Dynamic Fracture of the 20# Cylindrical Steel Shell under Inside-Explosion Loading

Dynamic fracture of explosion containment vessels subjected to internal blast loads is the foundation for conducting safety assessment and failure analysis of explosion containment vessels. The experiments were carried out to investigate dynamic fracture characteristics of cylindrical steel shells subjected to internal blast loadings at the centers. The elastic-plastic response of cylindrical steel shells was conducted using nonlinear dynamic finite element analysis code LS-DYNA. The fracture mode and fracture mechanism of a cylindrical shell were specially studied through analysis of deformation， macrographs of fracture surface and elastic-plastic response. The results show that dynamical ductility deformations appear and the shear bands form when the cylindrical steel shell expands under internal blast loading. The cylindrical steel shell fractures preferentially along the shear bands due to its softening effect. The fracture mechanism is that the shear bands tear under tensile circumferential stress. The shear bands and the tensile circumferential stress dominate the final fracture mode. The fracture mode is of the ductile fracture.