Interfacial characterization of pre-strained polymer coated steel by a numerical-experimental approach

In this paper, the delamination in pre-strained polymer coated steel is quantitatively characterized through a combined numerical–experimental approach. The surface roughening of the steel substrate is analyzed by a correlation technique and coupled to the pre-deformation of the coating. The polymer coating shows a clear stress relaxation after pre-deformation, which requires special attention for the correct numerical characterization of the interface. A large displacement cohesive zone model is extended with an interfacial pre-damage parameter representing the loss of adhesion due to substrate roughening. Finally, peel tests are performed on pre-strained specimens, on the basis of which the interface is characterized by an inverse parameter identification procedure.