Simulation of stage I fatigue crack growth in a polycrystal through coupled FEM and discrete dislocation dynamics

GRACIELA BERTOLINO; VÉRONIQUE DOQUET; MAXIME SAUZAY

Canada

Conferencia; First International Conference on Fatigue Damage of Materials; 2003

Wessex Institute of Technology

<!-- @page { size: 8.5in 11in; margin: 0.79in } P { margin-bottom: 0.08in } --> An attempt to model the variability of short cracks development in high-cycle fatigue is made by coupling finite element computations of the stresses ahead of a microcrack in a polycrystal with simulations of crack growth along slip planes based on discrete dislocations dynamics. The model predicts a large scatter in growth rates related to the crystallographic desorientations along the crack path. It also describes qualitatively the influence of the mean grain size and the fact that overloads may suppress the endurance limit by allowing arrested cracks to cross the grain boundaries.