Storage Tank Response to External BlastNonlinear Dynamic Response of Ethylene Storage Tank to Impulsive Loads
SC Solutions examined the dynamic response of an ethylene tank secondary (external) containment structure to the impulsive blast load due to a nearby external explosion. The nonlinear analysis included various pulse magnitudes and durations applied on a model of half the structure to investigate the robustness of the steel shell design of the containment structure.
The analysis revealed that most of the cylindrical base shell of the primary (internal) containment structure remained elastic through the impulsive load. The roof structure, comprised of a spherical shell supported by rings and radial stiffeners of the secondary (external) containment structure, experienced most of the damage; the radial stiffeners experienced plastic buckling, and the shell was plastically deformed with permanent deformation being readily visible after the event. However, even in the most severe cases, the deformation of the secondary tank was not enough to interact with the primary tank. The plastic strains in the roof were small enough such that no leaking of vapor would occur.
Our rigorous nonlinear blast analysis supported the evaluation against industry codes and requirements for this load condition.