浅埋炸药爆炸形貌及其冲击作用效应

为研究浅埋炸药爆炸形貌及其冲击作用效应，提出了一套新型试验工装，通过浅埋砂爆试验，系统探究了浅埋爆炸过程中冲击波的传播、爆炸产物与砂土的喷射轨迹、靶板的变形形貌以及爆炸载荷的空间分布情况。结果表明:浅埋爆炸在空气中产生冲击波，其传播速度大于爆炸产物与砂土的喷射速度；起爆后的爆炸产物与砂土迅速向外喷射，体积随时间不断膨胀，撞击到靶板后向四周扩散；通过特 殊设计的试验工装与靶板，定性得出浅埋砂爆载荷产生的冲量在空间中呈非均匀分布，即中间最大，向四周逐渐减小。对比分析2次不同试验，发现炸药埋深影响爆炸产物和砂土喷射时的相对位置:埋深较小时，爆炸产物会冲破覆盖的砂层，直接作用到靶板；埋深较大时，爆炸产物基本被砂层包覆，随砂土共同作用到靶板；此外，增大炸药埋深会延缓爆炸产物与砂土的喷射时间。砂土的类型直接影响靶板的变形形貌，按北约标准AEP-55配做的砂土不仅使靶板产生整体弯曲变形，还在靶板上形成大量凹坑，产生侵彻效果，而普通的河砂仅使靶板产生整体弯曲变形，无明显的侵彻效果。

Explosion morphology and impacting effects of shallow-buried explosives

In modern warfare, shallow-buried explosives, such as landmines and improvised explosive devices, pose serious threats to civil/military vehicles and passengers. To study the explosion morphology and impacting effects of shallow-buried explosives (TNT), a novel set of test facility was proposed in this study and used to perform shallow-buried sand explosion tests. By changing the type of sand and the buried depth of the explosives, the propagation of shock wave, the ejection trajectory of explosion products and sand, the deformation morphology of target plate, and the spatial distribution of explosion load were systematically investigated. It was demonstrated that shallow-buried sand explosion generated a shock wave in air, with a propagation velocity significantly greater than the ejection velocity of explosion products and sand. Upon detonation, the explosion products and sand were rapidly ejected outwards with continuously increasing volume, and spread around after hitting the target plate. The impulse generated by shallow-buried sand explosion was non-uniformly distributed in space, largest in the central explosion area and gradually decreasing outwards. The buried depth of explosives in sand affected the relative position of explosive products and sand when they were ejected. When the buried depth was relatively small, the explosive products would break through the covered sand layer and directly act on the target plate. When the buried depth was sufficiently large, the explosive products were essentially covered by a sand layer, which acted on the target plate together at a delayed instant. The type of sand used significantly affected the deformation morphology of the target plate. The sand purposely prepared in accordance with the NATO standard AEP-55 not only caused overall bending deformation of the target plate, but also formed a large number of pits on the target plate, thus generating a penetration effect. In contrast, the ordinary river sand only caused overall bending deformation of the target plate, with little penetration effect observed. The results obtained in this study are helpful for designing more effective protective structures against intense blast impacting from shallow-buried explosives.