Difference recurrence plots for structural inspection using guided ultrasonic waves

We propose a novel recurrence plot-based approach, the difference plot (DRP), to detect small deviations between measurements. By using prototypical model system, we demonstrate potential of DRPs and alternative measures, such as Pearson correlation, spectral analysis, or cross joint analysis. Real-world data comes from an application guided ultrasonic waves for structural health monitoring damages in composite plate. The specific challenge this damage detection is differentiate defects influence temperature. show that are suited following sense: two time series derive measurements at different temperatures hold practically full recurrence, whereas one measurement without with defect hugely reduced rate.