Simulating Elastomeric Engine Mounts for Large Amplitude Deflections

The ability to perform dynamic simulations of the motion of an engine on its mounting system during large amplitude deflections can provide important benefits in vehicle development. This information can aid in the packaging of components in the engine box area, it can provide insight into ways to improve the durability of the engine mounts, and it can provide insights into how large amplitude motions of the engine may be affecting vehicle noise, vibration, and harshness (NVH). One problem in simulating the motion of the engine for large amplitude deflections of its mounts is accounting for the hysteretic damping effects observed in elastomeric engine mounts.

This paper discusses a simple three element model for an elastomeric isolator that can represent this hysteresis effect. The model is used to predict behavior of an elastomeric isolator, and test results verifying the predicted behavior are presented. A test for obtaining parameter information for the model elements is also discussed, and additional data are presented to demonstrate the ability of the test procedure to provide parameter information that will accurately characterize the elastomeric isolator over a wide range of loads.