Non-Linear Modeling and Parameter Identification of Semi-Active Engine Mounts With Air Spring

Abstract

Car manufacturers have been motivated to apply semi-active engine mounts to ensure superior performance in vibration attenuation during idle condition and better ability to isolate vibration which is generated by engine unbalanced force at high frequencies. This paper develops a non-linear lumped parameter model of semi-active engine mounts with air spring that focuses on the non-linearity of the rubber diaphragm and the air chamber. Then, the main rubber dynamic stiffness parameters are identified through experimental approaches with a novel-designed test rig. Other parameters including effective pumping area, main rubber spring bulge stiffness, fluid channel inertia and resistance, rubber diaphragm, and air-chamber parameters are attained through finite element analysis (FEA). Supported by the identified lumped parameters, the non-linear mathematical model could be simulated. In addition, the dynamic characteristics of the semi-active engine mount are tested through the original test rig. Therefore, comparing with the tested dynamic characteristics, the simulation result can validate the developed model and thus facilitate the structure design of the semi-active engine mount.