The study of impact damage of carbon fiber wrapped cylinder with aluminum liner based on x-ray digital radiography

With the development of hydrogen fuel cell vehicles, Carbon Fiber Wrapped Cylinder with Aluminum Liner are widely used in the field of the on-board storage of compressed hydrogen. Impact damages are common in Carbon Fiber Wrapped Cylinder with Aluminum Liner because the composite laminate structure is sensitive to impact load. In this work, the DR method with the technology of compensation block is used to detect impact damage of Carbon Fiber Wrapped Cylinder with Aluminum Liner, and analyzes the expansion of impact damage after different number of pressure cycles. The main damage of Carbon Fiber Wrapped Cylinder with Aluminum Liner caused by impact are delamination of carbon fiber overwrap, debonding between cylinder liner and carbon fiber overwrap, and bulge inward of aluminum liner, and these damages become more serious as the impact energy increases from 500 J to 1500 J. As the pressure cycle test is performed to the Carbon Fiber Wrapped Cylinder with Aluminum Liner, the impact has a serious effect on the fatigue performance of the cylinder. In addition, the debonding between the cylinder liner and the carbon fiber overwrap and the bulge inward degree of the aluminum liner are reduced due to the internal pressure. When the impact energy is low (i.e., 500 J), the pressure cycle has no significant influence on the delamination defect of carbon fiber overwrap. Besides, under the high impact energy conditions (i.e., 1000 J and 1500 J), the delamination defect of the overwrap in the impact center appears obvious expansion with the pressure cycle, while the delamination defect at the impact edge does not propagate obviously.