大型航天器桁架式主承力结构构型拓扑优化研究

针对桁架结构和拓扑优化的特点,提出了一种连续体-离散体两级拓扑优化策略。应用该策略对大型航天器桁架式主承力结构的构型进行了优化设计。首先,使用HyperWorks软件对桁架结构的设计空间进行了有限元建模,应用连续体结构拓扑优化方法,得出了五传力点和七传力点两种准桁架结构形式,并提炼出与之对应的桁架结构;然后,对所得桁架结构进行拓展,并应用桁架式结构拓扑设计优化系统(TODOSST)对拓展后的桁架基结构进行了离散体结构拓扑优化,得到了五传力点和七传力点两种桁架方案。经对比,七传力点桁架构型方案在基频拓展性、设备预留空间可用性等方面均有比较明显的优势,可作为后续设计的基础。文章应用连续体-离散体两级拓扑优化策略,得到了满足基本设计要求的桁架结构基本构型,可为详细结构设计提供参考;所用优化策略也可为同类桁架结构设计提供借鉴。

Research on Configuration Topology Optimization for Main Truss Structure of Large Spacecraft

According to the properties of truss structure and topology optimization, a two-stage strategy of successively applying continuum and discrete structure topology optimization is pro- posed. An optimization design for the main truss structure of a large spacecraft is performed using the optimization strategy. First, a finite element model of the design domain for the truss structure is constructed in HyperWorks, and the topology optimization of continuum structure is then applied to generate a five-juncture structure truss-like configuration and a seven-juncture one, which are later transferred into corresponding truss structure configurations. Second, after adding other possible nodes and rods to the two kinds of configurations, the topology optimiza tion of discrete structure is carried out by using TODOSST （topology design optimization system of structure with truss） to achieve final truss configurations for the both truss structures. The one based on seven-juncture truss structure is selected as foundation for later design after compar- ison because of its clear advantages in first modal frequency expandability, equipment-reserved space usability and other aspects. By using the two-stage strategy of successively applying contin- uum and discrete structure topology optimization, this paper achieves the truss configuration which meets the basic requirements well and can be used as a reference for detailed structure de-sign. The optimization strategy offers an optional way to the design of similar truss structures.