Fracture Behavior Prediction of a High-Strength Aluminum Alloy under Multiaxial Loading

Abstract

This study presents a triaxiality analysis and fracture behavior prediction of a high-strength aluminum alloy, specifically AW5754, under multiaxial loading conditions. The primary objective is to obtain a triaxiality locus, which depicts the relationship between the equivalent plastic strain to fracture and the stress triaxiality factor. This locus provides comprehensive insights into the fracture behavior of the material under various stress states. Experimental tests employing various specimen geometries are conducted to acquire essential data for analysis and to facilitate the development of a finite element (FE) model. Quasi-static uniaxial tensile tests are performed on five different specimen types, and accurate deformation measurements are obtained using extensometers at critical locations. The simulation results from the FE models are then compared with the experimental measurements to ensure their accuracy. The developed FE models are used to calculate the equivalent fracture strain and stress triaxiality factor with the help of collected test data. These calculations enable the generation of a stress triaxiality locus through a curve-fitting process. An exponential curve fitting function is chosen to appropriately relate the equivalent plastic strain to the fracture and stress state for the AW5754 aluminum alloy. The resulting stress triaxiality locus serves as a valuable tool for predicting fracture strain and evaluating stress states more accurately. The outcomes of this study contribute significantly to our understanding of the fracture behavior exhibited by high-strength aluminum alloys under multiaxial loading conditions.