Measurement of dynamic properties of automotive shock absorbers for NVH

Document Type

Conference Proceeding

Publication Date

5-17-1999

Department

Department of Mechanical Engineering-Engineering Mechanics

Abstract

This paper describes a project on the dynamic characterization of automotive shock absorbers. The objective was to develop a new testing and analysis methodology for obtaining equivalent linear stiffness and damping of the shock absorbers for use in CAE-NVH low- to- mid frequency chassis models. Previous studies using an elastomer test machine proved unsuitable for testing shocks in the mid-to-high frequency range where the typical road input displacements fall within the noise floor of the elastomer machine. Hence, in this project, an electrodynamic shaker was used for exciting the shock absorbers under displacements less than 0.05 mm up to 500 Hz. Furthermore, instead of the swept sine technique, actual road data were used to excite the shocks. Equivalent linear spring-damper models were developed based on least-squares curve-fitting of the test data. The type of road profile did not influence the stiffness and damping values significantly for the range of amplitudes and frequencies considered. Finally, sensitivity of the vehicle level responses to the shock absorber rate change was studied, to finalize whether or not an upgrade to the existing shock absorber test procedure is necessary.

Publisher's Statement

Copyright © 1999 Society of Automotive Engineers, Inc. Publisher’s version of record: https://doi.org/10.4271/1999-01-1840

Publication Title

SAE Technical Papers

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