The mathematical modelling of a vehicle when it is driving into a fixed or deformable barrier or into another vehicle must allow to reproduce the deceleration field inside it and its structural and kinematic behaviour. Although a detailed view can be obtained using finite element modelling, the more global multibody approach has the advantage of requiring considerably lower computing costs, and therefore of studying quickly the behaviour for many input data.
The main difficulty in executing the above procedure is to determine the laws governing the behaviour of the deformable links. These can first be estimated either by finite element calculations, or by static or dynamic tests. This approach can be improved using an identification methodology, provided that the kinematics in a crash trial is well known.
A non parametric identification method has been considered. But the results have not been satisfactory enough.
Conversely, if an initial estimate of the set of parameters is available, a parametric identification can be preferred. Several have been tested. Once their respective stability and strength had been determined on one-dimensional test models with one and two degrees of freedom. Predictivity and reliability trials in the presence of noisy data have been envisaged. The results have permitted to highlight which is the best adapted to solve the problem.
We have applied the chosen approach in the case of the impact of guided vehicles (the TGV Atlantic high-speed “bullet” train) and road vehicles.