Tailored design of detonation reactions via gradient-structured charges for high-efficiency energy release

: Tailoring energy output represents a critical strategy for enabling multifunctional combat capabilities. The dual-stage energy release mechanism inherent to aluminized explosives provides a fundamental basis for regulating blast energy output. In this work, we designed and fabricated charges with positive gradient structures (PGS) and negative gradient structures (NGS), and achieved precise modulation of shock wave overpressure, ground overpressure, and blast impulse by adjusting charge compositions. Compared with the homogeneous structures (HS) charge, the positive-gradient charge effectively enhanced the near-field shock wave overpressure from 76.59 to 88.53 kPa at 2 m, corresponding to a 15.59% increase, and increased the blast impulse from 44.36 to 69.73 Pa·s at 2 m, corresponding to a 57.19% improvement. In contrast, the negative-gradient charge suppressed the extensive spatial dispersion of explosive energy. With the evolution of the positive gradient structure from PGS-0 to PGS-30, the near-field shock wave overpressure and blast impulse at 2 m declined progressively from 88.53 to 70.17 kPa and from 69.73 to 35.41 Pa·s, respectively. For the negative gradient structure transitioning from NGS-0 to NGS-30, these two corresponding parameters increased progressively from 49.69 to 59.47 kPa and from 29.75 to 36.26 Pa·s, respectively. Additionally, numerical simulations based on the ignition and growth model confirmed the differences between the two gradient charge configurations in detonation wave initiation and propagation, elucidating the intrinsic mechanisms governing their distinct energy output behaviors. This work provides an effective design strategy for developing munition charges with controllable and tailorable energy release characteristics.