Dynamic research on a projectile buckling instant ignition system

For fuzes used with 155 mm-caliber projectiles, an instantaneous fuze can detonate upon contact with the target, producing a near-surface explosion that is highly effective against personnel, steel plates, and light fortifications. To evaluate and quantify the reliability and responsiveness of the buckling-initiated ignition system, two key parameters are considered: the peak firing-pin (needle) impact velocity and the ignition delay time. The latter is defined as the elapsed time between the moment the fuze nose contacts the target surface and the moment the detonator receives sufficient energy to initiate ignition; this is hereafter referred to as instantaneity. In this study, numerical simulation methods are employed to analyze the operating process of the instantaneous ignition system, yielding a critical buckling load of 622 N. Optimization of dimensional tolerances, particularly through improved machining accuracy of key components, results in a 5.8% increase in firing-pin velocity and a 25.5% reduction in ignition delay compared with the baseline design. The simulation model is further validated against published experimental data on the axial impact buckling of cylindrical shells, showing a relative error of less than 3%, thereby confirming the reliability of the simulation results.