Computational study of the initiation of crack extension in a solid propellant with a circular hole or inclusion

The stress and displacement fields in the problem of the fracture of an orthogonal plate made of a solid propellant containing only a crack or a crack and a circular hole or a crack and a circular steel inclusion was studied. The specimens are subjected to a uniform displacement along its upper and lower faces. The solid propellant was simulated as a hyperelastic material with constitutive behavior described by the Ogden strain energy potential. A nonlinear finite-deformation analysis was performed based on the finite-element code Abaqus. A very detailed analysis of the stress field in the vicinity of the crack tip was undertaken. The results of stress analysis were coupled with the strain energy density theory to predict the initiation of crack growth as a function of the distance of the crack tip from the hole or the inclusion and the normal distance of the hole or the inclusion center from the crack axis.