基于液—固耦合有限元仿真的液阻悬置集总参数模型动特性分析

DYNAMIC CHARACTERISTIC ANALYSIS OF HYDRAULICALLY DAMPED RUBBER MOUNT:LP MODEL BASED ON FSI FE SIMULATION

探讨应用非线性固体有限元和液—固耦合非线性有限元仿真方法预测与识别液阻悬置集总参数模型的主要参数 (如上液室的体积刚度和等效活塞面积、惯性通道中的液体和解耦板及其附连液体的惯性系数与流量阻尼系数等 )的分析方法。在此基础上 ,利用集总参数分析模型对一种轿车用液阻悬置的动特性进行计算分析。数值预测结果与实测结果或近似解析计算结果的对比分析表明 ,基于液—固耦合有限元仿真方法的液阻悬置集总参数模型动特性分析技术是可行、有效的 ,其预测结果精度特性满足工程要求。应用这种方法 ,可以在液阻悬置的设计开发阶段较精确地预测产品的性能和进行优化设计 ,有利于提高产品设计质量。

Hydraulically damped rubber mounts (HDM) are now widely used as a highly effective vibration isolator in automotive powertrain. The lumped parameter (LP) models of HDMs are usually applied to their dynamic characteristic analyses. Physical parameters of the models are, in general, obtained by experiments. Nonlinear finite element analysis (FEA) and computational fluid dynamics (CFD) methods were applied to prediction or identification of the model parameters. A fluid structure interaction (FSI) FEA technique was used to estimate the volumetric compliances, the equivalent piston areas, the inertia and resistance of the fluid in the inertia track and the decoupler of the HDM. A nonlinear FEA method was also applied to determining the dynamic stiffness of the HDM rubber spring. The system parameters predicated using FEA was compared favorably with experimental data or analytical approximate solutions. A numerical simulation of an HDM with an inertia track and a free decoupler was performed based on the LP model and using the estimated system parameters, and again the results were compared with experimental data. The work conducted in the paper demonstrates that the method for estimating the system parameters in the lumped model of HDM is effective, with which the dynamic characteristic analysis and design optimization of a HDM can be performed before its prototype development, and this can ensure its high quality and low cost in product development.