Pseudo-static Analysis Of Steel Frame Used By Simplified Theoretical Model Of Reduced Beam Section Connection

Reduced beam section connection(RBS)is a new type of ductility connection,a large number of tests research and numerical analysis show that plastic hinge of ductility connection can move away from weld zone of beam end under earthquake,it can improve obviously energy dissipation capacity of the steel frame structures.It is gradually recognized and used in engineering field in view of its good seismic performance.Construction of RBS connection is more complex than ordinary connection,if space steel frame structures with RBS connections are calculated numerically with solid model,it must be time-consuming,to save cost and provide technical services for engineering quickly,it is necessary to simplify numerical analysis of steel frame structure with RBS connection.Structure includes many simplifications,such as simplification of the connection,load,bearing support and component,effective numerical calculation model is observed if each part of frame structure is simplified rationally.The paper focuses on simplification of RBS connection,finite element analysis of the frame structure is calculated used by simplification of RBS connection,and compared the results with the test research results and results obtained by beam188 element model,by comparing hysteresis curves,skeleton curves,bearing capacity decline curves,stiffness degradation curves and energy dissipation curves,it shows that it is feasible that simplified theoretical model of RBS connection is used in structure finite element numerical model.Simplified calculation of Steel frame structures with RBS connections is researched in detail used by theoretical analysis method,test research method and finite element method.The main research includes:1?loading plan and test results of the test device of 2-bay and 2-storey space steel frame with RBS connections under low cyclic loading are introduced firstly,then formation mechanism of plastic hinge in steel frame structure is researched by using incremental variable stiffness method,and analyzed appearing sequence of plastic hinge,which can afford reference for subsequent finite element calculation.2?According to the force characteristics of the structure,the steel frame with RBS connections is divided into many units,each unit is a connection model.To simply the connection model,simplified theoretical model of RBS connection is observed by introducing two spring elements which respectively simulate deformation of panel zone and components of both sides,it is the key problem to design stiffness of spring element,stiffness of spring element is observed by analyzing results of connection solid finite element model and modifying constitutive relation of connection.3?The theoretical model is applied to simplify steel frame and frame model are calculated by finite element method,results are compared with test research results,analysis show that hysteresis curve,skeleton curve,stiffness degradation curve of structure are almost similar to the results of experimental results;then comparing results with reaults of finite element model of variable cross-section,hysteretic curve of two kinds of structural model is in good agreement.Comprehensive analysis show that it is reliable to use RBS connection theoretical model to simplify frame calculation model.4?To further analyze reliability of simplified theoretical model of RBS connection,4-bay and 4-storey steel frame with RBS connection is analyzed by two kinds of models.model 1 is created by using simplified model of RBS connection,and model 2 is created by variable section beam188 element.The results of two kinds of models are analyzed,research results show that hysteresis curve,skeleton curve,the equivalent viscous damping coefficient are in good agreement,it further show it is reliable to use RBS connection theoretical model to simplify frame calculation model.Frame structure model with RBS connections is analyzed according to the ideal of connection model to frame model,all the results in the paper show that it can save calculation time and cost,and afford reliable technical service for engineering.