The 24th International Workshop on Electromagnetic Nondestructive Evaluation (ENDE2019)

260 / 2019-11-04 02:36:57

Evaluation of eddy current response due to applied stress on a steel plate using Phase diagram

eddy current, stress measurement, numerical simulation, phase diagram

Structural health monitoring of steel structures is crucial for inspection of corrosion and cracking in structural members, which when left unmonitored compromise the safety of overall structure. In the present study, the prospective of evaluation of change in stress state of structural member due to corrosion and cracking through eddy current based stress measurement is investigated. For this, three-dimensional numerical simulations are carried out in the FE software COMSOL Multiphysics 5.2a for a steel plate subjected to change in relative permeability, representative of change in stress state, whereby the eddy current indices are characterized, including the effects of additional influential parameters namely, lift-off, excitation frequency, and probe size. Phase Diagram is then proposed as a concise method to evaluate the variation of relative permeability and lift-off concurrently in a single graph for an excitation frequency and probe size. It further facilitates the selection of suitable excitation frequency and probe size to conduct the eddy current based stress measurement.