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Dissertations / Theses on the topic 'Brake testing'
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Stephens, Arthur William, and arthur stephens esb ie. "Aerodynamic Cooling of Automotive Disc Brakes." RMIT University. Aerospace, Mechanical and Manufacturing Engineering, 2006. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20070108.121737.
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Sufficient heat dissipation is crucial to the effective operation of friction based braking systems. Such cooling is generally provided by ensuring a sufficient supply of cooling air to the heated components, hence the aerodynamics in the region of the brake components is extremely important. The objective of the research was to develop an understanding of how aerodynamics could be used to improve the cooling of automotive disc brakes. Two separate sets of wind tunnel experiments were developed. Tests were performed on a vented disc (rotor) to measure the internal flow through the vents on a rotating vented disc under various conditions, including an isolated disc in still air, the disc in still air with the wheel on, the disc in moving air with the wheel on, and an on-road simulation using a ¼ car. On vehicle tests were also performed in a wind tunnel using a purpose built brake test rig. These tests measured the thermal performance of different brake discs under various operating parameters; including constant load braking, and cooling from high temperature under various speeds, wheels and disc types. It was found that airflow through vented rotors was significantly reduced during simulated on-road driving, compared to when measured in isolation, but not particularly affected by the vehicles speed. In the situations tested, vented discs offered a 40+% improvement in cooling over an equivalent sized solid rotors. However the research indicates that the greatest benefit of vented rotors over solid will be in vehicles where air entering the wheel cavity is limited, such as low drag vehicles. It was also found that the most significant improvements in brake thermal performance could be achieved by maximising the airflow into the region of the brake components; including increasing the open area of the wheel, and increasing the vehicle velocity. Other improvements can be achieved by using a wheel material with good conductive capability, and increasing the mass of the disc. Evidence of vortex shedding was also discovered in the airflow at the exit of an internal vented rotor, any reduction in this flow disturbance should lead to increased airflow with associated improvements in thermal performance.
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Drtílek, Juraj. "Experimentální identifikace NVH brzdových soustav." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2017. http://www.nusl.cz/ntk/nusl-318537.
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This Diploma Thesis is dedicated to solve the source of noise, observed during braking processes on tested vehicle, called Gouki noise and has been worked out in corporation with Federal Mogul company. The aim of this work to create test methology, which allows to experimentally detect the source of undesirable noise and eventually suggest next steps in its prevention.
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Farahnak, Nader. "Performance and modelling of rolling roads in a production environment." Thesis, Coventry University, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.342832.
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Kancharla, Sharath Chandra Reddy. "MODEL BRAKE MATERIAL FORMULATIONS AND THEIR TESTING AT DIFFERENT SCALE LEVELS." OpenSIUC, 2014. https://opensiuc.lib.siu.edu/theses/1571.
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Brakes, being considered as very important parts of automobiles and there have been many different types of brake formulations in use and many innovations are taking place in order to get formulations which gives better braking performance and also environmentally harmless. The possibility of using different solid lubricants in the formula for achieving better brake performance and also the best way of testing the material to be released into the market is investigated. The four pairs of "Crown Victoria 1999" model brake pads are made using the developed formula and tested. The pads are run over the inertia brake dynamometer and Friction Assessment Screening Test (FAST) machine to test their performance. The J2430 standard set by Society of Automotive Engineers (SAE) is followed for testing the brake performance. The friction layer is analyzed through the analysis techniques like Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD)
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Kortán, Daniel. "Analýza brzdění vozidla s nestandardním zásahem do brzdové soustavy." Master's thesis, Vysoké učení technické v Brně. Ústav soudního inženýrství, 2017. http://www.nusl.cz/ntk/nusl-367510.
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This master’s thesis focused on the issue of the possible conversion of liquid brake systems, in the form of replacement of wheel brakes. The first part focused on the function and description of the construction of different types of brakes. The second part is focused on description the types of brake system testing and the regulations regarding brake systems. The last part focused on the measurement of both vehicles and comparison of the results with the calculations.
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Khan, Aamir Khusru. "Design and Implementation of a Clutch and Brake System for a Single Wheel Indoor Tire Testing Rig." Thesis, Virginia Tech, 2017. http://hdl.handle.net/10919/79965.
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The primary goal of this work is to design and implement a clutch and brake system on the single tire Terramechanics rig of Advanced Vehicle Dynamics Laboratory (AVDL) at Virginia Tech. This test rig was designed and built to study the performance of tires in off-road conditions on surfaces such as soil, sand, and ice. Understanding the braking performance of tires is crucial, especially for terrains like ice, which has a low coefficient of friction. Also, rolling resistance is one of the important aspects affecting the tractive performance of a vehicle and its fuel consumption. Investigating these experimentally will help improve tire models performance. The current configuration of the test rig does not have braking and free rolling capabilities. This study involves modifications on the rig to enable free rolling testing when the clutch is disengaged and to allow braking when the clutch is engaged and the brake applied. The first part of this work involves the design and fabrication of a clutch system that would not require major changes in the setup of the test rig; this includes selecting the appropriate clutch that would meet the torque requirement, the size that would fit in the space available, and the capability to be remotely operated. The test rig's carriage has to be modified in order to fit a pneumatic clutch, its adapter, a new transmission shaft, and the mounting frame for the clutch system. The components of the actuation system consisting of pneumatic lines, the pressure regulator, valves, etc., have to be installed. Easy operation of the clutch from a remote location is enabled through the installation of a solenoid valve. The second part of this work is to design, fabricate, and install a braking system. The main task is to design a customized braking system that satisfies the various physical and functional constraints of the current configuration of the Terramechanics rig. Some other tasks are the design and fabrication of a customized rotor, selection of a suitable caliper, and design and fabrication of a customized mounting bracket for the caliper. A hydraulic actuation system is selected since it is suitable for this configuration and enables remote operation of the brakes. Finally, the rig is upgraded with the assembly of these two systems onto it.<br>Master of Science
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Motl, Jakub. "Vliv okamžité hmotnosti vozidel na jejich brzdnou dráhu." Master's thesis, Vysoké učení technické v Brně. Ústav soudního inženýrství, 2010. http://www.nusl.cz/ntk/nusl-232480.
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This diploma thesis is engaged in analysis of braking process of vehicles, especially heavy utility vehicles, with regard to their instantaneous weight. This thesis features survey and division of braking systems and function of brakes including schemes and descriptions. Also there is introduce of some systems improving vehicle properties. Furthermore this work puts mind to possibilities of examination of brakes, measurement of braking distance and braking retardation namely in brake test rooms or by outdoor driving tests including descriptions of particular methods and equipment. There is also mention about legislative requirements for braking distance and braking retardation. The conclusion of this thesis compares numerically predicted braking distance and real braking distance measured for factual vehicle during outdoor driving test
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Johannesson, Markus, and Anders Tolf. "Volvo GTT Brake Simulation Tool : Virtual vehicle using data driven approach for rapid testing." Thesis, Tekniska Högskolan, Jönköping University, JTH, Industriell produktutveckling, produktion och design, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-50119.
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The project has been conducted in collaboration with the company Volvo Group Truck Technology and deals with the area of brake development. The purpose of this thesis is to develop a simulation tool to perform rapid testing of the brake system. The brake system is introduced, where an explanation of what the brake systems role is in the vehicle and which kinds of brakes can be found in commercial trucks. Different trucks depend on different braking systems, a truck doing long-hauls will have different braking needs than a worksite transporter. It is important to have a customizable tool to be able to cover the different truck braking systems. Simulations cannot replicate reality perfectly; the results will always deviate from the actual value. There are countless of variables that can affect the braking torque, everything from mechanical efficiency to weather conditions. It is important to set limitations and boundaries for the tool. Four different methods have been used to develop the simulation tool. MATLAB pulls information from component test data stored in Excel sheets, then inserts it into the block diagram calculations in Simulink where the model has been created using a data driven method with a physics base. The tool has also been validated compared to component performance data and old truck dynamometer tests. The project presents how the development cost can be reduced by using the simulation tool instead of traditional testing. A simulation can be done in one minute, as opposed to the 14 days it takes to perform a physical test, this means that decisions can be taken quicker with minimal resource investments. The virtual vehicle customization is also presented, where the user can choose which specific components to test. Making the tool useful for different braking scenarios and different truck setups.
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Kancharla, SaiKrishna. "Effect of Humidity and testing strategy on Friction Performance of model brake pads containing Nano-additives." OpenSIUC, 2018. https://opensiuc.lib.siu.edu/theses/2456.
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Interaction of brakes with external environment can considerably influence their performance which could relate to friction instabilities. Humidity can alter the chemistry of friction surfaces that could relate to unwanted phenomena which increase the cost of product. In addition to the chemical phenomena leading to unwanted reactions, there are physical effects related to adsorption of humidity and to modification of adhesion, accompanied with changes in contact surfaces and contact mechanics. The goal of this paper is to address these chemical and physical phenomena occurring at friction interfaces of model friction materials and to relate them to their performance. Friction tests were performed by using the environmental (equipped with humidity and temperature chambers) bench-top UMT TriboLab friction tester (Bruker) with scaled-down parameters derived from adopted real vehicle braking scenario. Wear surfaces/mechanisms were studied by using scanning electron microscopy (Quanta FEG 450 by FEI) equipped with the energy dispersive X-ray microanalysis (Inca System), and 3D optical microscope (NPFLEX by Bruker). Vibrational response was monitored by triaxial ICP Accelerometer (PCB Piezotronics, Model=356A45) and Oscilloscope (Agilent Technologies, Model= MSOX2024A). The data were analyzed by use of Matlab (MathWorks, Version= R2015A). The physical adsorption is dependent strongly on the surface topography; nevertheless, the chemical species/products generated at the friction surfaces are dominant factor dictating the quantity of absorbed humidity/species. Their chemistry differs from the chemistry of bulk and a complex correlation must be further studied. Adsorption considerably influences the friction performance (friction and its stability, wear, noise and environmental response/pollution capacity) of brake pads. Further studies addressing these phenomena are recommended. Keywords – humidity, friction, scanning electron microscopy, brake pads and X-ray microanalysis.
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Sidhu, Anmol. "Development of an Autonomous Test Driver and Strategies for Vehicle Dynamics Testing and Lateral Motion Control." The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1269352974.
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Roughan, Craig. "Adaptive brake lights : an investigation into their relative benefits in regards to road safety." Queensland University of Technology, 2007. http://eprints.qut.edu.au/16335/.
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The implementation of In-Vehicle Intelligent Transport Systems (ITS) is becoming a common occurrence in modern vehicles. Automobile manufacturers are releasing vehicles with many forms of sophisticated technologies that remove much of the responsibility of controlling an automobile from the driver. These In-Vehicle Intelligent Transport Systems have stemmed from a genuine need in regards to road safety, however there are advantages and disadvantages associated with ITS. Each different form of technology has its own inherent compromises in relation to road safety, driver behaviour and driver comfort. This thesis outlines the benefits and detrimental effects associated with current In-Vehicle Intelligent Transport Systems and details the development and user interface testing of an adaptive brake light. The adaptive brakelight concept aims to provide drivers with the advantages of an In-Vehicle ITS whilst removing the disadvantages. The technology will help drivers judge the braking pattern of the car in front, thus allowing them to react appropriately and potentially reducing the occurrence of rear-end crashes. The adaptive brake light concept was tested in comparison to a standard brake light and BMW inspired brake light in a series of user interface tests. The adaptive brake light was shown overall to be an improved method of displaying the varying levels of deceleration of a lead vehicle. Whilst different age and gender groups responded differently to the adaptive brake light, it was shown to be of benefit to the majority and the most at risk groups responded positively to the adaptive brake light. This research shows that an adaptive brake light can provide a benefit in regards to road safety when compared to a standard brake light interface. It is hoped that further development of variable brake lights will result from this research and possibly lead to the implementation of the technology to automobiles and other forms of transport.
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Subra, Mani Vishnu Aishwaryan. "Design, Development and Characterization of a Wrap Spring Clutch/Brake Mechanism as a Knee Joint for a Hybrid Exoskeleton." Digital WPI, 2020. https://digitalcommons.wpi.edu/etd-theses/1359.
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Evolution had played a significant role in structuring on how humans stand, walk or run. The nervous system plays a major role in the control of locomotion and injuries to the system can lead to gait abnormalities or disabilities. A Spinal Cord Injury (SCI) causes lack of signal communication between the central nervous system and the muscle fibers leading to deprived or no activation of the muscles thus resulting in paraplegia or quadriplegia. Over the past decade wearable robotics and exoskeletons have been gaining outstanding recognition in the field of medical, assistive and augmentative robotics and have led to numerous new innovative mechanisms in the mechanical engineering field. Due to fast paced research activities, the critical importance and performance of mechanisms such as wrap spring clutch/brake,Wafer Disc brakes are overlooked or used ineffectively. So, researchers tend to create new actuators from scratch and have limited their use of previously available resources, which has prevented us to explore the potential of these devices.The research presented focuses on developing a mechanism (“A Wrap Spring Clutch/Brake Mechanism”) from scratch using a trade study approach. This thesis addresses the fundamental relationship between coefficient of friction, interference, spring diameter and the holding torque of the mechanism using analytical, testing and simulation results. The human biomechanical data during ground level walking was used as design targets to develop the mathematical model of the system. Data from the testing stated that these targeted goals have been achieved by the design. This mechanism is used as a Knee Joint for the Hybrid EXoskeleton (HEX) GEN-1 project which is developed at the Automation and Interventional Medicine (AIM) Robotics Research Laboratory to rehabilitate the SCI.
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Wang, Yuan. "Friction surface development and its structure on carbon fibre reinforced silicon carbide disc." Thesis, Loughborough University, 2011. https://dspace.lboro.ac.uk/2134/10003.
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Carbon fibre reinforced ceramic composites (Cf/C-SiC) have been explored as lightweight and durable disc in a friction brake. This composite was manufactured through infiltration of liquid silicon into a Cf/C perform. It has heterogeneous microstructure, composed of three key phases, silicon carbide, Cf/C, and un-reacted residual silicon. The development of the transfer layer on the friction surface of Cf/C-SiC was studied through microstructural image registration of the surface after a range of braking stops on a laboratory-scale dynamometer test rig. When an organic pad was used as the counter face brake pad, it was found that a steady transfer layer was developed in silicon regions right after initial stops; in carbon-fibre/carbon (Cf/C) regions and most of the silicon carbide region, the friction surfaces were unsteady and any possible friction transfer layers were hardly built up. Large voids and cracks/crevices likely became pools to quickly and efficiently collect the transferred materials generated by the friction, but the compacts formed inside the pools were susceptible to be stripped off by further braking operation. Three types of friction surfaces were generalized: type I, the friction transfer layer had a steady relationship with the matrix and respectable longevity; type II, the transfer layer had an unstable relationship with the matrix and poor durability; type III, the friction transfer layer had a steady relationship with the matrix but short lifetime. After testing against organic pads under the laboratory scale dynamometer testing condition, the friction surface of each key phase in Cf/C-SiC composites disc was studied by transmission electron microscopy (TEM). It was found that the transfer layer developed on Si consists of fine particles of metal silicides, silicates and minerals. The substrate damage of Si was not observed, while the precipitates having high oxygen content were found in the substrate. Formation of an interfacial bonding between transfer layer and silicon substrate is believed to be the key factor for the formation of a stable transfer layer on Si. However, the interfacial bonding between transferred materials and SiC was not detected. Kinks are common features developed on the friction surface of SiC. The interface between carbon fibre and carbon matrix was experienced mechanical damage, in form of microcracks, and the transferred material was developed in the interface. Instead of transfer layer, a thin amorphous film, produced by friction induced amorphisation of carbon fibre, was developed on top of carbon fibre.
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Berglund, Simon, and Joel Lennartsson. "Design of Power Off Brake : Utveckling av testutrustning." Thesis, Tekniska Högskolan, Högskolan i Jönköping, JTH, Produktutveckling, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-40340.
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The goal with this thesis is to find together with Saab Avionics Systems the correlation between applied current, air gap and forces that a brake with an electromagnetic release function have. This is achieved through theoretical calculations and practical tests. At the moment the brakes are used in electromechanical actuators that are applied in aircraft flap systems. These brakes have been in Saab’s collection of products since a decade and to keep on being a competitive supplier they need to optimize their design process. However, there are difficulties regarding calculating the force of the magnetic field of these brakes since it is very complicated. To better understand how the design can be altered the current product Power Off Brake needs to be tested and analyzed. The test equipment that was developed is designed so that the brake dimension, air gap and current can vary alongside a change of surrounding temperature. After a test in room temperature it was found that the test equipment had a margin of error about 10%. By testing Power Off Brake with the selected measuring method and test equipment Saab will get one step closer to better understand the relationship between theoretical calculations and practical tests. This can be used to reduce the safety margins when new brakes are to be developed since the test results provide insight about what happens when saturation in the material occur and how the brake perform in environmental conditions of an aircraft. Furthermore, the authors leave recommendations for continued work and suggestions for improved design.<br>Målet med detta examensarbete är att tillsammans med Saab Avionics Systems finna en korrelation mellan strömstyrka, luftgap och kraft hos en broms med en elektromagnetisk frisläppning. Detta utförs genom teoretiska beräkningar och praktiska tester. Idag används bromsarna i elektromekaniska aktuatorer som appliceras i klaffsystem hos flygplan. Dessa bromsar har funnits i Saabs sortiment sen ett årtionde tillbaka och för att fortsätta vara en konkurrenskraftig leverantör behövs en optimal designprocess. Det finns dock svårigheter då det är avancerat att teoretiskt räkna ut hur stor kraft som kan utvinnas av magnetfältet hos dessa bromsar. För att förstå hur designen kan förändras behöver den befintliga bromsen Power Off Brake testas och analyseras. Testutrustningen som togs fram är designad med avsikt att kunna variera dimension på broms, luftgap, ström och temperaturförhållande. Efter ett test i rumstemperatur konstaterades att utrustningen har en felmarginal på cirka 10 %. Genom att testa Power Off Brake med vald testmetod och testutrustning kommer Saab ett steg närmare att förstå relationen mellan teoretiska beräkningar och praktiska tester. Då kan säkerhetsfaktorer minskas när nya bromsar designas. Mätresultaten ger insikt om vad som händer när mättnad i materialet uppstår och hur bromsen presterar i miljöförhållanden som kan uppstå i flygplan. Vidare lämnar författarna rekommendationer för fortsatt arbete och förslag på förbättrad design.
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Bradley, Luke R. "Mechanical testing and modelling of carbon-carbon composites for aircraft disc brakes." Thesis, University of Bath, 2003. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.426204.
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Glatzel, Christopher [Verfasser], and Ingmar [Akademischer Betreuer] Ipach. "Fahrtauglichkeit nach Implantation einer Kniegelenkendoprothese - Testung von Kraft und Brake Response Time / Christopher Glatzel ; Betreuer: Ingmar Ipach." Tübingen : Universitätsbibliothek Tübingen, 2016. http://d-nb.info/1197694633/34.
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Odložilík, Daniel. "Zařízení pro testování diferenciálů." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2021. http://www.nusl.cz/ntk/nusl-445172.
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This master’s thesis deals with the design of equipment for testing differentials. The aim of the thesis is therefore the design of a special device that will be able to measure the steady and transient characteristics of differentials. Master’s thesis is divided into four chapters. The first chapter points out the disadvantages of fully open and closed differentials, the second deals with a basic overview of the structures and design of self-locking differentials. The third chapter deals with research of existing devices that test and measure the characteristics of differentials. The fourth chapter then discusses the possible drives of the tested unit. The fifth chapter focuses on the actual construction design of the test equipment. The subsequent sixth chapter then solves the strength calculations of the chosen structural elements of this device.
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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.<br>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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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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Stark, Richard A. "The effects of the ASO ankle brace and ankle taping on speed and agility in female softball athletes and male baseball athletes." Scholarly Commons, 1997. https://scholarlycommons.pacific.edu/uop_etds/2302.
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The purpose of this study was to compare the effects of prophylactic ankle bracing and the effects of prophylactic ankle taping on athletes' speed and agility. Thirty-one subjects, twenty-one male professional baseball players and ten female collegiate softball players with no history of an ankle injury the previous six months, participated in three performance tests while wearing the ASO ankle brace, a modified Gimby ankle taping, and unsupported. The subjects completed the flying forty yard dash for speed, the SEMO test for general agility, and the Edgren test for specific lateral agility. Multiple trials were administrated to account for learning effects. The resultant data were analyzed with a multivariate repeated-measures design. The data were tested for order effects; no significant differences were found. The data were then tested for multicollinarity by use of an intercorrelation matrix across the three dependent (compacted) variables. A 2 x 3 multivariate analysis of variance (MANOVA) was used to analyze gender and support conditions (with repeated measures) effects across the dependent variables; and significant differences were followed up with univariate analyses of variance (ANOVAs). Effects for interactions of gender x support condition were evaluated by Wilkes' A. There were no statistically significant interactions found. In univariate ANOVAs for post hoc testing significant differences were found for gender effect on speed (forty yd. dash), general agility(SEMO test), and specific lateral agility (Edgren test). ) A significant difference was found in the follow up univariate analysis across support conditions for general agility (SEMO test) wherein the unsupported condition was significantly faster (less time) than the braced or taped conditions.
On the basis of the findings, it was concluded that the subjects' speed in the forty yard dash was not significantly reduced by bracing or taping. It was concluded that the subjects' agility was significantly slowed by both prophylactic bracing and taping as demonstrated by performance in the SEMO general agility test. It was concluded that males and females are not differentially affected by bracing and I or taping. There was no significant statistical difference found between the ASO Ankle brace and the taped ankle in speed and agility tests. It can be concluded that budgetary considerations and personnel time maybe the critical factors when selecting certain ankle braces over ankle taping.
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Cheifetz, Nicolas. "Détection et classification de signatures temporelles CAN pour l’aide à la maintenance de sous-systèmes d’un véhicule de transport collectif." Thesis, Paris Est, 2013. http://www.theses.fr/2013PEST1077/document.
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Le problème étudié dans le cadre de cette thèse porte essentiellement sur l'étape de détection de défaut dans un processus de diagnostic industriel. Ces travaux sont motivés par la surveillance de deux sous-systèmes complexes d'un autobus impactant la disponibilité des véhicules et leurs coûts de maintenance : le système de freinage et celui des portes. Cette thèse décrit plusieurs outils dédiés au suivi de fonctionnement de ces deux systèmes. On choisit une approche de diagnostic par reconnaissance des formes qui s'appuie sur l'analyse de données collectées en exploitation à partir d'une nouvelle architecture télématique embarquée dans les autobus. Les méthodes proposées dans ces travaux de thèse permettent de détecter un changement structurel dans un flux de données traité séquentiellement, et intègrent des connaissances disponibles sur les systèmes surveillés. Le détecteur appliqué aux freins s'appuie sur les variables de sortie (liées au freinage) d'un modèle physique dynamique du véhicule qui est validé expérimentalement dans le cadre de nos travaux. L'étape de détection est ensuite réalisée par des cartes de contrôle multivariées à partir de données multidimensionnelles. La stratégie de détection pour l'étude du système porte traite directement les données collectées par des capteurs embarqués pendant des cycles d'ouverture et de fermeture, sans modèle physique a priori. On propose un test séquentiel à base d'hypothèses alimenté par un modèle génératif pour représenter les données fonctionnelles. Ce modèle de régression permet de segmenter des courbes multidimensionnelles en plusieurs régimes. Les paramètres de ce modèle sont estimés par un algorithme de type EM dans un mode semi-supervisé. Les résultats obtenus à partir de données réelles et simulées ont permis de mettre en évidence l'efficacité des méthodes proposées aussi bien pour l'étude des freins que celle des portes<br>This thesis is mainly dedicated to the fault detection step occurring in a process of industrial diagnosis. This work is motivated by the monitoring of two complex subsystems of a transit bus, which impact the availability of vehicles and their maintenance costs: the brake and the door systems. This thesis describes several tools that monitor operating actions of these systems. We choose a pattern recognition approach based on the analysis of data collected from a new IT architecture on-board the buses. The proposed methods allow to detect sequentially a structural change in a datastream, and take advantage of prior knowledge of the monitored systems. The detector applied to the brakes is based on the output variables (related to the brake system) from a physical dynamic modeling of the vehicle which is experimentally validated in this work. The detection step is then performed by multivariate control charts from multidimensional data. The detection strategy dedicated to doors deals with data collected by embedded sensors during opening and closing cycles, with no need for a physical model. We propose a sequential testing approach using a generative model to describe the functional data. This regression model allows to segment multidimensional curves in several regimes. The model parameters are estimated via a specific EM algorithm in a semi-supervised mode. The results obtained from simulated and real data allow to highlight the effectiveness of the proposed methods on both the study of brakes and doors
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Coy, Bradly B. "Buckling-Restrained Braced Frame Connection Design and Testing." Diss., CLICK HERE for online access, 2007. http://contentdm.lib.byu.edu/ETD/image/etd2030.pdf.
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Reed, Matthew Robert. "Development of an Improved Dissipative Passive Haptic Display." Thesis, Georgia Institute of Technology, 2003. http://hdl.handle.net/1853/5284.
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This project focuses on the design and modeling of a two degree-of-freedom dissipative passive haptic display. Haptic displays are man-machine interfaces that transmit forces to the human operator. A dissipative passive haptic display is one that may only remove energy from the system using actuators such as brakes and dampers, thus ensuring the safety of the human operator. These devices may be used to implement virtual constraints such as desired paths and obstacles. Traditional friction brakes have previously been used as dissipative and coupling elements in a two degree-of-freedom parallel manipulator, resulting in undesired effects such as vibration, stiction, and slow response times. Alternatively, the new robot is actuated by rheological brakes, which feature fast response times and smooth application of torque. This approach aims to improve upon the accuracy and feel of the previous design.
A commercial magnetorheological (MR) fluid brake was selected and put through an extensive series of tests. The data was used to develop a model that characterizes MR fluid behavior in low speed braking applications. A parallel five bar linkage was designed and built that has separate configurations corresponding to 3-brake and 4-brake operation. The length of each arm was chosen by means of a geometrical optimization that weighs the size and area of the workspace and actuator effects. A simulation was then developed by incorporating the brake model into the equations of motion of the robot. Next, two forms of path following velocity control were devised and tested in simulation. Finally, the accuracy, workload, and smoothness of both controllers and both configurations were examined in preliminary tests with human operators.
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Karrar, Carel [Verfasser], and A. [Akademischer Betreuer] Albers. "Ein Beitrag zur Entwicklung, Dimensionierung und Prüfung trockenlaufender Kupplungen und Bremsen in Antriebsstrangsystemen im Hinblick auf die Vermeidung von Reibschwingungen = A contribution for developing, dimensioning and testing of dry clutches and brakes in powertrains focused on the avoidance of frictional vibration / Carel Karrar ; Betreuer: A. Albers." Karlsruhe : KIT-Bibliothek, 2021. http://d-nb.info/1235072584/34.
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Mercklé, Jean. "Stratégies de détection de rupture de modèle appliquées à la recherche et à la localisation des défauts sur des produits sidérurgiques." Nancy 1, 1988. http://www.theses.fr/1988NAN10047.
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Élaboration de deux stratégies de "détection-localisation" de défauts dans les signaux issus du contrôle par courants de Foulcault des produits sidérurgiques. Validation de ces stratégies dans le contrôle qualité de trois procédés : élaboration de brames de coulée continue, élaboration de blooms de coulée continue et de tubes
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Chang, Cheng-Yang, and 張正暘. "Design and Testing of an Innovative Magnetorheological Brake." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/ga784r.
Full textAbstract:
碩士<br>國立臺北科技大學<br>車輛工程系所<br>98<br>The majority of current Magnetorheological Fluid (referred to as MR Fluid) brake is cylinder. The internal part is composed by outer tube with internal structure. The magnetorheological fluid is full around the inner disk uniformly. The extra magnetic field is constructed by C-type conductivity silicon iron or steel wrap the coil around the Magnetorheological fluid and it mainly causes a reaction with the fluid. Basically, C-type guide rail design concept is applied to magnetic field. However, the reaction is limited. Relatively, the MR Brake provides the braking force is much smaller.
This research proposed a new design for MR brakes. The main idea is to use distributed coil design to increase the reaction within the external magnetic field in the area of Magnetorheological fluid. Plural magnetic poles are placed around magnetorheological fluid, and each pole is arrayed with different directions of the magnetic field around the Magnetorheological fluid. In addition, MR brakes is placed on two poles, top and bottom so that the magnetic directions are all encircled in the cylinder that can generate more braking forces.
The computer simulation is applied to perform the optimization analysis of the newly designed MR break. Three parameters are considered to obtain the optimized breaking force. They are the pole pitch, number of poles and the flow gap of MR Fluid, respectively. The result of the simulation shows that in the optimization condition. By comparing with the commercial MR break, the performance of new MR break is 118% higher.
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Chen, Alan. "Mechanical testing and design of a lightweight novel WBD brake disc." Thesis, 2020. https://hdl.handle.net/10539/31228.
Full textAbstract:
A dissertation submitted to the Faculty of Engineering and the Built Environment, of the University of the Witwatersrand, in fulfilment of the requirements for the degree of Master of Science in Engineering, 2020<br>Limited research exists on the loading mechanism of a brake disc. The need to determine the mechanical stresses in typical brake disc set-up has never been necessary as these stresses are well below the strength of typical brake disc materials. A recently developed wire-woven bulk diamond (WBD) ventilated brake disc with superior thermal performance has initiated a need to understand how the mechanical stresses within a brake disc are developed. The loading mechanism was separated into the resultant compressive stresses due to the clamping load and the shear stresses due to the applied braking torque. These stresses were measured experimentally using strain gauges mounted on a solid brake disc tested on a custom-built test rig. For the clamping load test, the compressive stresses were concentrated at the disc/pad contact interface. For the applied torque load test, the disc face shear stresses were found to be distributed throughout the circumference of the disc. These results were applied to design the required reinforcement of a WBD brake disc. The analysis was based on the maximum possible deceleration conditions of a medium sized truck. While the WBD material was strong enough to withstand the shearing of the braking torque, the clamping load was determined to cause failure. Consequently, straight radial ribs were designed to reinforce the ventilated core. The final dimensions of the designed rib were 74 x 14 x 2.5 mm, manufactured from mild steel (SAE1006). The core will be reinforced with 10 ribs orientated radially and equispaced at 36° intervals. The 10 ribs adds 0.20 kg to the weight of the WBD disc. Thus, the newly reinforced WBD brake disc remains lighter than a commercially available pin-finned disc, has superior thermal performance and is strong enough to withstand the required mechanical stresses<br>CK2021
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LI, TSUNG-TUNG, and 黎宗東. "The performance testing and analysis for the brake system of light-rail vehicles." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/01755346222102693728.
Full textAbstract:
碩士<br>國立臺灣科技大學<br>自動化及控制研究所<br>93<br>Due to the complexity and difficulty of the brake safety testing and performance analysis on the practical light-rail vehicle (LRV) system, this paper aims to develop a test rig and a simulation software for analyzing the characteristics of the LRV.
The study includes the analysis of testing rig system, mathematics model constructions of the valve-controlled hydraulic system and the disc braking system, and the simulate programs development by MATLAB/SIMULINK. The simulation analysis for emergency braking, operational braking and continuous braking models are implemented.
According to simulation and analysis of the brake system, the characteristic curves for different braking conditions can be computed. Based on that, the performance of the light-rail brake system can be evaluated as the design references.
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Burns, Patricia Mary. "Testing the seams of the American dream : minority literature and film in the early Cold War." Thesis, 2011. http://hdl.handle.net/2152/ETD-UT-2011-08-3751.
Full textAbstract:
Testing the Seams of the American Dream: Minority Literature and Film in the Early Cold War delineates the concept of the liberal tolerance agenda in early Cold War. The liberal tolerance message of the U.S. government, the Democratic Party, and others endorsed racial tolerance and envisioned the possibility of a future free from racism and inequality. Filmmakers in often disseminated a liberal message similar to that of the politicians in the form of “race problem” films. My shows how these films and the liberal tolerance agenda as a whole promises racial equality to the racial minority in exchange for hard work, patriotism, education, and a belief in the majority culture. My first chapter, “Washing White the Racial Subject: Hollywood’s First Black Problem Film,” performs a close reading of Arthur Laurents 1946 play Home of the Brave, which features a Jewish American protagonist, in conjunction with a reading of the 1949 film version, which has an African American protagonist. The differences between the two texts reveal the slippages in the liberal tolerance agenda and signal the inability of filmmakers to envision racial equality on the big screen. “The American Institution and the Racial Subject,” my second chapter, discusses the 1949 film Pinky as well as Américo Paredes’s George Washington Gómez and Monica Sone’s Nisei Daughter. All of these works suggests that the attainment of education promises entry into the mainstream by racial minorities, yet Paredes and Sone question this process by interpreting it as resulting in the dual segregation of their protagonists. My third chapter, “Earning and Cultural Capital: The Work that Determines Place,” looks at the promise that with hard work anyone can attain the American Dream. I show how the 1951 film Go for Broke!, Ann Petry’s The Street, and José Antonio Villarreal’s Pocho work to dispel this American myth. My final chapter, “The Regrets of Dissent: Blacklists and the Race Question,” examines the 1954 film Salt of the Earth alongside Chester Himes’s If He Hollers Let Him Go and John Okada’s No-No Boy to reveal the dangerous mixture of race and dissent in this era.<br>text