Examination of the failure behaviour of wood with a short crack in the tangential–radial system by single-edge-notched bending test

Single-edge-notched tests of a tangential–radial system were conducted on agathis specimens to analyze the failure behaviour of wood with a short crack. The nominal bending strength and mode I critical stress intensity factors of the specimens with various crack lengths were measured, and the influence of the crack length on these properties was examined. The nominal bending strength of the cracked specimens was significantly lower than that of a crack-free specimen, even when the crack was extremely short. This finding suggests that the fracture mechanics theory is essential for analyzing the failure behaviour of wood with a very short crack. However, the mode I critical stress intensity factor still depended on the crack length. When considering the fracture process zone developing at the crack tip, the critical intensity factor could be predicted effectively.