Geometrical imperfection’s effect on thermal buckling of cylindrical water storage tanks subjected to fire

Global warming and occurrence of different fires in forests and residential areas, motivate the use of fire extinguishing equipment, such as water storage tanks, which are becoming increasingly popular today. Maintaining the tanks due to high cost and their sensitivity to fire is very important. In this study, a 20 m diameter circular pool-fire adjacent to a reservoir is considered, and the resulting temperature distribution on the shell is deduced through the half-cosine temperature distribution relation. Nonlinear structural stability analysis is conducted by using the Riks nonlinear method in Abaqus/Standard environment. The effect of geometrical imperfection on the buckling behavior of the structure and the critical thermal load of the reservoir for different imperfection intensities are evaluated under variable parameters such as diameter to height ratio and fire scenarios. The results show that for the empty tank by increasing the diameter to height ratio, the sensitivity of the imperfection amplitude to the critical buckling temperature increases by up to 40%. In addition, it is indicated that the more local the thermal load, the less geometrical imperfection will affect the critical buckling temperature.

Keywords:

Imperfection , Thermal Buckling , Pool-Fire , Storage Tank , Finite Element Method