Residual Strength Predictions for Multiple Site Damage Cracking Using a Three-Dimensional Finite Element Analysis and a CTOA Criterion
SourceFracture tests were conducted on 2.3 mm thick 2024-T3 aluminum alloy middle crack tension, M(T), compact tension, C(T), and multiple-site damage (MSD) specimens covering a wide range in specimen widths (30 to 610 mm). Three-dimensional, elastic-plastic finite element analyses were conducted for each experiment. A critical CTOA value of 5.25° was determined from a 152.4 mm wide C(T) fracture test and was then used to predict the fracture behavior of the other tests. The critical angle was within the scatter in the experimental surface CTOA measurements. All of the predicted failure stresses for the single crack specimens, except for the smallest C(T) and M(T) specimens, were within 5% of the experimental failure stresses. The CTOA criterion predicted stable tearing, link-up stresses, and maximum stresses to within 7% of the experimental measurements.