Ground Clearance Simulation at GM Europe using Hyperworks/MotionView

The early evaluation of vehicle and subsystem concepts, the reduction of the number of necessary test runs, the verification of multiple variants and the possibilities to do quick parameter studies are critical issues in modern engineering where sophisticated simulation methods are used to improve and to fasten the engineering process. Given the future legal requirements for CO2 emissions and the correlated measures to improve the aerodynamics of the vehicle the evaluation of ground clearance is one of the most important topics for the development of future passenger cars.

This paper describes how the multi-body simulation environment at GM Europe (GME) - consisting of the Hyperworks/MotionView pre-processing, the Virtual Modeling Components (ViMC) library and the Adams solver - is used to simulate ground clearance load cases (e.g. driving over curbs, ramps and speed humps with distinct speed and with distinct steering angles). Since it is important to use a high-performance tire model that models the deflection of the tire when driving over curbs or edges, the FTire tire model is used. A multi-body simulation with a full vehicle model based on the modular built GME vehicle dynamic master model is run to calculate the trajectories of the underbody. Using the CAD models of the chassis and the underbody and specific clearance tools critical points at the underbody are predicted and critical driving maneuvers are identified. Furthermore, the ground clearance performance is visualized in specific video sequences for more detailed analysis purposes.