Results are presented from a combined theoretical and experimental investigation into the effect of stretching-shearing coupling on the buckling and growth of near-surface delaminated regions. Honeycomb sandwich laminates with graphite/epoxy face sheets containing preimplanted, through-width delaminations were tested in compression. Two layups were tested. Each layup contained delaminated regions with identical in-plane and flexural moduli; however, one layup exhibited stretching-shearing coupling, whereas the other did not. Delamination buckling was predicted using a cylindrical buckling analysis, and energy release rates and fracture mode ratios were obtained by a crack tip element analysis. Delamination growth was predicted using a linear, mixed-mode delamination growth law. Significantly different delamination buckling and growth strains were predicted for the two layups. Predicted delamination buckling and growth strains correlated well with experimental results.
ASJC Scopus subject areas
- Ceramics and Composites
- Civil and Structural Engineering