关键词: 兵器科学与技术, 岩石材料, 爆炸载荷, 主动围压, 图像相关方法, Johnson-Holmquist损伤本构模型

Abstract: An experimental equipment including active confining pressure part and cylindrical charge part is set up for studing the fracturing process of deep rock under impact loading. The dynamic test technique, High-speed (HS) photography and digital image correlation (DIC) method are used to obtain the strain field and surface crack propagation of rock under static and dynamic loads.The breaking process of rock with different confining pressures is simulated based on Johnson-Holmquist (J-H) constitutive model. The results show that the circumference pre-stress field is produced by initial confining pressure, and decreases the circumference tensile failure from explosive loading. The number and size of radial cracks and the broken radius are significantly reduceed with the increase in confining pressure. With the increase in distance from borehole, the strength of explosion shock wave reduces and the confining pressure prevents cracks from propagating. The elastic mechanics and cylindrical elastic wave theory are used to study the propagation of stress wave, and find the pre-compression stress from initial confining pressure to reduce the tensile failure in circumferential direction after blast loading, which is the same as the experimental result. The numerically simulated results show that Mises stress increases and circumference tensile damage reduces with the increase in confining pressure, and the radius of broken zone and the crack shape are well agreed with experimental results. Key

Key words: ordnancescienceandtechnology, rockmaterial, blastloading, activeconfiningpressure, digitalimagecorrelation, Johnson-Holmquistdamageconstitutivemodel