高速3D-DIC测试技术在装甲钢贯穿试验中的应用

数字图像相关（digital image correlation, DIC）技术作为一种非接触、非干涉的全场无损光学量测技术，可获取材料表面的动态变形信息和破坏过程。为了评估装甲钢的抗弹性能并探索高速三维数字图像相关（3D-DIC）技术在钢板贯穿试验测试中的应用，基于氢氧爆轰驱动弹道枪开展了7发15 mm口径可变形弹体以不同速度（255～568 m/s）冲击不同厚度（5、8和10 mm）高强高硬装甲钢板的试验，并结合帧率为144 000 s⁻¹的高速3D-DIC测试技术获取了靶板的离面位移和应变时程。随后，基于前期标定并验证的装甲钢本构模型参数，对上述试验进行了数值模拟。通过对比弹体残余速度和长度验证了有限元分析方法的可靠性。进一步通过对比试验与数值模拟得到的靶背离面位移时程曲线和不同时刻靶背的应变云图，验证了高速3D-DIC测试结果的准确性。最后，对比分析了靶板最大离面位移与弹体冲击速度和装甲钢板厚度的关系。高速3D-DIC测试技术的应用可为相关试验测试提供参考，靶板最大离面位移分析结果可为屏障类防护结构的分析验证和优化设计提供试验依据。

Application of high-speed 3D-DIC measurement technology in perforation test of armor steel

As a non-contact, non-interference full-field non-destructive optical measurement technology, digital image correlation (DIC) technology can obtain the dynamic deformation information on the surface of materials and failure process. Aiming to evaluate the ballistic performance of armor steel and explore the application of high-speed three-dimensional digital image correlation (3D-DIC) technology in perforation test of armor steel plates, impact tests by seven shots on high strength and hardness armor steel plates with different thicknesses were conducted, in which 15-mm-caliber deformable projectile at various velocities were fired by using hydrogen-oxygen detonation ballistic gun, whilst the high-speed 3D-DIC measurement technology with frame rate of 144000 s−1 was adopted to extract the out-of-plane displacement and strain field-time histories of the target. Then, based on the calibrated and validated constitutive model parameters of armor steel obtained in previous work, the current impact test is numerically simulated and the corresponding finite element model is validated by comparing with the simulated residual projectile velocities and lengths with test data. Furthermore, by comparing the out-of-plane displacement-time histories and strain contours at the rear of target obtained by numerical simulation and test, the accuracy of results obtained by high-speed 3D-DIC is validated. Finally, the relationship between maximum out-of-plane displacement with projectile impact velocity and armor steel plate thickness is analyzed. The results show that the relatively smaller out-of-plane displacements were obtained due to the shear plugging failure for 8 mm-thick targets. Under the identical impact energy, the unperforated targets with the thickness of 10 mm absorb the most of energy and exhibit larger out-of-plane displacements compared with those in targets with the thicknesses of 5 mm and 8 mm. The application of high-speed 3D-DIC technology in this study can provide a reference for related tests, and the analysis result of maximum out-of-plane displacement of target can be used as the experimental basis for the analysis, verification and optimal design in protective barrier structures.