Enhanced Magnetic Flux Leakage Analysis of the Distribution of Flux and The Effects of Velocity of Mild Steel Plates

This thesis focuses on an investigation into the velocity effects of a permanent magnet based magnetic flux leakage system. Both experimental and finite element analysis methods have been utilised to undertake a parametric study of the velocity effects on the induced flux and its distribution in plate thicknesses of 6mm through to 20mm thick 1020 grade steel. When there is a velocity difference between the plate and the excitation system, eddy currents are induced opposing the applied magnetic field distorting its profile. This has an adverse effect on MFL inspection by altering signal responses thus limiting achievable inspection velocities. An investigation of velocities ranging from 0.5 to 3m/s is undertaken on both defect free plates and plates containing spherical defects cut with a 22mm ball end cutter and varying percentage wall loss defects simulated for both near/top and far/bottom surfaces. From the results, it is indicated that the flux density distribution through the plate decreases as a function

Name dc:type.qualificationname

phd

Level dc:type.qualificationlevel

doctoral

Grantor dc:publisher.institution

University of Wales Trinity Saint David

Year dc:date.issued

2024

Author dc:creator

• Pullen, Ashley Laurent

• Q Gwyddoniaeth (Cyffredinol)
• TA Peirianneg (Cyffredinol). Peirianneg Sifil (Cyffredinol)

Dc Identifier Grantnumber

UWTSD

OAI identifier oai:identifier

oai:repository.uwtsd.ac.uk:3196