【摘要】 为探索车轮在轮轨表面粗糙度激励下的振动辐射声场特征,利用有限元法-边界元法相结合的方法,完成了建立车轮和轨道的三维有限元模型,根据有限元法分析其结构振动模态和位移导纳特性,通过声学边界元软件Virtual. Lab对车轮辐射声场及真实激励下辐射声功率级进行预测研究。结果表明:轮轨接触点处车轮径向导纳变化剧烈,在计算频率范围内自振频率较多,而钢轨的垂向导纳变化整体较为平和,在钢轨Pinned-Pinned频率附近变化较剧烈;车轮的声辐射具有较强的指向性,其声辐射效率在低频时较小,随着频率增大而增大,并逐渐趋于1;计算得到的每单位粗糙度的接触力与D. J Thompson根据轮轨相互作用模型计算出的结果基本相符,真实激励下的声辐射功率总体来看高频范围的声功率级大于低频范围。研究结果可为进一步探讨列车车轮在真实激励下的辐射噪声预测及控制提供帮助与参考。更多还原

【Abstract】 In order to explore the characteristics of the vibration radiation sound field of the wheel under the excitation of the surface roughness of the wheel and rail,the three-dimensional finite element model of the wheel and the track was established by the combination of finite element method and boundary element method,and the structural vibration model was analyzed according to the finite element method. The characteristics of state and displacement admittance are predicted and studied by the acoustic boundary element software Virtual. Lab to predict the wheel radiated sound field and the radiated sound power level under real excitation. The results show that the radial admittance of the wheel at the wheel-rail contact point changes drastically,with more natural frequencies in the calculated frequency range,while the vertical direction admittance change of the rail is relatively smooth overall,and the change is sharp near the Pinned-Pinned frequency of the rail; Acoustic radiation has strong directivity,and its acoustic radiation efficiency is small at low frequencies,increases with the increase of frequency,and gradually tends to 1. The contact force per unit roughness and D. J. Thompson calculated by wheel rail interaction model are basically consistent. The sound power level under real excitation is generally higher in the high-frequency range than in the low-frequency range. The research results can provide help and reference for further discussion on the prediction and control of radiated noise of rail wheels under real excitation.更多还原