高层斜交网格结构斜交柱节点抗震性能研究

Research on seismic performance of the joint in high-rise non-perpendicular grid structure

以钢管混凝土(CFST)斜交交点为原型,利用ANSYS建立三维实体模型,对其进行往复荷载作用下非线性分析。分析在不同加载阶段钢管、加强环、竖向连接板、核心混凝土等各部件的应力分布情况,研究斜交节点的水平力-位移滞回曲线及横向刚度的退化。选取钢管内的核心混凝土强度等级、钢管的宽厚比D/t、竖向连接板厚度和2个斜柱夹角等4个控制参数,研究其对斜交节点的抗震性能的影响。研究结果表明:不同加载阶段各个部件的最大应力出现位置不同;钢管内的混凝土在初始压力以及钢管套箍的作用下表现出较高的延性与强度;斜交节点的滞回曲线饱满,初始刚度较大,且加载过程中横向刚度退化较为平缓,表明钢管混凝土斜交节点的抗震性能良好;钢管的宽厚比D/t、斜柱夹角可直接影响斜交节点的极限荷载、滞回性能及刚度退化,而核心混凝土强度等级、竖向连接板厚度对斜交节点的极限荷载、滞回性能及刚度退化影响较小。

Based on the prototype of the non -perpendicular CFST （Concrete Filled Steel Tube）joint,a 3D fi-nite element solid model was built by ANSYS,then the nonlinear analysis was conducted on the structure under the repeated displacement loadings.The stress distributions of steel tube,stiffening ring,vertical connecting plate and core concrete are researched at different stages,as well as lateral load -displacement hysteretic curve and stiffness degradation.The influence on the joint＇s seismic performance of the four control parameters （con-crete strength,width -thickness ratio of steel tube D /t,thickness of vertical connecting plate and angle between the two columns）was researched.The research results show that where the maximum stress emerges is different at different stages;under initial pressure and steel tube＇s confinement effect,core concrete bears triaxial pressure and it shows better ductility and strength.The hysteretic curve of non -perpendicular CFST joint is plump;its initial stiffness is high;in the loading process,the speed of stiffness degeneration is low,so the seismic perform-ance of non -perpendicular CFST joint is well.Width -thickness ratio of steel tube D /t and angle between two columns have influence on ultimate load,hysteresis property and stiffness degradation of the joint,but concrete strength and thickness of vertical connecting plate have little influence.