The Elastic-Plastic Finite Element Alternating Method (EPFEAM) and the prediction of fracture under WFD conditions in aircraft structures Part III: Computational predictions of the NIST multiple site damage experimental results

This report provides a summary of the Elastic- Plastic Finite Element Alternating Method (EPFEAM), the T*-integral fracture mechanics parameter, and the use of both the tools to predict the residual strength of aircraft panels with multiple-site damage. Because this report is meant to be self-contained and each of the three subjects is a considerable research topic in itself, the report is written in three parts. Part I, EPFEAM Theory provides a summary of the elastic-plastic finite element alternating method (EPFEAM) and the algorithms for fracture analysis and crack growth predictions. Part II, Fracture and theT*-Integral Parameter provides a complete description of the T*-integral fracture parameter including a detailed discussion of the theoretical basis of T* and the practical aspects of its use for fracture predictions. Finally, Part III, Computational Predictions of the NIST Multiple Site Damage Experimental Results provides a series of predictions of a number of fracture tests performed at the National Institute of Standards and Technology (NIST). These predictions are then compared with the experimental data, thus validating the present model for computing the residual strength under wide-spread-fatigue damage conditions.