Liu Ling, Li Jianqiao
State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081, China.
Materials (Basel). 2022 Jun 10;15(12):4124. doi: 10.3390/ma15124124.
Experimental and theoretical studies were carried out on the dynamic deformation and penetration response characteristics of metal ellipsoidal thin curved shells under impact loads. The deformation characteristics of the impacted ellipsoid shell was investigated via the use of a light gas gun to carry out impact loading experiments at different speeds. Ten cases of experiments were conducted with the impact velocities distributed between 25.69 m/s and 118.97 m/s. Stereo digital image correlation (3D-DIC) technology was applied to capture the dynamic deformation and penetration process of the impacted shell. The recovered shells were measured, and the deformation characteristics were analyzed, along with the dynamic evolution, as observed through 3D-DIC analysis. Based on the experimental results, the displacement mode was summarized and the displacement distribution of the locally impacted ellipsoid shell was proposed. The governing equations were derived for the dynamic deformation and penetration of the impacted ellipsoid shell by means of the Lagrange equation. The proposed theoretical model was verified based on the experimental results. Finally, the influence of the curvature distribution on the impact resistance of ellipsoidal shells is discussed. The results indicated that the proposed theoretical model was effective in analyzing the large deformation and the penetration speed. Stretching the axial length of the ellipsoid shell in the impact direction improved its resistance to penetration. Stretching the axial length of the ellipsoid shell perpendicular to the impact direction improved its resistance to deformation, but reduced its resistance to penetration. Maintaining the triaxial ratio and appropriately reducing the size of the ellipsoidal shell improved its resistance to both deformation and penetration. The above research provides a reference for the analysis of the impact resistance of thin-walled curved shell structures in engineering.
对金属椭球形薄曲壳在冲击载荷作用下的动态变形和侵彻响应特性进行了实验和理论研究。通过使用轻气炮以不同速度进行冲击加载实验，研究了受冲击椭球壳的变形特性。进行了10组实验，冲击速度分布在25.69 m/s至118.97 m/s之间。应用立体数字图像相关（3D-DIC）技术捕捉受冲击壳的动态变形和侵彻过程。对回收的壳进行测量，并分析其变形特性以及通过3D-DIC分析观察到的动态演变。基于实验结果，总结了位移模式并提出了局部受冲击椭球壳的位移分布。借助拉格朗日方程推导了受冲击椭球壳动态变形和侵彻的控制方程。基于实验结果对所提出的理论模型进行了验证。最后，讨论了曲率分布对椭球壳抗冲击性的影响。结果表明，所提出的理论模型在分析大变形和侵彻速度方面是有效的。在冲击方向上拉伸椭球壳的轴向长度可提高其抗侵彻能力。在垂直于冲击方向上拉伸椭球壳的轴向长度可提高其抗变形能力，但会降低其抗侵彻能力。保持三轴比并适当减小椭球壳的尺寸可提高其抗变形和抗侵彻能力。上述研究为工程中薄壁曲壳结构抗冲击性分析提供了参考。
