Abstract Loosening of threaded connection under impact loading is important in engineering structures such as the fuze on a projectile. It is difficult to predict the loosening behavior of threaded connection under impact loading due to their high nonlinearities introduced by friction and discontinuity. This paper investigated the loosening response of a threaded connection under a series of impact loadings using Hopkinson bar experiments. The loosening phase diagram was constructed by measuring the preload variation. The correlation between the preload variation and the loosening rotation angle was established by using high speed camera and digital image correlation technique. A 3D finite element model was developed to analyze the loosening mechanism of threaded connection. The transient behavior of threaded connection shows a tightening-loosening alternation process. This study provides an understanding of the loosening process of threaded connection under impact loading and is helpful for optimizing structural design under extreme conditions.

中文翻译：

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承受轴向压缩冲击载荷的钢制螺纹连接的松动

摘要 冲击载荷作用下螺纹连接的松动在弹丸引信等工程结构中具有重要意义。由于摩擦和不连续性引入的高度非线性，很难预测冲击载荷下螺纹连接的松动行为。本文使用霍普金森杆实验研究了螺纹连接在一系列冲击载荷下的松动响应。通过测量预紧力变化构建松动相图。利用高速摄像机和数字图像相关技术建立了预紧力变化与松动旋转角度之间的相关性。开发了一个3D有限元模型来分析螺纹连接的松动机制。螺纹连接的瞬态行为显示出拧紧-松开交替过程。该研究提供了对冲击载荷作用下螺纹连接松动过程的理解，有助于优化极端条件下的结构设计。