Abstract:

Using finite element method (FEM), the magnetostatic and transient emulation models of magnetic flux leakage (MFL) of oil tube are established. Parameters of the exciters, inspecting velocity and size of defects are analyzed by using two models respectively. Compared with static and transient simulation results, the limitation that uses magnetostatic model to simulate MFL of defects of oil tube is concluded. When the velocity is over 5m/s, simulating with magnetostatic model suffers somewhat inaccuracy. Although accurate results are usually obtained with transient model, the long elapsed time during the simulation process consumes a lot resources. At last, the conditions of using magnetostatic model to simulate MFL of defects are presented.

Key words: MFL, FEM, magnetization, magnetostatic model, transient model, oil tube