Advanced approach for mixed mode crack propagation

Abstract

In practical cases, manufacturing of components are not always perfect. The influence of cracks on structures are of interest here. In SONACA, Extended Finite Element Method (XFEM) was used earlier for the prediction of crack propagation and bifurcation angle. But due to some difficulties, we have developed a technique called Crack Box Technique (CBT) which had some difficulty in implementing into the model and is overcome by a new technique. In this thesis work, our objective is to confront the crack box approach for different models and analyse the results. A single edge notched specimen under tension of Steel materials is selected for static load cases. The results are successfully confronted using the crack box approach, analytical calculation and compared with the literature results. Then, we wanted to use the Crack Box Technique to determine the behaviour of crack propagation by fatigue load and the propagation path of the crack. The Compact Tension Shear (CTS) specimen under mixed mode loading is considered. The bifurcation angle is determined using the various available bifurcation criteria. The equivalent stress intensity factor is determined and crack propagation is studied using various approaches and compared with the crack box results.