基于振动控制的客车地板模态分析及结构优化

Modal analysis and structure optimization of bus floor based on floor vibration control

为了控制某轻型客车的地板后部在高速行驶工况中的剧烈振动,利用阶次跟踪方法和模态分析方法分析得出地板发生剧烈振动的原因是发动机和传动系的激励频率与地板后部局部鼓包模态的模态频率接近,进而发生了共振。采用Hyper Works软件建立了某轻型客车的车身车架有限元模型,利用Hyper Works软件的Opti Struct模块对地板各横梁板材的厚度进行模态灵敏度分析及尺寸优化,根据相关的分析结果设计了结构优化方案并进行了验证试验。试验结果表明,本文方法可以有效地控制地板的剧烈振动。

The rear area of the floor of light bus experiences severe vibration under high speed working condition. In order to solve this problem, order tracking analysis and modal analysis of the floor were performed to identify the root cause. It was found that the excitation frequencies of the engine and transmission system are overlapped with the modal frequencies of the floor, which has some local bump modals, resulting in resonance. A finite element model, including the body and frame of the floor, was established using HyperWorks software. Model sensitivity analysis and size optimization of the thickness of floor the beams were carried out using the OptiStruct module in HyperWorks. Then an optimal scheme was designed according to the finite element analysis results and the verification test was conducted. The test results demonstrate that the investigation method and the proposed optimal scheme can effectively control the severe vibration of the floor with low cost.