Fracture behaviour of notched round bars made of PMMA subjected to torsion at −60°C

This paper presents seventy new experimental results from PMMA notched specimens tested under torsion at -60 °C. The notch root radius ranges from 0.025 to 7.0. mm. At this temperature the non-linear effects previously observed on specimens of the same material tested at room temperature strongly reduce. The averaged value of the strain energy density over a control volume is used to assess the critical loads to failure. The radius of the control volume and the critical strain energy density are evaluated a priori by using in combination the mode III critical stress intensity factor from cracked-like specimens and the critical stress to failure detected from semicircular notches with a large notch root radius