A Study On Fiber Reinforced Composite Gas Cylinders

Composite materials have the characteristics of high strength-to-weight and stiffness-to-weight ratio, good corrosion resistance, high fatigue resistance, excellent design property and so on. Based on those, fiber reinforced composite cylinders made of composite materials have been successfully provided as high-pressure gas containment for those applications where minimal weight is critical.In this work, classical laminated plate theory, netting theory and Tsai-Hill failure criterion were introduced firstly. According to the property comparison, material used for the composite cylinder was selected. Structure of the fiber reinforced composite cylinder was designed based on the netting theory. A three-dimensional finite element model was built in different boundary conditions (autofrettage pressure, zero pressure, service pressure, test pressure, and burst pressure). The stress calculations were analyzed. Autofrettage was studied to pre-stress composite cylinder. The result shows autofrettage can reduce stress level of the liner on service pressure and the compressive stress in the sidewall of the liner at zero internal pressure is on60～95%of the minimum yield strength of the liner to extend the cylinder service life.To verity the finite element analysis, qualification tests had been performed. These qualification tests included burst test, ambient temperature cycling pressurization test, environmental cycling test, high temperature creep test drop test, flaw test, bonfire test and gunfire test. The testing results were verified to be coincided with those calculations. It indicated that the design is reasonable and reliable.