热载荷下星载天线逆有限元变形重构方法

Inverse finite element method based shape reconstruction for spaceborne antenna structures under thermal load

为实现星载天线结构在服役过程中的实时变形监测,针对真实分布式热载荷下的星载天线板结构,研究了基于应变监测的逆有限元变形重构方法.首先,针对星载天线板结构提出了一种基于四节点四边形逆向壳单元的变形监测方法,通过建立基于位移梯度的单元划分方法,对逆有限元单元划分进行优化,采用最小二乘误差函数构造结构应变与位移的矩阵关系.其次,建立天线板热试验系统,获取典型热载荷下的结构温度分布.然后,建立典型实验温差状态下的复合材料星载天线板结构有限元模型,获取结构表面应变和位移.最后,在典型热载荷下,验证所提变形重构方法的有效性.结果表明,变形重构的位移误差不超过0.5 mm,说明逆有限元法能够在典型热载荷下准确重构天线板变形.

To realize real-time deformation monitoring of spaceborne antenna structures in operation,the strain-based inverse finite element shape reconstruction method was investigated for satellite antenna structures under real distributed thermal loads.Firstly,the shape monitoring method based on four node quadrilateral inverse shell elements was proposed for antenna plate structures.The division of inverse elements was optimized by the established displacement-gradients-based element division method.The matrix relationship between the structural strain and the displacement was put forward by utilizing the least squares error function.Secondly,a thermal test system for the antenna plate was established and the temperature distribution of the structure under typical thermal loads was obtained.Then,a finite element model for composite antenna panel under typical experimental temperature difference conditions was established.The surface strain and the displacement of the structure were obtained.Finally,the effectiveness of the proposed shape reconstruction method was validated under typical thermal loads.The results show that the displacement error of the shape reconstruction was no more than 0.5 mm.Therefore,the inverse finite element method can accurately reconstruct the deformation of the antenna plates under typical thermal loads.