Buckling analysis of storage tanks based on the use of geometric imperfections measured by laser scan dimensional inspection techniques

Resumo

Storage tanks are thin-walled equipment often subjected to wind loadings, which may lead the
equipment to structural instability. The critical buckling load of storage tanks are too sensitive to structural
imperfections, that can be present at its structure taken into account damage mechanisms which tend to reduce
the structural integrity of this type of equipment along its life cycle. Inspection techniques are employed to
characterize damage mechanisms, which in turn are assessed to evaluate whether or whether not the equipment
may have a safe operation. The laser scan technique has been shown to be accurate in dimensional inspection of
storage tanks. This paper focuses on the structural integrity assessment of an actual damaged surface of a real
storage tank. The tank is 43.428 m in diameter and 14.63 m in height and is used for diesel storage.
Deformations are present at the structure of the tank, which are measured with an industrial laser scan. The point
cloud resulting from the dimensional laser scan inspection is used to build a finite element model taken into
account all geometric imperfection. Geometric and Material with Imperfection Nonlinear Analyses (GMNIA)
are performed considering different load combinations and different wind pressure coefficients to assess plastic
collapse, excessive local plastic strain failure and buckling. Simulations considering structural steel shapes at the
shell of the tank are performed to evaluate failure from wind induced buckling, once the structural integrity of
the equipment is reduced by deformations present at the structure of the tank. The results show that the
equipment