Acoustic emission technique for monitoring stay cable fatigue damage evolution of multi-aged bridge
LI Dong-sheng1，HU Qian1，LI Hui2，LANG Cheng-ming2
1.School of Civil Engineering, Dalian University of Technology, Dalian 116024, PR China;2.School of Civil Engineering, Harbin institute of Technology, Harbin 150090, PR China
Abstract：Stay cable is one of the most important components of the Cable-Stayed Bridge, However, stay cables are often suffered corrosion and fatigue damage and these factors threat the bridge safety in serve life. At present there is a dearth of studies regarding damage types and mechanism under fatigue load of the multi-aged stay cable. In this paper, acoustic emission（AE） technique was used to monitor their fatigue damage evolution process. Firstly, we got the relation of stress to strain through tensile test for corrosion and non-corrosion steel wires, and the results are shown that the mechanical performance of corrosion cable has great change. Secondly, we got the whole fatigue damage process AE characteristic parameters. It is found used AE energy cumulative parameters could accurately describe the fatigue damage evolution of multi-aged stay cable. At last, based on wavelet singularity theory, in each stage of AE, the burst signal is obtained and its time-frequency distribution is achieved through wavelet and FFT analysis. According to the analysis results, failure modes in each phase and type of acoustic emission source are easy to determine. The characteristics of waveform, types of damages, and frequency distribution of multi-aged stay cable in different damage phases are collected.
2012, Vol. 31 
