PBX模拟材料压剪应力状态下的幂函数M-C强度准则与失效特性  

Power Function Mohr-Coulomb Strength Criterion and Failure Characteristics of PBX Simulant Under Compression-Shear Stress State

作　　者：贾东[1] 高洋[1] 陈勇梅[1] 周燕良 郝志明[1] 黄西成[1] JIA Dong;GAO Yang;CHEN Yong⁃mei;ZHOU Yan⁃liang;HAO Zhi⁃ming;HUANG Xi⁃cheng(Institute of System Engineering,CAEP,Mianyang 621999,China)

机构地区：[1]中国工程物理研究院总体工程研究所

出　　处：《含能材料》2020年第1期32-37,共6页Chinese Journal of Energetic Materials

基　　金：国家自然科学基金资助(11472257)

摘　　要：为了研究高聚物粘结炸药(PBX)在压剪复合应力状态下的强度特性,采用变角剪切加载方法进行了0°,15°,30°,45°,60°,75°以及90°的压剪实验研究;建立了PBX模拟材料的幂函数Mohr-Coulomb(M-C)准则,并对其围压强度进行了预测;利用SEM对压剪加载下的细观失效特性进行了分析。结果表明,PBX模拟材料在加载角度θ为0°,15°,30°,45°时主要表现为沿压剪面剪切的破坏模式,在θ为60°,75°,90°时表现为剪切和张裂的混合破坏模式;在剪切破坏模式下,随着压应力的增加,PBX模拟材料剪切强度呈非线性增加的趋势,细观损伤会从颗粒剪断、破碎逐步发展到次生裂纹的形成与贯通。分析发现,幂函数M-C模型适用于描述PBX模拟材料剪切强度的非线性变化规律,拟合得到的强度准则能较为准确地预测不同围压下的轴向压缩强度;压应力增加引起的内摩擦阻力增大和颗粒破碎、次生裂纹等引起的内摩擦系数降低是导致PBX模拟材料剪切破坏强度随压应力增加而非线性增加的重要原因。To study the strength properties of Polymer bonded explosive(PBX)under compression-shear stress state,compression-shear test of PBX simulant was carried out by the experimental method of variable angle shear with loading angle θ 0°,15°,30°,45°,60°,75°,90°;The power function Mohr-Coulomb(M-C)criterion of PBX simulant was established,and compression strength under confining pressure was predicted. The mesoscopic failure characteristics of PBX simulant under compression-shear stress state were analyzed by SEM. The results showed that shear fracture pattern was along the compression-shear surface under loading angles 0°,15°,30° and 45°,and hybrid fracture pattern of shear and tension occurred under loading angles of 60°,75° and 90°;For the shear fracture pattern,with the increase of compression stress,the shear strength of PBX simulant showed a trend of non-linear increase,and the mesoscopic damage would gradually develop from particle shear fracture and breakage to the formation and penetration of secondary cracks. The analysis found that the power function M-C criterion could well describe the trend that shear strength of PBX simulant increased nonlinearly with the increase of compression stress,and predict axial compression strength of PBX simulant under different confining pressure more accurately. The increase of internal friction resistance caused by the increase of compressive stress and the decrease of internal friction coefficient caused by particle breakage and secondary cracks are the important reasons for the non-linear increase of shear failure strength of PBX simulant with the increase of compression stress.

关 键 词：PBX(polymer bonded explosive)模拟材料 压剪实验 幂函数Mohr-Coulomb(M-C)准则 失效特性 

分 类 号：TJ55[兵器科学与技术—军事化学与烟火技术] O346[理学—固体力学]