Abstract:
Local excitation method (LEM) on steel structure by using piezoelectric actuator is investigated as a damage detection method. Small damages of a steel railway bridge structure like crack and slit can be detected its location by measuring local vibration measurement and PSD (power spectral density) analysis over array sensing data for each acceleration measurement points. Reliability of damage detection by this method for steel structure is evaluated as results of damage location analysis method. The analysis is using PSD and difference of PSD before and after the occurrence of damage, and it is a measure of change of structural condition. It is shown that the result of this difference on each measuring point of sensors of the structure is stable even the structural condition was changed. Remote monitoring measurement needs wireless transmission of the data from bridge site to monitoring site. Portable wireless transmission system to send a saved data of measured acceleration by using LEM is tested and applicability of this method is investigated. It is shown that LEM measurement on remote steel structure is a new monitoring method to be able to monitor damages of the structure. This research was done as an international collaboration project supported by JST (Japan Science and Technology Agency) and NSF of United States of America.