To investigate the damage characteristics of spacecraft structures caused by external impacts and propose protective measures, this study utilizes two-stage light gas gun launcher with detonation capability. Hypervelocity impact experiments are conducted on composite laminates that incorporate varying proportions of shear stiffening gel (SSG). Polyvinylidene fluoride (PVDF) sensors are employed to collect response signals from the front corners, rear corners, and rear edges of the laminate, enabling an assessment of its behavior under impact conditions. By analyzing the signals acquired from the Polyvinylidene fluoride sensor, the study obtains the time-frequency response characteristics of the signals at various positions with different proportions of shear stiffening gel. The correlation between these response characteristics and the damage of the laminate is investigated. The analysis reveals that the vibration response at various positions of the laminate provides a comprehensive indication of internal delamination and surface damage. Moreover, this response is linked to the level of fragmentation of the projectile. The incorporation of shear stiffening gel in the laminate enhances its impact resistance and helps mitigate damage at the connection between the laminate and other components. Interestingly, the impact resistance does not follow a monotonic trend with respect to the proportion of shear stiffening gel. Based on the experimental results discussed in this article, the optimal proportion of shear stiffening gel is determined to be 5 %.

中文翻译：

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剪切硬化凝胶复合材料层合板超高速冲击响应特性及抗冲击性能


为了研究外部冲击对航天器结构造成的损伤特征并提出防护措施，本研究采用具有起爆能力的两级轻气炮发射装置。超高速冲击实验是在含有不同比例的剪切硬化凝胶 (SSG) 的复合材料层压板上进行的。聚偏二氟乙烯 (PVDF) 传感器用于收集层压板前角、后角和后边缘的响应信号，从而能够评估其在冲击条件下的行为。通过对聚偏氟乙烯传感器采集的信号进行分析，研究获得了不同剪切硬化凝胶比例下各位置信号的时频响应特性。研究了这些响应特性与层压板损坏之间的相关性。分析表明，层压板各个位置的振动响应提供了内部分层和表面损坏的综合指示。此外，这种反应与射弹的碎片程度有关。在层压板中加入剪切硬化凝胶可增强其抗冲击性，并有助于减轻层压板与其他部件之间连接处的损坏。有趣的是，抗冲击性并不遵循剪切硬化凝胶比例的单调趋势。根据本文讨论的实验结果，确定剪切硬化凝胶的最佳比例为 5%。