大直径拱顶储罐网壳强度计算与结构改进

Strength calculation and structure improvement of reticulated shell of large-diameter dome roof tank

目前国内大型拱顶储罐的最大直径已达60 m,其罐顶网壳强度校核多采用有限元计算软件。为计算简便,通常将网壳边界条件进行简化处理,忽略罐壁顶部变形对网壳结构的影响。对比介绍了各类单层球面网壳,总结了单层球面网壳基本设计原理,并以某设计院设计的拱顶罐为工程背景,采用有限元软件ANSYS建立拱顶网壳和罐壁一体的储罐模型。分别对拱顶储罐在静载、静载+风载、静载+均匀动载、静载+均匀动载+风载共4种载荷工况下罐顶网壳结构强度进行计算分析,并依据计算结果,提出将环板和肋板建于罐壁顶部的改进方案。对改进后的设计模型进行静载+均匀动载和静载+均匀动载+风载这两种工况下的仿真计算,结果表明:改进后的拱顶储罐结构受力更合理,承载能力更强。(图17,表4,参16)

Currently, a large dome roof tank available in China may have a maximum diameter up to 60 m, with its strength of reticulated shell at the roof calculated by finite element software. For purpose of convenient calculation, reticulated shell＇s boundary conditions are simplified as usual without taking the effect of tank roof deformation on reticulated shell structure into account. On the basis of contrast results from various single-layer spherical reticulated shells, this paper summarizes the basic design principles of such shells, and builds a tank model with integral dome reticulated shell and wall by using finite element software ANSYS, according to a dome roof tank developed by a design institute. The strength of reticulated shell is calculated under 4 conditions, i.e., static load, static load plus wind load, static load plus uniform dynamic load, and static load plus uniform dynamic load plus wind load. On this basis, an improvement is proposed to build annular plate and rib on the top of the tank wall. The improved model is enabled under 2 conditions, i.e., static load plus uniform dynamic load, and static load plus uniform dynamic load plus wind load. The results show that the improved structure of the vaulted tank is more reasonable under stress and more capable of loading. （17 Figures, 4 Tables, 16 References）