Observation of damage evolution in polymer bonded explosives using acoustic emission and digital image correlation

The Acoustic Emission (AE) and Digital Image Correlation (DIC) methods have been combined to measure and evaluate the damage evolution of Polymer Bonded Explosives (PBXs) under uniaxial compression. The global damage evolution was measured by AE and the local (spatial) distribution of damage observed by DIC. It was found that a Dominant Localization Band (DLB) plays a key role in the damage and fracture of the specimen. Because of the existence of the DLB, the specimen is essentially a structure with a weak plane during the nonlinear stage and, therefore, the nonlinear behavior is the average response of the structure. A simple model has been proposed to describe the mechanical behavior of the specimen based on the DLB and the measured damage parameters. The non-linear stress-strain relationship of the specimen is then deduced from the model and verified by experiment.