EuroBrake 2021 Technical Programme最新文献

{"title":"METROFLEXX: a step towards a safer railways brake control","authors":"Fabio Ferrara, Astengo Federico, Matteo Frea","doi":"10.46720/9619251eb2021-ibc-007","DOIUrl":"https://doi.org/10.46720/9619251eb2021-ibc-007","url":null,"abstract":"This paper describes the achievements and benefits obtained using an electronic-based Brake Control unit, METROFLEXX, suitable to perform Emergency and Service brake function with the high Safety Integrity Level (SIL). METROFLEXX replaces the complete traditional electro-pneumatic brake system, by performing a real time emulation of functions that are traditionally performed by pneumatic components. Therefore, METROFLEXX has been developed comply with the following CENELEC safety standards that represent the state-of-art for the railway transit market at European and worldwide level: EN 50126 (system level), EN 50129 (electronics hardware), EN 50128 (software), EN 50159 (safety related communication). An Independent Safety Assessment (ISA) has been completed by receiving the assessment report and the corresponding attestation of conformity from a recognized ISA company. Thanks to the METROFLEXX, several benefits can be achieved at system and train level, such as improved service reliability, improved safety and a better Total Cost of Ownership (TCO).","PeriodicalId":315146,"journal":{"name":"EuroBrake 2021 Technical Programme","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125269048","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Relationship between Mechanical Behavior and Microstructure Evolution of Sintered Metallic Brake Pad under the Effect of Thermomechanical Stresses","authors":"Hoang Long Le Tran, Anne-Lise Cristol, V. Magnier, J. Hosdez","doi":"10.46720/4525694eb2021-fbr-009","DOIUrl":"https://doi.org/10.46720/4525694eb2021-fbr-009","url":null,"abstract":"Sintered metallic composite is widely used as brake pad material for high energy railway thanks for its good resistance to severe solicitations caused by braking loads. Despite its efficiency, the degradation of the material properties under the effect of brake loads has been noticed in literature which is undoubtedly induced by the microstructure evolution. However, the microstructure evolution and its relation with mechanical behavior have so far not been intensively investigated due to the complexity of braking solicitations. To solve the problem without tackling it in all its complexity, two experimental tests were proposed where physics are decoupled; but still inspired by the braking sequence in terms of applied temperature and compressive load. The first one is the thermal solicitation test where a temperature gradient from 400°C to 540°C was applied to the material. The second one is the thermomechanical test where a compressive load at 20 MPa was applied under the same thermal gradient. The experiment time is fixed for two minutes, equivalent to the time of one braking stroke. Besides, the local microstructure evolution of the sintered metallic brake pad was characterized by Electron Microscopy (SEM) coupling with Energy-dispersive X-ray Spectroscopy (EDS) and X-ray microtomography. The evolution of mechanical properties was characterized by a series of compressive tests equipped with a Digital Image Correlation (DIC) for analyzing deformation behavior. Based on the deformation behavior characteristics, the considered thermal and mechanical solicitations have no separate effect on the mechanical properties of the material. The sole evolution of mechanical behavior is due to the coupled thermomechanical solicitation, which increases the hardness of friction material. From the strain field analysis, the evolution takes place on the strain lines determined by the compressive test, which strongly depends on the distribution of graphite inclusions in the microstructure. The change in mechanical behavior is induced by the local microstructure evolution. Indeed, thermomechanical stresses cause the densification of the graphite in the normal direction, this structural change induce some shear cracks in the basal plane. In terms of the metallic matrix, the segregation of carbon in steel is investigated as a reason for the increased stiffness.","PeriodicalId":315146,"journal":{"name":"EuroBrake 2021 Technical Programme","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131905354","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Simulation of Big Data from Railway Braking","authors":"Simon Westfechtel, Ingo Elsen, R. Pfaff, Marcel Remmy","doi":"10.46720/8277610eb2021-ibc-003","DOIUrl":"https://doi.org/10.46720/8277610eb2021-ibc-003","url":null,"abstract":"Condition Monitoring (CM) offers opportunities for improvement of safety, availability while typically also reducing maintenance cost. For some asset classes however, large up-front investments are required. Most notably, for the wagon subsystem of the freight rail system, a close monitoring of brake performance using on-board sensors for monitoring of the brake hardware using e.g. force sensor appears expensive and economically not viable. The approach outlined in this paper picks up on the approach of the author's contribution to Eurobrake 2019, where a big data approach merely based on accelerometer measurements was proposed. This yields the advantage of reducing hardware cost, both initial investment as well as maintenance cost, since accelerometers are everday electronic components which typically show a large lifespan with little degradation. This reduction in hardware cost needs to be compensated by more elaborate computational approaches, since it is based on the contribution of each individual wagon's brake to the braking performance of the entire train consist. By help of randomised mixture of the wagons during train formation, such an approach may be used to detect degradations of individual wagon brakes. Since such an approach relies on multiple train operations, it is obviously not suited for the replacement of the classical operator based pre-departure check. It may however increase safety and availability on an individual wagon basis due to the ability to observe degradation prior to becoming a functional limitation to be handled during a pre-departure check. Furthermore, it is well suited to supplement novel forms of brake assessments, such as automated brake tests or automated visual inspections and thus provide a higher level of safety and availability at reduced overall cost. The paper features a brief recap of the proposed method, integrated into the Wagon4.0 concept, which is one potential hardware and software basis as well as a review of big data approaches. The development of a simulation environment suitable for the generation of big data sets based on a headless MATLAB/Simulink setup on a cluster architecture is described. The model features an approximation of the pneumatic behaviour of the brake pipe, a simplified wheel-rail contact model, varying brake block friction as well as a parameter based model of a distributor valve for each simulated wagon. Thanks to the hardware and software setup, the simulation environment is able to generate braking data in the range of multiple Terabytes, which can then be analysed using big data approaches. Wagon parameters are sourced from a partly randomised digital wagon pool, which can be sent on virtual mission while observing their braking behaviour. The paper finishes with a preview of the intended analysis, which is currently being implemented on the FH Aachen cluster.","PeriodicalId":315146,"journal":{"name":"EuroBrake 2021 Technical Programme","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123361509","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Brake Actuation and Foundation Trends Driven by Electrification and Autonomous Driving","authors":"Patricio Barbale","doi":"10.46720/3756629eb2021-ibc-008","DOIUrl":"https://doi.org/10.46720/3756629eb2021-ibc-008","url":null,"abstract":"My presentation will show the future trends in the automotive sector with a particular focus on brake system. I will show the future solutions and penetration in the market for brake actuation systems (electro-hydraulic and electro-mechanical) and brake foundation, like disc vs drum penetration or electric parking brakes rates in the future scenario. All these technologies are linked with the radical changes we are experiencing today and mostly we will experience in the near future: electrification and autonomous driving.","PeriodicalId":315146,"journal":{"name":"EuroBrake 2021 Technical Programme","volume":"308 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124961069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Effects of Structural Stiffness in Vibration Transmission Paths on Friction-Induced Vibration","authors":"Qiang Liu, J. Mo, Zaiyu Xiang, A. Wang, Wei Chen, Honghua Qian","doi":"10.46720/3128189eb2021-fbr-004","DOIUrl":"https://doi.org/10.46720/3128189eb2021-fbr-004","url":null,"abstract":"Research and /or Engineering Questions/Objective: Friction-induced vibration is a common phenomenon on the frictional contact interface between two solids in relative motion, which can be observed in many mechanical applications, especially for the brake system. The friction-induced vibration originated from the friction interface can transmit through the rigid connection structure of mechanical system and forms a vibration transmission path. The vibration transmission path, mainly reflected by the natural frequency and the damping ratio, influences the friction-induced vibration of system, even under the same friction interface. However, there is limited report on the friction-induced vibration of mechanical system under different vibration transmission paths. Therefore, the effect of structural stiffness in vibration transmission path on friction-induced vibration is investigated and discussed. Methodology: The friction tests are carried out on a small-scale tribometer, which achieves a frictional contact between the balls and disc samples. The structural stiffness of vibration transmission paths is reflected by different fixtures of samples, whose dynamic characteristics are tested by the hammer method. In addition, a detailed three-dimensional finite element model based on different structural stiffness in vibration transmission paths is established to simulate the experimental process. At last, a four-degree-of-freedom friction-induced vibration model, including the interaction between the structure characteristics and the friction interface, is established to investigate the influence of the vibration transmission paths on the system stability. Results: The instability of the friction system decreases with the increasing structural stiffness in vibration transmission path. However, when the structural stiffness exceeds the critical value, the instability of friction system is excited again, accompanied by severe friction-induced vibration and high frequency squeal noise. Similarly, the wear morphology is also influenced by vibration transmission paths. The higher structural stiffness is, the better tribological behavior of the contact interface is displayed. Once the critical stiffness is exceeded, more complicated tribological behavior of the contact interface is shown. Limitations of this study: Applying the findings to practice system is still under studied since a real friction system is much more complex comparing to the customized small-scale tribometer.What does the paper offer that is new in the field in comparison to other works of the author: The effect of structural stiffness in vibration transmission path on friction-induced vibration is investigated. The conclusions obtained by experimentally and numerically are beneficial for understanding the effect of structural stiffness in vibration transmission path on stability, vibration response and tribological behavior of the friction system. Conclusion: The results show that the sta","PeriodicalId":315146,"journal":{"name":"EuroBrake 2021 Technical Programme","volume":"130 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122762697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Comparison between Stationary and Dynamic Wear Tests of Brake Pads","authors":"Jacek Kijanski, G. Ostermeyer","doi":"10.46720/3964237eb2021-fbr-001","DOIUrl":"https://doi.org/10.46720/3964237eb2021-fbr-001","url":null,"abstract":"Investigations of wear and wear dust behavior of brake systems are increasingly becoming the focus of research activities in science and industry. Environmental protection as well as health and economic aspects play a driving role in this context. In contrast to these important issues, the wear behavior of brake pads is still poorly understood. Due to the different material compositions of brake pads, it is also very difficult to gain universally valid insights, even when testing under stationary conditions. In previous publications, it was already identified that the friction history or a dynamic load collective can lead to different wear rates despite the same idle work. This was demonstrated by means of a multitude of real driving profiles and decreasing velocity profile measurements using the Automated Universal Tribotester at the Institute of Dynamics and Vibrations. The results of the investigations accordingly raised new questions, which will be addressed here. In addition, the knowledge gained here should serve as a metrological basis for the mathematical description of wear processes in the boundary layer of brake systems in the future. For this purpose, tests are carried out on the AUT with further load profiles on different brake pads. The results of these systematically performed measurements allow a step-by-step comparison of the wear results and friction coefficients as well as the surface topographies. This, in turn, makes it possible to establish a link between the results of the previously performed stationary wear procedures and real driving profile measurements, which leads to a better understanding of the wear behavior of brake pads and its influencing factors.","PeriodicalId":315146,"journal":{"name":"EuroBrake 2021 Technical Programme","volume":"100 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127172462","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Requirements and Test Cycles for Brake Systems of Autonomous Vehicle Concepts on the Example of an Autonomous Shuttle","authors":"H. Winner, Jens Hoffmann, S. Pla","doi":"10.46720/eb2021-ibc-006","DOIUrl":"https://doi.org/10.46720/eb2021-ibc-006","url":null,"abstract":"uring the development toward autonomous and electrified vehicles with low emissions, many visions for future mobility concepts arise, one of them being autonomous shuttles for urban areas. Most publications concerning these concepts focus on control and software while in this paper the change of requirements for wheel brakes is examined. The performance of wheel brakes for todays passenger cars is currently tested under different worst-case assumptions regarding area of operation and highest possible load resulting from human operation. Considering the capabilities of autonomous shuttles like autonomous driving and the availability of regenerative braking, these assumptions need to be reevaluated. This also includes comfort and lifetime requirements regarding wheel brakes for these concepts and takes in perspective that for an autonomous shuttle a certain area of operation is defined in their operational design domain (ODD) as well as a lower maximum velocity. To do so, different autonomous shuttle concepts are aggregated as well as their respective hardware and tech specs. To gather system requirements for the braking system of an autonomous shuttle a stakeholder analysis is performed, highlighting the underlying business model, driving tasks and passenger types as well as their needs and wishes. The shift in requirements is derived in comparison to conventional wheel brakes for cars. Usual performance tests for conventional wheel brakes for passenger cars are semantically analyzed to discuss their relevance and transferred into new performance tests for the given vehicle class. Three test scenarios are created, the first one being the “Emergency Braking Test”, which consists of two consecutive emergency brakings. Secondly a “Standard Operation Test” which consists of ten consecutive, comfortable accelerations and decelerations for passenger pickup and transport. Lastly, a “Hill Descent Test” on a long descent in the area of operation of the shuttle, like in the demanding urban topology of San Francisco. Based on the scenarios different availability levels of regenerative braking power are considered. Based on the developed test cycles a comparison is drawn for power and energy dissipation demand and the corresponding torques needed for an example vehicle under various levels of available regenerative braking power. While power and energy dissipation have decreased heavily, the torque demand is still as high as needed for a conventional vehicle. The changed requirements open up new possibilities for suitable braking concepts for autonomous shuttles. This may also reduce brake emissions depending on the chosen concepts.","PeriodicalId":315146,"journal":{"name":"EuroBrake 2021 Technical Programme","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116550077","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Topology Optimisation of an Automotive Disc Brake Rotor to Improve Thermal Performance and Minimise Weight.","authors":"Ahmed Oshinibosi, D. Barton, P. Brooks, C. Gilkeson","doi":"10.46720/4177245eb2021-ebs-002","DOIUrl":"https://doi.org/10.46720/4177245eb2021-ebs-002","url":null,"abstract":"Weight reduction has become a major topic in the automotive industry due to the environmental impacts of carbon emissions. When considering the thermal performance of disc brake rotors, it is increasingly important to optimise their design in a weight-efficient manner. With the advent of electric vehicles, which are heavy due to battery requirements, there is even more impetus to reduce total vehicle mass which can extend driving range. Furthermore, the brake disc constitutes part of the vehicle’s unsprung mass, so minimising brake rotor weight helps to improve ride comfort and reduce damage to the road surface. Considering thermal performance, the temperature rise produced by friction at the sliding interface leads to thermo-elastic deformation within the disc. Consequently, this can change the distribution of contact pressure and cause thermal localisation such as hot-banding and hot-spotting. The phenomenon is called thermo-elastic instability, and if severe, this can cause judder, as well as decrease the fatigue life of the disc. This paper introduces topology optimisation in the development of a ventilated brake disc used on a high performance passenger vehicle with the aim of improving thermal performance, while minimising mass. A baseline ground structure is formulated to enable new conceptual vane geometries for both improved thermal performance and lower disc mass to be derived. This approach allows novel disc designs not previously considered to evolve. Although possibly more difficult to manufacture than the conventional disc, the potential performance benefits of this more radical optimisation strategy are clearly demonstrated. Furthermore, CFD analysis is utilised to predict the air flow through the conceptual vane designs produced from the topology optimisation process. This allows for estimation of convective heat transfer coefficient for the novel design concepts and enables detailed flow patterns within the vane geometries to be predicted.","PeriodicalId":315146,"journal":{"name":"EuroBrake 2021 Technical Programme","volume":"266 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124324211","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Railway Brake System in Nordic Countried Application in Sweden's Challenges and Constrains","authors":"Denis Emorine","doi":"10.46720/7529563eb2021-mfm-003","DOIUrl":"https://doi.org/10.46720/7529563eb2021-mfm-003","url":null,"abstract":"Manufacturing train fleets for countries that have extreme weather/climatic condition is always a specific challenge, moreover when the concerned country has a huge difference itself inside. Even under such specific constraints and conditions, the train and in particular the brake system must remain reliable and available. Some simple examples: How can we (car builders) make sure that the train will still brake if ice or snow is built up on brake acting component? Or if the exhaust of brake pipe (emergency brake) is clogged by ice? If a train has failure between 2 far station (>250 km), it shall be able to run to reach the next (far) station. The presentation aims to: Present the fleet running locations, numbers and route distances, Present the requirements depending on the location (south vs north vs center Sweden), weather conditions (snowy, extremely cold)…, Overview of the specific solutions and features present to fit to the constrains: redundant AGTU for specific region, specific retardation test from brake and signaling system. We will present the real effect by examples of the snowy, extremely cold, humid climatic conditions: Pictures of a train with bogie completely hidden behind snow, Video of iced caliper moving by braking the ice (test bench) This will be just quick go through, since we plan a dedicated presentation for the winterization separately for the session in 2020. We will also present the specific feature of the brake and signaling system for Sweden: Retardation test. What is the aim? What is the historical development of it? How does it work? What are the attention compared to a performance test? What are the special solutions used for adapting the retardation test from UIC to a direct brake system?","PeriodicalId":315146,"journal":{"name":"EuroBrake 2021 Technical Programme","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127230546","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Particles Emissions and Understanding the Braking Tribological Circuit","authors":"Edouard David, Laurent Coustenoble, Y. Desplanques, A. Beaurain","doi":"10.46720/3966918eb2021-fbr-008","DOIUrl":"https://doi.org/10.46720/3966918eb2021-fbr-008","url":null,"abstract":"Particles detached from the first bodies (disc and pad) travel in the braking system by forming a tribological circuit. As the flows of particles in this circuit interact with the friction and wear mechanisms at the braking interface, their comprehension is crucial to better understand how the braking system behaves. Currently, identifying and quantifying those flows constitutes a scientific and technical challenge. The wear flow in particular, is made of the particles that permanently leave the system. Most of this wear goes airborne and disseminates quickly in the atmosphere.Many techniques measuring the brake particles emissions focus mainly on the resulting air quality, or on health hazard, and collect the particles far from the contact. These techniques, although very informative, do not enable to establish a clear link between the measurements and a wear flow. We thus designed a setup able to trace the quick evolutions of emissions during and after braking, while allowing to compare the relative quantities of particles between different configurations, for the range of 5 to 10000nm. Emissions showed a clear temporal signature, with in some cases, a strong release at contact opening. As expected, configurations causing severe wear mechanisms such as adhesive wear caused a much larger emissions than configurations featuring more conventional oxidation based mechanisms. The effects of other parameters, such as contact vibrations could also be witnessed.","PeriodicalId":315146,"journal":{"name":"EuroBrake 2021 Technical Programme","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126239678","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}