航天器舱壁结构碎片撞击声发射定位技术研究

Research on space debris impact location of spacecraft bulkhead structure based on the acoustic emission technique

撞击信号在航天器加筋舱壁结构中的传播规律非常复杂,对太空碎片撞击的快速定位产生阻碍。针对以上问题,提出了一种基于声发射的软阈值滤波双曲线算法。该算法通过软阈值方案解决了加筋结构中衰减声波到达时间判断的难题,通过滤波对波速最快的S0模态进行保留,减少了声波的模态转换对定位造成的影响。通过有限元模拟分析了加强筋对兰姆波的影响规律,得到了不同频带下S0模态兰姆波的能量通过比值,给出滤波频带确定依据。通过对20个撞击点的定位实验验证了算法的可行性,对实验样板来说,当频带为100~200 kHz时定位结果最佳,平均绝对误差为5.59 mm。

The propagation of the impact signal in the reinforced bulkhead structure of spacecraft is very complex, which hinders the rapid location of space debris impact. To solve these problems, a soft threshold filtering hyperbolic algorithm based on acoustic emission is proposed. The algorithm solves the difficult problem of judging the arrival time of the attenuation of the wave in the reinforced structure by the soft threshold scheme. The S0 mode with the fastest wave speed is preserved by filtering, which reduces the influence of the modal transition of the acoustic wave on the location. The influence law of ribs on Lamb waves is analyzed by finite element simulation. The energy passing ratio of S0 mode Lamb waves in different frequency bands is obtained to determine the filtering frequency band. The feasibility of the algorithm is verified by the location experiments of 20 impact points. For the experimental plate in this study, the best location result is obtained when the frequency band is 100~200 kHz, and the average absolute error is 5.59 mm.