The Research On The Magnetic Flux Leakage Field Of Tubing About Finite Element Analysis And Experiment

Tubing is widely used in the field of petroleum and petrochemical, the number of production and use is large, it is the only channel of oil from underground mining to the ground. In the course of long-term use, it was affected by cyclic stress on stretching,fracturing, bending, torsion, so that it would produce cracks. At the same time, it has been soaked in oil sludge, contacted with harmful substances closely, resulting in corrosion, so it may cause failure. So non-destructive testing can be used to ensure safety in production. How can detect accurately and efficiently becomes a problem that the inspection personnel concern.At present, the magnetic flux leakage testing can achieve comprehensive, overall scanning of tubing, its efficient is very high. In this paper tubing for the study, magnetic flux leakage testing as a principle, designing and developing a pipeline magnetic flux leakage testing instrument independently.The thesis adopts the method of finite element analysis and experimental to study magnetic flux leakage testing of tubing. Based on the magnetic flux leakage corrosion field theory, ANSYS was used to construct theoretical model, then analysis and calculation, to get a leakage magnetic field distribution of defects. Change the related parameters: Diameter cylindrical defects, defect depth and lift-off values, current size, crack defects coil circle number, coil diameter, width, depth, etc. Adopt the actual receiving way of sensor to extract data, analyzing the influence of different parameters on the magnetic flux leakage.According to some theoretical finite element obtained, to guide the design of the instrument. Use software to draw three-dimensional drawings, ensuring fit accurately,establish engineering drawing for processing. Formulate the systematic experimental scheme,exploit the instrument after assembling to experiment.Under laboratory conditions, establish artificial defects on the tubing, including cracks and corrosion pits different parameters. Analysis of the final data collected, validate finite element theory at the same time, test the accuracy of the instrument and scientific.