Size effects on fracture toughness of polymeric specimens weakened by V-notches with end holes (VO) subjected to opening mode loading

Purpose This study aims to investigate the effect of specimen size on the fracture resistance of V-notches with end holes (VO-notched) polymeric samples under opening mode loading experimentally and theoretically. Design/methodology/approach First, a number of VO notched Brazilain disk (VONBD) and VO notcehd semi-circular bend (VONSCB) samples with different sizes were made from polymethyl methacrylate and general-purpose polystyrene sheets and then were tested under pure Mode I loading. After that, it is tried to predict the fracture resistance of notched samples using two stress-based criteria [point stress (PS) and mean stress (MS)] considering the size effect. Findings First, it is found from experiments that the fracture resistance of polymeric VO-notched specimens varies with the size of specimen in such a way that notch fracture toughness increases by increasing the specimen size. Secondly, it is found that the PS and MS criteria are able to predict in good accuracy the fracture resistance of tested samples. Originality/value The size effect on the notch fracture toughness of VO-notched polymeric samples is investigated for the first time, and it is the main novelty of this research.