BEHAVIOUR OF COLD-FORMED STEEL BUILT-UP CLOSED SECTION WITH INTERMEDIATE WEB STIFFENER UNDER BENDING

In this paper, a study on experimental and numerical investigation of the flexural strength and behaviour of cold-formed steel built-up closed section with intermediate web stiffener is presented. Totally, nine built up beams with various cross section geometries are experimented under simply supported end condition with two point loading. The section geometries are chosen such that all types of buckling modes are met with. A finite element model is developed using ANSYS and verified with experimental results and found to be in good agreement. The material and geometric nonlinearities are included in the finite element model. The results indicate that flange width and depth of intermediate stiffener is significantly affecting the strength and buckling behaviour of the member. The experimental and finite element analysis results are compared with the strength predicted from the North American Iron and Steel Institute Specification for the cold-formed steel structure and suitable recommendations are made based on the results. The accuracy of the proposed design equation is established by comparison with an experimental results reported by other researchers.