Abstract
Ratcheting and shakedown anomalies are investigated for impulsively loaded vessels. Calculated results for explosive containment vessels subjected to repeated dynamic loading are used to illustrate behaviors that differ markedly from classical ratcheting/shakedown (i.e., the phenomenon associated with purely static loading and elastic-perfectly plastic material) and from the shakedown assessment procedure in API 579-1/ASME FFS-1. Results are similar to ‘pseudo-shakedown’ reported for other dynamically loaded structures. In addition, a simplified analytical model subjected to repeated impulsive loading is shown to demonstrate related characteristics. Experimental data presented elsewhere for explosive containment vessels subjected to repeated loading are used to further demonstrate the differences between conventional ratcheting and that observed for repeated loading of impulsively loaded vessels. These differences are believed to be associated with energy-based response as opposed to load-based response of statically loaded vessels.