Finite element-based parameter estimations for a characteristic simulation model of a hydraulically damped rubber mount for vehicle engines

Abstract

The hydraulically damped rubber mount (HDM) is widely used for vibration isolation in automotive powertrains and other dynamic systems. In predictions of its dynamic characteristics, some key parameters or parametric characteristics in the lumped-parameter dynamic analysis model of an HDM, such as the volumetric elastic characteristics of fluid chambers and the equivalent piston cross-sectional area of the upper chamber, must be especially determined, because they are difficult to measure by experiment owing to fluid-structure interactions (FSIs). In this paper, a numerical simulation approach of volumetric elastic characteristics is developed on the basis of finite element analysis methods relating to rubber material hyperelasticity and hydrostatic FSI using ABAQUS software. Volumetric elastic characteristics of the upper fluid chamber, including the main rubber spring and/or uncoupling rubber membrane, and that of the lower fluid chamber are identified; volumetric stiffness and equivalent piston cross-sectional area are also calculated for further dynamic characteristic simulations of HDM. The contributions of different rubber parts to the volumetric elastic characteristics of the upper chamber are revealed. Predications of dynamic characteristics and frequency response analysis of a typical HDM with fixed decoupler verify the effectiveness of the proposed parameter identification method. The proposed simulation methods of volumetric elastic characteristics can be applied to other FSI systems.