Research on the Magnetic Leakage Field of Internal Defects in Steel Wire Ropes Based on the Magnetic Dipole Model

The steel wire ropes are often used in a harsh environment and are susceptible to damage, with varying shapes and sizes of defects that may occur within it. This leads to potential safety risks during usage; thus, the detection and analysis of internal defects are especially necessary. Traditional magnetic dipole theory, a widely employed approach in non-destructive testing, often encounters limitations in accurately calculating the internal defects. This article introduces an advanced method in the magnetic dipole theory by incorporating equivalent magnetic charge calculations, thus developing a magnetic flux leakage (MFL) model specifically for internal defects in wire ropes. This enhanced model facilitates the analysis of MFL intensity caused by the defects of diverse geometries, including rectangular, trapezoidal, and triangular shapes. The theoretical results have been validated through simulations and experiments, maintaining a simulation error of approximately 3% and an experimental error under 10%. This validation emphasizes the effectiveness of the proposed theory in detecting internal defects in wire ropes, potentially enhancing safety measures during their usage.