STP722: Numerical Solution of Electromagnetic-Field Eddy-Current Problems in Linear and Nonlinear Metallic Structures: The RMS Phasor and Instantaneous Approaches as Potential Tools in Nondestructive Testing Applications

    Demerdash, NA
    Associate professor and assistant professor, Virginia Polytechnic Institute and State University, Blacksburg, Va.

    Nehl, TW
    Associate professor and assistant professor, Virginia Polytechnic Institute and State University, Blacksburg, Va.

    Pages: 26    Published: Jan 1981


    Abstract

    Two numerical analysis approaches for the determination of electromagnetic fields and induced eddy currents in nonmagnetic and magnetic metallic structures are presented. It is demonstrated how these techniques can best serve the purposes of nondestructive testing for material characterization etc. One method is based on instantaneous state-space or Crank-Nicolson discrete-time solution approaches, and is most suited for use with nonsinusoidal excitation wave forms and nonlinear materials. The other approach is based on a root mean square phasor concept and is best suited for sinusoidal excitation cases and linear nonmagnetic materials. Both methods are based on a magnetic vector potential formulation, and can be used in characterization of material conductivities and permeabilities. Results of application of the two methods to magnetic and nonmagnetic materials are reported.

    Keywords:

    nondestructive testing, eddy current, characterization of materials


    Paper ID: STP27576S

    Committee/Subcommittee: E07.07

    DOI: 10.1520/STP27576S


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