斜撑对装配式钢框架梁柱拼接节点抗震性能影响研究

针对装配式钢框架带柱座梁柱拼接节点连接受力复杂、强度和刚度影响因素多等问题,应用非线性有限元软件ANSYS对带斜撑和无斜撑的两种节点进行数值模拟,研究斜撑对装配式钢框架梁柱节点的滞回性能、极限承载力、延性系数、破坏模式等抗震性能的影响。结果表明:斜撑的设置,可较大幅度地提高节点的刚度和承载力,对于螺栓型连接的梁柱节点,斜撑的设置使其承载力提高3倍多,焊接节点的承载力提高约50%,延性系数提高约70%;且有效地转移了塑性铰,使节点破坏位置位于斜撑之外的桁架梁上,起到保护节点的作用,符合"强节点,弱构件"的设计要求。同时反复荷载作用下的滞回曲线更加饱满,具有更好的抗震性能。

SEISMIC PERFORMANCE RESEARCH ON BEAM-COLUMN SPLICE JOINTS OF PREFABRICATED STEEL FRAMED STRUCTURES WITH BRACES

For column-beam splice joint with flange-column of fabricated steel structure,the mechanical behavior and connection are very complex,and there are many influencing factors for its strength and rigidity. ANSYS finite element analysis software was used to analyze and simulate the beam-column's joint of the steel framed structure with or without braces. The seism-resisting behavior of the fabricated steel frame beam-column joints including the hysteretic behavior,ultimate bearing capacity,ductility coefficient,failure mode etc. were studied. The results show that for the fabricated steel frame beam-column joints with supports the joint's rigidity and bearing capacity are increased greatly.To bolt connection of beam-column joints with braces,the bearing capacity is improved by more than three times,and to welded joint,it is improved by about 50 percent,ductility factor is increased by about 70 percent. Through setting braces,the plastic hinge is transferred effectively,and the failure locations are located on the truss beam outside of the brace,which has played an important role in protecting the connection,and accorded with the design requirement of"strong connection,weak component". Meanwhile hysteresis curves display more fully under the cyclic reverse loading,indicating better aseismic performance.