Abstract: Analyzing the design features of the original physical prototype of a trailed forklift, the primary shortcoming in original design is pointed out, and a blue print of modification about the elastic structure in suspension is put forward to improve its high-speed running stability. Then the theory of optimization design is applied in the field of matching design on the elastic structure in suspension. Based on the dynamic and static mechanical analysis of vehicle system, and combining the discussing on the influence factors about high-speed running stability of entire car, the corresponding optimization model is set up and solved, by which, the optimum rigidity peculiarities of the elastic components in suspension are determined to satisfy the design requirements of high-speed running stability of the vehicle. Finally, the validity of the optimization design is validated. On the one hand, the functional virtual prototype(FVP) about matching analysis between suspension system and entire car is built to simulate the stability of the trailed forklift in state of high-speed dragging running, and the simulation results indicate that the high-speed running stability of the optimized vehicle is improved obviously. On the other hand, guided by result of the optimization design, a new round physical prototype is trial-produced, then the contrast tests between the original and the optimized physical prototypes about high-speed stability in state of dragging running on real road condition are implemented, and the test results also indicate that the high-speed running stability of the entire car is surely ameliorated by means of the optimization design of the elastic structure in suspension.

Key words: Optimization design, Elastic structure in suspension, High-speed running stability, Trailed forklift