A COMPUTATIONAL DYNAMICAL MODEL FOR TRAFFIC ACCIDENT RECONSTRUCTION

SINRAT is a computer program for reconstruction of traffic accidents, one that constitutes a powerful tool in the calculation applicable to the investigation, reconstruction and analysis of the damage produced in traffic accidents. SINRAT is provided with an input data pre-proces sor that allows the introduction of all the factors involved in an acc ident like braking, acceleration and steering manoeuvres executed by d rivers, road profile, etc. SINRAT includes a database where the techni cal features of about 7000 vehicles are found, so that when it is nece ssary to reconstruct an accident, you just have to indicate the make a nd model of the implicated vehicles. SINRAT incorporates a simulation model of the behaviour of vehicles using the bond graph technique. Eac h vehicle is considered as a three-dimensional body, linked to the whe els through the suspension system. The tyre-road contact is also model led. The collision model used permits simulation of the behaviour of t he vehicles before, during and after the collision. This collision tak es into account also the stiffness of the car's body and its energy ab sorption during the collision. SINRAT incorporates a driver model that determines the steering manoeuvre so that the vehicle traces a prearr anged trajectory. It incorporates also the possibility to introduce th e real profile of the road when it refers to the raisings, ramps, tran sition curves, etc. Even more, it includes an algorithm for the automa tic reconstruction of traffic accidents, which permits calculation of vehicle velocity from the data at the scene of the accident. Starting from these data, the program reconstructs the accident varying the col lision velocities until it reproduces the point of collision as well a s the final positions of all vehicles. Lastly, SINRAT possesses a grap hic post-processor which permits the visualization of the movements of the vehicles and the visualization of variables in terms of x-y plots .