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

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.