A fracture mechanics approach to accelerated life testing for cathodic delamination at polymer/metal interfaces

This work presents a fracture mechanics analysis of the cathodic delamination problem for the polyurethane/titanium and polyurea/steel interfaces. The nonlinear behavior of both polymers was investigated. The recent Marlow model was used to define the strain energy function of the polymers. Viscoelastic effects of the polyurea were also studied. The Marlow model was associated with a nine-term Prony series. This model was seen to represent experimental data relatively well for a wide range of strain rates both in tension and compression. The driving force for delamination, the strain energy release rate G, is presented for both interfaces. Cathodic delamination data for several temperatures are presented as crack growth rate as a function of crack driving force. The approach recognizes that both temperature and stress can be used as accelerated life testing parameters.