基于灵敏度分析的动车组车体结构模态提升研究

Research on Modal Enhancement of EMU Vehicle Carbody Structure Based on Sensitivity Analysis

[目的]为全面了解车体零件尺寸参数对车体模态的影响,对动车组车体模态灵敏度进行分析,以提升车体主要振动频率。[方法]根据灵敏度计算结果,制定了8种单变量厚度提升方案,进行车体结构主要模态对比分析;在此基础上,对主要振动模态影响最大的零件进行两两组合,在质量增加不大的前提下,制定了3种提升方案来研究多变量厚度变化对车体主要振动模态的影响。[结果及结论]侧顶板、圆顶板、侧墙板、侧墙梁柱、车顶弯梁、波纹地板和底架边梁的厚度对车体主要振动模态的灵敏度较高;增加以上单变量影响因素的厚度和多变量影响因素的厚度,车体结构主要振动模态频率相对于原结构均有一定提升;与单变量厚度影响因素方案相比,多变量厚度提升方案的各振动模态频率均有所上升,但变化幅值较小,大大低于2个单变量厚度影响因素单独对车体模态影响的叠加。

[Objective]To comprehensively understand the influence of carbody component dimensions on carbody modal characteristics,a sensitivity analysis of EMU(electric multiple units)body modal is conducted to enhance the main vibration frequency of carbody.[Method]Based on sensitivity calculation results,eight univariate thickness enhancement schemes are developed for comparison analysis of the main carbody modal.Subsequently,by pairing up components with the greatest impact on major vibration modal,three enhancement schemes are formulated to investigate the effects of multivariate thickness vibrations on the main carbody vibration modal while minimizing mass increase.[Result&Conclusion]The thickness of side top plates,circular top plates,side wall panels,side wall beams/columns,roof bending beams,corrugated floors and chassis edge beams exhibits high sensitivity to the main carbody vibration modal.Increasing the thickness of these univariate and multivariate influencing factors results in a noticeable improvement in the main carbody vibration modal frequencies compared to the original structure.Compared to the scheme of univariate thickness influencing factors,the impact of multivariate thickness enhancement schemes on individual vibration modal frequencies shows a slight increase.However,its smaller amplitude variations are significantly lower than the stacked effects of two individual unicarite thickness factors on the carbody modal.