Robust design of a vehicle suspension manufacturing process using multibody simulation

Product designers worldwide are confronted with highly competitive though conflicting demands to deliver more complex products. with increased quality in ever shorter development cycles. Optimizing design performance with purely test-based approaches is no longer an option and numerical simulation methods are widely used to model, assess and improve the product design based on virtual prototypes. Combined advances in test and simulation push the design envelope to shorter and higher quality product development cycles. However, while CAE methods allow improving nominal product design using virtual prototypes, variability in properties and manufacturing processes lead to scatter in actual performances. Variability must hence be incorporated in the CAE process to guarantee the robustness of the design. This paper presents the application of these variability quantification techniques for robust design to a vehicle suspension system. A multibody model of the suspension has been created to predict the response of the system in terms of riding and handling characteristics. Variability in the performance has been quantified and a robustness assessment carried out to predict the effect of design parameters variations on the desired performance. The results of the robustness assessment have been used to improve the manufacturing process of the suspension and drastically reduce the scattering in the output quantities of interest. With the robust design methodology, engineers can obtain a better understanding of the actual effect of the manufacturing tolerances and of other sources of variability. Based on the analysis results, the robustness of the design can be assessed and improved if needed.