Numerical Analysis Of The Fire Resistance Of Steel Frame Structure

The steel structure has the character of high intensity, light weight, plasticity and toughness, quick progress of construction and so on. It's suitable for each kind of engineering structure. But with the steel structure construction development, problems of fire-resistant protection are followed. Although steel is non- burning material, the steel is not fire-resistant, its fire-resistant limit is only 15 min. In the domestic and foreign steel structures research of fire-resistant performance mainly depends on the fire-resistant analysis of the member at present. However this method is very difficult to simulate entire process of the whole construction. Through the numerical analysis of the fire resistance of the steel frame, it is reasonable to confirm limit of the steel structure and protective measures of fire resistance.Based on the problems in the fire-resistant analysis and design, firstly the process of plane steel frame structure is analysed through the thermal-structure coupled analysis according to the transfer principium. The fire-resistant limit of the whole structure is analysed when fire occurs in the different rooms. Secondly, according to one building located in the business street of DaHutong in Tianjin, the three-dimensional steel frame model is built. The influence of fire-resistant limit of different room is analysed. And the situations influenced the whole structure whether the minor girder has fire-resistant protection or not. If the whole the structure can support the outside load in fire, the whole steel minor girder in structure can have no protective measures of fire resistance. At the same time, the catenary action is analysed due to increase of the girder's deflection. The fire-resistant limit is influenced by the catenary action. Lastly, the membrane action of concrete slabs in fire which influences the whole steel frame is analysed. Therefore, the real performance of the structure in fire can be illustrated.Considering integration of instantaneous temperature and fire response of the structure, the real station can be reflected by the numerical analysis of the fire resistance of structure. In order to reach to the rational design practical proposal is tabled.