Location

La Jolla ,CA

Start Date

1-1-1989 12:00 AM

Description

Electromagnetic nondestructive testing (NDT) methods use frequencies ranging from low (dc) to high (microwave) frequencies [1]. Applications of numerical methods to model two- and three-dimensional low-frequency (dc or eddy current) nondestructive testing phenomena, where displacement currents can be omitted, were extensively examined, [2,3]. These are all interior boundary value problems. Finite element study of ultrasonic wave propagation and scattering in metals, which is again an interior boundary value problem, was recently reported in [4]. However, modeling of wave propagation for high-frequency NDT problems have not yet been attempted. Recently, finite difference methods in time domain have been successfully applied to solve transient electromagnetic wave propagation problems over the atmosphere and the ground [5], and time-dependent eddy current problems [6]. The method used here is a generalization of this work and is designed for numerical modeling of high-frequency electromagnetic wave propagation arising from nondestructive testing applications. The physical situation includes examination of the scattering effects by cracks inside a piece of material (especially dielectrics) or due to surface variations when the material is illuminated by a TM plane wave. This leads to an interface type problem.

Book Title

Review of Progress in Quantitative Nondestructive Evaluation

Volume

8A

Chapter

Chapter 1: Fundamentals of Classic Techniques

Section

Eddy Currents

Pages

259-266

DOI

10.1007/978-1-4613-0817-1_33

Language

en

File Format

application/pdf

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Jan 1st, 12:00 AM

Numerical Modeling of Transient Wave Propagation for High Frequency NDT

La Jolla ,CA

Electromagnetic nondestructive testing (NDT) methods use frequencies ranging from low (dc) to high (microwave) frequencies [1]. Applications of numerical methods to model two- and three-dimensional low-frequency (dc or eddy current) nondestructive testing phenomena, where displacement currents can be omitted, were extensively examined, [2,3]. These are all interior boundary value problems. Finite element study of ultrasonic wave propagation and scattering in metals, which is again an interior boundary value problem, was recently reported in [4]. However, modeling of wave propagation for high-frequency NDT problems have not yet been attempted. Recently, finite difference methods in time domain have been successfully applied to solve transient electromagnetic wave propagation problems over the atmosphere and the ground [5], and time-dependent eddy current problems [6]. The method used here is a generalization of this work and is designed for numerical modeling of high-frequency electromagnetic wave propagation arising from nondestructive testing applications. The physical situation includes examination of the scattering effects by cracks inside a piece of material (especially dielectrics) or due to surface variations when the material is illuminated by a TM plane wave. This leads to an interface type problem.