The Steel Frame Fire Resistant Reaction

Compared to other forms of structures, steel structures have many obvious advantages, such as high strength, lightweight, big space, and good flexibility, hence are widely applied in engineering practices. However, unlike reinforced concrete structure and combination construction, which are fire-resistive constructions, the fire resistant capability of steel structures is very weak. In fire circumstances, the material characteristic of steel, such as yield strength and modulus of elasticity will drop rapidly, owing to temperature elevation of steel members. It can be a fatal defect that severely affect the application safety of steel structure and limit the practical application of steel structure to some extent. The purpose of fire resistance design of steel structures is to improve the fire resistance of steel structures, and make it safer in application.After consulting the home and overseas existing research results, this dissertation contrasts and analyzes the steel's material property under the high temperature in the fire, obtains the computing mode of the material property (yield strength and elastic modulus) fit for the fire resistance design of the steel structure.In this dissertation, after consulting lots of research literature and disquisitions, the finite element incremental approach for the analysis of behavior of plane steel frame subjected to fire is proposed, the finite element incremental approach and procedure for analysis of behavior of plane steel frame at elevated temperature is established by using the generalized Clough model as elemental calculation model.To develop a deep insight, this dissertation aims to provide the real ability of resisting fire of steel frame under practical fire condition. An advanced thermal and mechanical simulation techniques is adopted to assess the performance of frame structures under fire conditions with...