An analytical solution for elastic buckling analysis of stiffened panel subjected to pure bending

In this study, an analytical solution has been developed for the elastic buckling analysis of stiffened panels subjected to pure bending, and the effect of main geometric parameters of the stiffened panels on buckling strength has been investigated. A simplified model of stiffened panels has been proposed for buckling analysis, where an elastically built-in boundary condition replaces the skin's effect on buckling of the stiffened panels. The equilibrium method with a conventional rigid skin assumption and a new flexible skin assumption is developed for the simplified model to analytically capture the buckling behaviour of the stiffened panels. To consider the non-rigid rotation effect of flexible skin on buckling of stiffened panels, a new parameter, the effective width of stiffened panels, has been introduced, and a finite element (FE) assisted method has been employed to obtain its value for different stiffened panels. The results show that the flexible skin assumption significantly enhances the accuracy of buckling strength prediction compared with the conventional rigid skin assumption, and the maximum difference between analytical results and corresponding FE simulations is decreased from 12.2% with rigid skin assumption to only 3.9%. Based on the proposed analytical solution, effects of main geometric parameters of the stiffened panels (the stiffened panel length and width, the stiffener height, and the ratio of the skin thickness to the stiffener thickness) on their buckling coefficients have been discussed. Increasing stiffened panel length and/or reciprocal of stiffener height leads to an initial abrupt decrease of the buckling coefficient until reaching a stable level. When the stiffened panel width increases, the buckling coefficient first increases and then remains stable, whereas increasing thickness ratio leads to the increase of the buckling coefficient.