基于移动可变形组件法(MMC)的运载火箭传力机架结构的轻量化设计

传力机架是运载火箭箭体与发动机连接的关键部件, 负责将发动机推力载荷有效的传递至箭体, 其结构的轻量化设计不仅可以保障火箭发动机的推重比、提高火箭的稳定性, 还可以为我国未来可重复使用式火箭的研究提供一定的参考. 本文在移动可变形组件(moving morphable component, MMC)的框架下, 提出了一种解决传力机架结构轻量化设计的方法. 在该方法中, 机架结构的拓扑通过一组具有显式几何信息的组件来表示, 这使最终优化布局可以被少量的设计变量所描述. 通过分析传力机架结构设计的特点和要求, 以刚度最大化为目标, 体积分数(保证结构重量)为约束, 建立了基于MMC显式拓扑优化方法下的问题列式. 同时搭建了可对工程中传力机架结构轻量化设计的平台, 并进行相应结构的拓扑优化. 在两种载荷工况(即零位状态和摇摆状态)作用下, 最终优化结果在中间推力载荷区域与锥段相连位置之间, 所形成的较大翼板结构增强了传力机架的抗弯能力. 通过与传统机架结构的对比, 证明了本文所提出方法在传力机架结构轻量化设计方面的有效性. 

LIGHTWEIGHT DESIGN OF TRANSMISSION FRAME STRUCTURES FOR LAUNCH VEHICLES BASED ON MOVING MORPHABLE COMPONENTS(MMC) APPROACH

The transmission frame in launch vehicles is a key structure to transfer the thrust load between the rocket body and engine. The structural lightweight design can not only ensure the thrust-weight ratio of engine, and improve the stability of rocket, also provide reference values for the reusable launch vehicles in the future research. Under the moving morphable component(MMC)-based framework, this paper proposes an approach for solving lightweight design problem of transmission frame structures. In this method, structural topology can be described by using a set of morphable components with explicit geometric information, which renders the optimized layout in terms of a small number of design variables. By analyzing the characteristics and requirements of transmission frame structures, structural stiffness maximum under volume constraint is chose as the objective function, and the corresponding problem formulation based on the MMC explicit topology optimization method can be formulated. Thus, an optimization platform is established to achieve the lightweight design of transmission frame in practical engineering. Under two different load cases(i.e., the thrust load is located at zero angle and swing, respectively), the optimized result is that the large wing plate structure between the middle thrust load area and the connection position of conical structure is constructed to enhance the structural bending capacity. Compared with the traditional frame structure, the effectiveness of the proposed method in the lightweight design is proved.