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不对称非均匀雪荷载对单层球面网壳结构的稳定性有重要影响.基于非线性有限元分析理论,研究了K8型单层球面网壳结构在雪荷载下的非线性稳定性能,分析中不仅考虑了雪荷载在网壳结构投影面上分布区域的不对称性,同时考虑了雪荷载沿网壳结构径向分布厚度的非均匀性.在分布区域上分别考察了在雪荷载全跨、半跨、半跨最外两环3种情况,在分布厚度上分别考察了雪荷载均匀、非均匀2种情况.结合定量计算和概念分析,确定了网壳结构雪荷载的最不利分布状态.分析结果表明,单层球面网壳在雪荷载沿半跨最外两环非均匀分布时的稳定承载力最小,较雪荷载在全跨均匀分布、全跨非均匀分布时的稳定承载力分别下降36.4%和9.6%.基于此,建议我国现行《空间网格结构技术规程》在球面网壳稳定性验算时考虑雪荷载分布的不对称性和非均匀性.
The asymmetric nonuniform snow load has an important influence on the stability of single-layer spherical reticulated shell. Based on the nonlinear finite element analysis theory, the nonlinear stability of the single-layer K8 reticulated shell under snow load is studied. Considering not only the asymmetry of the snow load on the projection area of the reticulated shell structure but also the nonuniformity of the radial distribution thickness of the snow load along the reticulated shell structure in the distribution area, Half span and outermost two rings, the snow loads were investigated in two kinds of cases, which are uniform and non-uniform in distribution thickness.Combined with quantitative calculation and conceptual analysis, the most unfavorable distribution of snow load of reticulated shell structure was determined. The results show that the stability of single-layer reticular shell is the smallest when the snow load is distributed non-uniformly along the outermost two rings of semi-span and the uniform load of snow load is less than that of the other two rings. 36.4% and 9.6% respectively.Based on this, it is suggested that the current “Technical Specification of Spatial Lattice Structure” consider the asymmetry and non-uniformity of snow load distribution in the stability checking of spherical reticulated shells.