Comparison of Residual Strength Estimates for Bolted Lap-Joint Panels

Fracture analysis of cracks along mechanically fastened joints is a central issue in the damage tolerance assessment of semimonoque aircraft structures. Nonlinear elastic-plastic finite element analysis, employing the crack-tip-opening-angle criterion, was used to evaluate residual strength of bolted lap-joint 2024-T3 aluminum panels with multiple site damage subjected to Mode-I loading. A total of 36 different crack configurations were analyzed and compared to the experimental results. The effect of different aspects of the finite element modeling procedure on the accuracy of the residual strength predictions was investigated. Modeling of the geometric details of the test panels, such as fasteners and antibuckling restraints, was found to have a considerable effect on the predicted residual strengths. The nonlinear analyses provided reasonable estimates of the residual strength. The numerical results were compared with residual strength predictions obtained from a semi-empirical link-up model. Both approaches were comparable in terms of accuracy when compared to the test data.

Comparison of Residual Strength Estimates for Bolted Lap-Joint Panels Academic Article