Volumetric and Dynamic Performance Considerations of Elastomeric Components

Abstract

The scope of this article is limited to elastomeric mounts or bushings where the material is considered to be linear elastic with frequency dependent structural damping. Only the axial direction of a cylindrical component (as displayed in Fig. 1) is examined. The specific objectives of this article are as follows: 1. Design two illustrative cylindrical mounts that are scaled to have identical axial static stiffness of the same material and compare the dynamic behavior, 2. Develop a lumped parameter model that captures the

Estimation of the transient response of a tuned, fractionally damped elastomeric isolator

“…developed a lumped parameter model for an elastomeric joint which clarified the frequencydependent stiffness by capturing internal mass effects [6]. Their model offers good broadband dynamic stiffness predictions, but significant error is found in the lower-frequency regime (say, up to 100 Hz).…”

“…Their model offers good broadband dynamic stiffness predictions, but significant error is found in the lower-frequency regime (say, up to 100 Hz). This error is linked to the damping mechanism assumed in the model [6]. Neither structural nor viscous damping is able to produce the low-frequency behavior with a minimalorder model [15], although large, empirical viscoelastic networks may reproduce the effect on an ad hoc basis.…”

“…Elastomeric isolators are typically characterized in terms of dynamic stiffness spectra [1][2][3][6][7]. A comparison between the measured cross-point stiffness magnitude spectrum and finite element predictions of a laboratory bushing (very similar to production devices [6]) is given in Figure 1. Details and parameters of the finite element model are already reported in [6].…”

“…A comparison between the measured cross-point stiffness magnitude spectrum and finite element predictions of a laboratory bushing (very similar to production devices [6]) is given in Figure 1. Details and parameters of the finite element model are already reported in [6]. Good broadband accuracy is achieved by the finite element model; however, at low frequencies (below 100 Hz), the measurement reveals a damping mechanism which is not incorporated in the model.…”

“…In automotive suspension, for instance, bushings are used extensively to ensure vibration isolation and impedance mismatch between critical subsystems. Such isolators have been analytically studied with continuous system theory [1][2][3] as well as lumped parameter models on both the component [4][5][6] and system [7] level, often with many simplifications. In many cases, isolators exhibit nonlinear behavior [3][4][5]8] which may be more readily apparent from transient responses [4,5].…”