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

Abstract

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.

Keywords

• emu
• carbody structure
• sensitivity
• modal