轻轨车辆车轮NVH特征分析与校正

Analysis and Correction of NVH Characteristics of Light-rail Vehicle Wheels

为研究有效的降噪车轮方案,在柔性车轮和轮对的NVH特征分析基础上,提出阻尼环约束的降噪设想。通过柔性车轮NVH特征分析及相关的轮轨噪声预测与试验结果对比,可以认为由于轮轨接触摩擦约束作用,车轮不可能产生轮辐弯曲模态振动,因而也不会形成TWINS模型所预测的0.3 kHz噪声成分。在力锤以及轨道不平顺与粗糙度等效力谱激扰作用下,柔性车轮和轮对NVH特征对比表明:车轮噪声是由轮辋高阶模态振动引起的,而这些高阶模态振动的主要激扰源应当归结于轨道粗糙度;阻尼环约束对这些高阶模态振动稳定性具有非常理想的校正效果,因而可以作为构建未来降噪车轮技术的理论依据;轨道不平顺所形成的轨道力谱只能使车轮产生低频动力作用,并引起道床、桥梁和附近建筑物的低频机械振动。

In order to investigate the effective plan of the low-noise wheel,the tentative suggestion of damping ring constraint was proposed on the basis of the NVH characteristic contrast of the flexible wheel and wheelset.Through the NVH characteristic analysis of the flexible wheel and comparison with the correlative results of wheel-rail noise forecast calculations and measurements,it can be deduced that the 0.3kHz noise previewed by the TWINS-model,which is corresponding to the spoke bending mode,can not be produced by wheel due to the friction constraint of wheel-rail contact.Under excitation of the hammer,rail irregularity and roughness,the NVH characteristic contrast analyses show as follows： Wheel noises are caused by the high-order modal vibrations of rims,and the excitement of these high-order modal vibrations comes mainly from rail roughness;the damping ring has the excellent correcting effects on stabilizing these high-order modal vibrations,which can be in return as the theoretical foundation for the future techniques of low-noise wheels;and at the same time the force spectrum formed by rail irregularity can only make wheel produce the low-frequency dynamical interaction,which results in low-frequency vibrations of railway substructures,bridges and adjacent buildings.