Study on air-coupled acoustic resonance detection technique for metal component
Natural gas pipelines are prone to corrosion and thinning damage.Conventional magnetic flux leakage and contact ultrasonic methods are not suitable for internal inspection of medium-and low-pressure natural gas pipelines.In this study,an air-coupled acoustic resonance detection method was proposed.By using air as the coupling medium and combining with acoustic resonance technology,non-contact detection of wall thickness and local corrosion of metal components under large liftoff conditions were achieved.The differences in the distribution of the sound field and the time-frequency domain response of the echo under single-frequency sinusoidal excitation and wide-band linear frequency modulation excitation were analyzed through numerical modeling and experimental verification.The detection capabilities of focused and planar transducers for air-coupled acoustic resonance were compared,and experiments on wall thickness measurement and flat-bottom hole defect detection were conducted based on the interface echo signal differential method.Simulation and experimental results demonstrate that this method can effectively enhance the intensity of echo energy and accurately measure the wall thickness of metal components.It is capable of controlling the detection error of metal component wall thickness and local corrosion within±0.5 mm even under a lift-off height of 31 mm,which holds significant practical application value for ensuring the safe operation of pipelines.
metal componentair-coupled ultrasonicacoustic resonancecorrosion thinningnon-contact
万方数据
维普
