Abstract
Foam-core sandwich beam specimens for fracture toughness measurement are designed based on the prediction method of steady-state crack location in foam-core sandwich beams using the crack deflection model developed previously. This paper derives the necessary condition that face sheet debonding grows along the interface between the face sheet and the core during the fracture toughness tests, and shows the recommended specimen thickness ratios for several testing methods. Finally, the physical meaning of the derived condition is explained, and the effect of residual thermal strains on the condition.
