Material parameters for the VGM and SMCS model of ADC12 cast aluminium alloy: Calibration and verification

Cast aluminium alloy exhibits broad applicability in civil engineering, particularly for structural joints. To improve the engineering applications of cast aluminium alloys and ensure structural safety, it is essential to investigate their fracture behaviour. Micromechanical fracture models, including the Void Growth Model (VGM) and Stress-Modified Critical Strain (SMCS) model, provide a means of predicting the fracture behaviour of metallic materials by characterising fracture initiation through the growth and coalescence of internal micro-voids. In this study, the material parameters of the VGM and SMCS model for the ADC12 cast aluminium alloy were calibrated based on the experimental data obtained from the smooth notch tensile (SNT) tests. The calibrated parameters were then verified against the monotonic tensile tests conducted on centre-hole plate specimens. The results indicated that both micromechanical fracture models provided accurate predictions for fracture initiation in the centre-hole plate specimen, which demonstrated good consistency with the experimental results. Furthermore, fracture initiation and propagation in centre-hole plate specimens were investigated. Fracture evolution throughout the loading process was simulated by sequentially deleting elements identified as failed according to the VGM criterion. The load-deformation responses and fracture patterns obtained from finite element analysis exhibited close agreement with the experimental data, thereby validating both the calibrated material parameters and the VGM-based simulation approach for fracture propagation.