On local buckling of cold-formed channel members

• The aim of paper is to find close analytical solution of the critical stresses of local buckling problem of the flange, considering web-flange interaction.
• The fundamental differential equation of local buckling of the thin-walled channel member is derived and solved.
• Some numerical examples together with final conclusions are presented.

The paper deals with local buckling of the compressed flanges of cold-formed thin-walled channel beams subjected to pure bending or axially compressed columns. Arbitrarily shaped flanges of open cross-sections and the web-flange interactions are taken into account. Buckling deformation of a beam flange is described by displacement related to torsion of the flange about the line of its connection with the web. Total potential energy of the flange is a base for the fundamental differential equation of the critical stress of local buckling. The differential equation is derived by means of the stationary total energy principle. The critical buckling stress corresponding to a number of the buckling half-wave matches to the minimum eigenvalue of equation. Numerical examples dealing with single, double bend and lipped flanges are included. The analytical results are compared with the finite element stability analysis carried out by means of the computer systems ABAQUS and CUFSM.The aim of the paper is to find a closed-form analytical solution of the buckling problem, considering web-flange interaction. The results are compared with the finite element method outcomes. Some conclusions are formulated, too.