发动机油底壳的模态试验及优化设计

Modal Test and Optimization Design of Engine Oil Pan

以某轿车发动机油底壳为对象,通过混合建模方式(即简易力学模型与模态试验结合)对油底壳的动态特性进行研究,得到油底壳的模态频率和振型。根据分析结果提出对油底壳的结构优化措施,并对改进后的油底壳进行模态分析和声学验证,结果表明:改进后的油底壳由于增加了刚度,降低了模态频率密度,减少了发生共振的机会,油底壳辐射噪声对整机噪声贡献率明显降低。

In this paper, the oil pan of engine is taken an example to study, analyses the dynamic characteristics by the method of hybrid modeling, gaining the modal frequency and vibration mode of the oil pan. According to the results, measures to improve the structure of the oil pan are put forward, and the modal analysis and acoustic test have been made. The results show that, by increasing the stiffness of the oil pan that makes modal frequency density decreases, it reduces the possibility of resonance occurring, oil pan radiation noise contribution rate decreased to engine noise.