Experimental Research on the Stability behavior of Composite Curved Stiffened Fuselage Panel under Four-Point-Bending load

Abstract

In the design of fuselage structure, not only the longitudinal stability should be considered, but also the circumferential stability of fuselage structure is important because of its circumferential bearing of bending moment, shear force and axial force, as well as considering crash conditions. In this paper, the circumferential stability test researches of the fuselage structure were performed on the single-frame curved panel test specimens. The buckling and post-buckling characteristics of the single-frame curved panel under the negative bending condition were examined by four-point bending loading method. At the same time, the buckling mode, failure process and damage mechanism of single-frame curved panel were analysed through the load-strain curves of the skin and the different degree of damage of the three test specimens. The experimental results show that the buckling of skin is an important factor causing the debonding between the cap-stringers and the skin. The expansion of the debonding area greatly reduces the bearing capacity of the curved stiffened panel structure, which eventually leads to the breakage of the frame.