Nonlinear dynamic analysis of storage tanks when subjected to nondeterministic wind loadings

Resumo

Storage tanks are associated to thin-walled equipment subjected to wind-induced loads, which can
lead the system to structural instability. The storage tanks behavior is too sensitive to imperfections that can be
present on the structural system, taken into account damage mechanisms which tend to reduce the integrity of
this type of equipment along its service life. In fact, inspection techniques are employed to characterize the
damage mechanisms. This way, the laser scan technique has been shown to be accurate in dimensional
inspection of storage tanks. Therefore, this research work focuses on the nonlinear dynamic analysis of an actual
damaged surface related to a storage tank. The investigated tank presents a diameter of 43.428 m and height of
14.63 m, and is used for diesel storage. The deformations present on the tank structure were measured based on
the use of a laser scan. The point cloud resulting from the dimensional laser scan inspection was used to build a
finite element model taken into account all geometric imperfections. After that, the nondeterministic wind
loadings were used to perform the nonlinear dynamic analysis considering the actual deformed structural system
of the studied tank. In this investigation, the results have indicated relevant differences, when the geometric
nonlinearity effects were included in the structure dynamic response assessment, when compared to those
calculated based on the traditional static analysis.