Fracture Behavior Characterization of Automotive Aluminum Alloy Based on XFEM

Automotive thin-wall aluminum alloys 5052H32 and 6061T6 are widely used in the stamping sheet metal parts and structural parts of lightweight car bodies due to their excellent formability. To establish behavior characterization models reflecting the actual mechanical properties of materials,aiming at different development stages of elastoplastic deformation,damage evolution and ductile fracture in their nonlinear constitutive responses,J-C elastoplastic model,damage control model and J-C failure model,GTN meso damage model,MMC fracture model related to stress concentration state were developed respectively. The effective parameters of each model were calibrated by means of parameter inversion and genetic algorithm optimization to form the whole process characterization of mechanical evolution. Using the above models combined with extended finite element method,the tensile fracture process of thin-wall specimens was accurately simulated. The accuracy of the extracted constitutive property parameters was verified through the dynamic growth behavior of internal crack,strain field and fracture morphology consistent with the experiments. And the fracture prediction accuracy using the empirical MMC criterion reached the highest,with a deformation error of only 4. 7%. © 2024 Cailiao Daobaoshe/ Materials Review. All rights reserved.