一种空间可展开桁架结构杆件热膨胀系数的优化设计

文章就一种空间可展开平板天线支撑桁架结构的热膨胀系数设计,针对传统靠经验试凑的情况,提出了一种热膨胀系数优化设计方法。该方法首先通过分析计算各杆件轴的热膨胀系数对热变形的影响(即计算热变形对杆件轴向热膨胀系数的敏度),根据敏度绝对值的大小对杆件进行分组;其次,在给定最大热变形约束下,将敏感杆件组的热膨胀系数设为设计变量进行优化,计算杆件热膨胀系数极值,从而确定其所能允许的可行范围;最后对计算所得的热膨胀系数范围进行了校验和参数分配,经计算,在此范围内取值符合最大变形约束要求。

Optimization Design for Coefficient of Thermal Expansion of a Space Deployable Truss

An optimization design approach of the coefficient of thermal expansion of the space de- ployable truss with the flat panel antennas is presented in order to improve the traditional method based on experience. Firstly, the sensitivities of the thermal deformation to bars~ axial thermal expansion coefficient are analyzed as to separate the most sensitive trusses from all the trusses on the basis of the absolute values of sensitivities in the approach. Secondly, the feasible interval of the bars＇ axial coefficient of thermal expansion is determined by its extreme value obtained by the optimized analysis for maximum thermal deformation constraints by mean of selecting the bars ＇ axial coefficient of thermal expansion as the design variable. Finally, the validity of the range and the allocation of parameters is considered. It is proved that all the value in the range is practicable under the maximum thermal deformation constraints.