The energy release rate of a crack in the interfacial zone of particulate-reinforced composites

In this work, the energy release rate is computed for a curved crack in a two-phase particulate composite Al/SiC. The crack lies in a flexible interface between the spherical particle and the surrounding matrix. Applying classical approaches to calculate the energy release rate of that kind of crack is not an easy task, especially as the problem is of three-dimensional nature and the material is heterogeneous. Thus, the principles of the so-called θ-method are used to deal with these difficulties. Using the variational formulation, the method is rewritten for the case of cracks lying in compliant interfaces, which permits to obtain the expression of the energy release rate in the form of a domain integral. The expression is eventually discretized in the framework of the finite element method in order to have a usable form for the simulations. The validation of the method is made in the first place by considering the simpler case of a crack around a cylindrical inclusion, for which an analytical solution exists. The energy release rate is then evaluated for the cracked Al/SiC composite with compliant interfaces while making some micromechanical parameters vary, like the mechanical properties of the constituents. The evolution of the energy release rate is also represented with respect to growing crack lengths.