列车车轮的振动是轮轨噪声声源的一个重要的组成部分。利用有限元与边界元相结合的方法,着重研究列车速度变化对车轮的振动—声辐射特性的影响,计算模型中考虑轮轨间的垂向相互作用,并考虑轮轨接触斑的滤波作用。根据车轮的实际尺寸建立车轮的三维实体有限元模型,采用分块Lanczos法求解车轮的固有频率振型,然后采用模态叠加法计算单个车轮结构在垂向不平顺激励下的动态响应,将车轮表面的速度处理成声学边界元模型的输入条件,计算车轮的滚动辐射噪声。数值计算中,研究车轮的不同部位(踏面、辐板和轮辋)在声辐射中所占的比重,以及不同的列车速度对车轮振动声辐射特性的影响。数值仿真计算为高速列车的轮轨降噪措施的制定提供一定的参考。
Train wheel vibration is an important noise source of railway vehicle.A hybrid FEM-BEM vibro-acoustic model is used to investigate the effect of train speed variation on the acoustic radiation characteristics of wheel vibration.In the model the vertical interaction of wheel and rail and the filter action of wheel/rail contact patch are taken into account.Based on the actual wheel size,a three-dimensional finite element model of the wheel is built.The "Block Landzos" method is used to solve the nature frequency and vibration mode of the wheel.The mode superposition method is employed to calculate the dynamical response of a single wheel structure to the vertical excitation of the running surface roughness.Finally the wheel surface speed is processed as the input condition of acoustic boundary element model,so as to calculate the rolling radiation noise of the wheel.The numerical calculation determines the extent to which the wheel tread,web,and rim contribute to the allover noise generated by the wheel and the effect of different train speed on the acoustic radiation characteristics of wheel vibration.The numerical simulation calculation provides certain reference for taking measures to reduce wheel/rail noise of high-speed train.