T形钢管混凝土柱-钢筋混凝土梁外加强环筋式节点抗震性能分析

Seismic Performance of Outer Stiffening Ring Connection Between T-shaped Concrete-filled Steel Tubular Column and Reinforced Concrete Beam

运用ABAQUS有限元软件对T形钢管混凝土柱-钢筋混凝土梁外加强环筋式节点进行抗震性能分析,通过改变牛腿长度、环筋直径﹑环筋布置方式和轴压比,分析了各参数对节点抗震性能的影响。结果表明:牛腿能增加此表节点的刚度,使塑性铰外移,满足结构设计中"强柱弱梁"的原则;设置加强环筋可明显提高节点的极限承载力和初始刚度,增强节点的抗震性能,使节点的破坏形式由脆性破坏变为延性破坏;增大环筋直径能增加节点梁柱相对转角的刚度,但直径过大会导致钢管混凝土的材料性能不能充分利用;轴压比在0.2~0.6范围内变化对节点的抗震性能影响较小。

The seismic performance of out stiffening ring connection between T-shaped concrete-filled steel tubular column and reinforced concrete beam were analyzed by the finite element software ABAQUS.The influence of seismic performance of each factor on outer stiffening ring connection was analyzed by changing length of corbel,outer stiffening ring diameter,arrangement of hoop reinforcement and axial compression ratio.The experimental results show that by arranging steel corbel in the concrete beam,stiffness of joint area is enhanced,which leads to plastic hinge caused by bending shear failure going outward and appearing in the outside of corbel.This joint satisfies structural design principle of "strong column,weak beam".Setting up hoop reinforcement can obviously improve the ultimate bearing capacity and the initial stiffness of the connection,and strengthen the deformation ability and seismic performance of the joint so as to make point destruction change from brittle fracture to ductile fracture.The increase of outer stiffening ring diameter promotes the joint relative rotation stiffness.If this increase is too much,the material performance of the concrete filled steel tube can not be fully used.The change of the axial compression ratio at 0.2~0.6 range has few effects on the seismic performance of the joint.