Axial distribution of Fragment Velocities from cylindrical casing under explosive loading

• The influence of rarefaction wave on the initial fragment velocities was studied.
• The fragment velocities distribution was obtained by a flash X-ray imaging technique.
• A new expression was proposed which can predict the fragment velocities well.

The initial velocity distribution of fragments from cylindrical casing, which detonates at one end of explosive charge, is the key issue in the field of explosion technology and its protecting. Most of the formulae available can predict the average velocity or the velocities of fragments at the middle part of the cylindrical casing. However, due to the influence of rarefaction waves, often referred to as ‘edge effects’, which are generated at the two ends of the charge, most methods cannot accurately predict the velocities of fragments near the two ends of the cylindrical casing. The Fragment Velocities dispersal along the axis of a cylindrical casing, which was detonated at one end, was investigated experimentally in this paper, and the initial velocity distribution was obtained by a flash-radiograph technique. Thus, a formula for Fragment Velocities dispersing along the axis of the cylindrical casing, which is based on the Gurney formula, was proposed by the theoretical analysis and data fitting with the edge effects from the two ends of the charge. This formula has higher accuracy and wider applicability in the study of the Fragment Velocities dispersing along the axis of cylindrical casing under interior blast loading.