螺栓球节点试验及在单层网壳结构中的应用性

为充分利用螺栓球节点的抗弯刚度,实现其在单层网壳结构中的应用,针对螺栓球节点开展力学试验研究,配合以精细化的有限元分析,获得节点的抗弯性能,并采用弯矩-转角关系来描述.利用ANSYS程序,采用弹簧单元模拟节点弯曲与扭转性能并将试验获得的弯矩-转角关系引入节点属性中,构建了螺栓球节点单层网壳的有限元模型.在此基础上系统开展了网壳结构的稳定性能研究.结果显示:采用螺栓球节点的网壳对于荷载不对称分布较为敏感,而且失稳过程中总伴随有节点的弯折效应;单层球面网壳的极限承载力最低可达到对应刚性节点网壳的32%,最高则超过98%,而单层柱面网壳则仅为10%,这表明此类节点可以应用在单层球面网壳中,但不宜在单层柱面网壳中采用.

Experiment of bolt-ball joint and its application in single-layer reticulated shells

The bolt-ball joint system with actual bend-bearing capacity can be used in single-layer reticulated domes. Both experimental study and sophisticated finite element analysis were carried out to obtain the bending capacity of the joint which is described by bending-rotation curves. The finite element model of a single-layer reticulated dome with bolt-ball joints is established in ANSYS in which spring elements are used to simulate bending stiffness of the joint obtained experimentally. The stability of single-layer domes was analyzed and the results of these analyses indicate that single-layer dome with bolt-ball joints is sensible to asymmetry load distribution and its buckling process always accompanies bending of the joint. The critical load of a single-reticulated dome with bolt-ball joints is 32% as much as the rigid dome at least, and the percentage will be over 98% at most. But for a single-Layer cylindrical reticulated dome, the percentage is only 10%, indicating that the bolt-ball joint system can be used in single-layer reticulated domes, but should not be used in a single-Layer cylindrical reticulated dome.