A new strategy for predicting fracture of U‐notched specimens made of Al‐6061‐T6 and Al‐5083 using extended finite element method

Abstract

This research focuses on the numerical investigation of fracture loads of U‐notched specimens made of Al‐6061‐T6 and Al‐5083 under pure opening mode and mixed mode I/II loading conditions. A new methodology is introduced with the aid of the equivalent material concept (EMC) combined with the extended finite element method (XFEM) and linear cohesive zone model (CZM), and the outcomes are compared with a conventional elastic–plastic damage model. The combination of EMC and XFEM result in the numerical EMC‐XFEM model, which provides a fast and accurate method to assess the notch fracture loads and crack growth path. Considering the experimental results, a trial and error loop is performed to calibrate the ductile damage model, which is much more cumbersome than the proposed EMC‐XFEM model. Moreover, the computational cost of elastic–plastic model is much more than the EMC‐XFEM model, although both approaches provide appropriate predictions for fracture of ductile aluminum notches.

Revisiting classical concepts of Linear Elastic Fracture Mechanics - Part II: Stretching finite strips weakened by single edge parabolically-shaped notches

“…The same field was used by Sangsefidi et al [31], who determined the mixed-mode fracture toughness of rocks, again by means of the Brazilian disc test with specimens weakened by U-shaped notches. Nowadays, hybrid schemes are extensively used, combining successfully analytical solutions with experimental protocols and numerical tools [32][33][34]. In the light of the above discussion, it can be definitely stated that the question concerning the stress field in the vicinity of the crown of notched members is by no means closed.…”