Interaction of delaminations and matrix cracks in a CFRP plate, Part II: Simulation using an enriched shell finite element model

Abstract

Numerical simulations are presented of a recently developed test which creates multiple delaminations in a CFRP laminate specimen that grow and interact via transverse matrix cracks [1]. A novel shell element enriched with the Floating Node Method, and a damage algorithm based on the Virtual Crack Closure Technique, were used to successfully simulate the tests. Additionally, a 3D high mesh fidelity model based on cohesive zones and continuum damage mechanics was used to simulate the tests and act as a representative of other similar state-of-the-art high mesh fidelity modeling techniques to compare to the enriched shell element. The enriched shell and high mesh fidelity models had similar levels of accuracy and generally matched the experimental data. With runtimes of 36 minutes for the shell model and 55 hours for the high mesh fidelity model, the shell model is 92 times faster than the high-fidelity simulation.

An explicit delamination propagation algorithm to simulate delamination growth under quasi-static and fatigue loading without re-meshing using virtual crack closure technique and progressive nodal release

“…3,4 However, to simulate general delamination growth, the VCCT requires coupling with an additional strategy, such as re-meshing. 5,6 Alternatively, the delamination can be assumed to always conform to the underlying mesh, [7][8][9] and delamination growth can be simulated by releasing node pairs along the delamination front. Such a strategy [10][11][12][13] typically leads to artificial stress concentrations requiring corrections such as proposed.…”