A finite element model for the analysis of buckling driven delaminations of thin films on rigid substrates

Abstract

The delamination process of thin films on rigid substrates is investigated. Such systems are typically subject to high residual compression and modest adhesion causing them to buckling driven blisters. In certain cases buckles with the shape of telephone cords are observed. A finite element model for quasi–static delamination growth is developed. Applying a Reissner–Mindlin shell kinematic for the film allows C 0− continuous shape functions. The traction vector at the film–substrate interface is obtained from the derivative of a cohesive free energy. Incorporation of loading and unloading conditions is considered for the irreversible process. The equilibrium state is computed iteratively in dependence of the compressive residual stresses. The computed telephone cord delaminations are stable asymmetric configurations whereas the symmetric configurations are unstable.