Loading Pulse Width and Explosive Density Influence on the Non‐shock Ignition Criterion Mechanism of Polymer‐bonded Explosives

Understanding the response of polymer‐bonded explosives (PBXs) to low‐velocity impact loading is critical for ensuring the safety and effectiveness of these materials in various applications. The ignition behaviors of PBX under controllable low amplitude and long pulse load using the Split Hopkinson Pressure Bar‐Anvil technique were investigated. Non‐shock ignition was observed in the confined explosive specimens when the shock load velocity and pulse width exceeded the critical threshold. Scanning electron microscopy was employed to observe the microstructural changes in the sample materials pre‐ and post‐loading. Post‐experiment analysis indicated the presence of residual aluminum powder in the reacted samples, whereas unreacted samples retained a coating of the high melting explosive substrate. An increase in the loading pulse width led to a notable decrease in the impact velocity required for the explosive to ignite. The pulse width increased from 80 to 160 µs, and the required ignition energy increased from less than 120 J to nearly 200 J. The impact energy is less sensitive to specimen density than the loading pulse. The energy demand of the specimen with a density of 1.5 g/cm3 decreased by merely 12 J relative to the specimen with a density of 1.7 g/cm3, representing a reduction of under 9%.