Seismic Behavior Of Connections With Web Opening And Composite Effect

Steel Moment-Resisting Frame (MRF), with excellent capability to resist the effect of earthquake, has been widely adopted in the buildings of industrial zone, shoping district, and institutions in area with risk of earthquake since 1960's. However, the Northridge earthquake in 1994 and Kobe earthquake in 1995 challenged the conviction. Earthquake damage survey of earthquake region made it clear that a large number of steel Moment-Resisting Frames experienced brittle fractures at beam-to-column connections.The seismic design thought of strong connections, weak members was not achieved. Search for more reasonable new connections with good ductility was one of major job of seismic behavior of beam-column connections of Moment-Resisting Frame.By means of finite element analysis, the behavior of connection with web opening with composite effect is investigated in this paper. The main work includes:(1) This paper introduced nonlinear finite element method of study on mechanical behabior of composite connections. Its reliability was verified by comparison with test date.Finite element models of standard-type connections and connections with opening web considering composite effect were established. This paper studied influence law of mechanical behavior of standard-type connections and connections with opening web considering composite effect with slippage of shear connector, thickness of concrete slab, and reinforcement ratio of concrete slab.(2) This paper studied development of plastic hinge of connections with opening web considering composite effect, and influence law of the location of plastic hinge with different opening size was summarized. Besides, stress distribution of beam section of composite connections with opening web was studied. The microscopic reason why the plastic hinge occurs near the section reduced most is explained.(3) This paper studied influence law of mechanical behavior of connections with opening web considering composite effect with opening size, opening location, shear span tatio and column height.Besides, hysteretic behaviors of connections with opening web were studied with thickness of concrete slab, opening size, opening location, and shear span tatio. Based on finite elememt method analysis ,test sheme of seismic behavior of connections with opening web considering composite effect was made.All the results described above have brought valuable information to the development of the theory and method on the seismic design of composite joints. It can also promote the study on new type of joints that is more practical and more efficient.