A comparative study of dynamic, ductile fracture initiation in two specimen configurations

In this work a single edge notched plate (SEN(T)) subjected to a tensile st ress pulse is analysed, using a 2D plane strain dynamic finite element proc edure. The interaction of the notch with a pre-nucleated hole ahead of it i s examined. The background material is modelled by the Gurson constitutive law and ductile failure by microvoid coalescence in the ligament connecting the notch and the hole is simulated. Both rate independent and rate depend ent material behaviour is considered. The notch tip region is subjected to a range of loading rates j by varying the peak value and the rise time of t he applied stress pulse. The results obtained from these simulations are co mpared with a three point bend (TPB) specimen subjected to impact loading a nalysed in an earlier work [3] The variation of J at fracture initiation, J (c), with average loading rate j is obtained from the finite element simula tions. It is found that the functional relationship between J(c) and j is f airly independent of the specimen geometry and is only dependent on materia l behaviour.