Design optimization of a vehicle suspension systems for ride and handling performance

Abstract

Recently, many researchers have studied vehicle to improve the ride and handling performance. Ride and handling performance is affected by suspension of vehicle. So, in this study, we perform the optimization of suspension to improve the ride and handling performance. Also, we propose design strategy to efficiently carry out design optimization using CAE. The proposed design strategy is as follows. First we establish the CAE analysis procedure of ride and handling performance. Then, to enhance the efficiency of design work, we integrate and automate the established CAE analysis procedure using a commercial process integration and design optimization (PIDO) tool, PIAnO. Next, in order to assess relation between performances and design variables and to screen main design variables, we perform the DOE (Design of Experiments). Finally, to find the optimal solution, we used Progressive quadratic response surface method (PQRSM), one of the design optimization techniques equipped in PIAnO. We used two practical problems to verify the efficiency of the proposed design strategy. First, we perform the optimization of trailing arm bush in a vehicle rear suspension to improve the ride and handling performance. A design problem was formulated considering 2 objective functions and 7 constraints related to vehicle ride and handling performance. As an optimization result, we got an optimal solution and could improve lateral force steer off-center by 43.0% while decreasing brake compliance at wheel center by 8.1%. Next, hardpoint position optimization of vehicle front suspension was carried out. In order to improve ride and handling performance, a design problem was formulated considering 21 constraints and 1 objective functions related to vehicle ride and handling performance. As an optimization result, we got an optimal solution which decrease objective function (Ride steer linearity) by 61.8% and all design requirements were satisfied constraints. Thus, in this study, we proposed design strategy to efficiently carry out design optimization and we verified the efficiency of proposed design strategy from a practical problem. Also, by applying the proposed design strategy to various industrial product designs, we can improve performance and competitiveness of the products.