Transferability of the two-parameter fracture criterion for 2219 aluminium alloy cracked configurations

摘要

Two-dimensional elastic-plastic finite-element fracture simulations with the critical crack-tip-opening-angle fracture criterion were used to evaluate the two-parameter fracture criterion (TPFC). Three different crack configurations under tension and bending loads made of thin-sheet 2219-T87 aluminium alloy were analysed. A very wide range of widths (w = 76 to 2440 mm) and initial crack-length-to-width ratios (c_i/w = 0.05 to 0.95) were considered. A relation from the original TPFC was shown to fit the simulated fracture behaviour fairly well for the three different specimen types for net-section stresses less than the yield stress (σ_y) of the material. Comparisons were also made on measured and simulated fracture tests on middle-crack-tension specimens. A relation between the elastic stress-intensity factor, K_(le), and net-section stress, S_n, at failure was found to be linear for S_n ＜ σ_y. The results demonstrated the transferability of the TPFC for different crack configurations for S_n ＜ σ_y, but further study is needed for S_n ＞ σ_y.