Delamination defects in composite hydrogen storage cylinders: CT scanning and shearography measurement

Abstract

Carbon fiber-reinforced composite hydrogen storage cylinder is a key component used in hydrogen fuel cell electric vehicles. However, some micro defects such as voids and delamination are inevitable during the manufacturing process. An efficient detection method for manufacturing defects is still lacking at present. In this work, industrial computerized tomography (CT) scanning was carried out and a large number of micro delamination with scattered sizes and random locations were found in the filament winding layer. Shearography technique based on digital speckle pattern interferometry (DSPI) was used to measure the surface deformation of the cylinders. It was found that the "butterfly-shaped” interference fringes representing the anomalous responses from defects can be significantly observed at the pressure difference of 0.62%–0.69% working pressure. Also, the crack was found originated from the delamination defect with the most significant “butterfly-shaped” fringes, which leads to a large area of interlaminar destruction during the hydraulic bursting test.