基于代理模型的航天器振动夹具优化方法

航天器振动夹具的一般设计原则是在避免安装干涉的前提下,尽量提高其刚度,同时减小自身重量对试验条件制定的影响。文章从提高振动试验夹具设计的效率出发,在优化过程中引入Kriging代理模型来代替原有的动力学输入输出关系,最大程度地减少优化迭代过程中有限元模型重构与求解次数。为进一步提高代理模型更新的效率,提出了一种混沌邻域搜索的多点加点准则,在发掘当前最优点的同时,有选择性地加入了更多的预测点,用以快速改善代理模型的局部代理精度。数值仿真针对典型航天器力学环境试验夹具的几何参量进行优化,优化结果验证了该方法的有效性与高效性。

Optimization of vibration fixture for spacecraft based on surrogate model

In a general design guideline for the spacecraft vibration fixture, its stiffness should be as large as possible without any assembly interference to the tested product. Meanwhile, the weight of the fixture should be as small as possible for the consideration of the vibration test condition. In order to improve the efficiency of the fixture design and avoid problems of FE re-meshing and optimization at each iterative step, the Kriging surrogate model is employed to replace the original dynamical input-output relation. To further improve the efficiency of the surrogate model updating, a new multi-points addition criterion based on the chaos neighborhood search is proposed. It means that not only the current optimal point, but also the correlated points are added to update the surrogate model, which can improve the precision of the surrogate model in a short time. A numerical simulation of a typical spacecraft fixture for the dynamic environment test is performed, and the geometrical parameters of the vibration fixture are optimized. The effectiveness and the high efficiency of the proposed method are demonstrated by the obtained results.