Restraining stiffness method: A novel analytical approach to cross-sectional buckling under general loading

This article presents the Restraining Stiffness Method (RSM), an analytical approach for buckling analysis of open-section members under general loading. Based on Bleich’s coefficient of restraint method, RSM adopts power series, introduces a new restraining body concept, and allows transverse translation along junctions. It is validated against analytical (Bulson, Bleich) and numerical (FEM, finite strip) methods, showing a general error of about 2%. RSM requires fewer elements, converges quickly, and can identify the buckling-critical plate. Currently applicable to consecutive right-angled plates, RSM overcomes traditional analytical methods’ limitations and offers an efficient, accurate tool for complex structural analysis.