丝网防护屏碎片云特性数值模拟研究

Numerical Simulation of Debris Cloud Characteristics of the Mesh Shields

丝网作为一种颇具潜力的轻质防护屏候选材料,在新型防护结构开发中具有广泛的应用前景。为了掌握丝网防护屏超高速撞击特性,采用数值仿真方法模拟球形弹丸分别撞击连续型防护屏和丝网防护屏,研究相同厚度及面密度的2种防护屏受到弹丸撞击后产生的碎片云形态、质量、速度和动量分布的差异。结果表明,丝网防护屏碎片云随撞击位置不同呈现不同形态,但碎片云前端均存在带状碎片分布区域。在丝网防护屏产生的碎片云中,碎片主要分布于碎片云后端,丝网不能有效地减缓入射弹丸速度,其作用主要为切割弹丸。弹丸撞击2种防护屏后,弹丸破碎形成的碎片云中相同部位呈现不同速度变化规律。丝网防护屏碎片云动量密度峰值均高于相同厚度连续型防护屏碎片云,而相同面密度的2种防护屏碎片云动量密度峰值接近。

The hypervelocity impact interaction of the sphere projectile with continuous shield and mesh shield, which were of the same thickness or area density ,was investigated numerically. The study was aimed at mastering the hypervelocity impact characteristics of the mesh shield and applying effectively it in development of lightweight shields. The study involved the differences in the morphology and the distribution of momentum, velocity and mass of the debris clouds generated by impacting two kinds of shields. The calculations show that the morphologies of the debris cloud vary with the impact locations when a projectile impact the mesh shield,and there is the linear distribution of debris in the front of debris cloud. Comparison between the continuous shield and the mesh shield with the same thickness, the maximum of momentum density in the mesh shield is higher than that in the continuous shield, while the maximums of momentum density are almost near in the two kinds of shields with the same area density. The mesh shield does not effectively slow the penetration velocity of projectile,but can break it up. The dynamical response of the projectile varies with the shields. Impacting the mesh shield, the main part of debris is at the rear end of the debris cloud, which is different from the case of continuous shield.