Optimal design of a mono-symmetrical open cross section of a cold-formed beam with cosinusoidally corrugated flanges

The paper is devoted to a thin-walled beam with a flat web and cosinusoidally corrugated flanges. Considered beam has an open cross section and is mono-symmetric. Two different types of load are taken into account, i.e. pure bending and uniformly distributed load. The authors are searching for an optimal cross section shape of the beam. The beam cross section is characterized by dimensionless parameters, which are design variables. The dimensionless objective function is so defined as to comprise both a cross section area and a maximal allowable bending moment. The constraints follow from the local buckling condition for corrugated flange and geometric restrictions. The beams with different length to height ratio are analyzed. Results of the numerical calculations are presented graphically.