Study On The Mechanical Behavior Of Steel Structure Semi-rigid Joint Under Fire

Nowdays, steel structure has been widely applid because of its various advantages. Such as good anti-seismic performance, flexible structure layout, short construction period, good security and so on. But behind these advantages, the shortcomings of the steel structure can not be ignored either. Due to the various properties of steel will decline a lot under high temperature or fire, the fire-resistant performance of steel structure is poor. How to improve the fire resistance performance of steel structure is the key point in the research of steel structure. And in steel structure buildings, the semi-rigid jonits are widely used because of its good seismic performance and convenient construction. So in the research of steel structure fire resistance, to understand the perforemance semi-rigid joints under fire is essential. This paper selected a kind of semi-rigid joint —top seat angle steel connection to study. The main research contents of this article are as follows:Firstly, determined the material parameters according to the specification, Model the full-scale I-shaped beam I-shaped column top seat angle steel connection through ANSYS software and determine the mode of loading. Compared the rusults of temperature field analysis and thermal mechanical coupling analysis of finite element mode with existing test results. Confirmed the reliability and feasibility of the finite element analysis results in this paper at last.Secondly, the moment rotation curve of the connections will be obtained through the analysis of the connections at the different time under fire. And the relationship between the changing of connection’s property under the fire with time will be obtained through the result.Thirdly, confirmed the key factor that influence the joints’ property most through parameter analysis.Finally, confirmed the key factor that influence the joints’ fire resistance time most through parameter analysis. The joints’ temperature and fire resistance time with fire retardant coating are different from the joint with no preotection. To study the influence of thickness of fire retardant coating on the joints’ fire resistance time.The mechanical behavior of steel structure semi-rigid joint under fire and relationship between the parameters and structure fire resistance performance will be obtained through the above study. Given some suggestions for fire resistance research of steel structure through our results at last.