PBX炸药的拉伸断裂损伤分析

采用巴西实验作为间接拉伸加载手段,研究了某PBX(polymer-bonded explosive)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...

Fracture damage analysis of PBX

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 binders.