Roof is an important part of a storage tank and its buckling failure mode should be examined during design stage. However, some factors that affect buckling may appear after design. For example, the case studied in this paper was damaged by a construction accident on site. A weight hit a pothole on the roof. Obviously, such a construction defect would significantly impact the critical load of buckling. Due to the difficulty of repairing and a possible secondary damage during repairing, a buckling examination was necessary. However, formulas in the code can only be used for the roofs without such serious defect. A comprehensive numerical analysis (e.g. FEA) of buckling for this roof is necessary from a technical and economic point of view.
According to the Chinese code JBJ 7-2010Technical Specification for Space Frame Structures, the finite element models under different load cases are built for this kind of storage tank roof. Taking into account the initial defect caused by the structure manufacture, installation deviation and construction damage, the static analysis, linear buckling analysis and geometric nonlinear analysis were performed to track the whole process of load-displacement change, evaluate the critical load of buckling and achieve the reasonable repairing scheme of this tank roof.
Keywords:buckling analysis; tank roof; finite element method; non-linear.