Experimental and numerical study of delamination phenomenon in sandwich structures with hybrid corrugated core in the mode II of crack growth

The present study experimentally evaluates delamination of hybrid corrugated-core sandwich structures in the mode II of failure under flexural loading. Three sandwich structures with different cores, including core with no reinforcement, trapezoidal reinforcement, and triangular reinforcement, were fabricated. The strain energy release rate (G) of each specimen was then measured in the mode II of crack growth. The R-curves of the specimens were also extracted using experimental data, and by photographing the crack growth. Furthermore, the effects of the initial crack length on the R-curve were measured. In the last phase of this study, the specimens were numerically modeled using the finite element method (FEM). The delamination of the core and face sheets was modeled using the cohesive zone method (CZM), and the load–displacement curves of the specimens were extracted and compared to those of experimental data.