Abstract: Based on the principle of imaginary work, the formulas for analyzing the rigidity and damping characteristics of double-wishbone suspensions with torsion bar are strictly derived. The definition designing procedure of torsion rigidity and the shock absorber damping based on the settled biased frequency and relative damping ratio is presented. And a new method calculating the design parameters of the torsion bar and the shock absorber is presented. The experiment shows that the simulating results are in good agreement with the theoretical results. Using above results, useful software for designing the suspension system is developed, and is successfully applied in the design of a new type of four wheel drive fuel cell vehicle with steer-by-wire.

Key words: Rigidity, Double-wishbone suspension, Shock absorber, Torsion bar, Virtual test