网壳结构铸钢球节点弹塑性分析及试验研究

为了对重庆奥林匹克体育中心网壳结构铸钢球节点承载安全性作出评价,本文对一关键节点进行了弹塑性分析和实体试验研究。通过对该节点有限元模型的弹塑性分析,得到节点应力、应变分布情况。通过铸钢球节点结构的实体试验,得到表面各测点应力测试值。结合理论分析和实体试验,分析了铸钢球节点的传力路径和和受力特点,指出其应力从连接端口到球体“高-低-高-低”的变化规律,按VonMises强度理论对其承载能力做出了评价。将管身应力与管脚应力的比值作为反映应力集中程度的一项重要指标,对此进行分析并指出,大型铸钢球节点设计时可以通过控制该比值优化应力传递路径。

Elastoplastic analysis and experimental study on spherical cast-steel joint of reticulated shells

Elastoplastic analysis and full scale experiment of a spherical cast steel joint used in steel reticulated shells of Chongqing Olympic Stadium was carried out. By forming finite element model and performing elastoplastic analysis, the stress and strain distribution of the cast steel joint were obtained. The stresses on test points in the surface of the cast steel joint were gained from prototype experiment. Combining theoretical analysis with the prototype experiment, static behavior and stress transfer pathway of the cast steel joint are analyzed, and the‘high low high low’variation regularity of stress distribution from pipe shaft to surface of spherical joint are pointed out. Based on the Von Mises strength criterion, the security and load bearing capacity of the joint are evaluated. In addition, the ratio of stresses on pipe shaft and pipe foot, as a main factor to measure the degree of the stress concentration, is also analyzed. It is indicated that the distribution of stresses on large spherical cast steel joint can be improved by controlling the ratio of stresses.