数字全息测量超高速撞击碎片云实验研究

Experimental Study on Debris Clouds under Hypervelocity Impact with Pulsed Digital Inline Holography

在中国空气动力研究与发展中心(CARDC)超高速碰撞中心(HIRC)7.6 mm超高速碰撞设备的基础上,搭建纳秒级脉冲激光数字全息系统。提出滤波片和衰减片组合布置,减弱超高速碰撞等离子体自发光、提高信噪比的方法。实验获得了2.25 mm铝球弹丸以4.0 km/s的速度撞击0.5 mm厚铝板形成碎片云的全息图。采用小波变换算法对碎片云全息图进行重建,得到超高速撞击碎片云的三维结构和碎片大小。碎片云的轮廓呈椭球型,分为碎片云的前端、核心和外壳,碎片主要分布在弹丸破碎形成的碎片云核心,存在大碎片,且分布较集中,对后板的损伤也严重。

At the Hypervelocity Impact Research Center(HIRC)of the China Aerodynamics Research and Development Center(CARDC),based on the hypervelocity impact equipment with a 7.6 mm bore,the pulsed digital inline holography system is set up.Combination of the neutral density filter and the bandpass filter is proposed to eliminate the plasma radiation and enhance the signal-to-noise ratio of the hologram.The debris clouds hologram of 2.25 mm aluminum sphere impacting a 0.5 mm thickness aluminum target plate with a velocity of 4.0 km/s is obtained.The holograms are reconstructed with the wavelet reconstruction algorithm,and the three-dimensional structure and the shapes of the debris particles are determined.The results show that the outline of the debris clouds is ellipsoidal,and it is divided into the front end,core and shell of debris clouds.The debris is mainly distributed in the core of the debris clouds formed by the fragmentation of the projectile,and there are large pieces and obviously centralized distribution,which cause serious damage to the rear plate.