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1
Thuppal, Vedanta Srivatsan, and Naga Vamsi Krishna Kora. "HEAT TRANSIENT TRANSFER ANALYSIS OF BRAKE DISC /PAD SYSTEM." Thesis, Blekinge Tekniska Högskola, Institutionen för maskinteknik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-13461.
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Braking is mainly controlled by the engine. Friction between a pair of pads and a rotating disc converts the kinetic energy of the vehicle into heat. High temperatures can be reached in the system which can be detrimental for both, components and passenger safety. Numerical techniques help simulate load cases and compute the temperatures field in brake disc and brake pads. The present work implements a Finite Element (FE) toolbox in Matlab/Simulink able to simulate different braking manoeuvres used for brake dimensioning mainly in the early phase of car development process. The brake pad/disc geometry is considered as an axisymmetric body assuming negligible temperature gradient along the circumference of the disc. Calibration using three control factors namely: heat coefficient during braking , acceleration and emissivity for the implemented thermal model is performed using experimental investigation at Volvo Car Corporation (VCC) for three specific severe load cases. The thermal model is extended to measure brake fluid temperatures to ensure no vaporisation occurs. Simulation results of the brake disc and brake pad show good correlation with the experimental tests. A sensitivity analysis with the control factors showed convective coefficient during acceleration the most sensitive, with temperature change of around 16%.
2
Ahuja, Nitesh Raju P. K. "Some studies on modeling and simulation of a disc brake system for squeal prediction." Auburn, Ala., 2006. http://repo.lib.auburn.edu/2006%20Summer/Theses/AHUJA_NITESH_54.pdf.
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Balvedi, Alessandro Mattiuzi. "A study of squeal noise in a disc brake system and influence of rubber coated shims on system damping." Florianópolis, SC, 2002. http://repositorio.ufsc.br/xmlui/handle/123456789/82542.
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Tese (doutorado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia Mecânica.<br>Made available in DSpace on 2012-10-19T16:01:03Z (GMT). No. of bitstreams: 0Bitstream added on 2014-09-26T02:06:08Z : No. of bitstreams: 1
192285.pdf: 101649091 bytes, checksum: b90362d343d41980bde2a0e107057422 (MD5)<br>Ruído de alta freqüência (acima de 2000 Hz) em sistemas de freios tem recebido grande atenção por parte da indústria automobilística. Este tipo de ruído, também conhecido como "squeal", é percebido pelos usuários como um problema no sistema de freios. Esta percepção afeta de modo substancial não só índices de qualidade e satisfação, mas principalmente os custos relacionados à garantia e assistência técnica. O ruído de alta freqüência em sistemas de freios é resultado do acoplamento de dois modos de vibração dos componentes do freio, tais como disco, pastilha e pinça. Entre as técnicas utilizadas para o controle deste tipo de ruído, o aumento do amortecimento modal tem-se mostrado uma solução eficiente. O método mais comumente utilizado para aumentar-se o amortecimento modal do sistema tem sido a utilização de materiais multicamadas, também conhecidos como "shims", colados na parte anterior das pastilhas de freio. A configuração destes "shims" consiste de um ou mais materiais viscoelásticos (polímeros) restringidos entre duas camadas metálicas, usualmente aço. Em algumas configurações, uma camada viscoelástica, geralmente borracha sintética, é aplicada sobre a face externa destas camadas metálicas, com o objetivo de melhorar ainda mais as características de amortecimento do sistema. Estas configurações, com material viscoelástico na face externa do "shim", tem-se mostrado útil no controle de ruído de alta freqüência em alguns casos, sendo, porém, aplicadas sem sucesso em outros. O objetivo principal desta pesquisa é investigar a influência de tais configurações no amortecimento modal introduzido pelos materiais multicamadas. Para isto, a compreensão do mecanismo de geração do ruído de alta freqüência torna-se necessária. Neste trabalho, primeiramente, o mecanismo de amortecimento de materiais viscoelásticos é descrito. Em materiais multicamadas, este mecanismo é dependente, além dos parâmetros geométricos da configuração, da presença ou não de uma camada metálica restringindo o material viscoelástico. As medições das propriedades dinâmicas dos materiais viscoelásticos utilizados nesta pesquisa são também apresentadas.
4
Drabison, John Stephen II. "Experimental Investigation of Judder in a Floating Disc-Caliper Braking System with Focus on Pad Geometry." The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1276795212.
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Dobrovolný, Petr. "Návrh brzdové soustavy formulového vozu." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2017. http://www.nusl.cz/ntk/nusl-318535.
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Design of braking system for the formula student car. Calculation of basic forces acting in the braking system, including the design of hydraulic circuits. Mechanical analysis of the most important parts of the braking system and pedal assembly. Thermal analysis of the brake discs. Manufacturing and total cost calculation.
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Štylárek, Milan. "Konstrukce brzdového systému formule Student." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2014. http://www.nusl.cz/ntk/nusl-231480.
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Objective of this thesis is design of brake system of new car Formula Student class – Dragon 3. This car was built by students of faculty of mechanical engineering on Brno university of technology. Brake parts selection is described as well as designing hydraulic brake line circuits optimized for stable braking behavior on tracks of Formula Student competitions. One of main parts of this thesis is design of front and rear custom brake discs with related parts. These parts are FEM analyzed. In the end the whole brake system fitted on Dragon 3 car is tested on track and its performance is analyzed too.
7
Fieldhouse, John David. "An analysis of disc brake noise using holographic interferometry." Thesis, University of Huddersfield, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.358314.
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A predominantly experimental approach using the whole body visual technique of holographic interferometry is employed to investigate the mechanisms involved during a noisy brake application. Following the modal analysis of component parts, dynamic trials include the development of the holographic technique, making use of mirrors to permit three orthogonal views of the brake to be recorded simultaneously with smaller inset mirrors allowing for additional areas, such as the ends of the piston pad, to be observed at the same time. These dynamic experiments take the form of changing the operating parameters of the brake through variations in speed, pressure and temperature and through changes in the system geometry by adjustment of pad abutment and pad centre of pressure loading. The tests show that pad abutment plays an important role in the propensity of the system to generate noise and that a relationship between pad abutment, pad material coefficient of friction and interface coefficient of friction between pad-end and calliper-support finger exists which results in an offset in the pad centre of pressure with the spragging angle being satisfied and resulting noise. This is supported by basic theory. Additionally it is shown that the disc/pad interface relationship is complicated and that it is not reasonable to assume mechanical integrity of the pair and as a consequence the use of an "equivalent mass" is not appropriate for high aspect ratio pads. Advancements in the laser triggering process allow for holograms to be taken at specific stages over and along a cycle of excitation by delaying the laser triggering initiation to give variable time delays. The variety of techniques available are used to show that pad excitation plays an important role in the generation of noise and that the piston pad in particular is seen as the initiator leading to system excitation. Mechanical coupling of the component parts is also seen to be fundamental, but not essential, to the generation of noise. The techniques also show that, when complete coupling exists, the disc holds a diametral mode of vibration which travels around the disc at a speed related to the excitation frequency divided by the disc mode order. Results from the application of the techniques also allows component parts to be analysed over a typical cycle of excitation when it is shown that symmetrical components such as the pad are not necessarily excited in a symmetrical manner. Phase relationship between the component parts may also be determined by comparison of related holograms. Holographic interpretations are confirmed and validated by mechanical measurements when it is also demonstrated that noise is often preceded by, or accompanied by, a high frequency excitation which is experienced by the complete brake.
8
Chen, J. P. "Thermo-mechanical behaviour of heavy-duty disc brake systems." Thesis, Cranfield University, 2001. http://dspace.lib.cranfield.ac.uk/handle/1826/10701.
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In
heavy-duty disc brake systems, braking is a transient, non-linear and
asymmetrical thermo-mechanical process. Surface cracking, rather than wear, is the
major factor limiting the brake disc's life. The disc material (cast-iron), heat transfer
boundary conditions and pad-disc frictional reactions are characteristically non-linear
and
asymmetrical during the friction process. Non-uniform deformation and surface
cracks in brake discs result from the accumulation of excessive residual stress/strain.
During braking processes, many factors affect the distributions of the residual
stress and strain in discs, and hence the propagation of the surface cracks. The disc
material, structure and boundary conditions are three of the crucial aspects. From the
structure, a brake disc could be either solid or ventilated. In practice, solid structures
always have higher anti-cracking performance than the same class of ventilated
designs. However solid discs cost more material and have lower cooling efficiency.
This thesis
presents an improved finite element analysis for heavy-duty disc
brakes and identifies
design improvements. As the friction pads slide against the
disc's surfaces
continuously, the thermal and mechanical loads are functions of time
and
spatial coordinates. A 3-D asymmetrical finite element model was developed to
achieve more accurate simulations of the thermo-mechanical behaviour of brake discs
during braking processes. A non-linear inelastic material model for cast-iron was
employed in the FE model. Permanent plastic stress and strain fields were predicted
and
analysed for multi-stop drag operations. The residual stress/strain fields in the
discs are
investigated to understand the differences between solid and ventilated discs
in terms of the
cracking resistance ability. Several engineering solutions are
recommended for
optimising the performance of the disc brake system. _
The thesis is
organized in five chapters. Chapter One introduces the
background concepts about the commercial disc brake system. In this part, the brake
structure, material and previous researches are reviewed. The goals for this
investigation are also summarised at the end of this chapter. Chapter Two introduces
the
general finite element modelling knowledge, procedures and the modelling
boundary conditions and material models. Chapter Three presents an analysis of the
disc brakes thermo-mechanical behaviour and the
affecting factors. Chapter Four is
focused on the residual stress field
prediction and cracking behaviour analysis. The
project conclusions and further research recommendations are presented in Chapter
Five.
9
Chen, Jing Ping. "Thermo-mechanical behaviour of heavy-duty disc brake systems." Thesis, Cranfield University, 2001. http://dspace.lib.cranfield.ac.uk/handle/1826/10701.
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In heavy-duty disc brake systems, braking is a transient, non-linear and asymmetrical thermo-mechanical process. Surface cracking, rather than wear, is the major factor limiting the brake disc's life. The disc material (cast-iron), heat transfer boundary conditions and pad-disc frictional reactions are characteristically non-linear and asymmetrical during the friction process. Non-uniform deformation and surface cracks in brake discs result from the accumulation of excessive residual stress/strain. During braking processes, many factors affect the distributions of the residual stress and strain in discs, and hence the propagation of the surface cracks. The disc material, structure and boundary conditions are three of the crucial aspects. From the structure, a brake disc could be either solid or ventilated. In practice, solid structures always have higher anti-cracking performance than the same class of ventilated designs. However solid discs cost more material and have lower cooling efficiency. This thesis presents an improved finite element analysis for heavy-duty disc brakes and identifies design improvements. As the friction pads slide against the disc's surfaces continuously, the thermal and mechanical loads are functions of time and spatial coordinates. A 3-D asymmetrical finite element model was developed to achieve more accurate simulations of the thermo-mechanical behaviour of brake discs during braking processes. A non-linear inelastic material model for cast-iron was employed in the FE model. Permanent plastic stress and strain fields were predicted and analysed for multi-stop drag operations. The residual stress/strain fields in the discs are investigated to understand the differences between solid and ventilated discs in terms of the cracking resistance ability. Several engineering solutions are recommended for optimising the performance of the disc brake system. _ The thesis is organized in five chapters. Chapter One introduces the background concepts about the commercial disc brake system. In this part, the brake structure, material and previous researches are reviewed. The goals for this investigation are also summarised at the end of this chapter. Chapter Two introduces the general finite element modelling knowledge, procedures and the modelling boundary conditions and material models. Chapter Three presents an analysis of the disc brakes thermo-mechanical behaviour and the affecting factors. Chapter Four is focused on the residual stress field prediction and cracking behaviour analysis. The project conclusions and further research recommendations are presented in Chapter Five.
10
Mohd, Ripin Zaidi Bin. "Analysis of disc brake squeal using the finite element method." Thesis, University of Leeds, 1995. http://etheses.whiterose.ac.uk/4588/.
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The problem o f disc brake squeal has been examined by developing a finite element model of the coupled pad-disc system , conducting complex eigenvalue analysis and associating unstable modes with potential squeal problem areas. A key issue in this process is the representation of the contact pressure distribution at the frictional interface between the disc and the pad. Non-linear contact analysis using the finite element model of the pad revealed that contact is only partial at the pad-disc interface and that the contact pressure distribution depends on the friction coefficient, Young’s modulus of the friction material and the way the applied pressure is distributed on the pad backplate. A new method is proposed in which interface contact stiffness is related to brake line pressure using a statistical approach based on the measured surface properties of the interface. Complex eigenvalue analysis of the coupled pad-disc system has shown that unstable modes exist within different ranges of contact stiffness thereby providing an explanation of the effect of varying line pressure on squeal. The two most unstable modes from the analysis show good correlation with experimental squeal results. The coupled model is then used for parametric studies the results of which indicate that high coefficient of friction and uniform contact pressure distribution increase instability whilst a trailing edge biased pressure distribution and a high support stiffness at the pad backplate reduce it. Limiting the disc symmetry by introducing equispaced slots was shown to be effective in reducing instabilities involving diametral modes of the disc with the same order of symmetry only Other modes were stabilised by increasing the rigidity of the pad. The overall results suggest that either the pad or the disc can be mainly responsible for the instability depending on the mode thus unifying the different approaches to disc brake squeal and enabling the most appropriate component to be targeted for squeal abatement purposes.
11
Hagler, Lisle Bruce. "Friction induced vibration in disk brake systems /." Thesis, Connect to this title online; UW restricted, 1998. http://hdl.handle.net/1773/7119.
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12
Leonardi, Mara. "Development of novel eco-friendly friction materials for disc brake systems." Doctoral thesis, Università degli studi di Trento, 2020. http://hdl.handle.net/11572/255825.
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Due to new environmental regulations, the demand for brake systems producing low polluting emissions and keeping high performance, is increasing. Therefore, a reduction in the toxic substances contained in brake friction materials is required that still meets all applicable safety standards and retaining properties such as low wear, high temperatures resistance, friction coefficient stability and consistency.
Among the various ingredients used in formulations, copper has recently become the subject of different regulations on brake pad materials and will be reduced, or even prohibited, in the coming years. Recent studies have found that brake pads are major contributors to the deposit of copper in rivers and lakes, and this has a toxic impact on the environment. This metal is currently added in brake material formulations because of its good physical properties and its contribution to the formation of a uniform and stable friction layer. Its characteristics make it a constituent that is not easy to replace and an adequate substitute covering all the roles of copper has not been found as yet.
The present research aims at developing, producing and testing new formulations for brake pads without copper. A relatively wide range of friction materials was investigated, in order to understand the role that selected constituents have in friction and wear behaviour.
In the first place, an investigation on the role of copper in friction materials was performed. The study was followed by the selection of a suitable replacement for this constituent in the formulation. To do so, different friction components were studied. Additionally, other aspects relating to friction materials, such as the deterioration of the binder, were subject of investigation.
The novel formulations, produced starting from commercially available compositions, were ranked in terms of wear and friction behaviour by means of a pin-on-disc tribometer. Cylindrical specimens were produced directly from powders, so that constituents could be easily modified based on the test outcome. This is a very effective method to study the role of individual constituents in the mixture, considering the relatively small amount of each specific composition to be prepared and the ease of processing it. In order to identify the principal wear mechanisms and their dependence on material properties and test conditions, the worn materials were analysed via scanning electron microscopy (SEM) techniques and Energy Dispersive X-Ray Spectroscopy (EDXS).
Part of the acquired knowledge from the first part of the work was used in the initial stages of the ECOPADS project (the project started during the doctoral period) to develop and manufacture real brake pads that were tested on brake dynamometers and evaluated in terms of both performance and emissions.
13
Lindberg, Eskil. "Vehicle Disc Brake Roughness Noise : Experimental Study of the Interior Noise andVibro-Acoustic Modelling of Suspension Systems." Licentiate thesis, KTH, MWL Strukturakustik, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-39554.
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Prediction of vehicle disc brake roughness noise is a non-trivial challenge. In fact, neither the source mechanisms, nor the transfer paths are so far well understood. Traditionally, disc brake noise problems are studied as part of the friction-induced noise field, where the source is considered to be a more or less local phenomenon related to the brake disc and brake pad. However, for the roughness noise of interest here this viewpoint is not adequate when attempting to solve the interior noise problem since the transfer of vibro-energy from the brake into the vehicle body is a crucial aspect and plays an important role in the understanding and solution to the problem. The vibroacoustic energy transfer associated with the brake roughness noise is a problem where geometrical complexity and material combinations, including rubber bushings, pose an intricate modelling problem. Additionally, system altering effects from moving parts and loadings are important, e.g. due to the steering or brake systems. In addition, the source mechanisms themselves must also be understood to be able to solve the problem. The current work constitutes a combined experimental and theoretical investigation, aiming at an increased understanding of the source, the transfer paths and how they are a affected by change in the operational state. The experimental study of the vehicle disc brake roughness noise, is based on measurements conducted in a laboratory using a complete passenger car. It is found that the interior noise is a structural-borne broadband noise event well correlated to vehicle speed and brake pressure. The results suggest that the friction source may be divided into vibrations created in the sliding direction and vibrations created normal to the contact plane, where the sliding direction levels appear to be proportional to brake pressure according to Coulomb’s friction law; the vibration level in the normal direction of the contact plane on the other hand has behaviour proportional to Hertz contact theory. The measurements also indicate that the brake force created carried by the suspension system when braking will also alter the vibro-acoustic response of the system. To facilitate the theoretical simulations, an approach for modelling of the suspension system is developed. The vibro-acoustic transfer path model developed is using a modal based on the Craig-Bampton method where a restriction on the coupling modes is suggested. The approach suggested uses undeformed coupling interfaces, to couple structures of fundamentally different stiffness such as may be the case in a vehicle suspension system where for instance rubber bushings are combined with steel linking arms. The approach show great potential inreducing computational cost compared to the classical Craig-Bampton method.<br>QC 20110913
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Lindberg, Eskil. "A Vibro-Acoustic Study of Vehicle Suspension Systems : Experimental and Mathematical Component Approaches." Doctoral thesis, KTH, MWL Strukturakustik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-121575.
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The objective of the present work is to study the vehicle suspension as a vibro-acoustic system of high complexity, consisting of many sub-systems with fundamentally different acoustical properties. In a parallel numerical and experimental modelling effort, important contributions to the understanding of its behaviour have been achieved. These findings are based on a balance between component investigations and global modelling of the complete system; they have been formulated for the transmission of both tyre-road excitation and friction-induced vibrations in the brake system. Initially an experimental study was conducted on a full vehicle test rig studying the broadband interior brake noise problem of, here named, roughness noise. The purpose of the study was twofold: first, to determine if the transmission from the source to the interior of the vehicle was structure-borne; second, to study the complexity of the suspension as a vibro-acoustic system. Parameters a_ecting the vibro-acoustic source were varied to gain understanding of the source mechanisms. This experimental study laid the foundation of the first part of this thesis (paper A) and provided the directions for the second part, the development of a mathematical modelling approach (paper B and C). In these two papers, methods for analysing the complex vibro-acoustic transfer of structure-borne sound in a vehicle suspension system were developed. The last part was then focussed on the wheel rim influence on the vibro-acoustic behaviour (paper D) of the suspension system. As a whole, the work clearly demonstrates that it is possible to conduct component studies of subsystems in the vehicle suspension system; and from these component studies it is possible draw conclusions that very well may avoid severe degradations in the interior noise of future vehicle generations.<br><p>QC 20130503</p>
15
Dunn, Ashley L. "Jackknife stability of articulated tractor semitrailer vehicles with high-output brakes and jackknife detection on low coefficient surfaces." The Ohio State University, 2003. http://rave.ohiolink.edu/etdc/view?acc_num=osu1061328963.
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Mao, Yen-Chieh, and 毛彥傑. "Research on the Hydraulic Disc Brake System for Bicycles." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/89093950661205120314.
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博士<br>國立交通大學<br>機械工程系<br>92<br>A common problem on a current bicycle hydraulic disc brake system is that the unwanted friction may occur during free running if the lining pad does not depart away from the disc rotor. This friction may induce vibration, noise, power consumption, higher operating temperature and the braking force reduction. Another problem is that the improper braking force by the rider may induce slippage between the tire and road surfaces in the circumstances of inferior road surface conditions. This slippage may lead to chassis spin, yaw and increase the stopping distance. Aimed at these problems, this study collects relevant literatures, theoretically acquaints their operating principles and inducts possible research directions. By utilizing these remarks, this study proposes two solutions for brake systems by utilizing the methodology of creative design. The first solution is a caliper piston retractor that focuses on the lining pad departure from the disc rotor, reducing the drag force during non-braking mode. The second solution is a hydraulic pressure regulator that can modulate the pressure in the caliper, preventing the excessive pressure in the master cylinder applied by the rider from entering the caliper. This regulation can result in a reduced possibility of tire slippage on the road surface and intensify the effectiveness of stopping the vehicle if cooperating with a suitable control algorithm. The design, manufacturing and assembly processes of a bicycle brake system test rig are accomplished in another phase of this study to examine these apparatus performances.
The retracting stroke of the piston retractor is achieved and pre-definable for designers or manufacturers by modifying the design parameters in the evaluative production stage. Therefore, designers can provide users a maintenance-free usage of this product after the product marketing stage. This stroke adjustment characteristic helps users to reduce the possibility of brake performance variations when inferior tuning. The pressure regulator can reduce the hydraulic pressure in the caliper via a solenoid-controlled fluid passage. Compared with current automobile or motorcycle hydraulic pressure regulators, the proposed design provides lower operating frequency, yet it is small in size, economical in electric power consumption and light in weight. This regulator can be equipped on a lightweight motorcycle or bicycle with proper control algorithms. Finally, the proposed brake system test rig is verified with experiment results. The test rig is also utilized to examine the performances of the piston retractor and the hydraulic pressure regulator. Their experiment results show that the new designs can solve the problems and achieve their aims, respectively, on the bicycles for the hydraulic disc brake system.
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Tai, Shih-Wen, and 戴士文. "Thermal Analysis of Vented Rotors in Automotive Disc-Brake System." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/02974284561377052116.
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碩士<br>國立高雄應用科技大學<br>模具工程系<br>98<br>Ventilated rotors are used in most automotive disc brake. More cooling surface area is achieved by the setup of vanes. Several different designs of the internally vented rotors have been invented to enhance the pumping action for airflow so as to increase the heat convective coefficient. In this study, we intended to analyze the effect of the vents through temperature evolution and heat transfer in the vented disks. A model on the basis of COMSOL multiphysics was proposed for simulation, with the aid of MATLAB coding. In order to treat the dynamic thermal contact problem occurred at the contact surface of the disk and pad, an ALE mode is added to the convection and conduction heat transfer mode in COMSOL.
At any instant of time, heat generation due to frictional sliding at the contact surface is distributed to the disk and pad. According to Limpert's formula, the percentage of heat absorbed by the disk is approximately 82% to 88% of the total heat, depending on the thermal properties of the disk and pad. The results obtained from COMSOL model reveal a larger proportion for disc, about 95% to 97%. A simplified model is thus created, with a specified ratio of heat input to the disk, only heat transfer in the disk is considered. In the present work four kinds of disks were investigated, including a solid disk, a straight radial vane rotor, a sloped vane rotor, and a rotor with diamond and teardrop pillars. There are two brake conditions to be investigated: they are emergency-stop braking and constant-load braking. It is found that the maximum temperature of vanes rotors is much less than that of a solid disk in constant-load braking process. On the other hand, no obvious differences were observed for different types of vanes.
Keywords: disk brake, ventilated rotor, heat transfer for frictional sliding, COMSOL, ALE
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Qiu, L., Hong Sheng Qi, and Alastair S. Wood. "A new paradigm for disc-pad interface models in friction brake system." 2014. http://hdl.handle.net/10454/7921.
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In this paper a 2D coupled thermal-stress finite element model is established and used to predict thermal phenomena at the disc-pad interface of a disc brake system. The importance of certain critical settings and parameters for the 2D FE model has been identified (such as, a limited degree of freedom for a brake pad in place of accepted practice that considers uniform contact), here a non-uniform pressure distribution resulting from friction bending moment effects due to the introduction of a pivot point. These parameters affect the distributions of both interface temperature and pressure. The simulation results show that when the interface conductance h is 10^6 W/m^2K or higher, the interface temperature distribution is no longer sensitive to friction bending moment effects. However, when h is 30000 W/m^2K or lower, the interface temperature distribution and heat partition ratio are significantly affected by the setting used for the rotational degree of freedom of the pad. The simulation results provide a useful reference for a better design of a disc brake system for different applications.
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Hsiao, Jui-yuan, and 蕭瑞源. "The Study of Disc Thermal Effect to Active Control in Vehicle Brake System." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/44215032023151182146.
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碩士<br>中華大學<br>機械工程學系<br>105<br>The emergence of vehicle brings the world of science and technology change. Because the changing speed of vehicle, shortening the distance between the two places reduce the time, money and distance in certain situation. Nevertheless, derived from the problems caused by the traffic accidents such as physical disability, trauma, limb function to the people. Therefore, the evolutions of vehicle protection designs, knowledge and awareness are provided. The vehicle is equipped with a suspension, brake system, steering system, which the most important subsystem is braking system.
When the vehicle is traveling under repeated brake actions, the brake disc might overheated and the brake oil temperature is too high due to the brake action caused by friction. These phenomenal may cause in a failure of the braking system rendering a traffic accident.
This article investigated a device to reduce the temperature of brake disc and brake oil. In order to improve the braking system, when the vehicle is traveling at a high speed, so that the "brake system fan is used for heat dissipation" is performed. The system design fixed cooling hood and the installation of the cooling device without the installation of the brake system. A static and dynamic test analysis were performed and found that when the brake oil temperature reaches to higher temperature. The Arduino controller was designed to start the fan resulting in heat dissipation. The test results of the three points temperature change, after 1, 2, 3, 4, 5 minutes respectively were presented. It was shown that a fixed cooling hood of the brake system temperature drops of about 8 to 10 %. It is speculated that the system can solve the problem of the rising temperature of the braking system of the traveling vehicle, and then reduce the traffic accident and realize the benefit of the public.
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Sarip, S. Bin, Andrew J. Day, Peter Olley, and Hong Sheng Qi. "Analysis of the transient thermomechanical behaviour of a lightweight brake disc for a regenerative braking system." 2013. http://hdl.handle.net/10454/9721.
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no<br>Regenerative braking would extend the working range of an EV or HV provided that any extra energy consumption from increased vehicle mass and system losses did not outweigh the saving from energy recuperation, also reduce duty levels on the brakes themselves, giving advantages including extended brake rotor and friction material life, but more importantly reduced brake mass, minimise brake pad wear. The objective of this research is to define thermal performance on lightweight disc brake models. Thermal performance was a key factor which was studied using the 3D model in FEA simulations. Ultimately a design method for lightweight brakes suitable for use on any car-sized hybrid vehicle was used from previous analysis. The design requirement, including reducing the thickness, would affect the temperature distribution and increase stress at the critical area. Based on the relationship obtained between rotor weight, thickness, undercut effect and offset between hat and friction ring, criteria have been established for designing lightweight brake discs in a vehicle with regenerative braking.
21
Chen, Yu-Hsuan, and 陳雨軒. "Reliability Study of Motorcycle Disk-Brake Systems." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/19436915714675045547.
Full textAbstract:
碩士<br>國立臺灣大學<br>機械工程學研究所<br>100<br>The scooter has many advantages such as easy to ride, low cost and can be operated under various traffic conditions. It is not only a major product for the motorcycle manufacturers but also a useful transportation tool for people living in densely populated countries such as Taiwan. How to improve a scooter’s quality and performance and lower its cost has been a challengeable task for scooter manufactures. The purpose of the present thesis is to carry out a reliability study of the scooter’s disk-brake system that is considered one of the key components of a scooter. In the study, failure mode effect analysis (FMEA) is first used to identify possible failure modes of the disk-brake system and its subsystems. Their effects on the disk brake system are evaluated as well. Aside from the qualitative evaluation, a quantitative analysis is also performed to appropriately allocate the components’ failure rates while maintaining the required manufacturing cost and system reliability. Since wear of the brake-pad is firstly identified to be the most serious problem of the disk-brake system, five types of brake-pad made of different percentages of borosilicate glass matrix, SiC fiber and C fiber are chosen to be studied in detail. Reliability tests are carried out for these brake-pads and the cost of brake-pads is also considered. It is found that brake-pad made of 50% of borosilicate glass matrix and 50% of fiber is the best choice among all. It is also found and recommended that, for this type of brake-pads, it had better be replaced with a new one every 21,900 km to guarantee a 99%-reliability and insure the riders’ safety.
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Hung, Chia-Hung, and 洪嘉鴻. "Reliability Study of Vehicle Disk Brake Systems." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/70517245940498264285.
Full textAbstract:
碩士<br>國立臺灣大學<br>機械工程學研究所<br>96<br>Brake is considered one of the most important systems related to the safety of a vehicle. How to provide strong and stable deceleration by brakes has long been a major design concern for engineers. In general, brake parts face various aging problems after a long period of operation. It definitely affects the safety of a vehicle. The purpose of the present thesis is to carry out a reliability study of disk brake systems used in vehicles. First, failure mode and effect analysis (FMEA) is carried out to find possible failure modes of components of a brake system, and to identify the key component that is most vulnerable to failure. Tribology theory is then used to construct a life prediction model of the key component. The life of the brake system can be evaluated accordingly. Afterwards, a probabilistic assessment model is proposed to estimate the reliability and failure rate of the key component. Finally, ARINC method is adopted to allocate component failure rates of the brake system. Through the study, it is found that sliding wear of the brake pad is the most serious problem of a disk brake system. The cup and seal are other components that have to be watched carefully. The thesis also illustrasted that, under reasonable assumptions, the expected life, reliability and failure rate of the brake pad can all be predicted.
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Chen, Jyh-Haur, and 陳志豪. "The performance and Safety analysis of a disk-brake equipped with suspension systems." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/32840156506489886880.
Full textAbstract:
碩士<br>國立清華大學<br>動力機械工程學系<br>90<br>This thesis presents an investigation on the interaction between the characteristics of suspensions and disk-brake safety performance. The study limits the bicycle riding along a straight path. Therefore, a mathematical model for in-plane dynamic analysis of the bicycle equipped with suspension systems is first constructed.
The dynamic equations, which governing the linear and rotational motions of the front and rear tires, the rotations of the swing arm, rear suspension and frame, linear motion of the front suspension, are then developed based on Lagrange method. The braking performance and the vibrations of suspensions of a bicycle riding along continuously bumping road are also analyzed. The braking force mainly results from friction between tires and road. Larger braking force would make wheels lock-up to generate danger. An ideal braking performance curve is drawn based on the distribution of braking forces between front wheel and rear wheel. Riding comfort is effected upon the suspension parameters.
Experiments study the effects of braking performance on bicycle riding safety has been performed .An experimental platform is employed mainly for measuring the forces including braking force, lateral force, front-wheel and rear-wheel load. The braking distance could also be estimated in this experiment.