Abstract
The effect of specimen geometry on tensile impact fracture toughness, and the relation between toughness and breaking energy were investigated on glass fiber reinforced polycarbonate plates.
The apparent strain fracture toughness of thick plates showed a constant value independent of the relative crack length and that of thin plates increased with increasing the relative crack length. However, the fracture toughness decreased with increasing the plate thickness at a given crack length. The fracture toughness of plates thicker than a given value reached a constant, but it was with much thinner plates than those satisfying the condition of plane strain fracture toughness defined by ASTM criteria.
The toughness calculated by the fracture mechanics was in good agreement with that determined experimentally from the breaking energy.
