Residual Strength of Aging Aircraft with Multiple Site Damage/Multiple Element Damage

A numerical study is presented of the residual strength of an aircraft fuselage in the presence of multiple site dam-age (MSD)/muItiple element damage. The analyses were carried out using a software package that was developed to facilitate automated analyses of full-scale fuselage panels with widespread fatigue damage, using a hierarchi-cal approach and elastic-plastic finite element alternating method. The present study shows the importance of elastic-plastic fracture mechanics in the assessment of the residual strength of a fuselage with two-bay longitudi-nal/circumferential lead cracks, with and without MSD, and of the interaction between multiple lead cracks. I