Experimental and numerical investigations of crack growth under mixed-mode loading

Fatigue fracture is the one of the most common failures of mechanical components. This is caused by the initiation and growth of cracks. In this study, mixed-mode I/III fatigue crack growth was studied experimentally and numerically for a cylindrical specimen with a stress ratio R = 0.1 for both loadings. A digital camera was used to monitor the crack growth path in the experimental studies. The crack growth path, crack tip profiles, variations in stress intensity factors (SIFs) and equivalent SIFs were calculated by using the Ansys, FCPAS and Solidworks software, and the results were compared with experimental data. Modeling, meshing and problem-solving were performed using the Ansys software, and the resulting SIFs and equivalent SIFs along the crack front were calculated using the FCPAS software, which was employed with enriched elements. It is seen that the criteria from the literature (Richard, Tanaka, Pook and Ayhan–Demir) can be successfully applied to the problem. The results show that very good agreement is obtained between the results of the simulation and experiment in terms of both the evolving crack growth paths and crack tips. The presented methodology can be used to predict both the surface and interior crack paths for various loading conditions and applications.