Monitoring damage evolution of steel strand using acoustic emission technique and rate process theory

DENG Yang(邓扬)^{1, 2}, LIU Yang(刘扬)^{1, 2}, FENG Dong-ming(冯东明)³

(1. Key Laboratory for Safety Control of Bridge Engineering of Ministry of Education
(Changsha University of Science & Technology), Changsha 410004, China;
2. Key Laboratory for Safety Control of Bridge Engineering of Hunan Province
(Changsha University of Science & Technology), Changsha 410004, China;
3. Department of Civil Engineering and Engineering Mechanics, Columbia University, New York, NY 10027, USA)

Abstract:Utilizing the acoustic emission (AE) technique, an experimental investigation into the damage evolution for steel strand under axial tension was described. The damage evolution model for steel stand relating the damage evolution to acoustic emission parameters was proposed by incorporating the AE rate process theory. The AE monitoring results indicate that damages occur in both elastic and plastic phases of steel strand. In elastic phase, AE signals are mainly sent out from the micro damage due to the surface friction among the wires of steel strand, while in plastic phase, AE signals emitted from the plastic deformation of wires. In addition, the AE cumulative parameters curves closely resemble the loading curve. The AE cumulative parameters curves can well describe the damage evolution process including the damage occurrence and damage development for steel strands. It is concluded that the AE technique is an effective and useful nondestructive technique for evaluating the damage characteristics of steel strand.

Key words:acoustic emission; rate process theory; steel strand; damage evolution model; surface friction