Title: A Reference-free Damage Identification in FRP-reinforced Bridge Girders 51.3

Author(s): Mohammad Moravvej and Mamdouh El-Badry

Publication: Symposium Paper

Volume: 327

Issue:

Appears on pages(s): 51.1-51.20

Keywords: bridges; damage identification technique (DIT); discrete wavelet transform (DWT); fiber-reinforced polymer (FRP); reference-free; relative wavelet entropy (RWE); structural health monitoring (SHM); vibration.

DOI: 10.14359/51713372

Date: 11/1/2018

Abstract:
Utilization of fiber-reinforced polymers (FRPs) in concrete structures, particularly bridges, has promised a safe and satisfactory performance. However, the structural performance of FRP-reinforced bridges can be affected by occurrence of various types of damage. This paper presents structural damage identification in FRP-reinforced bridge truss girders tested under static and fatigue loading. The proposed technique combines discrete wavelet transforms (DWTs) and spectral entropy in a relative procedure to detect and quantify the damage-induced disturbances in the measured vibrational signals of the girders. Various types of test-induced damage were identified using the vibrational signals obtained only from the damaged state of the girders. Results of damage identification were verified by data obtained through instrumentations and by visual inspection of the actual state of damage in the girders during and after the tests. The results show that the technique can be implemented in a protective structural health monitoring (SHM) system to identify imminent failure. It can also help with the decision-making process regarding maintenance of FRP-reinforced concrete bridges. The technique is a practical means for damage identification in in-situ cases, where the normal operation of bridges cannot be interrupted, and the data obtained from a reference state of bridges are not available.