Resistance To Overturning Critical Force Research Of Cold-formed Thin-walled C Steel Compression Member

In china, the traditional residential structure mostly is made of brick or reinforced concrete. But in some developed countries such as Europe countries, Japan and the United States the light steel structure made of cold-formed thin-walled C steel or channel steel has been widely used recently, which has some features like high strength, light weight, easy to put into industrial production in volume and series.The subject investigated of the paper is the compression member made of cold-formed thin-walled steel structure. With Column Deflection Curve Method (CDC method) it analyzes the bearing capacity of the member according to effective section. There are two factors to be considered.(1) Initial deviation. When the structural member is manufactured, installed, piled and lifted, it will be unavoidably bent for its weight. On the other hand the member is difficult to be manufactured absolutely straight. All these initial warps will reduce the loading capacity of the member. has given limitations of the maximum data. This code is applied mainly to normal rolling section or welded-combined section, but the plane of cold-formed thin-walled C steel structure is so thin that it is very difficult to meet the limitations. So, the paper want to give some theoretical gist whether the manufacture and installation's error of cold-formed thin-walled steel structure can be enlarged by researching the effect of initial deviation error to the member's bearing capacity.(2) Semi-rigid connections: The cold-formed thin-walled C steel compression member always be used in framing column or truss, if we treat the connection of the compression member as rigid connection and make relevant mechanics model, that will over-evaluate the structure's bearing capacity; if we treat connection as pinned joint and make mechanics model, that will be too conservative. Therefore, during the structure analysis and design, we should consider the effect of semi-rigid connection.Actually, the member is bent-pressed member considering initial deviation or semi-rigid connections. The most important influencing factor of the bearing capacity of steel bent-pressed member is the calculation length. The calculation length of bent-pressed member with any supporting status can be expressed as: l0 =μl, μis length calculation coefficient and / is the geometrical length of member. doesn't consider effective section -, initial deviation and semi-rigid connections at the same time. This article is to research theeffect of initial deviation and semi-rigid connection on resistance to overturning bearing capacity and offer a reference to Chongqing-.