crack propagation; linear elastic fracture mechanics
In linear fracture mechanics, it is common to use the local Irwin criterion or the equivalent global Griffith criterion for decision whether the crack is propagating or not. In both cases, a quantity called the stress intensity factor can be used. In this paper, four methods are compared to calculate the stress intensity factor numerically; namely by using the stress values, the shape of a crack, nodal reactions and the global energetic method. The most accurate global energetic method is used to simulate the crack propagation in opening mode. In mixed mode, this method is compared with the frequently used maximum circumferential stress criterion.