Fracture Behavior of Tubular Bombs

The plastic deformation behavior and modes of fracture exhibited by tubular bomb casings are greatly influenced by the stress state imposed by explosive and inertial forces. These forces combine to produce triaxial compression over a varying inner portion of the tube wall. Noting that compressive hoop stresses would exist over a portion of the wall, Taylor has previously developed a hypothesis for prediction of fracture radius, assuming a radial fracture mode. This paper introduces hypotheses related to the influences of stress state and thermoplasticity upon fracture mode as well as fracture radius. The resulting prediction model closely predicts fracture radius and explains the development of commonly observed shear‐lip fractures. It illustrates why radial fractures are typical only when detonation pressures are relatively low, and why shear fractures are typical when detonation pressures are high.