Dynamic buckling of cylindrical storage tanks under fluctuating wind loading

Significance 

Cylindrical storage tanks are generally susceptible to wind-induced buckling and vibration due to relatively low flexural rigidity of the tank shells, especially in empty- or partially filled tanks. Open-topped tanks are more vulnerable compared to closed-topped tanks owing to the effect of larger negative pressure acting on the internal surface. For decades, the study of wind-induced buckling of thin cylindrical shells has been mainly based on three approaches: wind tunnel experiments of wind pressure distributions and buckling, finite element analysis and time-history response analysis. However, despite the extensive research efforts, dynamic buckling studies of cylindrical storage tanks in turbulent boundary layers have not been fully explored in the literature.

To this note, Dr. Jumpei Yasunaga from JFE Steel Corporation in collaboration with Dr. Yasushi Uematsu from the National Institute of Technology investigated the characteristics of dynamic buckling and vibration of cylindrical storage tanks under fluctuating wind loading in the turbulence boundary layer. In particular, they conducted wind tunnel experiments and time-history response analysis using the finite element method, focusing mainly on the effects of the vibration of tank shells on the buckling behaviors. Their research work is currently published in the journal, Thin-Walled Structures.

In their approach, the authors carried out their experimental investigation using empty ring-stiffened open-topped tank and close-topped tank under construction, otherwise referred to as tank with ring and tank without ring respectively. The distributions and time history of wind force coefficients were measured to evaluate the characteristics of wind force distributions. A buckling test, based on two polyester film elastic specimens, was conducted to describe the dynamic behaviors of the cylindrical tanks, under the same turbulent boundary layer. Lastly, the dynamic buckling load was evaluated by comparing the buckling loads obtained from the experiments together with the time-history response analysis with the results of static buckling analysis.

Results showed that the dynamic buckling of the tanks was mainly caused by the instantaneous positive wind forces in the windward area. However, the effects of the inertia forces induced by the vibration on the dynamic buckling behaviors were noted to be relatively small. The authors confirmed the feasibility of using static buckling load based on quasi-steady buckling phenomena in evaluating the buckling load of tanks under fluctuating wind loading. The dynamic buckling occurred in the elastic range of the steel material for the tank with a ring while it was accompanied by plastic deformation for a tank without a ring. Interestingly, the static buckling analysis with elastic and non-elastic materials exhibited small differences, suggesting that the dynamic buckling of the tank without the ring could as well be determined based on the static buckling load in the elastic range of the material. Based on these results, the authors further proposed formulas for estimating the buckling loads in tanks with and without rings.

In a nutshell, Yasunaga and Uematsu studied various aspects of the wind-resistant design of cylindrical storage tanks based on wind tunnel experiments and time-history response analysis. Based on the results, formulas for evaluating the buckling loads in empty ring-stiffened open-topped tanks and close-topped tanks under construction were proposed and verified. In a statement to Advances in Engineering, the authors observed that their study would be of importance in the effective design of high-performance cylindrical storage tanks for practical applications.

Reference

Yasunaga, J., & Uematsu, Y. (2020). Dynamic buckling of cylindrical storage tanks under fluctuating wind loading. Thin-Walled Structures, 150, 106677.

Go To Thin-Walled Structures

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