Non-local continuum damage mechanics-based crack growth modelling for high-performing steel structures

Abstract

This study describes a non-local continuum damage mechanics-based model for crack initiation and growth modelling. The focus is on its application in high-performing welded structures, where crack initiation and short crack growth play an important role. The introduced model uses local stress-strain field and microstructure-dependent material units together with continuum damage analysis, allowing the same modelling principle used for initial geometry and following crack growth analysis, i.e. whole fatigue damage process from crack initiation to final failure. This modelling enables an explicit consideration of micro-scale geometry, residual stress conditions, and material mechanical properties to estimate fatigue life accurately. An application case using a mild notch geometry illustrates the evolution of local fatigue response during crack initiation and growth, offering insights into surface integrity effects on fatigue behavior. Also, examples of welded joints are also given to demonstrate the model’s capability in estimating total fatigue life and S - N curves.