铁路车辆盘形制动尖叫噪声的有限元分析

Finite Element Analysis on the Squeal Noise of Railway Vehicle Disc Brake

为降低铁路车辆盘形制动尖叫噪声,应用全模型直接复特征值分析方法研究制动系统的运动稳定性。使用NASTRAN有限元软件建立了包括制动盘、闸片、闸片托、制动杠杆和杠杆托等部件的全尺寸铁路车辆盘形制动系统有限元模型。在模型中,制动摩擦面间的法向力用线性弹簧力表示,摩擦力取为线性弹簧力与摩擦系数的乘积。应用Hess方法解有限元系统特征方程的特征根,根据特征根实部的正负,判断制动系统发生制动尖叫噪声的趋势。计算结果表明,摩擦系数、制动盘转动方向以及闸片托的厚度对制动尖叫噪声都会产生重要影响,可以通过优化制动系统闸片托的厚度来抑制制动尖叫噪声。

In order to suppress the squeal noise of railway vehicle disc brake, motion stability of brake system was studied using a direct complex eigenvalue analysis technique of full scale models. Finite element software NASTRAN was applied to establish a full scale model of a railway vehicle disc brake system, which included a brake disc, brake pads, pad brackets, brake levers and a lever bracket. In the model, the normal force at the contact interface was shown with linear spring force. The friction force was taken as the product of linear spring force and friction coefficient, and Coulomb＇s friction law was applied. The Hess method was applied to solve the latent root of the eigenvalues equation of finite element system. If the real part of an eigenvalue is positive, the corresponding mode is unstable, which may result in squeal. Numerical simulation result shows that the friction coefficient, rotation direction of the disc and thickness of the brake pad bracket have significant influence on the occurrence of brake squeal. Brake squeal noise can be suppressed by optimizing the thickness of the brake pads.