城际动车组车体模态灵敏度分析

Research on Modal Sensitivity of Intercity EMU Bodywork

建立了某城际动车组车体有限单元模型,计算了车体模态,得到了车体模态频率及振型.用数值微分法计算了车体模态频率对车体结构参数的灵敏度,计算结果表明车体前三阶模态频率对底架、侧墙、顶板壳厚度的灵敏度为正值,即车体模态频率随着这些板件厚度的增加而增大;前三阶模态频率对车体端墙和牵枕缓部位结构厚度灵敏度为负值,即车体模态频率随这些板件厚度的增加而减小.在保持车体重量基本保持不变的前提下,用灵敏度信息对车体结构进行修改,使车体前三阶模态频率均得到了提高.

A finite element model of a intercity EMU bodywork is established, the bodywork modals are extraded,and the modal frequencies are achieved for the first four. Then, the modal frequency sensitivities withrespect to the plate thicknesses are calculated by using of numerical differentiation method. The results showthat the sensitivity values of the first three modal frequencies with respect to the bottom plates , side wall andtop plate are positive, which means that the first three modal frequencies is increased with rising plate thickness.While the sensitivity values of the first three modal frequencies with respect to plate thickness of end walland traction pillow are negative, which means that the first three modal frequencies is decreased with risingplate thickness. Based on the modal sensitivities, the first three modal frequencies of bodywork have been successfullyimproved by structure modification, but the weight of the EMU bodywork is not increased.