Static Performance and Elastic Buckling Analysis of Stiffened Plates with Flat Flanges

Abstract: The present work investigates the static performance and stability of the thin-walled plates with flat stiffeners under uniform compression. An experiment was first performed to investigate the effects of the steel thin-walled box beam-column with intermediate flat stiffeners on the static performance and stability. The test proved that the external flange could enhance the static load-carrying capacity, but the external flange's local buckling predominantly affects the members' buckling performance. The theoretical solution of the stiffened plates can be focused on improving the buckling performance. The ideal formula for calculating the stiffened flange's elastic buckling coefficient with three simply-supported edges and one stiffened edge is derived based on the potential energy method. The elastic constraint coefficients between the stiffener and the stiffened plate are also introduced and fitted by regression with the 95% confidence interval's verification to consider the effects of the boundary condition and double-sided arrangement of the stiffeners. The effects of the stiffness ratio between the stiffeners and the stiffened plates and the geometry parameters of the stiffened plates and the stiffeners on the buckling coefficients have been analyzed. Based on the results, the simplified equations suitable for determining the buckling coefficients for the plates with the four simply-supported edges, and the three simply-supported edges, and one free/elastic stiffened edge, are also suggested. Research shows that the calculating results of the modified equations are in good agreement with that of the finite element method, which is also applicable to the stiffened flange without stiffeners. Graphic Abstract: [Figure not available: see fulltext.]