Axial Bearing Property Of Cold-Formed Steel Sandwich Penal Wall Frame

With the increasing exaltation of manufacture and development of materials technology, cold-formed steel, as a new type of building structure, are being widely used around the world. Cold-formed wall frame is usually composed of U-shaped or C-shaped of cold-formed steels. Such as the advantages of saving materials, reasonable section and simple construction, cold-formed structure is favored by the designers who work in the field of low-rise residential design. The production of cold-formed steel members are inclined to be thinner and higher strength. In fact, a lot thin-walled members below2mm have been invested in engineering practice. Currently, our calculations about cold-formed steel members are according to The Cold-formed Thin-walled Steel Structure Specification GB50018-2002which is for formulated for2mm to6mm wall thickness members. At present, there is less standard for the design thin-walled members below2mm in China. Lack of relevant technical standards of professional guidance has become a major "bottleneck" of cold-formed steel design development. Therefore, this paper, as the way from the local member to the overall structure, introduces the theoretical calculation and experimental research of typical cold-formed steel short columns and its composite wall frame. The theoretical calculation includes two methods, namely, the effective width method and direct strength method to solve the stability capacity of short columns under axial pressure. In order to verify the current effective width method from GB50018-2002is suitable and correct for thin-walled members below2mm, two series cold-formed steel short columns with different sectional dimensions will be test. At the same time, this paper, based on the study of cold-formed wall frame, added polyurethane insulation board to the frame spacing, to explore whether the sandwich penal can significantly improve capacity of the columns.Finally, the finite strip software CUFSM and the finite element program ABAQUS are used to simulate the cold-formed steel. The direct strength method recommends CUFSM which is an effective way with high speed to solve the critical stress of local buckling and distortional buckling. On the other side, ABAQUS can accurately simulate and contrast the improvement of polyurethane board for the wall frame. Finally, both simulations agree with the experiment suitably, which can provide a theoretical basis for the following research and the project.