Evaluation of the Effective Stress Intensity Factor Using Thermoelastic Stress Analysis and 2D Digital Image Correlation

Abstract

In the present work, fatigue crack tip shielding influence is assessed via two full-field optical techniques which are thermoelastic stress analysis and digital image correlation. Two different crack tip field models (CJP and Muskhelishvili) were combined with experimental data from both optical techniques to determine the ΔKeff. The crack tip fields were measured on an aluminium alloy (7050-T6) specimen during fatigue crack growth testing for different R-ratios. The obtained results agree well in terms of ΔKeff showing a variation in ΔK as the R-ratio changes. Hence, the ability of both techniques and crack tip field models to measure effective fatigue crack driving forces is highlighted.

Keywords

• effective stress intensity factors
• crack closure
• TSA
• DIC