单层板撞击成坑声发射辨识及参数估计研究

空间碎片撞击航天器的威胁对发展在轨感知系统提出需求,为研制基于声发射技术的感知系统,有必要研究利用声发射波形分析对防护结构进行损伤模式辨识的方法.文章利用超声传感器进行了铝弹丸超高速撞击单层板的声发射信号采集实验及其数值仿真,并对波形在时域和频域内进行分析,结果表明:声发射波形的主波谷值随撞击速度增加而线性增加,直到防护结构被击穿;声发射波形中的高频分量与低频分量幅值之比存在一个区别成坑模式与击穿模式的阈值.基于上述结果提出了一种在撞击弹丸尺寸已知条件下辨识成坑模式并对其撞击速度及其弹坑尺寸进行估计的方案.

Research on Identification and Parameter Estimation of Cratering Induced by Impact on Single Plate with Acoustic Emission Signals

Due to the threat of impact to spacecraft from space debris,the space debris in-suit detection system is required.For developing the detection system based on acoustic emission(AE) technique,means of failure mode identification by AE signals from hypervelocity impact on protection structure is necessary.AE waves were obtained with experiments of hypervelocity impact on single plate and numerical simulations and were analyzed in time domain and frequency domain.The results indicate that the main trough value increases linearly with the increase of impact velocity till the plate is penetrated.A threshold value that divides the penetration and cratering in the failure modes of plates can be defined on the ratio of high frequency component amplitude to low frequency one.A method was presented which identifies cratering mode of single-sheet plate and estimates the impact velocity and size of crater assuming certain diameter of projectile.