COMBINED APPROACH USING TEST AND F.E.M. ANALYSIS IN CAR BODY DESIGN

In the early design stage of a new car, theoretical studies and analyses are a fundamental guide to the designer, but, to be an effective tool, mathematical models must be quick to prepare, ready to use and easy to modify in order to follow with efficiency the evolution of the design. Therefore in this phase, in terms of finite element models of the car body, only simple beam-and-shell models can be profitably used, models developed to provide macro-informations and to pursue parameter studies. But when prototypes are available, it is worth it to develop a more refined F.E.M. model which, after an intensive correlation process with experimental tests, can be so representative of reality as to provide precise information on the key parameters at the origin of the structural behaviour, thus allowing the full understanding and the optimization of the body. The present paper shows how these refined models have been used in the lightening and optimization process of a medium large saloon car.