Plastic buckling of fixed-roof oil storage tanks under blast loads

Abstract

This paper deals with the dynamic behavior of cylindrical shells under blast loads, with special reference to plasticity and plastic buckling. Interest in this problem focuses on the response of steel vertical oil storage tanks with a flat roof under a nearby explosion. The problem is modeled using a finite element discretization of the structure, with the loads represented by an impulsive pressure which is variable around the circumference. The results for tanks with flat roof show that there is an elastic behavior of the shell at low pressure levels, and first yield occurs at the center of the tank as the peak blast pressure is increased. For subsequent increases of peak pressure, the dimple extends in the area affected by the pressures, so that vertical stripes with plastic material behavior are formed from top to bottom of the shell. For even higher pressures, a global mode develops with large amplitude displacements. The total plastic energy is investigated under increasing peak pressure levels.