Search Results

Rear end break-away, or skate, is a phenomenon that occurs when live axle equipped vehicles are driven aggressively on rough, winding roads. This paper reviews instrumented dynamic testing of a specially built vehicle. Initial testing linked skate to the tramp oscillation mode of the rear axle. Two variables were evaluated for reducing skate: shock absorber valving and shock absorber placement. The principal conclusion of this work is that although some reductions in skate are possible by adjusting shock absorber valving, optimum control of skate is facilitated by packaging the shock absorbers near the wheels.

A computer program which simulates a Formula SAE race car during transient cornering was developed as a design tool. The program incorporates a non-linear tire model based on empirical tire testing. This allows simulation of vehicle performance at the limits of tire adhesion. The simulation was validated using competition results and an instrumented four wheel steer (4WS) Formula SAE car. The simulation was used to investigate the dynamic characteristics of two mechanical 4WS systems during severe cornering. Each system was found to improve performance under different conditions. Lateral response was found to be independent of body roll for the vehicle studied.