网架网壳结构半刚性节点试验研究

为研究网架与网壳等空间结构中常用的半刚性Socket节点在纯弯和压弯荷载作用下的受力性能, 完成了3个Socket节点试件在纯弯荷载作用下的试验和6个Socket节点试件在不同比例的压弯荷载作用下的试验,并将节点在纯弯荷载和压弯荷载作用下节点的受弯承载能力进行了比较。在此基础上,提出了节点弯矩 转角曲线的简化模型。研究表明：Socket节点在纯弯荷载和压弯荷载作用下都表现出了较好的弯曲承载力和延性;节点在压弯荷载作用下的初始弯曲刚度和屈服弯矩要高于其在纯弯荷载作用下的初始弯曲刚度和屈服弯矩;节点的初始抗弯刚度随着压弯荷载比例的增大而增大;对于以Socket节点连接的空间结构,采用纯弯荷载作用下得到的节点抗弯刚度计算结构的承载力偏于保守。

Experimental research on semi-rigid joints used in grid structures and reticulated domes

In order to study the mechanical behavior of semi-rigid Socket joint widely used in space structures, tests on 9 specimens were carried out. 3 of the specimens were under bending moments and 6 of the specimens under bending moment and compressive axial force together with different ratio of bending moment to compressive axial force. The results of the specimens under different loading conditions were compared. Furthermore, a simplified model for moment-rotation curves of Socket joints was established. The experimental studies indicate that the Socket joint system has good bending moment capacity and ductility, the initial bending stiffness and critical bending moment of the joint under bending moment and compressive axial force together are higher than that of the joint under bending moment only, the initial bending stiffness of a joint increases when the ratio of bending moment to compressive axial force decreases. So, the load-bearing capacity of the space structures with Socket joint system calculated using the bending stiffness obtained through the specimens under bending moment only is conservative.