The projection angles of fragments from a cylindrical casing filled with charge initiated at one end

Cylindrical casing filled with charge is one of the most common structures used in warhead design. In order to enhance the warhead design, it is necessary to predict both the velocity and the projection angles of the fragments accurately. In present study, we focus on the projection angle of a cylindrical casing filled with charge under one end initiation. The in-house code based on the generalized interpolation material point (GIMP) method is validated in handling the dynamic fragmentation of cylindrical warheads and then utilized to study the characteristic acceleration time. After that, a revised complete formula based on the analytical formula proposed by Chou [1] is developed to predict the projection angle of a fragmentation warhead under one end initiation. In this formula, four factors are considered, including the ratio of the charge mass to the case mass, the charge diameter, the axis rarefaction effects and the influence of off-axis initiation. Finally, two simulations are conducted to validate the present formula. The good agreements between the calculated results and the data from current simulations and published experiments indicate the good accuracy of the formula in predicting the projection angles of fragments from a cylindrical casing filled with charge under one end initiation.