Experimental study on low-velocity impact ignition for HMX granular explosives

Optical measurement components were designed and machined to be equipped in the conventional drop-weight system. Based on the improved drop-weight system, the response processes of different-mass HMX particles impacted by the different falling-height weight drops were recorded by a high-speed camera on the microsecond time scale. The processes consisted of the following phenomena: explosive particle deformation, melting, ignition, combustion and explosion. And a series of analysis were carried out for the influences of drop-weight falling height and explosive incompactness degree on explosive particle deformation, ignition duration and combustion intensity. Investigated results show that the higher the falling height of the drop weight, the longer the duration of the plastic deformation, the ignition of the explosive instead of the injection is apt to occur; that the lower falling height of the drop weight tends to induce the explosive to intensively jet rather than be ignited; that the higher the incompactness degree of the explosive, the shorter the duration of the plastic deformation, multiple hot spots are easier to form and coalesce which leads to high combustion probability.