Investigation on the Mechanisms of Strain Growth in Cylindrical Containment Vessels Subjected to Internal Blast Loading

Strain growth is a phenomenon observed in the elastic response of containment vessels subjected to internal blast loading. The local dynamic response of a containment vessel may become larger in a later stage than its response in the earlier stage. In order to find out the possible mechanisms of the strain growth phenomenon, the natural frequencies and mode shapes of various vibration modes in cylindrical shells with different boundary conditions are obtained theoretically and numerically. The dynamic elastic responses of cylindrical shells subjected to internal blast loading are studied by theoretical analysis and finite element simulation using LS-DYNA. It is found that strain growth in cylindrical containment vessels is mainly caused by linear modal superposition and nonlinear modal coupling. The effects of the reflected blast shock waves and structural perturbation are discussed. The proposed theory for the strain growth mechanisms may guide the safe design of cylindrical containment vessels.