A methodology for simulating plasticity induced crack closure and crack shape evolution based on elastic-plastic fracture parameters

A methodology for simulating plasticity induced crack closure and crack shape evolution based on elastic-plastic fracture parameters is proposed, which represents a new way to predict fatigue crack growth in small and large scale yielding scenarios. The methodology consists in solving iteratively a single elastic-plastic finite element model, for which the load history is kept by remeshing and mapping and crack advance is performed by node releasing. Aiming to illustrate and validate the approach, the growth of an initially straight crack is simulated in a compact tension specimen subjected to small scale yielding conditions, using the plastic crack tip opening displacement range (Delta CTODp) as the crack driving force. The predicted crack shape shows high agreement with experimental observations and the crack opening load trends are consistent with the literature, demonstrating that the methodology proposed can be relevant for further crack growth studies.

Automated summary

A new methodology for predicting fatigue crack growth in small and large scale yielding scenarios is proposed based on simulating plasticity induced crack closure and crack shape evolution. By simulating crack growth in a compact tension specimen subjected to small scale yielding conditions, the predicted crack shape shows high agreement with experimental observations, indicating the relevance of the proposed methodology for further crack growth studies.