Design wind force coefficients for open-topped oil storage tanks focusing on the wind-induced buckling

Wind force coefficients for designing open-topped oil storage tanks have been investigated both experimentally and analytically. First, simultaneous pressure measurements were carried out at many points both on the outside and inside of the wall of a rigid model in a turbulent boundary layer. A conditional sampling of pressures was made for investigating the pressure distribution at an instant when the external pressure at a reference point, roughly corresponding to the windward stagnation point, became the maximum peak value. The instantaneous distribution of wind force coefficients, or the pressure difference coefficients at this moment was found to be similar to that of the mean wind force coefficients. Then, the buckling behavior of thin cylindrical shells was investigated based on a wind tunnel experiment with elastic cylinders. Furthermore, a finite element analysis of the buckling behavior under static wind loading was carried out. The results indicate that the buckling behavior is mainly affected by the magnitude and extent of positive wind force coefficient on the windward area of the cylinder. Finally, a discussion is made of the wind force coefficients to be used for the design of open-topped oil storage tanks, based on the above-mentioned wind tunnel experiments and finite element analysis.