Research For In-line Stress Measurement Based On Barkhausen Effect

In the long-term operation of the pipeline,tiny corrosion and cracks formed on the surface of the pipe wall,which will result in pits,metal loss,and even perforations,reducing the service life and safety of the pipeline.Regular inspection is a necessary means to ensure the safe operation of the pipeline.At present,the most effective method of pipeline inspection is in-line inspection,but conventional in-line inspection methods can only detect the macro defects that have been produced,for minor cracks,corrosion,and scratches,the detection of micro-damage is insufficient.As a magnetic stress detection method,Magnetic Barkhausen Noise(MBN)method can detect the micro-defects of pipelines by detecting local stress concentration,and make assessments for defect identification and development,which is of great significance for ensuring the safe operation of pipelines.In this paper,the basic research on pipeline stress in-line detection method based on the magnetic Barkhausen effect is carried out,which based on the engineering requirements for pipeline in-line stress detection.The main research contents are as follows:(1)Explore the mechanism of magnetic Barkhausen effect detection.The mechanism of the MBN is elaborated from the perspective of microscopic magnetic domains,and the main influencing factors of the magnetic Barkhausen signal are summarized.The feasibility of MBN detection system and the Continuous Barkhausen Noise(CBN)detection system are verified through practical examples.(2)Research on excitation effect of pipeline based on ANSYS simulation.Through ANSYS simulation,the pipeline-electromagnet excitation model is established,the magnetization law of the pipeline is studied,the arrangement of the sensors in the detection system was optimized,and the ideal excitation parameters of the magnetic Barkhausen noise were investigated.(3)Design of detection system based on the magnetic Barkhausen effect.The hardware modules of the MBN detection system and CBN detection system are designed and selected,and the data acquisition and signal processing software is developed based on the LabVIEW platform.(4)Construction and testing of pipeline defect detection platform based on the magnetic Barkhausen effect.A pipeline defect detection platform is design and build.The MBN detection method and CBN detection method on the platform were test.The test signal was processed and analyzed,which exploring the possibility of the method being applied to pipeline inspection.