On January 22, China's first prototype of a 3.35-meter-diameter composite material storage tank was born in the First Academy (Rocket Academy) of the Aerospace Science and Technology Group. The storage tank is mainly used in liquid oxygen environment. Compared with the metal storage tank, it can reduce the weight by 30% and has higher strength. It can greatly improve the structural efficiency and carrying capacity of the rocket. It is a new type of lightweight storage tank.
The birth of the prototype of the composite material storage tank marks that my country has broken the foreign monopoly and has become one of the few countries in the world that has the ability to design and manufacture composite material storage tanks.
Breakthrough ten key technologies
The project is a typical "production, learning, and research" joint research project that is controlled by the General Design Department of the Rocket Academy, and the Aerospace Materials and Technology Research Institute and many domestic universities. The research team has overcome ten key points after more than two years. technology.
Structure Design Technology of Composite Liquid Oxygen Tank
Meso-Damage Mechanics Analysis Technology of Low Temperature Composite Materials
Multi-scale composite material leakage suppression technology
Preparation technology of low temperature liquid oxygen compatible resin system
Design and manufacture technology of split and detachable composite tooling
Precise assembly technology of composite tooling
High-precision automatic placement technology
Ultra-thin prepreg preparation technology
Composite flange sealing technology
Reliable bonding and sealing technology for composite materials
30% weight reduction compared to metal storage tanks
As the section with the largest proportion of the weight of the rocket structure, the weight reduction of the tank is of great significance to the improvement of the rocket's carrying capacity.
Material knowledge
The density of the composite material is about 1.7g/cm³, the density of the aluminum alloy is 2.8g/cm³, and the density of the aluminum-lithium alloy is 2.7g/cm³. The specific strength of the composite material is 8 times that of aluminum alloy and 6 times that of aluminum-lithium alloy.
In the aerospace field, a large number of composite materials are used in some sections of active rockets in my country to reduce the structural weight.
Compared with the metal materials used in the current rocket tank structure, composite materials have the advantages of lower density, higher specific strength, and better fatigue resistance. Compared with metal storage tanks, composite storage tanks can reduce the weight by about 30%, which can greatly reduce the weight of the structure and improve the carrying capacity of the rocket. Therefore, the development of composite material storage tanks is one of the key technologies to achieve the purpose of rocket weight reduction, and it is also a new field that international aerospace powers are vying to explore.
The successful development of the principle prototype of the 3.35-meter-diameter composite material storage tank indicates that my country has mastered the full-link technical process from composite material storage tank structure design, material preparation to forming and manufacturing, and has become one of the few in the world with composite material storage tank design and manufacturing. Capable country.
Comprehensive cost reduction by 25%
The greater the rocket carrying capacity, the relatively large increase in the ability to enter space, opening up a larger stage for China's aerospace. The weight of the tank structure accounts for more than 50% of the total weight of the rocket structure. Therefore, the lightweight of the tank is one of the important ways to improve the carrying efficiency of the rocket.
Compared with the metal tank used in the liquid hydrogen and liquid oxygen environment, the composite material tank is mainly used in the specific liquid oxygen environment and can be used in the final stage of the rocket. According to data, every 1 kg weight loss of the rocket's final stage tank means an increase of 1 kg in carrying capacity. In addition, the composite material storage tank has the advantages of fewer production processes and short cycle times. From the perspective of foreign research results, the use of composite material tanks can reduce the overall cost of rockets by 25% compared to metal tanks.
In the future, the promotion and application of composite material storage tanks in the final stage of rockets will greatly increase the carrying capacity of the rocket, and will have a profound impact on the exploration of reducing rocket costs.
Automatic laying technology of composite material storage box
The successful development of the principle prototype is only a small step in the development of my country's composite material storage tank technology, and it is just one of the milestones.
Wu Huiqiang, deputy director of the structure room of the overall design department, introduced that the follow-up development team will also carry out a series of assessment tests and evaluations on the 3.35m composite material storage tank principle prototype, further carry out key technical research, improve the technical maturity of the composite material storage tank, and promote The application of composite material storage tanks on rockets truly gives full play to the major advantages of composite material storage tanks in terms of light weight and high strength, realizing substantial weight reduction and carrying capacity improvement of future rocket structures, and enhancing my country's deep space exploration capabilities and levels.
