Papers by Author: Chan Seok Park

Abstract: An automotive bushing is a device used in automotive suspension systems to reduce the load transmitted from the wheel to the frame of the vehicle. A bushing is a hollow cylinder, which is bonded to a solid steel shaft at its inner surface and a steel sleeve at its outer surface. The relation between the force applied to the shaft and the relative deformation of a bushing is nonlinear and exhibits features of viscoelasticity. In this paper, an automotive bushing is regarded as nonlinear viscoelastic incompressible material. Instron 8801 equipment was used for experimental research and ramp-to-constant displacement control test was used for data acquisition. Displacementdependent force relaxation function was obtained from the force extrapolation method and expressed as the explicit combination of time and displacement. Pipkin-Rogers model, which is the direct relation of force and displacement, was obtained and comparison studies between the experimental results and the Pipkin-Rogers results were carried out.

Abstract: An automotive transmission (TM) rubber mount is a device that is used in automotive systems to cushion the loads transmitted from the vehicle body structure. A TM rubber mount is used to support the engine in the vertical direction. However, the dynamic behavior of loaded rubber mount is not yet known to a reasonable degree of accuracy. The relationship between the force applied to a TM rubber mount and the resulting deformation exhibits features of viscoelasticity. Therefore, in this study, viscoelastic properties were measured during ramp-toconstant displacement control tests. A force-displacement relationship for a TM rubber mount is important for multi-body dynamic numerical simulations. Hence, an explicit force-displacement relationship was developed and expressed in terms of a force relaxation function. A method that can be used to determine the force-displacement relationship from experimental data for a TM rubber mount was also developed. Solutions were obtained and the results were compared with experimentally measured force-displacement behavior. The predictions of the proposed forcedisplacement relationship were in very good agreement with the experimental results.