Validation of the Two-Parameter Fracture Criterion using finite-element analyses with the critical CTOA fracture criterion

Elastic-plastic finite-element analyses employing the critical crack-tip-opening-angle (CTOA) fracture criterion were used to simulate fracture on thin-sheet middle-crack-tension, M(T), specimens made of several aluminum alloys over an extremely large range of widths (18-5700-mm) for a wide range in crack-length-to-width ratios. A linear relation between elastic stress-intensity factor (K-Ie) and net-section stress (S-n) at failure was observed for Sn less than yield stress of the material. Test data on two aluminum alloys (2024-T3 and 2219-T87) over a wide range of M(T) specimen widths (76-600-mm and 76-1200-mm, respectively) supported the linear relationship that validated the Two-Parameter Fracture Criterion. (C) 2015 Elsevier Ltd. All rights reserved.