Microstructural Effects on the Fragmentation of High-Carbon Steel Cylindrical Shells Under Explosive Loading

This paper integrates a comprehensive overview of cylindrical shell simulations by means of finite element analysis, focusing on both ductile and brittle fracture behaviors under explosive loading. Special attention is given to high-carbon alloy steels that exhibit pronounced cleavage or quasi-brittle behavior and can produce smaller, higher-velocity fragments under certain conditions. We discuss key numerical approaches for fragmentation modeling and shrapnel kinetic energy calculations, and explore the relevant constitutive equations, particularly the Johnson-Cook law for high strain-rate plasticity and Linear Elastic Fracture Mechanics (LEFM) parameters for cleavage-type fracture. Emphasis is placed on microstructural factors (grain size, carbide distribution) that govern fracture and fragment mass distribution. We incorporate experimental findings on brittle fracture of steels under internal blast, highlighting how microcrack formation, alloy carbides, and high hardness can alter fragmentation and shell initial velocity.