节点域箱型弱轴连接全焊加强型节点抗震性能分析

SEISMIC BEHAVIOR ANALYSIS WELDED STEEL FRAME CONNECTIONS IN BOX STRENGTHEN-JOINT REGION FOR WEAK AXIS

为了更全面地对比分析节点域箱型弱轴连接不同局部加强型节点的抗震性能,以及局部构造对节点的抗震性能及破坏形态的影响。采用有限元软件ABAQUS建立多种不同局部加强型节点有限元模型,并将不同局部加强型节点与标准型节点在承载能力、滞回性能、刚度、断裂指数、退化性能、破坏形态及塑性铰形成位置等方面进行对比分析,同时结合国内节点域箱形弱轴连接研究课题组的试验和已有的焊接节点试验,验证了有限元模拟的准确性。研究结果表明:节点域箱型弱轴连接节点局部构造形式可以改善节点的破坏形态,实现塑性铰的外移,防止节点脆性断裂;采用节点域箱型弱轴连接的节点形式,同时考虑抗震及经济性等指标,腋板加强型节点承载力及刚度有较大的提高且滞回曲线饱满,耗能性能及延性也较好。因此建议节点域箱型弱轴连接的节点应采用腋板加强型节点。

In order to have a more systematic and comprehensive comparison for the seismic behavior of different structural constructions of steel-frame-welded connections in box strengthen-joint region for weak axis,and the influence of local constructions on the seismic behavior and ductility of the structure,the efficient and accuracy finite element models of different local constructions were build by ABAQUS. The finite element software ABAQUS was used to establish the nonlinear finite element model, and the bearing capacity, hysteretic behavior, performance, stiffness, fracture index,degradation,failure mode and plastic hinge formation position were compared and discussed in detail. The accuracy of finite element simulation was verified by welded joint tests. The results showed that the local structural construction of connections could improve the failure mode of the connections,and realize the migration of plastic hinge,and prevent the joint brittle fracture; considering the building seismic effect and economy,the bearing capacity and stiffness of joint reinforced with haunch board had a great improvement and full hysteretic curve,the energy dissipation and ductility were better. Therefore,the joint reinforce with haunch board should be adopted in box strengthen-joint region connection for weak axis.