爆炸驱动亚毫米级金属颗粒群的飞散特性

Scattering Characteristics of Sub-Millimeter Metal Particle Group Driven by Explosion

采用试验与数值模拟相结合的方法,研究了爆炸驱动下亚毫米级WC颗粒群的飞散特性及其影响因素。首先对重金属嵌层碳纤维复合材料(CFRP)壳体开展静爆试验研究,测得距爆心一定距离处颗粒速度;然后基于离散元方法(DEM),依据实体情况对WC颗粒层的颗粒进行无序建模与数值模拟,分析了颗粒无序排列时不同颗粒、装填比及长径比对颗粒速度的影响规律。结果表明:在相同装填比下,颗粒粒径越大,单个颗粒所获得的速度越小;端部附近内外层颗粒速度相同,相对轴向位置X/L=0.62附近速度差最大;长径比在0.5~1.5范围内时,随着长径比的增加,颗粒的速度及速度差增大,起爆端相对于非起爆端颗粒速度增加较小。

Under the implosion of the carbon fiber composite(CFRP)shell embedded in dense inert metal particle,the damage elements dominated by dense inert metal particles will be formed.Thus,accurately acquiring and predicting the scattering performance of heavy metal particle cluster driven by internal-burst is of great significance for the design and evaluation of damage capability of low collateral damage munitions.In this paper,both the experimental study and numerical simulation are adopted to investigate the scattering characteristics and influencing factors of the sub-millimeter WC particle group under explosion.Based on the discrete element method(DEM),the disordered model and numerical simulation of particles in WC particle layer are carried out according to the entity condition,the effects of different particles,loading ratio and length-to-diameter ratio on particle velocity are analyzed.The results show that the larger size of a particle can result in a lower velocity under the condition of the same loading ratio.The outer layer particle velocity at the end is the same,but the velocity difference near the relative axial position X/L=0.62 is the largest.When the ratio of length to diameter is in the range of 0.5–1.5,both the particle velocity and velocity difference increase with the ratio of length to diameter,and the incremental velocity of the particles at the detonating end is smaller than that at the non-initiating end.