The detection of damage in reinforced concrete bridge using vibration characteristics has been the topic of much research in the last two decades. Since reinforced concrete structures are nonlinear in behaviour, even with relatively low levels of damage, it is difficult to make a reliable estimate on the modal properties for use in the damage detection/health monitoring. The Hilbert-Huang transform (HHT) comprises the empirical mode decomposition (EMP) of the data and performing the Hilbert transform (HT) on each mode, and it is an effective method to analyze the nonlinear and non-stationary time series data. This study focuses on studying the signature of non-linear characteristics in the vibration of damaged reinforced concrete beams using HHT, and to investigate the possibility of using changes in these nonlinear vibration characteristics to detect damage in reinforced concrete structures. Vibration tests of several reinforced concrete beams with different damage scenarios are conducted in laboratory. The measured signals are decomposed into intrinsic mode function (IMF) using EMP and the Hilbert-Huang spectrum is obtained by the HT of each IMF. Results show that the method based on Hilbert-Huang spectral analysis is quite effective for the damage assessment of the reinforced concrete structures
The detection of damage in reinforced concrete bridge using vibration characteristics has been the topic of much research in the last two decades. Since reinforced concrete structures are nonlinear in behaviour, even with relatively low levels of damage, it is difficult to make a reliable estimate on the modal properties for use in the damage detection/health monitoring. The Hilbert-Huang transform (HHT) comprises the empirical mode decomposition (EMP) of the data and performing the Hilbert transform (HT) on each mode, and it is an effective method to analyze the nonlinear and non-stationary time series data. This study focuses on studying the signature of non-linear characteristics in the vibration of damaged reinforced concrete beams using HHT, and to investigate the possibility of using changes in these nonlinear vibration characteristics to detect damage in reinforced concrete structures. Vibration tests of several reinforced concrete beams with different damage scenarios are conducted in laboratory. The measured signals are decomposed into intrinsic mode function (IMF) using EMP and the Hilbert-Huang spectrum is obtained by the HT of each IMF. Results show that the method based on Hilbert-Huang spectral analysis is quite effective for the damage assessment of the reinforced concrete structures