Papers by Keyword: Short Fatigue Crack Growth

Abstract: The influence on the fatigue crack growth behaviour of a short edge crack due to different configurations of a nearby located low angle grain boundary is investigated under quasi-static and plane strain conditions. The geometry is modelled by dislocation dipole elements in a boundary element approach, and the plasticity is modelled by discrete dislocations. The crack is assumed to grow in a single shear mechanism due to nucleation, glide and annihilation of dislocations in the material. It was found that the sign of the dislocations in the grain boundary, the distances between them and the placement of the dislocations in the grain boundary with respect to preferred slip plane directions, all strongly influenced the growth behaviour.

Abstract: A new theoretical approach is presented for investigating fatigue crack growth in plates of finite thickness. The developed approach utilizes a modified strip-yield analysis and the concept of plasticity-induced crack closure. A number of typical fatigue crack growth phenomena are investigated including the thickness effect on constant amplitude fatigue crack growth, retardation due to a tensile overload cycle, and short crack growth from sharp notches. Theoretical predictions are compared with experimental data and are found to be in very good correlation.