Abstract
This paper describes the experimental testing and validation of the analytical models developed in our companion paper (IMECE2005-81581) for the nonlinear kinematics and dynamics of the suspension linked to a nonlinear rack and pinion steering system model. More specifically, the experimental results are used to cross verify the numerical simulations of the nibble using custom built analytical and ADAMS models, described in the companion paper. For this, shop floor based quasi-static Kinematic and Compliance (K&C) and dynamic testing results along with track testing on special purpose track at Michelin are presented. Other results include impulse testing of the steering system, as mounted on the vehicle, as well as shaker testing to verify the results. Road testing is also carried out at speeds close to the vehicle critical speed in order to compare and validate the suspension models using the quasi-static K&C testing. The road testing results demonstrate the variation of forces in the steering system due to tire imbalances, emphasizing the nonlinear effects in the vehicle system modeling as well as the variation of the shimmy phenomenon with vehicle speed and tire imbalance.