A synthesis of Polymethylmethacrylate data from U-notched specimens and V-notches with end holes by means of local energy

In this paper a volume criterion based on a simple scalar quantity, the mean value of the strain energy (SED), has been used to assess the static strength of notched components made of Polymethylmethacrylate (PMMA). The control volume is thought of as dependent on the linear elastic ultimate tensile strength and the fracture toughness in the case of brittle or quasi-brittle materials subjected to static loadings. The local-strain-energy based approach has been applied to two well-documented set of experimental data recently reported in the literature. Data refer to blunt U-notched specimens of commercial PMMA subjected to static loads and characterised by a large variability of notch tip radius (from 0.25 mm to 2.5 mm). Critical loads obtained experimentally have been compared with the theoretical ones, estimated by keeping constant the mean value of the strain energy in a well-defined small size volume. In addition, some new tests dealing with V-notched specimens with end holes have been carried out to investigate the effect of the notch opening angle and thirty new data have been summarised in terms of the SED. The new data have permitted to strengthen the validation aspects of the modelling. (C) 2013 Elsevier Ltd. All rights reserved.