遥感卫星结构在轨热应变光纤光栅监测方法

Remote sensing satellite structure in-orbit thermal strain Bragg fiber grating monitoring method

遥感卫星结构在轨服役期间易受空间极端温度变化与微重力环境影响容易产生热应变,严重影响探测精度,而现有方法难以实现热应变在轨监测。针对这一问题,提出具有温度解耦功能的热应变光纤光栅监测方法。采用数值模拟方法开展结构热应变计算分析,得到结构整体和局部热加载下温度场和应变场分布特征及变化规律。设计构建热应变光纤监测试验系统,对卫星天线结构模拟试件进行热加载光纤测量试验,测试分析热应变光纤监测精度,验证了方法的有效性。研究结果表明,在-120~120℃温度变化范围,利用光纤布拉格光栅传感器和温度解耦方法监测温度和热应变的相对误差分别为1.02%和2.45%;在30~100℃局部热加载作用下,结构温度场和应变场的重构误差分别为3.24%和6.61%。该方法在卫星结构在轨监测领域中具有良好的应用价值与前景。

Remote sensing satellite structures are susceptible to thermal strain during in-orbit service due to extreme temperature changes in space and microgravity environment,which seriously affects the detection accuracy.However,the existing methods are difficult to achieve thermal strain monitoring in orbit.To solve this problem,a thermal strain fiber grating monitoring method with temperature decoupling function is proposed.The thermal strain of the structure is calculated and analyzed by numerical simulation,and the change of temperature and strain fields under overall and local thermal loading are obtained.A thermal strain fiber optic monitoring test system is designed and constructed,thermal loading fiber optic measurement test on satellite antenna structure specimens is conducted,the accuracy of structural thermal strain fiber optic monitoring is tested and analyzed,and the effectiveness of the method is verified.Research results show that in the temperature variation range of-120-120℃,the monitoring accuracy of temperature and thermal strain by fiber Bragg grating sensor and temperature decoupling method are 1.02%and 2.45%,respectively.The reconstruction errors of the structural temperature and strain fields are 3.24%and 6.61%under the action of local thermal loading from 30℃to 100℃,respectively.The method has the prospect of application in satellite structure in-orbit health monitoring.