竖向荷载下半刚接组合框架的有限元分析

为了分析连接弯矩-转角关系和荷载大小对组合框架性能的影响,该文采用有限元方法,考虑了连接弯矩-转角关系、楼板的组合效应和几何非线性的影响,通过引入能直观反映连接刚度的端部约束系数来修正现有刚接框架的结构刚度矩阵和杆件固端力。研究表明:连接弯矩-转角关系对框架内力和位移影响较明显;在半刚接阶段0.143

FINITE ELEMENT ANALYSIS OF SEMI-RIGID COMPOSITE FRAMES UNDER VERTICAL LOADS

To study the effects of moment-rotation characteristics of connections and load magnitude on the behavior of composite frames, nonlinear finite element method is presented considering the effects of the moment-rotation characteristics of beam-to-column connections, composite action of slab and geometric nonlinearity. The stiffness matrixes of structures and fixed-end forces of members are modified by introducing an end-fixing factor. The results indicate that the moment-rotation characteristics of connections affect the forces and deformations of the composite frames, while the load magnitude has no significant effect in the range of 0.143< r0<0.727. In addition, the effects of semi-rigid connection and composite action of slab on the behavior of steel frames must be properly considered in design. The proposed finite element method can be used in practice.