中文摘要：

采用巴西实验作为间接拉伸加载手段，研究了某PBX（polymer-bondedexplosive）炸药试样拉伸作用下的断裂损伤特性。发展了PBX炸药的光学制备技术，获得了试样在光学显微镜下的细观表面形貌和断裂损伤形貌，结合高速摄影和数字相关分析技术获得了试样的形变和破坏过程。实验结果表明该PBX炸药的静态拉伸强度低于3MPa，破坏应变也非常小。根据观测结果，运用晶体穿晶断裂和临界脱粘理论对PBX炸药的拉伸断裂模式进行了分析，认为脱粘裂纹在加载早期即可成核；当晶体开始发生断裂后试样发生宏观破坏。颗粒尺寸较大的晶体容易发生穿晶断裂，颗粒尺寸很小的晶体则容易发生界面脱粘。

英文摘要：

The quasi-static Brazilian test was performed on the MTS machine to investigate the tensile fracture modes of the PBX specimen. An optical preparation technique for the PBX specimen was developed to obtain more vivid microstructure features under optical microscopes. And the deformation and damage evolutions of the specimen were gained by adopting a high-speed camera and the digital image correlation method. Results show that the tensile strength of the PBX is less than 3 MPa and its failure strain is considerably small. Based on the observed results, the tensile fracture modes of the PBX explosive specimen were analyzed by applying the Griffith fracture criterion and the interface debonding theory. Analysis reveals that the interface debonding crack will initiate in the early stage of load and the transgranular fracture leads to the failure of the specimen. Larger crystals are prone to crack through themselves, and smaller ones can keep themselves from trangranular cleavage fracture but only debond from the hinders.