K6型铝合金板式节点网壳稳定承载力设计方法

凯威特K6型是铝合金板式节点网壳最为常见的形式，而板式节点是一种典型的半刚性节点，其节点刚度对网壳整体稳定承载力的影响不可忽略。通过ANSYS有限元软件建立了K6型铝合金板式节点单层球面网壳数值模型，采用非线性弹簧单元COMBINE 39引入节点半刚性的影响，并基于该数值模型对网壳的弹塑性整体稳定承载力进行了参数分析。分析结果显示，网壳整体稳定承载力随矢跨比、环数、节点刚度的增大而提高，随跨厚比、半跨活荷载系数、初始几何缺陷幅值的增大和材料非线性的引入而降低。通过对8000多个数值模型的分析结果进行统计回归，得到了K6型铝合金板式节点网壳弹塑性整体稳定承载力计算式，该计算式能较准确地预估无缺陷网壳的稳定承载力。

Design method for buckling capacity of K6 single-layer reticulated shells with aluminum alloy gusset joints

The K6 single-layer reticulated shell belongs to a common aluminum alloy gusset (AAG) shell system. The AAG joint is a typical semi-rigid joint system, and the influence of the joint stiffness on the global stability of shell cannot be ignored. The finite element (FE) models of K6 single-layer reticulated shells with AAG joints were established using ANSYS, and the semi-rigidity of the AAG joint was introduced by adopting non-linear spring element COMBINE 39. The elasto-plastic global buckling behavior of these FE shells was analyzed considering various parameters. The results reveals that with the rise of the height-to-span ratio, rings, and joint stiffness, and the drop of span-to-thickness ratio, semi-cross live load factor, and initial geometric imperfection, the global elasto-plastic stability of the shell improves, while the introduction of material non-linearity reduces the buckling capacity of the shell. According to the results of more than 8000 shell models and the statistical regression technology, the theoretical formulae which provids an effective tool for designers to accurately estimate the elasto-plastic buckling load of AAG joint shells are proposed.