Geometry effects on fracture trajectory of PMMA samples under pure mode-I loading

Mode-I fracture strength and crack growth trajectory of polymethylmethacrylate (PMMA) samples have been investigated experimentally and theoretically for five different cracked specimens. Although all the specimens have been tested under pure mode I loading conditions, the crack growth paths and the values of apparent fracture toughness have been found to be significantly different. The crack trajectory and the fracture strength can be estimated theoretically by using a modified form of the strain energy density criterion. The observed differences in the crack trajectory and the fracture strength of different specimens have been found to be related to the magnitude and sign of the T-stress.