Study on dynamic behavior and crack propagation mechanism of the tanks in one-step BLEVE accident

Abstract

A boiling liquid expanding vapor explosion (BLEVE) is one of the most serious accidents which generates overpressure and ejected fragments with potential great impact on the safety of the tank area. Hence, it is important to reveal the dynamic characteristics of the axial crack propagation at the top of the horizontal tank in a BLEVE accident. The rupture behavior of tanks under one-step BLEVE accidents is investigated and the detailed dynamic characteristics of crack opening angle and crack propagation rate were assessed through the small-scale BLEVE experiments with variations in tank wall thickness and filling levels. An extended Gurson-Tvergaard-Needleman (GTN) model was proposed to calculate the dynamic damage of the tank during the rupture process. The dynamic stress-strain damage characteristics of the tank during the one-step BLEVE process and the circumferential transformation mechanism of the axial crack were explored. Based on an analysis of the material damage and the size characteristics of the tank structure, criteria were proposed for judging whether the direction of crack growth will change.