Abstract: Aiming at the problem of car-body optimization, the frequency response sensitivity analysis is used to reduce the response displacement of the car-body structure. Based on the finite element model of the car-body，the frequency response is calculated，and the displacement response curve of driver’s seat bracket is obtained，from which the vibration peak for a given frequency is found. To reduce the vibration peak, an optimal design based on the frequency response sensitivity analysis is carried out by selecting the appropriate design parameters. After the optimization，the response displacement?at key frequencies of the car is obviously reduced，and the riding comfort of the car is improved.

Key words: vibration and wave, optimization, FEM, frequency response sensitivity, harshness

摘要： 针对车身优化的问题，采用频率响应灵敏度分析来降低车身结构的响应位移。在车身有限元模型的基础上计算频率响应，并求得驾驶员座椅支架处的响应位移曲线，从中找出某频率处的振动峰值;为了降低振动峰值，通过频率响应灵敏度分析选择合适的设计变量进行优化计算。优化后车身关键频率处的响应位移明显减小，提高乘坐的舒适性。

关键词: 振动与波, 优化, 有限元模型, 频率响应灵敏度, 舒适性