Experimental Study on Fatigue Performance of TC4 Titanium Alloy Liner Carbon Fiber Composite Cylinders in Seawater Environment

Abstract The corrosive nature of seawater poses significant challenges to the design of gas cylinders in marine environments. Currently, TC4 titanium-alloy cylinders are predominantly used because of their resistance; however, they are costly and challenging to manufacture. To address this issue, this study proposes employing TC4 titanium alloy liner carbon fiber composite cylinders, which can reduce the manufacturing cost and processing difficulty while ensuring excellent protection against seawater corrosion and fatigue resistance. The fatigue life of the cylinders was predicted and analyzed using the finite element method, and a prototype was manufactured for verification. The results show that the composite layer can effectively share the stress load for the liner under the working pressure cycle, which increases the fatigue life of the titanium alloy liner carbon fiber composite cylinders and provides strong support for their application in marine engineering.