The aim of this work is to develop a simulation tool able to foresee the dynamic behaviour of a vehicle involved in an emergency manoeuvre. This tool is suitable to reproduce the real dynamic of an accident and 50 could be exploited both for road safety analyses and both for accident reconstruction. In order to perform the dynamic analysis we have developed a detailed three dimensional handling model able to estimate interactions between tyres and road; furthermore an interaction model is required to simulate the interaction between vehicles and/or between vehicle and ground, taking into account high speed plastic strain. The latter interaction was evaluated according a three dimensional simplified model, called "collision points model", based on the assumption that bounding surface of the car, meshed with a polyhedron, is connected to the rigid body representing the car, by means of a damper and a spring in series. After contact detection, interaction loads are computed imposing equilibrium and compatibility conditions. Overall interaction loads together with external forces due to weight are used to integrate equations of motion for each rigid body on a explicit time step basis. Correctness of handling model was checked simulating a standard test and obtaining a very good agreement between numerical and experimental results. Interaction capability were widely tested starting with simple applications consisting in a bouncing sphere and a spinning top. Capability to reproduce accident dynamic was also tested on the basis of measured data. (A)
Abstract