FE model property definition for reliable prediction of spot weld behaviour

The goal of the activity is the development of a FE Model for the characterization of the mechanical properties of the spot weld taking into account its deformation and failure.
The requirement is fit as best as possible the different diagrams Force vs. displacement obtained at bench test, changing the virtual spot weld parameters property, to obtain realistic prediction, useful for achieve reliable crash simulation results on full vehicle model.
Test data came from experimental acquisition on welded steel plate having:

• two different grades of steel
• for each of these materials, three different thicknesses
• for each thickness: 5 different load conditions of the spotweld
  Optimization tool helped us in fit in the best way as possible the curve (test vs. simulation) with automatic and fast procedure.

This work has been coauthored together with Marco Barbi.