The electromagnetic nondestructive evaluation of cracks in ferromagnetic structures was investigated with respect to the changes of eddy current stream and magnetic flux flow. Numerical simulation showed that both the changes result in detectable signals. The amplitude and phase angle of signals comply with different variation patterns in terms of crack orientation, crack location, the frequencies of excitation current, and etc,. When a back-side crack is respectively inspected under the configurations of perpendicular to and parallel to the eddy current streams, the phase difference between the signals of the two configurations is a linear function of crack depth and can be used for crack’s depth sizing.

Topics
Eddy current, Nondestructive testing techniques, Computer simulation
1.
J.
 
Blitz
,
Electrical and Magnetic Methods of Nondestructive Testing
, (
Adam Hilger, Aristol
,
Philadelphia and New York
,
1991
), pp.
89
–
152
.
Google Scholar
 
2.
Nondestructive Testing handbook, Vol. 5, Electromagnetic Testing
, edited by
S.S.
 
Udpa
,
P. O.
 
Moore
, (
American Society of Nondestructive Testing
,
Columbus, OH
,
2004
),. pp.
46
–
55
, pp. 227-245, pp. 248-268.
Google Scholar
 
3.
M. C.
 
Lugg
, “Alternating Current Field Measurement,” in
Electromagnetic Testing
, edited by
S. S.
 
Udpa
,
P. O.
 
Moore
 (
American Society of Nondestructive Testing
,
Columbus, OH
,
2004
), pp.
257
.
Google Scholar
 
4.
D.
 
Jiles
,
Introduction to Magnetism and Magnetic Materials
(
Chapman & Hall
,
1998
), pp.
44
.
Google Scholar
 
This content is only available via PDF.
© 2017 Author(s).
2017
Author(s)