Prediction of residual strength and curvilinear crack growth in aircraft fuselages
Journal
AIAA Journal
Journal Volume
40
Journal Issue
8
Pages
1644-1652
Date Issued
2002
Author(s)
Abstract
Two practical engineering approaches to assess the structural integrity of aircraft fuselages are presented. Both approaches combine fracture mechanics with thin-shell finite element analyses to predict structural responses quantitatively. The first approach uses the crack-tip opening angle fracture criterion to predict residual strength of KC-135 fuselages. The second approach uses T-stress and fracture toughness orthotropy to predict crack-growth trajectory in narrow-body fuselages. For residual strength prediction 12 damage scenarios, which might occur in applications, are examined. It is found that the model with small multiple-site cracking and material thinning caused by corrosion damage has the worst load-carrying capacity. For curvilinear crack-growth simulation a directional criterion based on the maximum tangential stress theory accounting for the effect of T-stress and fracture toughness orthotropy is used to predict crack-growth trajectory. Both T-stress and fracture toughness orthotropy are found to be essential to predict the observed crack path, where the trajectory experiences crack turning and flapping phenomena.
Type
journal article