A physically consistent virtual crack closure technique for I/II/III mixed-mode fracture problems

We present a physically consistent virtual crack closure technique (VCCT) that can be applied to three-dimensional problems involving I/II/III mixed-mode fracture. The crack-tip forces exchanged between the nodes of the finite element model along the crack front are decomposed into the sums of three energetically orthogonal systems of forces. The modal contributions to the energy release rate are associated to the corresponding amounts of work done to close the virtually extended crack.