Abstract:As an ideal layout scheme for launch vehicleꎬ co ̄bulkhead tank can improve the slenderness ratio of
launch vehicleꎬ reduce structure weight and increase structure efficiency and carrying capacity of launch vehicle. This
paper systematically studied the structure designꎬ key manufacturing technology and structural property of the alumi ̄
num alloy panel/ polymethacrylimide (PMI) foam ̄sandwiched cryogenic tank co ̄bulkheadꎬ which successfully passed
the air ̄tight testꎬ the low ̄temperature pressure test and the thermal insulation test. The single ̄bottom inner pressure
was 0.54 MPaꎬ and the low ̄temperature pressure in coal oil tank and liquid oxygen tank were 0.40 MPa and 0.47
MPa respectively. The co ̄bulkhead was not wrinkling or collapse after the testsꎬ and the temperature of the coal oil
was higher than 17℃.The sandwiched co ̄bulkhead meets the using requirements of large temperature differenceꎬ light
weight and no vacuum pumping for thermal insulation before launchingꎬ laying technological foundation for successful
development of the new ̄generation launch vehicles.