重复使用运载器是未来航天的发展方向，越来越受到重视。重复使用运载器形成了双层融合式结构——内层贮箱和外层机身，内层贮箱在加注低温燃料后会产生较大的收缩变形，内外层的变形协调问题十分突出。针对这一问题，提出了动态轴向静不定连接形式来实现内外层的连接，即在静定结构的基础上，通过设置轴向档块，使之在贮箱收缩后变成静不定结构，既满足了变形协调的要求，又能使内外层合理分配载荷；在此基础上，设计了固定铰接连接接头用以传递轴向载荷，设计了活动铰接点连接接头来实现变形协调。
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.
