铁道车辆几何滤波现象及弹性车体共振分析

运用简化铁道车辆模型,对几何滤波现象进行了分析.建立了刚柔耦合弹性车体模型,分析了几何滤波现象对车体响应功率谱的影响,以及几何滤波与弹性车体共振频率的关系.研究表明,几何滤波分为轴距滤波和定距滤波.在某些特定轨道不平顺波长下,车体的点头和浮沉响应均为零,该现象称为轴距滤波;定距滤波是指在某些波长下,车体的浮沉或者点头响应为零.在车体空点头响应频率附近,轨道对车体浮沉振动的加速度传递率达到局部最大,当车体的垂向1阶弯曲频率与这些峰值频率吻合时,将产生车体弹性共振现象.

Analysis on Geometric Filtering Phenomenon and Flexible Car Body Resonant Vibration of Railway Vehicles

The geometry filter phenomenon is analyzed with a simplified vertical railway vehicle. Then the relationship between geometry filter phenomenon and the resonant vibration of flexible carbody is studied with a full vehicle model. It is found that geometry filter phenomenon consists of "wheelbase filter" effects and "bogie center filter" effects. It is called wheelbase filter effect when there is neither car body bounce nor pitch responses at some wavelengths. And it is called bogie center filter effects when there is no car body bounce or pitch response at some track wavelengths. Near the null pitch response frequenaes, the acceleration transmissibility from track unevenness to carbody bounce will reach local maximum. So if the carbody first bending frequency coincides with the frequenaes which have the peak values of acceleration transmissibility, resonant vibration of flxible carbody will bappen.