Improved line-element formulations for the stability analysis of arbitrarily-shaped open-section beam-columns

Abstract Open-sections are often used in structural applications because of their material efficiency in providing members of high strength and stiffness. Although previous research has made significant progress in accounting for the effects when the shear-center and centroid are not coincident for such sections, the compression buckling strengths of non-symmetric sections, for example unequal-leg angles, are sometimes over- or under-predicted unless their principal axes’ properties are properly defined. This paper improves existing beam-column line-element formulations for accurately simulating the axial buckling behavior of arbitrarily-shaped open-sections. Detailed derivations are given and implemented within the educational software MASTAN2. Several verification examples are provided.