VCCT with Progressive Nodal Release for Simulating Mixed-Mode Delamination: Formulation, Algorithmic Improvements and Implications

To simulate the propagation of cracks using the Virtual Crack Closure Technique (VCCT), intermediate crack positions between existing node pairs can be modeled by progressively releasing the nodes using fracture mechanics principles. This approach has been implemented in commercial software and can be applied to simulate delamination growth. Recent research has provided insight into the synchronized mixed mode nodal release, extending and formalizing the methodology for delamination growth. This paper documents the development of the Jacobians associated with delamination propagation under quasi-static mixed-mode conditions, leading to improvements in convergence of the implicit nonlinear solvers used.