Effect Of Fuselage Frame And Tear Strap In Arresting A Two-Bay Crack In Fuselage Structure

Currently large transport airplanes are being developed with �Large damage tolerance capability� as a design goal. An important concept in the design of the pressurized fuselage of large transport aircraft is the provision of crack stopper straps to arrest the fast fracturing of a crack. Current study includes the role of the fuselage frame and crack stopper strap in the fail-safe design of the fuselage. As a first approximation a stiffened flat panel with a center longitudinal crack is considered. The strength of this cracked panel is investigated as a function of crack length in the absence of crack stopper straps, but only with the frame present. Crack stopper straps are then introduced at the locations of stiffeners perpendicular to the crack line and strength of the cracked flat panel is investigated as a function of crack length in the presence of crack stopper straps. The bulkhead dimensions and the thickness of the crack stopper straps are varied in the parametric study.