Automotive vehicle engine mounting systems: A survey

This study divided into three portions to provide performance requirements; overview and development of various engine mounts; and the optimization of engine mount systems. The first part provides an insight about the ideal e ngine mount system that should isolate vibration caused by engine disturban ce force in various speed range and prevent engine bounce from shock excita tion. This implies that the dynamic stiffness and damping of the engine mou nt should be frequency and amplitude dependent. Therefore, the development of engine mounting systems has mostly concentrated on improvement of freque ncy and amplitude dependent properties. The second part starts discussion o n the conventional elastomeric mounts that offer a trade-off between static deflection and vibration isolation. The next level, passive hydraulic moun ts can provide a better performance than elastomeric mounts especially in t he low frequency range. Subsequently, semi-active and active techniques are used to improve performance of hydraulic mounts by making them more tunabl e. The active engine mounting system can be very stiff at low frequency and be tuned to be very soft at the higher frequency range to isolate the vibr ation. The final part is about the optimization of engine mounting systems. An overview of the current work on this optimization shows some limitation s. Further study is needed to consider the nonlinearities and variations in properties of different types of mounting systems.