基于模态分析的某客车车身NVH性能优化

Modal analysis and NVH performance optimization of the body-in-white

针对某客车存在的车身共振问题,对白车身进行模态分析、获取其模态参数,分析出产生共振的原因为车身一阶模态频率与轮胎不平衡产生的激励频率相近;建立白车身有限元模型,进行模态仿真分析;通过对比试验及仿真的白车身模态参数,验证模型的准确性;针对其一阶模态频率,对白车身模型进行模态应变能分析,选取车身一阶模态振型下刚度不足位置,对白车身进行加强,提高白车身一阶模态频率,使之避免与轮胎激励频率相近而造成的车身共振,实现白车身NVH性能的改善。

For avoiding the resonance of the vehicle＇ s body, experimental modal analysis method is used to obtain the modal pa-rameters of the vehicle＇ s body-in-white. The resonance is caused by the coupling of the l^st modal frequency of body-in-white and the offset frequency of the wheel. The finite element model is established and verified by comparing the simulation and experimen-tal modal analysis results. Based on modal strain energy analysis, the large deformation parts of the body-in-white are defined. To avoid the resonance, improve the first step frequency by adding stiffener supports and adjusting the thickness of the parts accord-ing to the strain energy analysis result.