Williams' blister test analyzed as an interface crack problem

A model is constructed to analyze more carefully the energy release rate for Williams' blister test. The model, which consists of an interface crack between two elastic layers, is loaded by uniform internal pressure. The singular integral equations for the dislocation densities are derived and solved using numerical quadrature and the energy release rate is calculated directly from the dislocation densities. Both the two-dimensional and axisymmetric penny-shaped crack problems are considered, and it is noted that there are significant differences between these two cases. It is found that in some cases crack propagation will not be catastrophic.