空间伸展臂热应变与热变形光纤监测技术

Optical Fiber Monitoring Technology for Thermal Strain and Thermal Deformation of Spatial Deployable Mast

针对空间伸展臂在热载荷作用下承载特性与形态变化的监测需求,提出了一种基于分布式光纤传感器的伸展臂结构温度、热应变以及热变形集成监测技术。借助ANSYS Workbench有限元分析软件,构建了单端热载荷作用下铝合金空间伸展臂结构热-力模型,分别得到不同局部热载荷下伸展臂轴向温度、热应变以及热变形分布与变化规律。在此基础上,提出了基于有限元分析与热传导理论的两类伸展臂轴向热变形计算方法。构建了分布式光纤传感监测系统,实时监测伸展臂若干关键位置的温度值与应变值,进而反演出结构轴向温度场、应变场连续变化信息。研究表明:采用有限元拟合法与热传导解析法计算所得伸展臂轴向热变形误差分别为5.256%与3.556%。相关成果能够为未来航天器在轨服役状态监测与辨识提供技术支撑。

Aiming at the requirement of monitoring the load-bearing characteristics and the morphological changes of spatial deployable masts under thermal load,an integrated monitoring technology for the temperature,thermal strain,and thermal deformation of a deployable mast based on distributed optical fiber sensor is proposed.With the help of the ANSYS Workbench finite element analysis software,the thermal-mechanical model of aluminum alloy spatial deployable mast under single-ended thermal load is established,and the distributions and variations of the axial temperature,thermal strain,and thermal deformation of the deployable mast under different local thermal loads are obtained.On this basis,two kinds of methods for calculating the axial thermal deformation of the deployable mast based on the finite element analysis and the heat conduction theory are proposed,respectively.A distributed fiber-optic sensor monitoring system is constructed to monitor the temperature and strain values at several key positions of the deployable mast in real time,and then the continuous change information of the temperature and strain fields along the axis direction of the structure is retrieved.The results show that the axial thermal deformation errors of the deployable mast calculated by the finite element method and the heat conduction analysis method are 5.256%and 3.556%,respectively.The related results can provide technical support for the monitoring and identification of future spacecrafts in orbit.