace on Seismic Resistant Structural Systems." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/zfjv49.
Full textAbstract:
碩士國立臺灣科技大學
營建工程系
94
A Buckling Inhibited Brace, or BIB, is composed of a main load-carrying element and a lateral-support element. The axial forces are taken only by the main load-carrying element. The lateral-support element provides continuous lateral support for main load-carrying element to prevent the load-carrying element from buckling. The aim of this study is the application of BIBs in Self-Centering Steel Concentrically-Braced Frame Systems (SC-CBFs) and Truss-Girder Frame Systems (TGs). Software ANSYS was used to investigate the hysteretic behavior of the two systems. SC-CBFs consist of CBFs, prestress tendons, and BIBs. Gap-opening behavior at the bottom of these systems makes BIBs dissipate energy, and prestressed tendons will pull the structure back to its original position.The mainly parameters are pre-stress level, tendon extended length, strength in energy dissipated zone of BIBs, tendon areas, height-width ratio, increment of vertical loading, the location of prestressed tendons, and the part of columns replaced by BIBs in concentrically braced frame. Results obtained from this study are as follows : (1) pre-stress level, tendon extended length, strength of BIBs, tendon areas, and height to width ratio of frame are the parameters that affect the behavior of SC-CBF；(2) vertical loading can increase the strength of SC-CBF；(3) The vertical displacement of SC-CBF caused by lateral force is quite significant；(4) The frame with tendons installed in the middle of steel shear walls has the best hysteretic behavior；(5) The frame with tendons installed on the ends of steel shear walls can decrease vertical displacement of the column in the first floor；(6) Use BIB as column member in concentrically braced frame can decrease vertical displacement of the column. TG systems consist of columns and truss-girders. In this research we apply BIBs in truss-girders to improve ductility. Results obtained from this study are as follows：(1) It will be a better configuration to install BIBs on the bottom chords of both ends of truss girder in a frame；(2) BIBs on the bottom chords of both ends of truss girders in a frame cause the smaller displacement in the middle point of girders, and the structural behavior is better than that of ordinary moment resisting frames.
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Ogawa, Shiro. "Stochastic averaging level control and its application to broke management in paper machines." Thesis, 2003. http://hdl.handle.net/2429/16004.
Full textAbstract:
Averaging level control refers to liquid level control of storage tanks, where the objective is to keep the outlet flow u(t) as smooth as possible against the fluctuating inlet flow, while at the same time keeping the tank level y(t) within high and low limits. The thesis treats the stochastic averaging level control problem, where the input disturbance is a stochastic process. The problem is formulated to minimize a weighted sum of Var[u(t)] and Var[u(t)] subject to the target Var[y(t)]. The state-space linear quadratic optimal control method is used, resulting in a linear state feedback controller. When the input disturbance is modelled as the output of a first-order low-pass filter driven by white noise, the optimal controller is a phase-lag network. Broke storage tank level control is important in stabilizing the paper machine wet end. It is treated as a special type of averaging level control, where the input disturbance F[sub b](t) is a two-state continuous-time Markov process. The spectrum of F[sub b](t) is obtained and the linear optimal controller is designed with the same methodology as for the general averaging level control problem. Taking this very specific nature of F[sub b](t), a new nonlinear control scheme called the minimum overflow probability controller (MOPC) is designed, and tested against data collected from a paper machine. The MOPC performs better than the optimal linear controller and manual control. A new theorem on the state probability distribution of a continuous-time Markov jump system is presented, which leads to new methods for evaluating the mean and the variance of the state of a linear jump system, and a new reliable numerical method to calculate the state distributions of jump systems. These results are utilized to evaluate the overflow probabilities of controllers.Applied Science, Faculty of
Electrical and Computer Engineering, Department of
Graduate
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Mohan, S. "Design And Development Of An Improved Anti-Lock Braking System For Two-Wheelers." Thesis, 2010. http://etd.iisc.ernet.in/handle/2005/1279.
Full textAbstract:
In today’s fast moving world, automobiles are facing challenges in terms of having to survive road accidents, increasing traffic, bad road-conditions and high/express ways. Brake systems play a vital role in controlling the vehicle speed while avoiding road accidents. The conventional brake systems consist of basically an actuator, transmission and frictional parts. This system is difficult for manipulated control by the driver during emergency and panic braking situations. In particular road and environmental conditions, it requires certain skill to have safe and effective brake control, which is always not possible from all drivers. Wheel locking is a predominant phenomenon during panic braking and this will cause vehicle skidding resulting in injuries and road accidents. In the case of a two-wheeler, being a single-track vehicle, skidding is one of the major causes for fatal road accidents due to loss in lateral balance. As the road safety regulations are becoming more stringent, the anti-lock brake systems (ABS) will replace the conventional brake systems in all road vehicles to avoid accidents and to improve vehicle safety.
Early ABS systems, developed in the last 100-years, use intermittent and cyclic brake pressure control by sensing the wheel speed or wheel-slip as one of the major control inputs. Regulating the brake pressure with a preset threshold value is another method. These ABS systems have used electronics, or hydraulics or pure mechanical control. However, such ABS are not widely used in two-wheelers and other low cost vehicles till now, because of several limitations identified as follows: High cost, power supply needed for its operation in the case of intermittent and cyclic brake control, susceptibility to failure in the electronics system, interference from RF signals (from cell-phones for example), uneasiness to drivers from pedal pulsations with pedal noise, heavier weight, increased vehicle vibrations and failure modes of wheels due to torsional vibrations.
The present research work is carried out to develop a new mechanical ABS concept, which will address most of the above problems. During braking, the change in rider-input force will change wheel reactions. This change is made proportional to the change in rider input force only upto wheel locking. Such a principle is used to develop the new mechanical ABS.
The new concept regulates the output force from the ABS, by sensing the dynamic wheel reactions with increase in rider-response. The ABS output force is regulated by one of the following ways: (a) Slipping-down the lever-ratio or (b) preventing the excessive brake input force. Based on the parameters like less number of parts, least weight, simplicity, reliability, efficiency, durability, time-response, etc., the second method (of preventing the excessive brake input force) has been chosen.
Further a new concept of ABS interconnecting system is proposed for usage between the front and rear wheels of the vehicle. This interconnecting system will ensure that the two mechanical ABS systems function at any kind of braking-balance between the front and rear applications.
An analytical vehicle model has been developed with several input parameters like mass, geometry, inertia, aerodynamic properties, frictions of road and bearing-supports, road gradients, etc. From this analytical model, the dynamic wheel reactions and limiting adhesion of each tyre for various braking conditions are determined and the results are used to design the mechanical ABS. The same analytical model is used to predict the brake performance like stopping distance, vehicle deceleration and the vehicle speed variation for ideal braking conditions.
The new ABS is modelled in Pro-E using the inputs from the analytical model. To evaluate the concept, a functional proto-type is built and fitted on a motorcycle. The ABS is evaluated for its functionality and performance at different road (level surface, up-gradients and down gradients) and environmental conditions (dry and wet road conditions). Using the VBOX II, proximate sensors and load-cells fitted on the vehicle, the vehicle stopping distance, wheel slip and pedal force are measured. The results show that wheel locking does not occur under panic driving conditions, which is the primary objective. In addition, the results show a good agreement with the predicted stopping distance and vehicle deceleration from the analytical model.
As there is good scope for this new mechanical ABS for use in two-wheelers and other low cost vehicles, further research is needed to make this system work in curvilinear motion & banked surfaces.
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Lin, Jiun-Jie, and 林俊杰. "Development and Clinical Application of VisualAudio Biofeedback Proprioception Training System and a Passive Rehabilitation Brace of Hip Dislocation Prevention." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/79670738252548660009.
Full textAbstract:
碩士長庚大學
醫療機電工程研究所
95
Total hip replacement patients always suffered from hip abductor weakness and proprioception deficit, caused by deficit of hip abductor and ligament of head of femur. The above problems would cause some complications such as instability of joint and dislocation, an even more important cause of uneven weight bearing, poor balance and abnormal gait pattern. In order to reach functional activity, the recurrent dislocation will happen and the patients should receive secondary surgery. Several literatures indicated that the motor control training with an appropriate visual and auditory biofeedback could guide patients in reconstruct proprioception and enhance their motor relearning performance. Therefore, this study developed a visual-audio biofeedback proprioception training system for total hip replacement patients, and a Passive Rehabilitation Brace of Hip Dislocation Prevention. This study found that the subjects after visual/audio biofeedback training could improve their proprioception performance as the same to the traditional training program. But they had difference improvement ratio such as 11.5%(experiment group) and 9.3% (control group) in JPS；13.0% (experiment group)and 14.3%(control group) in SBT. And a passive rehabilitation brace could allow freedom movements before hip flexion 90 degree, but limit hip adduction as over 90 degree. Future medical trials are required to establish clinical efficacy in rehabilitation.
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Su, Hsun-kuan, and 蘇訓寬. "The Conflict and Cooperation: The Application of Game Theory in North Korea Nuclear Crisis Which Broke Out in 1993 and 2003." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/96552763401444679899.
Full textAbstract:
碩士國立彰化師範大學
政治學研究所
95
North Korea has been a latent and unsettled factor of the North-east Asia area. Especially in 1993, after North Korea withdrawing from the Nuclear Non-Proliferation Treaty one-sidedly, nuclear threat seems becoming the main strategy that North Korea uses it to extort United States and gets political and economical interests. Game theory is one of the branches of the Rational Choice approach. Using game theory to analyze the developing direction of North Korea Nuclear Crisis also becomes an important approach. This paper bases on Realism’s viewpoint to define Nation’s behavior; realist regards Nation as rational actor who has the trait of self-interest. However, the international society is anarchy by nature. For living, Nation’s action Nation’s interests are interdependent. The game repeats. If North Korea and United State adapt “cooperation” options and obey The Agreed Framework to keep the stability in the North-east Asia area, this strategy will not create conflict between them. Then, North Korea will obtain assist of development in energy and economy from Nations; United State can maintain international order and the peace of the North-east Asia area. On the contrary, if North Korea and United State adapt “conflict” to deal with the crisis, both sides would be mired in “brinkmanship” situation. United States possibly will adapt pre-emptive attack to break down North Korea’s strategy in nuclear crisis.
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Chang, Che-Yuan, and 張哲源. "A Study on Application of Low Yield Strength Steel Knee Brace and New-Type Bracing for the Seismic Retrofit Design of RC School Building." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/37767925216664814890.
Full textAbstract:
碩士國立高雄應用科技大學
土木工程與防災科技研究所
99
This study applies low yield strength steel (LYS 100) knee brace and new-type bracing retrofit, which are developed by China Steel, into architectural structure of low-profile reinforced-concrete school building. Through finite element analysis, design response spectrum analysis and nonlinear static pushover analysis, this paper investigates the seismic performance of school building that is retrofitted through knee brace, new-type bracing, shear wall and wing wall. Low yield strength steel plate is a kind of good seismic resistant materials because of its advantages in many aspects such as intensity, stiffness and toughness; therefore, these merits can be used for eliminating damages to structures caused by earthquake energy and reducing casualties. Research results show that bars are still destroyed after applying knee brace retrofit into the school building. The number of destroyed bars decreases from 17 to 8, which means that bracing retrofit somewhat enhances the seismic capacity of structure system. However, retrofitting effect is limited by the over-great Y-direction span; therefore, it’s necessary to consider other retrofit methods. With regard to new-type bracing retrofit, this study finds the ground acceleration is improved to meet standard demands. This new-type bracing retrofit is another choice for retrofitting school buildings.