The Dynamic And Seismic Analysis Of Steel Frame With Semi-rigid Connections

Nowadays, with the development of steel structure technology in our country,the use of steel frame structures is becoming more and more widely, and the key of steel frame structures design work is nodes design.Theoretically say, the connections between beams and columns of a frame structure can be divided into three types, rigid connection, hinged connection as well as semi-rigid connection.While in fact, most of the node connections are semi-rigid.In the past decades, both domestic and foreign scholars have did a lot of theoretical and experimental studies on the mechanical properties of semi-rigid steel frame structures under dynamic action, according to these studies we can see that this kind of structure has stronger deformation and energy dissipation capacity, therefore they can act effectively when under earthquake load and semi-rigid connections have a non-negligible influence on the dynamic response of steel frames.The paper introduces the research background, the meaning, the status as well as some specific engineering applications of semi-rigid structure, and gives detail descriptions about the nodes performance of semi-rigid steel frame structures,including semi-rigid concept, classification, some general structural forms,connectivity features and connectivity features analog(M-θ model). Under earthquake, there are many factors that will have effects in dynamic response of a semi-rigid frame structure, and they can lead to different dynamic actions, while the previous research in this area is less, so the paper has a research on two factors that influence the seismic performance of semi-rigid structures under three kinds of seismic waves, that means node rotational stiffness and combination type. With the help of finite element software ANSYS, the paper builded various different kinds of finite specimens of six layers space across a steel frame, by changing the node initial rotational stiffness and layout of the semi-rigid nodes, then respectively studied their modal analysis and time history analysis under seismic loads, concluding the general regular of the natural frequencies, vibration mode and seismic response.As one of the key engineering research topics, research on dynamic characteristics of steel frame with semi-rigid connections has a broad research and application prospect. It will provide a reference for the later written of relevant norms and benefit the earthquake disaster mitigation.