Abstract: The finite element model of a vehicle body was established based on a kind of vehicle at first, and the computational modal analysis was conducted. Computed results was compared with experimental ones, the validity of the finite element mode was verified. Based on the results of modal analysis, the improving method of the vehicle body’s vibration and noise control was given out. Then the vehicle structure was improved on the model and the vehicle interior noise of the improved vehicle structure was computed. The result indicated that the improving method could control the interior low frequency noise of the vehicle.

Key words: modal analysis, finite element, the low frequency noise

摘要： 首先针对某型客车建立了汽车车身结构的有限元模型，对建立的模型进行了有限元模态分析；通过比较计算得出的模态数据和实车试验得出的模态数据，验证了该车身结构有限元模型的正确性。基于模态分析的结果，提出了车身减振降噪的改进方案, 在车身模型上对结构进行了改进并且对改进前后的车内噪声进行分析。分析结果表明，该改进方案能有效降低车内的低频噪声。

关键词: 模态分析, 有限元, 低频噪声