Feasibility study of fatigue damage detection of strands using magnetostrictive guided waves

Fatigue is one of the common damages in strands for long-term using. Therefore, the detection of fatigue damage in strands is very important to guarantee its reliable operation. In this paper, the feasibility of fatigue damage detection of strands using magnetostrictive guided waves is studied. The coupling efficiency of magnetostrictive guided waves is used to distinguish the fatigue damage of strands. A direct current solenoid magnetizer is used to get the relationship between the strength of bias magnetic field and the peak to peak value of magnetostrictive guided wave signal on fatigue and no fatigue area of a strand. The coupling efficiency of excitation and receiving process of magnetostrictive guided wave is obtained by the relationship. The results show that the fatigue damage reduces the coupling efficiency of excitation and receiving process of magnetostrictive guided waves. Besides, the optimal bias magnetic field strength which makes the highest coupling efficiency of fatigue area is larger than no fatigue area. These results well verify the feasibility of using magnetostrictive guided wave technology to detect fatigue damage of strands. This study provides a new method for fatigue detection of strands.