Fig. 1. FBG sensor network layout of remote sensing satellite active phased array antenna

Fig. 2. Finite element calculation process of thermal strain field of satellite antenna structure

Fig. 3. Characteristics of strain field distribution under uniform temperature load at 120 ℃

Fig. 4. Strain field variation curves under uniform temperature load

Fig. 5. FBG sensor temperature and strain monitoring system for high and low temperature environments. (a) Monitoring test system composition; (b) Physical photo of the monitoring test system: 1.PC 2.Strain gauges 3.FBG demodulator 4. Temperature test chamber

Fig. 6. Aluminum structural specimens. (a) Layout of structural specimen sensor; (b) Diagram of structure physical: 1.Resistance strain gauge 2.FBG strain sensor 3.FBG temperature sensor

Fig. 7. FBG temperature sensor center wavelength versus temperature. (a) Warming process; (b) Cooling process

Fig. 8. Thermal strain measurement of FBG strain transducer as a function of structure temperature. (a) FBG1; (b) FBG2; (c) FBG3

Fig. 9. Distribution characteristics of the temperature and strain fields of the satellite antenna under the temperature load of 100 ℃. (a) Distribution characteristics of the temperature field; (b) Distribution characteristics of the strain field

Fig. 10. Distribution characteristics of temperature and strain fields of satellite antenna under long time high temperature environment. (a) Distribution characteristics of temperature field; (b) Distribution characteristics of strain field

Fig. 11. Diagram of the independent variable of the change curve

Fig. 12. Temperature variation curve under different temperature loads

Fig. 13. Strain variation curve under different temperature loads

Fig. 14. Schematic diagram of measurement points and error evaluation points

Fig. 15. Satellite antenna thermal strain field fiber optic monitoring test system. (a) Thermal strain field monitoring test system composition; (b) Photos of the thermal strain field monitoring test system: 1. structural specimen 2.Strain gauges 3. Thermal loading device 4. Multi-channel pyrometer 5. FBG Demodulator 6.PC

Fig. 16. Satellite antenna under 100 °C temperature load. (a) Reconstructed temperature field; (b) Reconstructed strain field

Fig. 17. Comparison of measured and reconstructed values under 100 ℃ temperature load. (a) Comparison of temperature fields; (b) Comparison of strain fields

Table 1. Material parameters of finite element model of satellite antenna structure

Table 2. FBG temperature sensor sensitivity and linearity

Table 3. FBG strain sensor maximum absolute error and average relative error

Table 4. Reconstruction error of temperature field and strain field at different temperatures

Table 5. Reconstruction errors between reconstructed strain field and theoretically calculated strain field at different temperatures

Table 6. Reconstruction error between reconstructed strain field and real strain field at different temperatures

Table 7. Reconstruction errors of structural temperature and strain fields under thermodynamic coupling