基于遗传算法的动力总成悬置模态解耦及隔振性能优化

Optimization design for improving the vibration modes decoupling rate and vibration isolation performance of a powertrain mounting system based on the genetic algorithm

针对某SUV模态解耦率以及隔振性能不达标问题开展优化研究。运用两个三向刚度弹簧对后悬置独特结构进行简化并基此建立四点悬置六自由度多体动力学模型。以橡胶三向静刚度为优化变量,以悬置模态解耦率为优化目标,采用遗传算法对悬置参数进行优化。结合原悬置非线性刚度段的设计参数,对优化后的悬置进行通用28工况仿真以评判悬置限位作用。分析和测试结果表明,优化后悬置模态解耦率有大幅提升且悬置能够满足隔振以及限位要求。

Aiming at improving the insufficient vibration modes decoupling rate and disappointing vibration performance of the suspended powertrain mounting system in a SUV,a four points suspension 6-DOF multi-body dynamic model for optimizing the power assembly was established based on the simplification of the rear suspension to two3-directional elastic springs. The three direction stiffnesses of the suspension were taken as optimal variables,and the natural frequencies and modal decoupling rate were taken as optimization objectives in the optimization model. The optimized linear suspension stiffnesses combined with the parameters of original nonlinear stiffness were applied to judge the limiting action of the suspension. The results show that the distribution of different order modal frequencies of the suspension is reasonable,the decoupling rate between Z and Rx directions is highly improved,and the limiting action of the suspension is satisfactory.