A Research On Simulation Techniques For Structure-Fluid Interaction Of Hydraulically Damped Rubber Mount

The hydraulically damped mount (HDM) is a newly vibration isolator of vehicle engine system. The dynamic stiffness and damping of HDM can be frequency and amplitude-dependent, which provides better vibration isolation performance than conventional elastomeric mounts, thus are widely used in vehicle. This paper analyses the typical structure, working principle and characteristics of two hydraulic mounts, addresses in detail the modeling methods of engine hydraulic mounts.Firstly, considering the structure characters of inertia track-decoupling hydraulically damped mount, the nonlinear mechanical and mathematical model is established using the lumped parameter method The influence of rubber structure, fluid oscillatory, and pressure loss in inertia track as well as the shape of inertia track on the character of HDM are considered in the established model. Also, the according evaluation standard is established.Secondly, the nonlinear characters of HDM are investigated. The influence of rubber spring, parameters of inertia track and physics characters of fluid on the dynamic characters of HDM are studiedThirdly, the modeling methods for HDM with FSI FEA techniques are discussed, and FSI FEA models for dynamic analyses of an HDM with an inertia track and a free uncoupler are established The static and dynamic characteristics of the HDM are predicted with the models and the results are compared favorably with experimental data. Calculated results of some variables in the model, such as the pressure distribution in the fluid chamber, the velocity distribution of the fluid in the inertia track and the displacement of free uncoupler under different excitations, elucidate the working mechanism of the HDM.Finally, the experimental method and theoretical analysis outlines for establishing rubber hyperelastic constitutive model are studied. The elastic properties of a rubber spring of the HDM are estimated from nonlinear FEA method, and the results are in good agreement with the experimental data, which demonstrates that the FEA method for the analysis of rubber products discussed in the dissertation is useful for the performance analysis and optimization of the rubber springs with complex configuration.