构型弹体跌落冲击载荷及结构响应特性

为深入认识跌落冲击条件下构型弹体内部的载荷传递规律及结构响应特征，促进战斗部装药安定性评估和结构设计，结合数值模拟和应力波分析手段，研究了构型弹体在跌落过程中的冲击响应特征，主要关注内部药柱的变形和损伤特性，并讨论跌落姿态、装药构型和跌落高度等因素的影响。结果表明，在跌落冲击条件下，构型弹体装药的变形并非由药柱同壳体的直接撞击作用主控，而主要受到弹体内部应力波传播的影响。装药结构最大变形和损伤区域并不位于药柱外侧同壳体相接触的位置，而位于内部区域。冲击应力波在壳体和药柱之间的透射特征、在壳体和装药内部的反射和叠加特性等决定了药柱的主要变形区域及其变形程度。跌落姿态对药柱的响应特征和变形形貌具有重要影响，导致装药安定性风险从高到低排序的跌落姿态依次为尾部向下垂直跌落、水平跌落、头部向下垂直跌落和倾斜跌落。药柱构型也具有重要作用，其中药柱分段界面容易使得药柱变形程度增大，但对装药过载以及变形分布特征的影响相对较小；隔板结构则容易增大装药过载，同时导致药柱的局域变形位置和变形程度均发生改变。跌落高度对药柱变形区域分布特征的影响较小，对载荷幅值、变形程度和分布范围大小等则具有重要作用，随跌落高...

Loading characteristics and structural response of a warhead during drop impact

To promote the explosive safety assessment and the warhead structure design, the loading characteristics and structural response of the warhead during the drop impact process were analyzed based on numerical simulation and shock wave analysis, focusing on the deformation and damage characteristics of the explosive subassembly. And the influences of various factors, including drop posture, explosive configuration, drop height, etc., were discussed in detail. In the numerical simulations, materials were characterized by the viscoplasticity constitutive model combined with the accumulative damage model, which considers the effects of strain rate and temperature. The thermodynamic equation of state was employed to calculate the pressure in materials during the deformation process. Firstly, the effect of drop posture was investigated by comparative analysis among five typical cases, i.e., tail-downward vertical drop, nose-downward vertical drop, horizontal drop, tail-downward inclined drop, and nose-downward inclined drop. Secondly, the influence of warhead configuration was analyzed based on three configurations, i.e., one explosive segment warhead, eight explosive segment warheads, and eight explosive segments combined with a separator warhead. Finally, the effect of drop height was discussed, where the height ranges from 3 m to 40 m. Related results indicate that during the drop impact process, the deformation of the explosive subassembly is dominated by the stress wave propagation rather than the interaction between the explosive subassembly and warhead shell. Correspondingly, the severest damage zone in the explosive subassembly is located in its internal region instead of the outer region, which contacts the warhead shell. The transmission of stress waves between explosive subassembly and warhead shell and the reflection and superposition of stress waves within the structures dominate the major deformation region in the explosive subassembly and the deformation degree. Furthermore, the drop posture significantly affects the response characteristics and the deformation of the explosive subassembly. The most dangerous drop posture which leads to high safety risk is, in turn, tail-downward vertical drop, horizontal drop, nose-downward vertical drop, and inclined drop. The explosive configuration also acts an important role. The explosive segment interface can easily induce an increase in the deformation degree, but it has little influence on the acceleration and distribution of the deformation region. The separator usually leads to high acceleration, and it changes the location of the deformation region as well as the deformation degree. Comparatively, the drop height has little influence on the distribution feature of the deformation zone. It mainly affects the loading amplitude, the degree of the deformation, the size of the deformation zone, etc. The influences of these factors increase with increasing drop height. The present method, which investigates the structural response of complex warheads based on numerical simulation integrated with stress wave analysis, has built an effective bridge linking the basic theory and the engineering application.