Vehicle Dynamics Simulation at Commercial Vehicle Development 2012-36-0018

This paper discusses the benefits of truck simulation for ride and handling tuning at product development. Virtual simulation can guide the conception of new vehicles to a better "first guess" of dynamics characteristics, providing calibrated options to define parameters for springs, dampers and anti-roll bars, closer to the desired condition. TruckSim™, from Mechanical Simulation, was the chosen software due to its user-friendly interface, fast modeling and post-processing that matches with challenging product time-to-market.

The scope of analysis is to evaluate/compare virtual results against subjective/objective tests on real prototypes, in order to proof software correlativity. The first step was to develop the vehicle model, using 3D CAD models information, data acquired from real prototypes and product specifications. The chosen vehicle was a 9-ton 4X2 rigid truck. The next step was to model the procedures: constant speed at 60 km/h, pass through a smooth bump at 15 km/h, double lane change at 60 km/h (ISO 3888) and step steer at 45 km/h (ISO 7401). These procedures were simulated with different sets of dampers and anti-roll bars. Comparative tests were performed in order to evaluate simulation results with empirical procedures, both for comfort level and cornering. The outputs chosen to validate the simulation were: acceleration, displacements of the CG and tires reaction forces at the contact path.

The analysis indicated that it is possible to reduce loops of suspension tuning therefore reducing time of tuning, saving prototype/test cost and development time. So far, simulated procedures are recommended even in conceptual phase to shift vehicle dynamic parameters into confident initial approaches.