Finite Element Modeling and Design of Single Angle Member Under Bi-axial Bending

Practical single angle members are mostly subjected to eccentric forces due to the end connections to their legs. Plastic Class 1 and compact Class 2 angle cross-sections are allowed for using their plastic reserves. However, most of the interaction equations in the current design codes are linear whereas the nonlinear equations associated with plastic surface are provided in the literature. In this study, a new design method for single angle member to address the plastic failure as well as stability checks is proposed. The first yield moments at different critical points due to the interaction between the normal forces and the biaxial bending are provided. Moreover, the elastic flexural and flexural-torsional buckling loads for single angle member are calculated using a simplified equation rather than the complex design charts or series of equations in literature or design codes. New buckling curves, taking the Eurocode 3 design rules into account, are presented for single angle member subjected to eccentric load about both major and minor principal axes. A reliable and efficient finite element model is provided to verify the proposed equations and to investigate the different parameters affecting the buckling behavior. Finally, various initial geometric imperfections together with a residual stress distribution pattern are studied and provided in this paper.