Research on the prediction method of Ⅰ+Ⅱ mixed-mode crack growth rate in 6005A-T6 aluminum alloy based on limited samples
HE Han
BAI Xiaoning
CAO Yang
Abstract：To evaluate the performance of various equivalent stress intensity factor models in predicting mixed-mode fatigue crack growth and to address the challenge of parameter estimation under limited sample conditions.A crack growth parameter estimation method based on the Bootstrap method resampling technique was proposed firstly.Mode Ⅰ fatigue crack growth tests were conducted on CT specimens to obtain the material parameters,and the proposed method was employed to expand the sample set and mitigate the issue of data scarcity.Then,using the statistically augmented material parameters,mixed-mode Ⅰ+Ⅱ fatigue crack growth experiments were performed on 6005A-T6 aluminum alloy CTS specimens under loading angles of 0°,30°,45° and 60°,employing a Richard-type loading fixture,to validate the accuracy of various equivalent stress intensity factor models.The results indicate that the Irwin model achieved the highest goodness-of-fit,with a value of 0.942 1,demonstrating the best crack growth prediction performance.Increasing the loading angle was found to reduce the initial crack growth rate,highlighting the need for angle-specific experiments to obtain appropriate Paris law parameters.This study confirms the applicability of multiple ΔKeq models and provides theoretical support for fatigue life prediction in mixed-mode crack growth scenarios.
Keywords：Aluminum alloyMixed-mode crackEquivalent stress intensity factorBootstrap methodLocal displacement field
Publication Date：2025-10-15
Online Publishing Date：2026-09-12(First online date of this platform, not the publication date of the document)
Pages：8( 131-138 )