Mechanism Study of Bi-Material COPV Structure Based on Composite Structure Design Theory

Abstract

Composite over-wrapped pressure vessels (COPVs) are widely used in aerospace, aviation, army, Navy, nuclear industry and other military and civil fields because of their light weight, high strength, high reliability and safety, leak before burst (LBB) failure mode safety and many other characteristics. Because the aerospace field has very strict requirements on the weight of platform structure products including COPV, it is necessary to improve the mass efficient of COPV and achieve the characteristics of light weight and high strength. In this paper, through the optimization of composite material grid theory algorithm, the relationship between bidirectional stress and internal pressure of cylinder and dome of isotropic material is deduced. On this basis, the grid theory equations of bidirectional stress and internal pressure load of COPV cylinder and dome are deduced, and the wall thickness equations of ordinary rotating curve head, equal tension head and hemispherical head are proposed. According to the grid theory model of membrane stress of COPV cylinder, the author completed the grid theory algorithm derivation of elastic and plastic lined COPV. This paper is the exploration of composite dome structure analysis, which lays a foundation for the subsequent solution of composite dome grid theory.