Progressive delamination analysis through two-way global-local coupling approach preserving energy dissipation for single-mode and mixed-mode loading

Together with fiber breakage and matrix cracking, delamination is one of the common damage mechanisms occurring
in laminated fiber-reinforced composite structures. Delamination initiates due to the relatively low interlaminar
strength of adjacent plies. Delamination onset and propagation can be induced by various combinations
of loads and usually leads to a significant reduction of the load-carrying capacity of the structure. For this
reason, an efficient and reliable progressive failure analysis capability is required. In this work, the delamination
process is simulated by means of a two-way global-local coupling approach. In particular, within this novel
global-local approach a method is introduced that ensures the preservation of the dissipated energy when switching
between the global and local level. This approach is tested and illustrated under single-mode I and II, and
mixed-mode loading in the double cantilever beam (DCB), the end-notched flexure (ENF) and the mixed-mode
bending (MMB) benchmark tests, respectively, and the results are compared to available analytical solutions.
Finally, the developed method has been applied to a one-stringer stiffened panel and a good agreement was attained
compared to the full reference solution.