EuroBrake 2021 Technical Programme最新文献

{"title":"Investigation of Tribological Behavior and Airborne Emissions During the Bedding Stage","authors":"Ana Paula Gomes Nogueira, S. Candeo, G. Straffelini, M. Leonardi","doi":"10.46720/3069063eb2021-ebs-005","DOIUrl":"https://doi.org/10.46720/3069063eb2021-ebs-005","url":null,"abstract":"Tribological transitions are frequent when two new surfaces are placed in contact under load and sliding conditions. These transitions usually occur not only by the changes on the surface roughness, but also by the characteristics of the third body formed between the mating surfaces. The present work investigates the tribological behavior and the related airborne particles emissions of a Cu-free brake friction material during the initial stage of braking (bedding), starting from a virgin material. The tribo-tests have been conducted using a reduced-scale dynamometer, and the number distribution of the airborne particles was simultaneously measured by an Optical Particle Sizer (OPS). The tests were stopped with 25, 50, 100 and 130 brake events in order to analyze the surface of the friction material. Bedding showed two distinct stages regarding the friction and emissions behaviors. The first is characterized by a pronounced increase in both friction coefficient and particles emissions, achieving the highest value around 35 brake events. Successively, a smooth decrease is observed until reach the steady-stage of the friction coefficient. The friction layer formed on the surface of friction material seems to be correlated with the tribological and emissions results; in which the achievement of the state-state on the friction coefficient is coincident with the progressive compaction and area-increase of the secondary plateaus.","PeriodicalId":315146,"journal":{"name":"EuroBrake 2021 Technical Programme","volume":"11 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":"133063040","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 Squealing Noise on Nodic Trains Application in Sweden.","authors":"Denis Emorine","doi":"10.46720/1624539eb2021-ebs-011","DOIUrl":"https://doi.org/10.46720/1624539eb2021-ebs-011","url":null,"abstract":"All train manufacturers have one day experience squealing noise issue by braking in the stations. This noise could be high frequency or low frequency. It is in any case an issue when it’s disturbing noise (in the human ear frequency).This issue causes disturbance for the population leaving close to the railway stations and it’s taken seriously into consideration in the recent project: for instance, in Sweden. To avoid or reduce this noise, what are the possible levers for it? What are the effective influence of each levers on the noise? It’s always a fine compromise to find between wear (LCC), performance (thermal) and noise. Therefore, the presentation will target to provide actual answers on a real example experienced on Nordic trains in Sweden by ALSTOM Transport. It will show - the initial situation of each Swedish fleet and its chronology (wear, noise), - the corrective actions chosen within the project developments,- the issue encountered with the correctives actions, - the experimental researches to identify where come from the noise generation (18 different pad variants, different caliper fixations, SW action on the brake force…), - the analyze of the results with their weighting on interest/cost and beside requirements (wear/performance), - the final retained solutions, - Actual final accepted end solution.","PeriodicalId":315146,"journal":{"name":"EuroBrake 2021 Technical Programme","volume":"12 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":"114493084","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":"Nonlinear Dynamic Analysis of CRH5 Disc Brake System","authors":"Quan Wang, Zhiwei Wang, J. Mo","doi":"10.46720/2771993eb2021-fbr-005","DOIUrl":"https://doi.org/10.46720/2771993eb2021-fbr-005","url":null,"abstract":"Research and /or Engineering Questions/Objective: The disc friction brake which consumes the kinetic energy of the high-speed train through disc-pad friction is one of the important approaches to brake or decelerate the train as well as the safety and performance assurance. However, the friction between the brake pad and the disc may lead to the vibration of the brake components in the braking process. And when the friction-induced vibration of the disc brake system is transmitted through the suspension system to the bogie, it not only reduces the stability of the train operation and the ride comfort for the passengers, but also causes damage to the brake device and reduces the service life of such system. what’s worse, the vibration may provoke noise problems. Therefore, the mechanism of friction-induced vibration of the disc brake system and the method to eliminate the unstable vibration require in-depth research. Methodology: The experimental research, finite element method and numerical simulation are widely used in the analysis of the disc brake system and a great deal of meaningful research achievements have been obtained. In this article, to reflect the vibration response of the disc brake system more realistic in the braking process, a three-degree-of-freedom dynamic model of the disc brake system for the China Railways High-Speed train CRH5 is established by considering the effect of the wheel/rail adhesive characteristics and the number of brake units (the powered wheelsets installs two brake units and the non-powered wheelsets installs three on CRH5). Then, the model is applied to analysis the nonlinear dynamic response under different brake conditions to investigate the stability of the disc brake system using the numerical integration method. And diagrams of bifurcation, phase plane, Poincaré map and time domain response are used to discuss the vibration characteristics of the disc brake system in details. Innovation: The nonlinear friction between the brake disc and pad, and the nonlinear interactions between the wheel and rail are considered in this three-degree-of-freedom model. And it can be applied to investigate the effect of wheel/rail adhesive characteristics, parameters and the number of brake units on the disc brake system Results: Results show that with the increasing of the brake force, the brake pad occurs periodic motion and chaotic motion alternately, and the region of chaotic vibrations is growing while the region of periodic vibrations is decreasing. In addition, the stick-slip vibration of the brake pad and the torsional vibration between the brake disc and the wheelset are more complicated and violent with a larger brake force. It also shows that the chaos phenomenon of the disc brake system only occurs when the vehicle speed is less than the critical speed, and after that the system maintains stable periodic vibrations. Moreover, the results obtained with different number of brake units reveal that the chaotic reg","PeriodicalId":315146,"journal":{"name":"EuroBrake 2021 Technical Programme","volume":"9 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":"125262682","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":"\"Road Vehicles - Brake Linings Friction Materials - Visual Inspection\" - ISO DIS Upgrade","authors":"A. Jandl","doi":"10.46720/1418471eb2021-mfm-002","DOIUrl":"https://doi.org/10.46720/1418471eb2021-mfm-002","url":null,"abstract":"This project consists in converting the existing ISO PAS 22574 (Publicly Available Specification) into an ISO DIS Standard, the purpose of which is to define characteristic features for the visual inspection of friction materials in the unused state, used for disc and drum brakes of passenger cars (PC) and commercial vehicles (CV). Since this standard, as a visual inspection catalog, is intended to play an important role in applied quality management and in the formation of quality awareness among friction material manufacturers, system suppliers and vehicle manufacturers, special attention must be paid to the validation and compliance with the formalism of the contents of this standard.","PeriodicalId":315146,"journal":{"name":"EuroBrake 2021 Technical Programme","volume":"42 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":"116326227","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":"Influence of Pad Retraction and Air Gap Width between Brake Disc and Pad on PM10 Wear Emissions During Cruising Conditions","authors":"Hartmut Niemann, H. Winner, C. Asbach, H. Kaminski, G. Frentz","doi":"10.46720/3999227eb2021-ebs-004","DOIUrl":"https://doi.org/10.46720/3999227eb2021-ebs-004","url":null,"abstract":"According to estimations, brake wear particle emissions contribute with a share of up to 21 % to the traffic related PM10-emissions in urban environments. Depending on the brake system, a significant proportion of those emissions occurs under cruising conditions with released brake. During a WLTP exhaust cycle with two sliding calipers used in this study 16 % respectively 30 % of the total PM10-emissions occur during off-brake-phases. The influencing parameters and formation processes of those off-brake-emissions are subject of current research to evaluate potential reduction approaches. A residual brake torque due to a disc-pad contact in the off-brake-phases as well as an air flow in the air gap between disc and pad are discussed as potential causes for the generation of those emissions. In the current state of research it is neither known how off-brake-emissions can be influenced during operation of the brake nor how a potential off-brake-emission reduction would affect dust release during the brake events and emission factors for whole test cycles. An experimental setup for the independent adjustment of the air gap and retraction force on the brake pads is used to investigate the influence on PM10-emissions during WLTP cycle with two different sliding calipers. Therefore, the air gap is varied between 0.17 mm and 5 mm and PM10-emission factors are compared to the reference brake systems without pad retraction. The share of off-brake emissions to the overall PM10-emission factor during the off-brake-phase is reduced from 16 % respectively 30 % to 3 % during a WLTP cycle with pad retraction. Associated with this decrease during the off-brake phases, an increase of the emission during the on-brake-phases occurred with pad retraction. During the performed WLTP the pad retraction leads to a decrease of the PM10-emission factor by 4.5 % for the first sliding caliper, which was smaller than standard deviation and by 6.0 % for the second sliding caliper, which was slightly higher than the standard deviation of the emission factor. No significant variance of the PM10-emission factor between 0.17 mm and 5 mm air gap could be determined. Instead a binary behavior with and without retraction was observed. Based on literature and the observations in this study, two mechanisms remain as possible origin for the major share of brake wear emission during off-brake-phases. A residual torque combined with a reservoir behavior as well as an airflow through the air gap between disc and pad smaller than 0.17 mm could be the causal mechanisms for off-brake-emissions. A residual torque as a source for contious particle generations and centrifugal forces acting on adhesive particles on the disc were excluded due to findings gained in the pad retraction experiments respectively by the observations described in the state of research.","PeriodicalId":315146,"journal":{"name":"EuroBrake 2021 Technical Programme","volume":"44 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":"115558916","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":"Determination of the Influence of Metal Sulphides on the Tribofilm and the Friction Behavior","authors":"G. Macías, C. Lorenzana, Javier Fernández","doi":"10.46720/3291380eb2021-fbr-003","DOIUrl":"https://doi.org/10.46720/3291380eb2021-fbr-003","url":null,"abstract":"Metal sulphides are additives that are used in brake pad formulations because they help to stabilize the coefficient of friction, reduce wear and improve NVH. Previous rimsa studies have shown that the oxidation mechanism of metal sulphides is one of the key properties that explain their contribution to performance and wear. Depending on the metal sulphide, the oxidation mechanism is different and so is the tribochemistry. Hence, the transfer layer formed will strongly depend on the metal sulphide used. This work is focused on establishing a connection among the metal sulphide oxidation, the transfer layer formed and the performance. The friction behavior was determined through two tests, J2522 and J2707, using a NAO formula where only the metal sulphide was varied. While the transfer layer characterization was carried out through pad SEM-EDS cross-section analysis, after each test. The differences in thermal profile of J2522 and J2707 illustrate the correlation between performance and wear and different oxidation mechanisms depending on the metal sulphide used. SEM characterization of pad surface also shows that the transfer layer morphology varies depending on the metal sulphide used in the formulation. Hence, the results of this research indicate that the morphology of the transfer layer and the friction behaviour strongly depend on the oxidation mechanism of the metal sulphide.","PeriodicalId":315146,"journal":{"name":"EuroBrake 2021 Technical Programme","volume":"8 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":"117151061","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":"Alumina-coated Brake Discs with Intention for Reduced Non-exhaust Emission and Increased Ride Comfort of Electrical Vehicles","authors":"X. Nie, Ran Cai, Jingzeng Zhang, J. Tjong","doi":"10.46720/5555629eb2021-mds-002","DOIUrl":"https://doi.org/10.46720/5555629eb2021-mds-002","url":null,"abstract":"Regenerative brake, disc coatings or pad formulations with new tribology aim to avoid generating brake wear particulates on one hand. On the other hand, vacuum and filter systems aim to collect the particulate matter for disposal. This paper will briefly describe the non-exhaust emission (NEE) and corrosion issues of brake systems of electrical vehicles (EV). The methods reported for NEE reduction will then be concisely reviewed. A new cost-effective coating technology, called PEA (plasma electrolytic aluminating), will be particularly presented in this talk for fighting NEE where alumina-coatings are prepared on commercial cast iron brake discs. Brake dynamometer test results show the coatings can increase friction levels and reduce wear for both brake discs and pads. The coatings can greatly increase corrosion/rust resistance. A car test also shows that the coated discs can reduce the braking distance and make wheel rims much cleaner. The better driving comfort and modulation should result from more consistent friction forces and less stick-slip problems during each brake event, which is a very important performance factor for advanced driver assistance systems (ADAS) and autonomous driving systems of EV. It is expected that the coated discs may last as long as the lifespan of passenger cars. Therefore, the sapphire coatings would benefit the brake system in terms of better sustainability and environmental friendliness.","PeriodicalId":315146,"journal":{"name":"EuroBrake 2021 Technical Programme","volume":"88 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":"122693590","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":"Lifetime Protection of Iron Casted Brake Discs for Electric Vehicles through Advanced Heat Treatment Technology","authors":"Franco Arosio, Ingo Lange","doi":"10.46720/1978791eb2021-mds-006","DOIUrl":"https://doi.org/10.46720/1978791eb2021-mds-006","url":null,"abstract":"The rise of Electrical Vehicles (EVs) is unstoppable and EVs will become a key part of the mainstream automotive market. According to recent post-COVID-19 scenarios based on IHS data, EVs will surge up to 14% of global passenger car sales in 2027 and go up to 57% in 2040. The electrification of future mobility concepts is going along with new requirements also for the brake system. EVs with regenerative braking applications utilize the traditional friction brakes in fewer circumstances due to recuperation: therefore the risk of superficial corrosion increases. In case of an emergency brake situation the basic requirement is that the braking surface will be free of corrosion to have maximum brake power. Thus, the corrosion-free condition on the braking surface is a safety requirement at any time. The state of the art solution consists of paintings or “coatings”, such as ultraviolet (UV)-hardening paint, Zn or Zn/Al paints, which can perform well in new conditions (e.g. up to 120 hours in standard UNI ISO 9227 salt fog chamber). But these solutions will be easily abraded within approximately 20 standard-condition braking applications. The corrosion-free condition during the lifetime of the disc is not achieved yet in the current state of the art; rust or corrosion can seriously downgrade the braking performances. This paper is describing an innovative 2-step process to improve the corrosion and wear resistance of standard cast iron brake discs. In the first step, the amount of undesired graphite lamellae will be reduced from the surface with customized parameters, according to the individual types of grey cast iron material of the substrate. This pre-process is followed by a thermochemical diffusion process including controlled oxidation of the substrate resulting in high corrosion protection of the rotors. The authors will produce proof of corrosion resistance up to 300 hours in salt conditions according to UNI ISO 9277. In addition, bench tests and vehicle endurance tests have been performed in cooperation with Tier 1 and OEMs and have shown increased wear resistance even with non-electric cars and with standard ECE brake pads. The novel surface solution could be also applied to non-functional areas of the brake disc like cooling channels, bell and swan neck in order to substitute the current paintings. In summary, the new 2-step heat treatment process is a price competitive solution for corrosion protection of functional and non-functional areas of iron casted brake discs over the entire lifetime, especially on EVs with strong recuperation. But this solution also works for hybrid and conventional cars in preferably on the rear axis with low-abrasive brake pads (e.g. NAO pads). Finally, even when the vehicle fleet goes all-electric, dust emission from brakes and tyres will still pollute the environment. Addressing this topic, the authors will provide an outlook of the ongoing activities to reduce brake dust emissions with innovative surface solut","PeriodicalId":315146,"journal":{"name":"EuroBrake 2021 Technical Programme","volume":"24 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":"125955942","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}