PSI - Issue 52

Yingwu Li et al. / Procedia Structural Integrity 52 (2024) 709–718

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Author name / Structural Integrity Procedia 00 (2023) 000–000

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Fig. 6. The Cumming plot of temperature-frequency shift coe ffi cients obtained from the experiments in the first group

Fig. 7. The Cumming plot of temperature-frequency shift coe ffi cients obtained from the experiments in the second group

In the third group of experiments, all SMF sensors were coated with polymer, resulting in a di ff erent temperature frequency shift coe ffi cient compared to the previous two groups. The detailed results of experiments in this group are presented in Figure 8. According to the figure, the temperature-frequency shift coe ffi cient of SMF sensors coated with polymer is approximately -1.28 ◦ C / GHz. This value is slightly smaller than that observed for SMF sensors coated