Ductile fracture in metallic alloys often follows a multi-step failure process involving void nucleation, growth and coalescence. Because of the difference in orders of magnitude between the size of the finite element needed to resolve the microscopic details and the size of the engineering structures, homogenized material models, which exhibits strain softening, are often used to simulate the crack propagation process. Various forms of porous plasticity models have been developed for this purpose. Calibration of these models requires the predicted macroscopic stress-strain response and void growth behavior of the representative material volume to match the results obtained from detailed finite element models with explicit void representation. A series of carefully designed experiments combined with finite element analyses of these specimens can also be used to calibrate the model parameters. As an example, a numerical procedure is proposed to predict ductile crack growth in thin panels of a 2024-T3 aluminum alloy. The calibrated computational model is applied to simulate crack extension in specimens having various initial crack configurations and the numerical predictions agree very well with experimental measurements.
13th International Conference on Fracture
Gao, Xiaosheng, "A Mechanism-Based Approach for Predicting Ductile Fracture of Metallic Alloys" (2013). Mechanical Engineering Faculty Research. 945.