Location

Williamsburg, VA

Start Date

1-1-1986 12:00 AM

Description

The a.c. field measurement technique has been developed at University College London for the purpose of fatigue-crack detection and sizing. The technique consists of applying an alternating current to a metal specimen, either by direct contact or by induction, which is then confined to a thin layer near the surface by the skin effect. The variations in the surface electric field strength due to the presence of a crack are measured using a voltage probe. The crack depth can then be calculated without the need for prior calibration by comparing voltage readings with those predicted by a theoretical solution.

Book Title

Review of Progress in Quantitative Nondestructive Evaluation

Volume

5A

Chapter

Chapter 2: Inversion, Imaging and Reconstruction

Section

Inversion

Pages

403-408

DOI

10.1007/978-1-4615-7763-8_41

Language

en

File Format

application/pdf

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Jan 1st, 12:00 AM

The A.C.F.M. Technique: Recent Advances in Crack Depth Measurement

Williamsburg, VA

The a.c. field measurement technique has been developed at University College London for the purpose of fatigue-crack detection and sizing. The technique consists of applying an alternating current to a metal specimen, either by direct contact or by induction, which is then confined to a thin layer near the surface by the skin effect. The variations in the surface electric field strength due to the presence of a crack are measured using a voltage probe. The crack depth can then be calculated without the need for prior calibration by comparing voltage readings with those predicted by a theoretical solution.