Pipeline damage detecting and locating based on the sound propagation velocity difference between transverse and longitudinal wave
Changsheng Ai, Wenjie Chu, Honghua Zhao, Xuan Sun · 2008
In order to protect the safe operation of pipelines from actions of damage, pre-monitoring and positioning is an important technological means. Theoretical and experimental analysis showed the hitting sound signals propagate in the form of transverse wave and longitudinal wave at different speed along the pipeline. In accordance with their arrival time difference and acoustic velocity difference coefficient, we can measure the distance between the sound source and the sensor that installed on the pipe. Arrival time difference can be got by calculating the wave chronometry when transverse wave and longitudinal wave arrive at the sensor by the means of the short-time energy and cross zero rate; Acoustic velocity difference coefficient can be automatically completed by a given distance and relevant delay time, which is an all-around result considering all actual affections, has higher accuracy than theoretical calculation.