In this book chapter it is shown that the LFE is an interesting alternative to the well-established ECT technique when in nonferromagnetic conductors deep internal defects/anomalies have to be identified. In such cases, complicated structures with moving components lead to very high computational costs, i.e. it is highly preferably to apply fast numerical models for solving the forward problem. Solving the inverse problem, i.e. the identification of defects or conductivity anomalies, requires efficient solution strategies. In most cases, the number of optimization methods that can be applied for this purpose is limited because usually only derivative-free methods can be used.

Chapter Contents:

• 5.1 Identification of conductivity anomalies
• 5.2 Inverse solution techniques
• 5.2.1 Theory
• 5.2.2 Classification of inverse problems
• 5.2.3 Regularization
• 5.3 Lorentz force evaluation
• 5.4 Summary

Inspec keywords: computational electromagnetics; conducting materials; electromagnetic forces; inverse problems; eddy current testing; flaw detection

Other keywords: nondestructive testing; nonferromagnetic conductors; inverse problem; internal defects/anomalies; Lorentz force evaluation; derivative-free methods; optimization methods; conductivity anomalies; defects; motion-induced eddy current techniques

Subjects: Mathematical analysis; Nondestructive testing: eddy current testing and related techniques; Electromagnetic induction; Materials testing; Steady-state electromagnetic fields; electromagnetic induction