Fatigue crack growth in CFRP foam-core sandwich structures

Sandwich structures offer a good ratio of bending stiffness and strength to weight. A typical sandwich failure mode is the occurrence of cracks in the interface between face sheet and core caused by impact. In the last resort the impact damage is non visible and propagates in service under cyclic loads up to global failure. Quasi-static and cyclic modified DCB and ENF tests were run to investigate the crack propagation under global Mode I and Mode II load.