A variational-based modeling for energy release rate of fiber/matrix interfacial fracture

An algorithm to determine the energy release rate (ERR) of pull-out test specimens based on variational principles is introduced. To study the radial dependency of the axial deformations of the matrix on the energy release rate, a displacement function which satisfies the required kinematic and kinetic boundary conditions is considered. The displacement function will include shear deformations. While obtaining the parameters of this displacement function from the principle of total potential energy, two distinct solutions were recognized, both have physical interpretations. One solution includes the shear deformation and the radial dependency. The second solution simulate the case of a constant normal strain. Employing the proposed modeling, the effects of various geometrical and material parameters on ERR were studied. Numerical results are presented to show the accuracy and efficiency of this model in comparison with other modelings.