PSI - Issue 64

Mariniello Giulio et al. / Procedia Structural Integrity 64 (2024) 2101–2108 G. Mariniello, D. Coluccino, A. Bilotta, D. Asprone / Structural Integrity Procedia 00 (2019) 000 – 000

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The correlation coefficient is estimated for different peak thresholds (T) as outlined in the previous section to assess the linear correlation's performance for peaks of varying magnitudes. This investigation is motivated by the expectation that wider deflections measured by diagonal sensors experience less significant noise, resulting in more accurate deflection estimation. However, as shown in Fig. 8, the number of samples decreases significantly for T values greater than 1 mm, limiting the sample size for correlation evaluation and error estimation, thereby restricting a comprehensive statistical analysis.

Fig. 7 Sample number for each Threshold

Fig. 8 illustrates the mean error and standard deviation in estimating the L3 variation, derived from L1 and L4 measurements, against the peak threshold T. As the threshold value increases, both the mean value and standard deviation decrease, enhancing measurement accuracy. For peaks below 0.4 mm, there is a notable correlation with a 30% error rate (0.12 mm error for a peak of 0.4 mm). Conversely, for peaks exceeding 1.2 mm, the average error drops below 20% (0.24 mm error for a peak of 1.2 mm), demonstrating a strong correlation between the two measurements.

Fig. 8 Mean and standard deviation of E