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

摘要

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