钢框架梁柱弱轴连接节点地震下的断裂行为

The Fracture Behavior of Beam-to-column Web Connections in Steel Frames under Earthquakes

钢框架梁柱弱轴连接同强轴连接一样普遍,其理论分析和设计更为困难,研究其节点的性能具有重要的理论意义和重大的工程应用价值.考虑几何、材料和接触3种非线性因素,选用ANYSYS有限元软件对钢框架梁柱弱轴连接节点在循环荷载作用下的断裂行为进行研究,结果表明:通过对接焊缝沿梁高度和宽度2个方向的开裂指数分析,在循环荷载作用下对接焊缝是断裂最易发生的薄弱环节,而脆断的主要原因是焊缝两端存在严重的应力集中及焊缝处于三向受力状态.并提出了节点脆性断裂的预防措施.

The beam-to-column web connections are as common as flange connections in steel frames. Their theoretical analysis and design are more difficult, so studies on the behavior of this connection are not only significant to the theoretical research,but also important in enginecring application. The fracture behavior of beam-to-column web connections in steel frames under cyclically lateral loads is analyzed by ANSYS involving the material,geometry and nonlinear status. The result indicates that, based on the analysis of rupture index,the butt welding along the beam＇s height and width directions is the weakest link of fracture under cyclically lateral loads. The brittle factures, are mainly caused by high stress concentrations at the terminations and by the three dimensional stresses at the welding jiont. The preventiue measures are also put forward.