Damage pattern recognition and damage evolution analysis of unidirectional CFRP tendons under tensile loading using acoustic emission technology

The purpose of this paperis to use acoustic emission (AE) technology to realize the damage pattern recognition and the damage evolution of unidirectional (UD) CFRP tendons in the tensile process. In order to realize this goal, the tensile test of UD CFRP tendons was carried out. The adaptive Hilbert–Huang transform was used to analyze the AE signal in time–frequency domain to obtain the Hilbert marginal energy spectrum (HMES) and instantaneous energy spectrum (IES) of the signal. Damage pattern recognition was realized through HMES and IES. In this paper, a mutation function and a cumulative function were proposed based on HMES to study the evolution of different damage mechanisms and the internal relationship between them. In order to verify the reliability of the proposed method, digital image correlation (DIC) technique was used to obtain the strain distribution of the UD CFRP tendon specimen to determine the occurrence of local damage. The results of this investigation can be used to guide the establishment of the health monitoring mechanism for prestressed CFRP structures based on AE technology.