A Fatigue Crack Growth Analysis Method Based on a Simple Representation of Crack-Tip Plasticity

A new approach to fatigue crack propagation is described. The key element in the analysis is the inclined strip-yield superdislocation representation of crack-tip plasticity. The basis of the model is given and its potential application in a cycle-by-cycle analysis of fatigue crack growth under arbitrary cycle-by-cycle loads indicated. It is shown that, to perform a fatigue crack growth computation for a given load sequence, only the material's shear modulus, tensile yield strength, and Poisson's ratio need to be specified. In the process, some account is taken of crack closure during the load cycle. Illustrative calculations for uniform cyclic loading are described and comparisons with experimental results made.