Extension of the virtual crack closure technique to cracked homogeneous bodies undergoing large deformations

In this work, energy release rates evaluated by means of the virtual crack closure technique (VCCT) are analyzed for structures undergoing large deformations. For this, nonlinear finite element (FE) analyses are carried out on edge notched and pure shear specimens in Abaqus. Two hyperelastic constitutive material models: incompressible Mooney–Rivlin (I-MR) and incompressible Ogden (I-Ogden) were used. For the nonlinear elastic analyses, the relationship between the force and displacement at a node may not be linear. Hence, the nodal point forces need to be integrated over the corresponding displacements to evaluate the energy release rates. The need for transforming the nodal point forces and displacements into a local nodal coordinate system to determine the energy release rates and mode mixity is examined. The relation between the total energy release rates G_T evaluated from the nodal point forces and displacements in the global and local nodal coordinate system is derived analytically and analyzed numerically. Finally, G_T evaluated by VCCT for the pure shear and edge notched specimens are compared to the J-integral.