盘式制动器制动尖叫的有限元分析与试验

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。     

Analysis of automotive disc brake squeal considering damping and design modifications for pads and a disc

The squeal noise occurring from the disc brakes of passenger cars has been analyzed by using the complex eigenvalue method numerically. The contact between a disc and two pads was analytically modeled as many linear springs and dampers in an effort to develop the improved equation of motion derived on the basis of Lagrange’s equation and the assumed mode method. The finite element modal analysis results for disc brake components constitute an eigenvalue matrix in the analytical equation of motion. The complex eigenvalue analyses based on the equations of motion are able to examine the dynamic instability of a brake system, which is an onset of squeal, by considering the disc rotational effect. Numerical analyses showed that the modes unstable in an undamped analysis became stable in a damped case, which illustrates the important effect of damping on the squeal instability in a brake squeal simulation. Then several modified brake models were suggested and investigated how effectively they suppressed the occurrence of squeal noise. The brake parts such as a pad chamfer and a disc vane were modified and the influence of pad chamfer and vane shapes on squeal occurrence was proved to be significant. The numerical results showed that proper structural modification of a disc brake system can suppress the brake squeal to some extent.     

盘式制动器制动尖叫的研究

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     

盘式制动器制动尖叫计算模型的建立

借助于有限元和模态综合技术，建立了盘式制动器制动尖叫的摩擦耦合模型。通过复特征分析，得到了对应于每阶段动模态的阻尼与频率，模态阻尼值揭示了哪 些模态不稳定并有可能产生尖叫；最后运用耦合模型研究了摩擦系数和子结构模态对制动尖叫的影响。     

用模态综合模型对制动器噪声进行模拟分析与抑制

综述了对于制动器噪声问题能进行较为有效控制且得到应用的研究技术成果,利用在研究制动器噪声问题发生机理的基础上发展的系统模态综合模型分析方法,对一个存在低频噪声的制动器进行了分析.找出了影响噪声发生的关键构件是制动器支架,对其进行了改进设计,通过按照SAE J2521标准进行的台架试验,证明其有效性,并将原制动器按SAE...     

汽车摩擦制动噪声研究进展与发展趋势

总结汽车摩擦制动噪声的产生机理、噪声特点和影响因素,回顾并分析抑制和防治制动噪声的理论与工程研究进展,提出开发新型高阻尼摩擦制动材料来降低或抑制制动噪声的思路和措施。     

AUDI盘式制动器的幂函数乘积模型

本文采用正交及回归试验设计技术，以制动压力与制动初速度为试验因素，以制动力矩为试验指标，在JF－132型汽车制动器试验台上进行了AUDI盘式制动器摩擦特性的回归实验，根据实验结果，建立了AUDI盘式制器的幂函数乘积模型并进行了统计检验。     

Brake pad taper wear on brake moan noise

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.     

抑制制动器振动噪声的阻尼方法的探讨

针对在盘式制动器制动块底板上粘贴一层阻尼层(Insulating Shim)的阻尼处理方法，首先指出制动块底板上阻尼层的减振机制在于粘弹性材料在接触面间表现出的摩擦作用，尤其取决于材料本身的迟滞效应。然后．定量分析了阻尼层对制动器噪声的抑制效果；利用能量等效原理将接触摩擦转换成系统中粘性阻尼后进行特征分析．考察系统稳定性。     

结构参数对鼓式制动器高频噪声的影响

本文在建立鼓式制动器高频噪声问题的结构闭环耦合计算模型的基础上，对某国产车的高频噪声问题进行了计算。分析中所用的制动底板，鼓和蹄的结构参数均取自实际结构。计算分析的结果表明：制动器所有部件的结构参数对制动高频噪声均有重要影响，过去仅把产生高频器材怕的原因归结为蹄与鼓间的参数匹配是不正确的。对计算结果的归纳表明：对制动器高频噪声起决定作用的是鼓子结构和包含有底板，蹄，分泵及油路操纵系统在内的ＰＳＰＯ     

电磁制动与摩擦制动集成系统测试台架设计及试验研究

根据电磁制动与摩擦制动集成系统的工作原理,设计了一种电磁制动与摩擦制动集成系统测试台架.为检验该测试台架的性能.以某型轿车为对象.选择电磁制动器的磁极与制动盘间间隙、线圈匝数和磁极中心到制动盘中心距离为因素.进行3因素3水平正交试验.试验结果表明,采用所设计的测试台架对不同车型进行试验,可得到电磁制动与摩擦制动集成系统的最佳结构参数和安装参数.     

利用子结构动态特性优化设计抑制制动器尖叫

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     

Hot judder simulation of a ventilated disc and design of an improved disc using sensitivity analysis

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.     

汽车气压盘式制动器的结构特点与性能分析

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.     

某型轿车盘式制动器制动噪声的控制

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。     

鼓式制动器结构振动噪声研究

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。     

Numerical Study for Brake Squeal by Machining Patterns on Frictional Surface

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.     

面向制动噪声的盘式制动器零部件实模态分析

基于实模态分析理论和有限元法，研究了某盘式制动器的制动噪声问题，分别建立了制动盘、制动块、制动钳钳体和制动钳支架的有限元模型，计算了它们固有频率在20kHz以下的各阶实模态，并对与制动噪声有关的各阶模态进行了分析。     

Measurement of the disc-pad friction coefficient for mechanical brakes using direct and indirect methods

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).     

Load and Load Dependent Friction Identification and Compensation of Electronic Non-Circular Gear Brake System

Control of the electronic non-circular gear brake (ENGB) involves challenges, including the non-linear variation of loads and the effect of friction, which is dependent upon load. The controller must be designed based on modelling information in order to enhance control performance. This study performed model identification of the ENGB system using a DOB-based model identification method. By employing the nearest neighbor search method, the even-odd disturbance was separated without the influence of hysteresis even in situations with low control precision. The accuracy of the resulting ENGB system model was validated through experiments. The self-energizing effect due to friction between the brake disc and pad within the mechanical system was also validated.