2025 Volume 81 Issue 13 Article ID: 24-13551
Since the Hyogo-ken Nanbu Earthquake, laminated rubber bearings have been actively used. Several decades have passed since their installation, and ruptures have been reported in the Tohoku Pacific Offshore Earthquake, the Kumamoto Earthquake, and the Noto Peninsula Earthquake. The authors have been evaluating the damage to rubber bearings using the AE method, a non-destructive testing method. Historically, AE measurements were performed by applying traffic loads to rubber bearings in service. However, this method does not apply to cases of unexpected traffic vibration. Therefore, we focused on the waveforms obtained from AE measurements of rubber bearings vibrated by a function generator. In this study, we conducted laboratory experiments on rubber bearings with simulated defects and confirmed the frequency characteristics of AE waveforms detected by FFT. Comparing the results of the laboratory experiments with the results of field measurements of the rubber bearings damaged in the 2024 Noto Peninsula Earthquake, it was confirmed that there was a correlation in the frequency components of the Fourier spectrum.
