Steady-State Delamination in Multilayers

In this chapter, the framework to analyze a multilayer stack of blanket films is presented. Emphasis is placed on stacks with piecewise-linear distributions of misfit, or ‘eigenstrain’, strain variations within each layer allowing for the possibility of discontinuities from layer to layer. In addition to being applicable to thermal problems with steady-state thermal distributions through the multilayer, the formulation encompasses layers with residual processing strains which vary from layer to layer and possibly within layers. The principle focus of this chapter is on computing the steady-state energy release rate for a semi-infinite crack. The results of the analysis are algebraic but nevertheless will usually require some computation. As the framework is applicable to any number of layers, it provides the basis to derive the results presented in Chapter 4 for bilayers.