Fatigue crack growth determination under in-phase and out-of-phase mixed-mode loading conditions using an automated DIC evaluation tool

Abstract

In this study Digital Image Correlation (DIC) is utilized for measuring complex fatigue crack paths under spatial mixed-mode loading conditions. Therefore, an existing automated script was extended by two criteria for measuring the crack length versus the number of load cycles. Experimental investigations were conducted under mode I conditions, to calibrate the new evaluation routine. Moreover, in-phase and out-of-phase mixed-mode experiments under superimposed tension-torsion loading were performed to validate the method. The results show that the newly presented procedure provides an accurate, automated evaluation tool for mixed-mode fatigue crack growth tests, independent of the crack orientation and possible branching.