Finite Element Modeling Of Behavior Of Steel Structure Connection In Fire

Both the simple T-stub steel connection and endplate connection of steel structure are semi-rigid. There is non-linearity relationship between loading and deformation of the connection under both room temperature and high temperature, which has great influence on performance of steel structure. So it is very important to study the behavior and optimizing design method of semi-rigid connection of steel structure in fire at present. In this paper, finite element soft ANSYS is applied to analyze the non-linearity of the connections, and analysis results are validated by experimental data. The following contents are studied this paper:(1) 3D models of simple T-stub steel connection and endplate connection are developed, implementing geometric non-linearity, material non-linearity in both room temperature and high temperature as well as contact non-linearity in fire.(2) Simulating the impact of bolt preloaded force on the connection, analyzing the response of the model under fire and the effect of temperature load on the connection.(3) Modeling the loaded capacity and fire resistance time of the endplate connection, rotation-time curves of the connection being obtained; analyzing deformation and stress distribution of components, deformation and Mises stress contours being also obtained. Then the influences of several parameters on the behavior of connection in fire are also debated, such as loading ratio and thickness of endplate, diameters of high strength bolts, thickness of stiffeners.(4) Developing the simple module by finite element method to analyze semi-rigid connection, which being validated by experimental data. Then the simple module being applied to finite element analysis of steel frame integral structure.The following contents are first developed in the research field:(1) Analyzing the behaviors of semi-rigid connection of steel structure in fire through parameters of the connection, and the optimizing design method of steel structure connection being brought forward.(2) Developing the simple module for finite element analysis of semi-rigid connection; when the module being applied to finite element analysis of steel frame integral structure most of the nodes and elements of the semi-rigid connection being decreased.