Model-based inverse methods for bolt-holt eddy current (BHEC) inspections

This work presents a comprehensive approach for model-based inversion of crack characteristics using eddy current nondestructive evaluation (NDE) and includes a demonstration using a bolt-hole eddy-current (BHEC) technique. Data were acquired using standard eddy current hardware for crack and notch samples of varying size and profile. The inversion results were found to be accurate within 10% for sizing the depth of through cracks and able to accurately bin mid-bore cracks by size.