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

Abstract

AbstractTwo‐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 (ci/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 (σy) 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, KIe, and net‐section stress, Sn, at failure was found to be linear for Sn < σy. The results demonstrated the transferability of the TPFC for different crack configurations for Sn < σy, but further study is needed for Sn > σy.