Structure Design Study of Composite Overwrapped Pressure Vessel with Plastically Working Liner

The shell structure with ultra-thin metal liner and carbon fiber reinforced plastic (CFRP) has been widely applied to composite overwrapped pressure vessel (COPV) in order to increase the performance factor of COPV used in space system. A novel design theory was proposed for calculating stress distribution in COPV, which allows the liner to be designed to cycle plastically during operation, based on traditional grid theory optimization. The stress distribution of liner and CFRP was calculated by solving static equilibrium equations and strain continuity equations systematically. The finite element analysis (FEA) of composite layers and the titanium liner were carried out in terms of laminated plate theory of CFRP and elastic-plastic theory of liner respectively by ANSYS software. The results show that the FEA is good agreement with the calculation of the grid theory. The COPV was fabricated for the propulsion system of satellite and was tested for qualification program, and its working pressure and burst pressure are 30MPa and 60MPa, respectively. The test results meet the design requirement. The results show that the precise calculation of stress and strain distribution can be obtained by the present theory, and it can be used to the structure design of COPV with plastically working liner. © 2022, Editorial Department of Journal of Propulsion Technology. All right reserved.