PSI - Issue 54

Mohammad Shamim Miah et al. / Procedia Structural Integrity 54 (2024) 3–10 Author name / Structural Integrity Procedia 00 (2023) 000–000

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Fig. 4. Summary of maximum and minimum values of acceleration data.

Fig. 5. Evaluation of the resonant frequency using measured data from all sensors.

quite well but the frequency values are not same for different peaks. In other words for different loadings and different sensors locations the frequency values have been changed. Furthermore, the spectrogram of those peaks have been evaluated. However, due to the space limitation it is not possible to accommodate all the results e.g. damping ratios, spectrograms of all peaks. Hence, among them two peaks spectrogram results have been shown here. In Fig. 6, the spectrogram of peak P 1 can be found and, in Fig. 7, the spectrogram of peak P 7 is plotted. The usefulness of the spectrogram is that it can provides not only the frequency information but also the excitation’s time. More specifically, the spectrograms can offer exact time when that particular frequency took place on the structure. From those figures it can be easily observed that the first resonant frequency was excited all the time, however, the rest of the higher frequencies (e.g. higher dynamics) were not excited. It needs to be noted that even the