﻿ 低温贮箱连接匹配技术研究

# 低温贮箱连接匹配技术研究Research on Connection and Matching Technology of Low Temperature Tank

Abstract: Reusable launch vehicle is the development trend of aerospace in the future, and more and more attention has been paid to it. The reusable launch vehicle has formed an integrated double-layer structure, the inner tank and the outer fuselage. The inner tank will cause the greater shrinkage deformation after being filled with low-temperature fuel. The problem of deformation coordination between the inner tank and the outer fuselage is very prominent. In order to solve this problem, the dynamic axial statically indeterminate connection structure is put forward to realize the connection between the inner tank and outer fuselage; that is, on the basis of the statically determinate structure, the axial stop block is set to become the statically indeterminate structure after the tank shrinks, which not only meets the requirements of deformation coordination, but also enables the inner tank and outer fuselage to reasonably distribute the load. On this basis, the fixed hinged joint is designed to transfer the axial load, and movable hinge joint is designed to realize the deformation coordination.

1. 引言

2. 融合式双层结构的变形协调问题

RLV需要水平着陆，一般具有类似飞机的外形。由于其需要在大气层中作较长时间的水平飞行，载荷情况复杂，贮箱一般设计成只承受发动机推力和惯性载荷引起的轴向载荷，而气动载荷引起的总体载荷则由机身来承受。因此，RLV形成了独特的融合式双层结构——内层贮箱和外层机身(图1)。

3. 融合式双层结构的连接形式结构设计

Figure 1. RLV integrated double-layer structure: outer fuselage and inner tank

Figure 2. Axial connection between tank and fuselage

1) 后连接点为轴向固定铰接，可以传递轴向推力；中连接点和前连接点为轴向活动铰接，不能传递轴向推力；该连接结构为轴向静定结构，简称为固–铰–铰；

2) 后连接点和中连接点为轴向活动铰接，不能传递轴向推力；前连接点为轴向固定铰接，可以传递轴向推力；该连接结构也为轴向静定结构，简称为铰–铰–固；

3) 后连接点和前连接点为轴向固定铰接，可以传递轴向推力；中接点点为轴向活动铰接，不能传递轴向推力；该连接结构为轴向静不定结构，简称为固–铰–固。

(a) 固–铰–铰 (b) 铰–铰–固 (c) 固–铰–固

Figure 3. Connection form between inner tank and outer fuselage of integrated double-layer structure

Figure 4. Axial static connection between tank and fuselage

(a) 贮箱自然长度状态(b) 加注低温燃料后贮箱收缩状态

Figure 5. Axial dynamic and statically indeterminate connection between tank and fuselage

4. 固定铰接点连接接头设计

4.1. 球头–球座连接形式

Figure 6. Ball joint

Figure 7. Deformation cloud chart of ball head

Figure 8. Stress cloud chart of ball head

4.2. 推力销连接形式

Figure 9. Thrust pin joint

Figure 10. Deformation cloud chart of thrust pin

Figure 11. Stress cloud chart of thrust pin

5. 活动铰接点连接接头设计

Figure 12. Movable hinged joint

Figure 13. Geometric relationship of movable hinged joint between tank and fuselage reinforced bulkhead

6. 结论

1) 在静定结构的基础上，通过设置轴向档块，使内层贮箱收缩后与外层机身形成静不定结构，即采用动态轴向静不定连接形式，可以实现内层贮箱和外层机身的连接，既满足了变形协调的要求，又能使内外层合理分配载荷；

2) 采用球头–球座接头或推力销接头的形式，可以实现内层贮箱与外层机身的固定铰接点的连接，连接接头重量轻且满足强度要求；

3) 通过设计活动铰接点连接接头，实现了变形协调。

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