Local strain energy density to predict mode II brittle fracture in Brazilian disk specimens weakened by V-notches with end holes

Abstract

Abstract The present paper reports some experimental, theoretical and numerical results on brittle fracture of notched components made of Polymethylmethacrylate (PMMA). First, fracture experiments were carried out at room temperature on V-notches with end holes (VO-notches) under mode II loading by means of a recently proposed disk-type specimen, called the Brazilian disk containing central VO-notches (VO-BD specimen) made of PMMA for different notch angles and various notch radii. Then, the well-established averaged strain energy density (SED) criterion over the specified control volume which embraces the notch border was formulated and employed to predict theoretically the experimental fracture loads. The center of the control volume is located on the notch edge, where the principal stress reaches its maximum value. The correct orientation is obtained by a rigid rotation of the crescent-shaped volume while the size depends on the fracture toughness and the ultimate strength of the material. This methodology has been already used in the literature to analyze U- and V-shaped notches subject to different loading modes with very good results and advantages with respect to classic approaches. In this contribution it was demonstrated that SED works well also on VO-notches under pure mode II loading.