Analysis Of The Seismic Behavior Of Steel Frame With Opening In Beam Web Considering The Effect Of Composite Action

The steel structure has excellent seismic behavior, but repeatedly earthquake damage survey found that many steel frame beam-to-column connection at the weld area suffered from brittle failure. For this phenomenon, scholars from various countries proposed many kinds of connection to improve the seismic behavior of these joints. The connection with opening in the beam web (OBW), is a connection that open a hole in the beam web away from the column flange. Not only to make the plastic hinge away from the weld zone, but also allows the pipelines to pass through the hole in order to increase clear height of the building. And the existence of concrete floor would affect the seismic behavior of the connection and the whole structure in steel moment-resisting frame. Considering the above factors, based on the researches of OBW connection considering the effect of concrete slab, the seismic behavior of steel frame with opening in beam web considering the effect of composite action are discussed in this dissertation.The connection model is modeled using ABAQUS, and yield load reduced ratio is calculated from the M-(?) curves. The effect of composite action is analyzed. To facilitate comparison, four kinds of steel frames are modeled in SAP2000according to whether have the concrete slab and OBW connection. The OBW connection is simulated using the plastic hinge model.Pushover analysis and dynamic elastic-plastic analysis is carried out on these models:In the Pushover analysis, the Pushover curves are gated under two different lateral load distribution mode, the performance point of the structures are calculated based on the capacity-spectrum method, and the seismic behavior of the four kinds of steel frames are assessed. Two strong earthquake records and an artificial seismic wave are selected for the dynamic time-history analysis. Base Force time history curves, the Top Displacement time history curves and the displacement angle between the layers of the structure are extracted. At the same time, the average stiffness of the structure is calculated. Analysis result show that, the OBW weaken can make plastic hinge move away from the connection, as well as the structure of bearing capacity and stiffness fell, make the displacement angle between the layers increases. After considering the effect of composite action, the stiffness of the structure increased and the OBW weaken to the structure behavior would decreased. Finally, based on the frame and connection separately, the factors which affect plastic hinge moving away from the connection are analyzed; the suggestion to use and design this kind of structure form is put forward.