航天器天线桁架结构多目标优化设计

针对有附加结构的卫星天线桁架结构，提出了一种实现结构多目标优化的综合设计方法。首先，探讨了附加结构刚度对桁架结构动力学特性的影响，以便建立精确的有限元模型，为进行优化设计奠定基础。之后，交替采用代理模型方法和人机交互方式进行结构拓扑构型设计。其中代理模型是采用优化拉丁超立方法进行试验设计，结合径向基函数近似方法生成的。最后，应用NSGA-II全局优化方法实现以重量最小化和频率最大化的多目标优化设计，并根据分层图定量可视化地从Pareto前端和Pareto最优解集中筛选最优设计方案。优化结果表明，相对于初始方案可以在基频几乎不变的情况下，重量减小29.66%。该方法有利于提高设计效率，降低全局优化的复杂度，同时能够得到满足设计要求的设计方案，适用于多目标结构优化设计。

MULTI-OBJECTIVE OPTIMIZATION DESIGN FOR TRUSSES OF SPACECRAFT ANTENNA

A multiobjective structure optimization method is presented for trusses of spacecraft antenna with appended structures. To set up an accurate finite element model for optimization design, the effect of appended structure stiffness on the truss dynamics characters is discussed. The structure topology configuration is decided using the surrogate model and the man-machine interactive method. For the surrogate model, optimal Latin hypercube sampling method is used as the design of experiments strategy, and radial basis functions are selected as the approximation method. The multiobjective evolutionary algorithm NSGA-II which produces a set of Pareto solu-tions is employed as the optimization strategy to trade off the minimization of weight and the maximization of natural frequency. The optimum solution is visually identified with the level diagrams which is a graphical repre-sentation of the Pareto front and the Pareto set. The results demonstrate that the weight is reduced by 29.66% with-out decreasing the natural frequency relative to the initial design scheme. This method not only can maintain good design efficiency, but also increase the global search capability. It is very useful for the multiobjective optimization design of spacecraft structures.