Abstract: Aiming at decreasing shock absorber’s side load in the MacPherson suspension system, improving suspension performances and reducing manufacture cost, a multiobjective optimization approach was proposed. This virtualprototypebased approach combines the penalty function algorithms SUMT, vehicle system dynamics simulation and finite Element Analysis. Taking a small passenger car as an example, structure parameters were optimized for this curved side load spring. The results of vehicle dynamics simulation, the experimental data of test rig and on road test indicate the improvement of ride performances, in which the side load on damper rod reduces almost to zero and the first resonance peak amplitude of the body acceleration decreases by nearly 24.37%. Besides, the average weight of spring samples also reduces by 2.71% so as to save the manufacture cost.

Key words: MacPherson suspension, spring, side load, multiobjective optimization