Hill Engineering Blog

New Publication: Measurement-driven, model-based estimation of residual stress and its effect on fatigue crack growth. Pt 2: fatigue crack growth testing and modeling

Hill Engineering recently published new research outlining a approach for predicting fatigue crack growth in the presence of residual stress fields. The paper is titled Measurement-driven, model-based estimation of residual stress and its effect on fatigue crack growth. Part 2: fatigue crack growth testing and modeling and appears in International Journal of Fatigue. The abstract text is available here along with a link to the publication.

This paper assesses the accuracy of fatigue crack growth (FCG) predictions for high-strength aluminum samples containing residual stress (RS) and complex two-dimensional cracks subjected to constant amplitude load. FCG predictions use linear-elastic, multi-point fracture mechanics. A first prediction includes RS estimated by the model described in Part 1; a second prediction includes RS measured by the contour method. FCG test data show a significant influence of RS. Ignoring the RS results in a +60% error in predicted FCG life (non-conservative). Including RS improves predictions of crack growth significantly (errors better than +26% (estimated RS) and -14% (measured RS)).

Collection of line plots showing the residual stress intensity factor around the crack tip for different residual stress states
Maximum stress intensity factor for different residual stress conditions

If you are interested, the full publication is available here.