Fracture prediction in flat PMMA notched specimens under tension - effectiveness of the equivalent material concept and fictitious material concept

Abstract

The fracture of notched elements under mode I loading (tension) remains an inexhaustible research topic, especially when it comes to the fracture of thermoplastic materials such as polymethylmethacrylate (PMMA), which experience considerable plastic strains under tension. The paper points out that traditional brittle fracture criteria such as mean stress (MS) or maximum tangential stress (MTS) criteria used to predict this phenomenon do not accurately indicate the value of the critical load. They work much better when combined with the equivalent material concept (EMC) and fictitious material concept (FMC). The effectiveness of both concepts depends on the size of the notch root radius, and thus on the yield zone size.