Abstract
Currently, the bridges which were built in period of high economic growth are accounting for about 40% of all bridges and the deterioration of the high-strength bolts has become the important problem. The impact acoustics method is one of the diagnosis methods of the axial force. The impact acoustics method is low risk, low cost and easily work. However, the impact acoustics method that rely on the experience and intuition of a skilled technician has problems such as lack of skilled technician, establishment of a method that can accurately efficiently diagnosed in unskilled technician is required.
In this study, we hit a high-strength bolt with a hammer, to obtain the frequency data from the waveform data of impact vibration. Moreover, we obtain attenuation rate from the original sound waveform data. To diagnose the axial force of the high-strength bolts by using the Machine learning, and compared the recognition accuracy.
