Electromagnet Design for a Time Varying Magnetic Flux Leakage System

The aim is to design and build an optimized electromagnet for a time varying magnetic flux leakage (MFL) system that can operate within a frequency range of 0 – 10 Hz. The system will be used for the inspection of fuel storage tank floors. The advantage over DC systems is that the response of each frequency component would help in estimating the remaining plate thickness at a defect location; this is usually the main concern for fuel tanks. The electromagnet is designed with finite element modeling using COMSOL Multiphysics. Experimental results are compared with simulations and are used to validate the design. A prototype MFL system that utilizes the electromagnet is tested by inspecting steel plate samples with machined defects of different depths. Simulations are then used to demonstrate the ability of AC MFL to differentiate between defects that would be difficult to characterize with DC MFL alone.M.A.S