Effect of the variation of conical liner apex angle and explosive ignition point on shaped charge jet formation

摘要

Shaped charge technology has an important role in the military and commercial areas, as bullets and warheads made by the shaped charge principle are especially used for penetration to target and demolition purposes. In early studies, the solution of shaped charge problems has been obtained by using analytical methods. However, over the past decade, numerical methods based on finite difference and finite element methods are used for simulating this complex process. In this study, the effects of varying parameters (conical liner apex angle and explosive ignition place) are investigated by a numerical modelling of the shaped charge performed using the Dyna2D hydrodynamic code. The 81 mm precision shaped charge warhead which is designed by Ballistic Research Laboratory (BRL) is taken as a reference charge. The simulations are carried out from 13 deg to 46 deg of the apex angle because both the jets do not occur completely for the apex angles equal or smaller than 13 deg and the velocity decreases for the apex angles larger than 46 deg . The velocity of the jet tip increases very slowly with the decrease of the apex angle from 38 deg to 13 deg. When the apex angle in this range decreases the jet tip becomes shorter while the jet slug gets longer and thicker. Additionally, it is realized that it needs longer time for the jet formation, and moreover, the jet does not occur completely, For those reasons, the parametric evaluations are realized by changing the conical liner apex angle (38 deg, 40 deg, 42 deg, 44 deg, 46 deg) and explosive ignition place (central point, plane and ring). As a result of the variation of the parameters, some important variations are determined in pressure, velocity gradient and jet formation of the shaped charge through simulation. The present results are found in good agreement with the reported results.