Design of acoustic emission detection system for fastener and characteristic analysis of damage signal

Fracture disease of fasteners and elastic strips is one of the risk sources of train operation safety. The fastener sling status detection is mainly based on manual inspection, which is difficult to detect in a timely manner, and there is a lack of effective non-destructive testing methods. The acoustic emission technology was applied to the damage detection of fastener sling, and a fastener acoustic emission signal acquisition system was developed; type B sling static load compression experiment system was built; the complete acoustic emission signal during the fracture and damage of the type B strip was acquired. Using the acoustic emission parameter analysis method to analyze the three damage stages of the slug fracture process, the crack extension stage acoustic emission events are more active and the amplitude is higher. The characteristics of the acoustic emission signal at the different damage stages were obtained by acoustic emission waveform analysis method, and the energy of the acoustic emission signal from the crack initiation to the extension to the fracture damage stage increased in the frequency band, and the later stage of damage, the higher frequency component of the acoustic emission signal.