网格加筋结构集中力扩散肋的传力机理研究

Research on Concentrated Force Diffusion Through Radial Ribs in Grid Stiffened Structures

运载火箭贮箱结构与发动机机架连接时,会承受发动机推力所引起的分布式集中力载荷。为均匀扩散此类集中力、避免引起贮箱结构局部强度破坏,结构设计上常对贮箱底部网格加筋短壳采用扩散肋的结构形式。火箭运载能力的提高使得贮箱短壳所承受集中力随之增大,扩散肋的设计难度进一步提高,因此亟待开展相关的精细化分析和设计方法研究。首先,阐明扩散肋传力机理,为扩散肋的精细化设计提供了理论基础;其次,提出一种基于等几何分析及传力机理的扩散肋结构布局和截面尺寸协同优化设计方法;最后,通过板壳结构的集中力扩散算例验证本方法的有效性。旨在对扩散肋的传力特性进行深入发掘,进而提升箭体结构中扩散肋的设计水平,为扩散肋的结构优化提供新思路。

When the storage tank structure of a launch vehicle is connected to the engine frame,it must withstand the distributed concentrated force load caused by the engine's thrust.To prevent local damage to the tank structure from these concentrated forces,mesh reinforcement short shells at the tank bottom often incorporate diffused ribs in their design.As the carrying capacity of rockets increases,the concentrated force borne by the tank short shell also increases,making it more difficult to design diffused ribs.Therefore,there is an urgent need to conduct research on fine analysis and design methods.This study aims to meet the rapid design requirements of diffused ribs for tank short shells.Firstly,the force transmission mechanism of diffused ribs is explained,providing a theoretical basis for their fine design.Secondly,a diffused rib structural layout and sizing optimization method based on isogeometric analysis and force transmission mechanism is proposed.Finally,the effectiveness of this method is verified through an example of concentrated force diffusion in a plate shell structure.The study aims to explore the force transmission characteristics of diffused ribs and improve the progressiveness of design in rocket body structures,thereby providing new insights for their structural optimization.