基于模态灵敏度分析的客车车身优化

针对提高国产某轻型客车的乘坐舒适性，解决车内振动和噪声剧烈问题，本文首先基于有限元仿真和道路试验的阶次跟踪方法进行振动和噪声原因分析，所确定的原因为轮胎激励引起的车身结构共振。为避免共振，以白车身钣金件和骨架的厚度为设计变量，以提高白车身前两阶固有频率为目的，用模态灵敏度理论对白车身进行优化设计和灵敏度分析。然后结合各钣金件和骨架的模态灵敏度和质量灵敏度，设计最优的改进方案并进行试验分析。对比优化前后的试验结果，验证了该优化方案的有效性与合理性。

Modal Sensitivity Analysis and Structure Optimization of Light Bus Body-in-White

In order to solve the abnormal vibration and noise of a domestic light bus, finite element simulation and order tracking analysis of road test was made to identify the vibration source, finding that the rotation angular frequency of the wheels and the first two natural frequency of the body structure overlapped, resonance occurring which lead to increased vibration. To stagger the first two natural frequency and excitation frequency of the body, thickness of sheet metal and skeleton of body-in-white were chosen as the design variables, rise of the first two natural frequency of body-in-white as the optimization objective, optimization design and sensitivity analysis of the body in white was carried out. According to the modal sensitivity and mass sensitivity of sheet metal and skeleton, the optimum design was achieved and tests analysis was conducted. Comparing the test results before and after optimization, the effectiveness and rationality of the optimization was verified.