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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
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盘式制动器的制动抖动现象,会影响车辆的行驶安全性和驾驶舒适性,其产生原因是制动盘的原始几何尺寸及热膨胀作用造成几何变形的共同作用引起制动压力的波动,进而产生对制动系统及悬架和转向机构的激振作用。制动管路和悬架等传递途径的自振特性,也会对抖动的振幅产生影响。文章在结合国内外相关文献和实验分析数据的基础上,对盘式制动器特有的制动抖动现象进行了研究。主要包括制动抖动现象的成因和相关各方面的实验与分析方法,最后提出了改进建议。 相似文献
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K. S. Sim J. H. Lee T. W. Park M. H. Cho 《International Journal of Automotive Technology》2013,14(4):587-594
Brake judder is abnormal vibration, which is mainly generated by uneven contact between the brake disc and pad. The abnormal vibration from BTV (Brake Torque Variation) is transferred to the suspension and the steering system during braking. In this paper, judder simulation is carried out using a multi-body dynamic analysis program to analyze the relationship between judder and the transfer mechanism, which consists of the suspension and the steering system. In order to verify the analytical model, test results are compared with the simulation results. A sensitivity analysis is also carried out. In addition, an optimization method is presented for judder reduction, using the design of experiments. 相似文献
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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
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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
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车载ATP安全系统作为信号系统主要组成部分,对列车的安全性起着决定性作用,必须保证其具有高度的可靠性.传统上采用故障树分析方法(FTA)对车载ATP安全系统可靠性进行分析,但是在处理复杂系统时,存在着计算量大、步骤复杂等缺陷.文中在FTA方法的基础上,采用基于迭代法的BDD分析.实验数据表明,在保证计算精度的同时,能够减少分析的复杂度和计算量,并可直接计算出不同重要度,进一步对基本事件排序方法进行了优化. 相似文献
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C. Szczepaniak A. Kesy Z. Kesy 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》1991,20(5):283-295
In this work three first-order nonlinear, nonstationary differential equations describing a hydraulic torque converter in a power transmission system are used.
A linear model is obtained on the basis of these equations. This model is verified both theoretically and by an experimental test. On the basis of the calculations the torsional damping was determined. This permitted the damping performance of a power transmission system with a hydraulic torque converter to be defined and established. 相似文献
A linear model is obtained on the basis of these equations. This model is verified both theoretically and by an experimental test. On the basis of the calculations the torsional damping was determined. This permitted the damping performance of a power transmission system with a hydraulic torque converter to be defined and established. 相似文献
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Mohamed M. ELMADANY 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》1988,17(4):193-210
Stochastic optimal control and estimation theories are used to design an active suspension system for a cab ride in a tractor-semitrailer vehicle. A discrete-continuous vehicle model with eleven degrees of freedom is augmented by a stochastic road excitation model and a human perception of vibration shape filter. Both perfect measurement and estimated state cases are considered. The impact of the measurement noise on the design of the optimal controller is demonstrated. The performance of the optimally controlled system is compared with an optimal passive system. It is shown that significant improvements in ride comfort can be achieved through the use of actively controlled cab suspensions. 相似文献
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《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(5):283-295
Abstract In this work three first-order nonlinear, nonstationary differential equations describing a hydraulic torque converter in a power transmission system are used. A linear model is obtained on the basis of these equations. This model is verified both theoretically and by an experimental test. On the basis of the calculations the torsional damping was determined. This permitted the damping performance of a power transmission system with a hydraulic torque converter to be defined and established. 相似文献
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