Optimization of Suspension Elastomeric Bushing Compliance Under Constraints of Handling, Ride and Durability

Elastomeric bushings are widely used in the passenger cars to make the cars have an ideal vehicle Noise, Vibration and Harshness (NVH) performance. However, elastomeric bushings also influence on the vehicle handling, ride and the durability performance of each component in the vehicle suspension system. It is relatively easy and cost effective to change the compliance of the bushing components compared with other method because they are made of elastomeric materials. The design of an elastomeric bushing is really a big challenge. One of the main difficulties comes from the different target compliance is wanted according to the handling, ride and durability demand at each different orientation (indicated by X Y Z) of the bushing. In this paper the following procedure was used for optimization of suspension elastomeric bushing compliance. Firstly, a detailed multi-body model was built including the nonlinear bushing effects and lower control arm flexibility. Secondly, a series of virtual proving ground experiments are evaluated, such as step input and steering wheel releasing test, and impulse input test for handling, road cleat test for ride comfort, random input running test for the durability performance of components in the vehicle suspension system. Finally, a multi-objective optimization algorithm is taken as the appropriate framework for the definition the compliance of the bushing components of the addressed multi-objective optimization problem. The proposed optimal design process for elastomeric bushing compliance made it easy to evaluate and improve the vehicle handling, ride and the durability performance of the vehicle suspension components in the vehicle development process.