Study on Material Damage Characterization of High-Pressure Hydrogen Storage Vessels Based on DIC and Acoustic Emission Entropy

In this paper, a method of combining acoustic emission (AE) and digital image technology is proposed to study the damage evolution law of pressurized hydrogen storage cylinders under different loading methods. The statistical parameter, standard deviation (SD), is introduced into the digital imaging of the specimen, and the SD of the surface strain of the specimen is used to characterize the plastic evolution law of the material under the fatigue state. Moreover, the SD is combined with the Shannon entropy based on the AE time domain, both from the inside and the surface of the specimen. The two levels are the same. The results show that the digital image correlation analysis method with the SD value as a parameter can accurately reflect the surface strain evolution law of the material fracture failure process, and superior results are obtained than the traditional accumulation rate analysis.