Rubber Bushing Design and Shape Optimization Based on Fatigue Life Prediction

The design of rubber bushings affects vehicle noise and vibration, riding response and comfort. Due to the complex geometry, material and coupling phenomena, obtaining a design that meets the stiffness compliance requirements and warranted life can be challenging and expensive. Finite Element Analysis (FEA) offers a cost effective solution for accurate prediction of resulting bushing behaviors under multi-axial, variable amplitude loadings. Numerical fatigue analysis provides an effective approach to quickly assess safety and reliability. By adding numerical fatigue analysis and optimization methodology to FEA, an automated workflow is proposed for the design engineers to obtain an optimum design of the rubber bushing that satisfies the preferred stiffness compliance and exhibits long fatigue life. The workflow includes two optimization procedures: a parametric optimization of the bushing geometry to achieve the preferred stiffness compliance; and a non-parametric optimization to maximize the fatigue life of the bushing.