Analysis of the Strength of the Interface between Frame and Skin in a Bonded Composite Fuselage Panel

During the NASA sponsored Advanced Technology Composite Aircraft Structures (ATCAS) research program conducted at Boeing, a composite cocured skin/stringer/frame construction was identified as a potentially cost effective structural configuration for the fuselage of a wide-body civilian transport aircraft. One of the critical areas of the design was identified as the bonded interface between the skin and frame. The outline of a global/local approach to analyzing the bondline under internal pressure and axial fuselage loading is presented. Results from a geometrically nonlinear finite element (FE) of a panel bay are combined with the results of detailed local FE models of the frame to skin bondline. Both a strength of material and a strain energy release rate approaches are used to examine the onset of failure and its subsequent propagation.