Li Zhao, Xu Xiangzhao
State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081, China.
Materials (Basel). 2020 Nov 26;13(23):5372. doi: 10.3390/ma13235372.
Experimental and theoretical investigations on the failure behaviors of projectile during high-speed impact into concrete slabs were performed in this study. The ogive-nose projectiles after impact experiments were recovered and their microstructures were observed by scanning electron microscope and metallographic microscope. Mass abrasion and nose blunting are the typical failure models of steel projectile. Furthermore, thermal melting and cutting are the two main failure mechanisms. Based on the microscopic experimental results, a theoretical model of ogive-nose projectile subjected to impact loading considering the melting and cutting mechanisms was proposed. A modified cap model is introduced for describing the failure behavior of concrete targets, and then the dynamic cavity expansion theory is used to determine the resistance of projectiles during penetration. Besides, combining with the two-dimensional heat conduction equation and abrasive wear theory, the two main abrasion mechanisms of melting and cutting are included in the proposed model, which breaks through the framework of previous abrasion models with single abrasion mechanism. The predicted results of the present abrasion model are in good agreement with the experimental data, which indicates that the proposed model can effectively predict the failure behavior and penetration performance parameters of high-speed projectiles during penetration into concrete targets, such as mass loss, nose blunting, and depth of penetration.
本研究对高速撞击混凝土板过程中弹丸的失效行为进行了实验和理论研究。回收了撞击实验后的卵形头部弹丸,并通过扫描电子显微镜和金相显微镜观察其微观结构。质量磨损和头部钝化为钢质弹丸的典型失效模式。此外,热熔和切削是两种主要的失效机制。基于微观实验结果,提出了考虑熔化和切削机制的卵形头部弹丸在冲击载荷作用下的理论模型。引入了改进的帽盖模型来描述混凝土靶体的失效行为,然后利用动态空穴扩展理论确定弹丸侵彻过程中的阻力。此外,结合二维热传导方程和磨料磨损理论,所提出的模型包含了熔化和切削这两种主要磨损机制,突破了以往单一磨损机制磨损模型的框架。本磨损模型的预测结果与实验数据吻合良好,表明所提出的模型能够有效地预测高速弹丸侵彻混凝土靶体过程中的失效行为和侵彻性能参数,如质量损失、头部钝化和侵彻深度。