Title: Optimisation of engine mounting systems using experimental FRF vehicle model

Authors: Reza Madjlesi, Amir Khajepour, Fathy Ismail, Michael Wybenga, Bernie Rice, Joe Mihalic

Addresses: University of Waterloo, Department of Mechanical Engineering, Waterloo, Ontario N2L 3G1, Canada. ' University of Waterloo, Department of Mechanical Engineering, Waterloo, Ontario N2L 3G1, Canada. ' University of Waterloo, Department of Mechanical Engineering, Waterloo, Ontario N2L 3G1, Canada. ' University of Waterloo, Department of Mechanical Engineering, Waterloo, Ontario N2L 3G1, Canada. ' Cooper-Standard Automotive, Mitchell, Ontario N0K 1N0, Canada. ' Cooper-Standard Automotive, Mitchell, Ontario N0K 1N0, Canada

Abstract: Engine and body mount systems play a crucial role in vehicles| comfort. Engine mounts protect the engine from excessive movement and forces due to low frequency road and high frequency engine excitations. On the other hand, body mounts protect the cabin from vibration forces exerted by the body. Normally, a complete set of mounts is conceived at early stages of design, subsequently the set is tuned in the refinement stage to improve the vehicle|s noise, vibration, and harshness (NVH) response. Currently, noise path analysis (NPA) is used for mount tuning. This method is helpful, but it is based mostly on trial and error, and it does not lead to an optimum mounting set. In this work, a new technique is implemented to simplify vehicles| mount optimisation. This technique employs substructuring synthesis and standard NVH testing to obtain frequency response function (FRF) model of a vehicle. The model is linked to several optimisation routines to predict the optimum set of mounts for a desired objective function. For verification and evaluation, the method is applied to tuning the mounting set of a pick-up truck. Experimental measurements showed good correlation with optimised response.

Keywords: FRF modelling; frequency response function modelling; substructuring; hybrid modelling; engine mounting; NVH; vehicle noise; noise path analysis; NPA; vehicle vibration; harshness response; mount tuning; mounting set; pick-up trucks.

DOI: 10.1504/IJVNV.2005.007525

International Journal of Vehicle Noise and Vibration, 2005 Vol.1 No.3/4, pp.232 - 250

Available online: 02 Aug 2005 *

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