Kriging metamodel global optimization of clinching joining processes accounting for ductile damage

Clinching is a very cheap and efficient cold forming process that enables to join two sheets without any additional part such as a rivet or a bolt. This paper deals with the optimization of the final mechanical strength of a joined component using a global optimization technique based on Kriging meta-model. The optimization process includes both the joining stage and the mechanical strength simulations. It is shown that accounting for plastic strain, residual stresses and damage occurring during clinching is essential if one wants to study the final mechanical strength of the clinched component. The global optimization leads to a 13.5% increase of the mechanical strength for tensile loading and to 46.5% increase for shear loading. The global optimization procedure also enables to study the influence of input geometrical variability on the final mechanical strength, which is essential from an industrial point of view.