共查询到20条相似文献,搜索用时 31 毫秒
1.
建立了产生制动尖叫的钳盘式制动器各主要零件的有限元模型,并通过集成构建了制动器总成的接触摩擦耦合有限元模型,计算了制动器振动系统的复特征值分布和模态,分析了可能产生制动尖叫的不稳定模态,并与制动噪声台架试验统计结果进行了对比,结果表明所建模型能够较好地预测出制动器发生制动尖叫的倾向;分析了各零件的振动模态对产生制动尖叫不稳定模态的贡献大小,揭示出有尖叫倾向的不稳定模态是由子结构未耦合时的多阶振动模态叠加而成;分析讨论了摩擦因数、摩擦片结构及其背板阻尼对制动尖叫的影响,为控制制动尖叫提供了途径。 相似文献
2.
M. S. Xie G. R. Zhang J. H. Li R. Fritsch 《International Journal of Automotive Technology》2014,15(4):565-571
Automotive brake systems today have many factors that can contribute to brake noise. Modern approaches to reduce the propensity of brake noise mostly target high frequency brake squeal. A more difficult constituent of brake noise to address is low frequency moan, which is typically caused when the brake system excites a suspension member with a constrained natural frequency in the range of excitation. Although most modern CAE techniques utilized to diagnose and solve brake noise issues focus on new brake pad condition, this paper will show the benefit of understanding a common wear mechanism “Taper Wear,?and attempt to correlate its effects on brake moan. In order to study this phenomenon, a finite element model of a disc brake is established, and a complex eigenvalue analysis (CEA) of the brake system is performed. The propensity of brake moan noise is evaluated on basis of damping ratio of a dynamic brake system model. By using the finite element model, effects of the brake pad taper wear on brake moan noise is studied. The results show that the brake pad taper wear is a significant factor for generating the instability causing the brake moan noise. The study is performed at various levels of brake pad taper wear. When the brake pad taper wear is more than 0.5 mm, the value of negative damping ratio rapidly increases, and the propensity of brake moan noise is greatly magnified. In this study, the simulation result correlated well with the test result, which provides the theory and guidance for brake moan noise control. 相似文献
3.
Analysis of disc brake instability due to friction-induced vibration using a distributed parameter model 总被引:1,自引:0,他引:1
Y. -G. Joe B. -G. Cha H. -J. Sim H. -J. Lee J. -E. Oh 《International Journal of Automotive Technology》2008,9(2):161-171
This paper deals with friction-induced vibration of a disc brake system with a constant friction coefficient. A linear, lumped,
and distributed parameter model to represent the floating caliper disc brake system is proposed. The complex eigenvalues are
used to investigate the dynamic stability, and, in order to verify simulations which are based on the theoretical model, an
experimental modal test and dynamometer test are performed. The comparison of experimental and theoretical results shows good
agreement, and the analysis indicates that modal coupling due to friction forces is responsible for disc brake squeal. Also,
squeal type instability is investigated, using a parametric analysis. This indicates which parameters have influence on the
propensity of brake squealing. This is helpful for validating the analysis model and establishing confidence in the experimental
results of the modified system. These results may also be useful during system development or diagnostic analysis. 相似文献
4.
Hot judder simulation of a ventilated disc and design of an improved disc using sensitivity analysis
J. H. Park T. W. Park J. H. Lee M. H. Cho 《International Journal of Automotive Technology》2014,15(1):1-6
In a disc brake system, thermal expansion of the material is caused by friction energy that is generated by the sliding contact between a disc and pad during braking. This phenomenon, thermo-elastic instability, can lead to hot spots on the disc surface and a hot judder phenomenon. Transient finite element analysis has been used to simulate this phenomenon. Three dimensional finite element models of a disc, pad, and cylinder were created. Each part was connected by a joint. Contact condition was applied to the disc and pad with a friction coefficient (μ) of 0.4. A convective heat transfer coefficient was set as 40 W/m2K. Using a commercial program SAMCEF, the simulation of the thermo-mechanically coupled system was performed. In order to find the sensitive parameters of brake judder, sensitivity analysis was carried out with consideration for disc design parameters. As a result, the hot spot phenomenon was confirmed and hot judder was predicted. Moreover, the more sensitive parameters of the hot judder phenomenon were presented. Finally, an improved disc model and an analysis technique were verified by comparison to dynamo test results. 相似文献
5.
对某型轿车盘式制动器进行了台架试验,发现该制动器主要制动噪声频率在3kHz附近。采用有限元FEA分析手段对制动盘、制动钳壳体、制动钳支架和摩擦片进行了振动特性分析。结果表明,制动钳支架的7阶振动模态是导致制动噪声产生的原因之一。对制动钳支架结构设计进行了改进,并对装有改进后制动钳支架的盘式制动器进行了台架试验。结果表明,制动器冷态制动噪声从100.5 dB下降为73.4 dB,达到了该车型对制动器噪声的限值要求。 相似文献
6.
Taeksu Jung Yunhwa Hong Sungsu Park Cheongmin Kim Younghoon Hong Chongdu Cho 《International Journal of Automotive Technology》2018,19(2):281-289
Automotive brake noise has become a stubborn problem as automotive cars achieve higher driving torques, since that the increased torque induces the generation of severe noise dissipation during brake operation. Moreover, the global brake tuning market for achieving higher performance of the vehicle has expanded recently. The need to control the noise grows more in this connection. The tuning brake kits have employed cross-drilled and slotted machining pattern on the surface of the rotor. These designs have advantages to improve air ventilation, temperature control, and surface cleaning of brake pad. However, the effects of modal frequency by patterned rotor surfaces are rarely discussed, even if it is highly related with brake squeal phenomenon. Therefore, this study deals with the relationship between patterned surfaces and brake squeal through the numerical methods. The commercial software of a finite element analysis is employed for calculation by varying geometric design factors of each rotor pattern. As a result, the cross-drilled machining patterns are concluded to be an influential factor for in-plane mode frequency while the slotted patterns have more leverage for out-of-plane mode frequency. 相似文献
7.
盘式制动器制动尖叫的研究 总被引:3,自引:1,他引:3
制动尖叫是由摩擦耦合诱发和顺各部件的模态参数匹配不当引起的系统不稳定现象,针对一个有尖叫倾向的实际样车,通过有限元方法提取制动器各部件的模态参数,以制动器的每个部件作为一个子结构,应用自由界面法进行模态综合,得到了与实际尖叫情形相符的耦合模型;应用耦合模型,通过分析子结构模态与耦合系统不稳定模态的关系,这量地得到了各子结构模态对制尖叫的影响大小,从而得到了决定尖叫产生与不否的关键因素-支架的第11 相似文献
8.
《JSAE Review》2001,22(1):57-62
As automobiles become quieter, the noise of wiper blade rubber in motion may become a problem for passengers. To resolve this noise, especially the squeal noise, we constructed an equation of motion for the wiper blade vibration by observation and FEM stress analysis. Based on the derived equation, we discovered several important design and material items which can be utilized to reduce squeal noise. 相似文献
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10.
Y. -G. Kim S. -W. Kim C. -K. Park T. -W. Park Y. -M. Kim 《International Journal of Automotive Technology》2011,12(1):51-58
It is necessary to guarantee the proper brake force to stop a train safely in a limited distance and o adjust its speed. Currently,
most trains are run by electrical power and have a combined electrical and mechanical (friction) braking system. The mechanical
brake force is determined by many parameters, such as the friction coefficient of the brake disc and pad, the pressure in
the brake cylinder, the brake cylinder’s cross sectional area and the brake linkage ratio. In general, the friction coefficient
data of the brake disc and pad have been taken through a dynamo-test in a laboratory, but these data might not be well matched
with real data under operating conditions because of the difference in data acquisition conditions. The present study examined
two methodologies that can measure the friction coefficient of the brake pad and disc based on a train’s real operating conditions.
The first method was the direct method, which measured the brake force and clamping force applied on the mechanical brake
by using strain gauges installed on the brake to calculate the friction coefficient. The second was an indirect method that
obtained the friction coefficient by using the weight of the train and the equivalent brake force. Those variables were calculated
from the longitudinal dynamic characteristics, such as resistance to motion, gradient resistance and curved resistance. These
two methodologies were used to obtain the disc-pad friction coefficient for the mechanical brakes of a Korean high-speed train
(HSR350x). 相似文献
11.
利用子结构动态特性优化设计抑制制动器尖叫 总被引:3,自引:1,他引:3
针对制动器噪声分析研究所提出的对子结构修改以抑制噪声发生的目标 ,探讨了优化设计的修改方法。在对有制动尖叫倾向的制动器进行建模分析并确定其关键子结构动态特性修改方向的基础上 ,在部件子结构中引入设计参数 ,用最优化的方法按照设定的目标函数对结构动态特性进行修改。最后通过模型验证 ,表明部件子结构动态特性修改后制动器系统在原来尖叫频率的不稳定模态不再出现 相似文献
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14.
S. -H. Kim E. -J. Han S. -W. Kang S. -S. Cho 《International Journal of Automotive Technology》2008,9(2):233-247
This paper investigates the brake corner system to reduce brake torque variation in the brake judder problem. A numerical
model for determining brake torque variation was constructed using the multi-body dynamics model. Using this model, the brake
torque variation for a given disc thickness variation was obtained in the time domain. The multi-body dynamics model was verified
by a dynamometer test via the comparison of brake torque variation and load distribution patterns of the pad. To reduce the
simulation time and cost required to determine factors that influence the reduction in brake torque variation, a simple mathematical
model was constructed and used to determine both the brake torque variation and influential factors. The multi-body dynamics
model and dynamometer test were modified on the basis of the results of the simple mathematical model and deformed shape of
the multi-body dynamics model. These influential factors were verified to reduce the brake torque variation. 相似文献
15.
鼓式制动器结构振动噪声研究 总被引:3,自引:1,他引:3
本文阐述了制动器制动噪声发生的一般机理,给出了鼓式制动器低频(发啃)和高频(尖叫)振动噪声的实际结构闭环耦合模型,较为完善地考虑了各种结构系数的影响。模型的仿真分析结果和试验结果取得良好一致。提高了对制动噪声的定量分析,证明了通过改变结构的特性参数匹配可有效地抑制制动噪声的发生。 相似文献
16.
M. Pevec I. Potrc G. Bombek D. Vranesevic 《International Journal of Automotive Technology》2012,13(5):725-733
In the process of developing the brake disc, it is necessary that we predict the suitability of the design. In this manner, we can affirm that even the first prototype will satisfy all of the customer homologation requests. Usually those comprise different sequential braking tests in which the maximal achieved temperature is the criterion that governs brake disc suitability. The knowledge of how to predict the behavior of a brake disc in the early pretesting phase has a significant impact on development costs and time. The common method that is used for predicting the temperatures in the brake disc during braking is numerical simulation analysis. With the help of Computational Fluid Dynamics, the flow through a vehicle ventilated brake disc of known geometry was determined, and the wall heat transfer coefficients for all vehicle speeds and brake disc temperatures were calculated. The results were then imported into a thermal numerical simulation of a sequential-braking vehicle test. The results showed that the consideration of cooling factors has a significant impact on temperature courses. To obtain accurate results from the numerical simulation and to simulate the vehicle test precisely, the proper wall heat transfer coefficients must be considered. The proposed method produces more accurate numerical results and enables the development engineer to develop suitable brake disc geometry in the early pretesting phase. 相似文献
17.
In the present work, different ventilated disc brake rotor configurations were analysed to enhance the heat transfer rate and obtain the uniform temperature distribution in the rotor. CFD code used in this work was validated at using experimental results obtained by conducting experiments on a test rig. The experimental analysis was performed to calculate the mass flow rate and heat dissipation through the rotor. Further, different types of rotor configurations viz. straight radial vane (SRV), tapered radial vane (TRV), alternate long and short vane (ALSV), variable diameter circular pillars (VDCP) were considered for the analysis. A rotor segment of 20° was considered for the numerical analysis due to its rotational symmetry. CFD results were in good agreement with the experiments. The maximum deviation of the numerical results were about 12 % from the experimental results. It is found from the analysis that among the different types of rotor configurations; variable diameter circular pillars (VDCP) rotor gives better rate of heat dissipation with more uniform temperature distribution in the flow passages. Hence for modern high speed vehicles VDCP rotor may be more appropriate. 相似文献
18.
分析了气压盘式制动器在城市客车上应用的可能性与可行性,重点论述了5.5T盘式制动器前桥的开发,并对盘式制动器前桥与鼓式制动器前桥的制动力矩进行对比计算。 相似文献
19.
汽车气压盘式制动器的结构特点与性能分析 总被引:4,自引:0,他引:4
介绍了几种国内外重型汽车气压盘式制动器的结构及其特点,从左右轮制动力差异,制动器的效能因数与摩擦系数的关系及迟滞量等方面对盘式制动器与鼓式制动器进行性能对比分析,说明盘式制动器在制动效能、制动效能的稳定性以及制动时汽车的方向稳定性上比鼓式制动器具有明显的优势,理论和试验表明盘式制动器与ABS、ASR、EBS等系统匹配时可简化系统结构、优化系统性能,并对重型汽车装用盘式制动器带来的制动系统的相关问题进行了探讨. 相似文献