• Aerospace Engineering and Technology
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• v.2 no.2
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• pp.124-132
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• 2003

This paper described the structural design and the fabrication procedure of KSR-III composite pressure tank. The type of the composite pressure tank was COPV(Composite Overwrapped Pressure Vessel). A non-load sharing liner was made of aluminum 6061-0 and the liner provided a helium gas seal. The composite pressure tank was winded using T700 carbon/epoxy on the liner. Because the aluminum liner was thin, multiple cure cycles were applied to the filament winding technique. The multiple cure cycles prevented the liner-cylinder from losing a circular shape. A fitting force at the metallic boss was spread to the carbon fiber by a boss ring. The boss ring also prevented a local deformation at the boss part.

• Composites Research
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• v.36 no.2
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• pp.132-139
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• 2023

A linerless composite propellant tank was designed and manufactured by using the carbon fiber-reinforced composite materials which have superior strength-to-weight ratio in order to reduce weight of the tank. In this research, we designed a sub-scale composite propellant tank with a diameter of 800 mm to withstand an MEOP of 1.7 MPa. We manufactured the boss of the tank by using the same composite materials to reduce the thermal expansion difference between the boss and the secondary-bonded composite layers of the barrel in the cryogenic environment. We used the collapsible mandrel to manufacture the tank without any liner. The mandrel was made from epoxy-based composite tooling prepregs to reduce weight of the mandrel. We manufactured the test tanks by laying up the carbon fiber fabric prepregs manually on the mandrel and then applying the autoclave cure process. We performed a proof test, a helium tightness test, a repeated pressurization test, and a burst test in room temperature. The test results demonstrate that the proposed design and manufacture process satisfies all strength requirements as well as an anti-leakage requirement.