Widespread damage in aging aircraft is becoming an increasing concern as both civil and military fleet operators are extending the service lifetime of their aircraft. Metallic components undergoing variable cyclic loadings eventually fatigue and form dislocations as precursors to ultimate failure. In order to characterize the progression of fatigue damage precursors (DP), the acoustic nonlinearity parameter is measured as the primary indicator. However, using proven standard ultrasonic technology for nonlinear measurements presents limitations for settings outside of the laboratory environment. This paper presents an approach for ultrasonic inspection through automated immersion scanning of hot section engine components where mature ultrasonic technology is used during periodic inspections. Nonlinear ultrasonic measurements were analyzed using wavelet analysis to extract multiple harmonics from the received signals. Measurements indicated strong correlations of nonlinearity coefficients and levels of fatigue in aluminum and Ni-based superalloys. This novel wavelet cross-correlation (WCC) algorithm is a potential technique to scan for fatigue damage precursors and identify critical locations for remaining life prediction.

1.
T.
Grobstein
,
S.
Sivashankaran
,
G.
Welsh
,
N.
Panigrahi
,
J.
McGervey
and
J.
Blue
, “
Fatigue damage accumulation in nickel prior to crack initiation
,”
Mat. Sci. Engr.
,
A138
,
191
203
, (
1991
).
2.
R.
Fay
, “
Oppositely Directed Plane Finite Waves
,”
J. Acoust. Soc. Am.
,
29
:
11
,
1200
1203
, (
1957
).
3.
M.
Breazeale
and
W.
Lester
, “
Demonstration of the “Least Stable Waveform” of Finite Amplitude Waves
,”
J. Acoust. Soc. of Am.
,
33
:
12
,
1803
, (
1961
).
4.
D.
Thompson
,
M.
Tennison
and
O.
Buck
, “
Reflections of Harmnonic Generation by Finite-Amplitude Waves
,”
J Acoust Soc Am
,
44
:
10
,
435
6
, (
1968
).
5.
M.
Nikoonahad
and
D.
Liu
, “
Pulse-echo Single Frequency Acoustic Nonlinearity Parameter (B/A) Measurement
,”
IEEE Trans. Ultras. Ferroelec. & Freq. Control
,
37
:
2
,
127
, (
1990
).
6.
F.
Meulen
and
L.
Haumesser
, “
Evaluation of B/A nonlinear parameter using an acoustic self-calibrated pulse-echo method
,”
Appl. Phys. Lett.
,
92
, (
2008
).
7.
S.
Saito
,
J.
Kim
and
K.
Nakamura
, “
Automatic measruement of the nonlinearity parameter B/A in liquid media
,”
Ultrasonics
,
44
,
1429
1433
, (
2006
).
8.
A.
Voronovich
, “
On the conservation of momentum for a sound pulse reflecting from a pressure-release boundary
,”
J Acoust Soc Am
,
123
:
5
,
2480
3
, (
2008
).
9.
D.
Kourtiche
,
L.
Allies
,
A.
Chitnalah
and
M.
Nadi
, “
Harmonic propagation of finite amplitude sound beams: comparative method in pulse echo measurement of nonlinear B/A parameter
,”
Meas Sci Technol
,
12
,
1990
5
, (
2001
).
10.
S.
Best
,
A.
Croxford
and
S.
Neild
, “
Pulse-Echo Harmonic Generation Measurements for Non-destructive Evaluation
,”
J. Nondestructive Eval
,
33
, pp.
205
215
, (
2014
).
11.
Y.
Ohara
,
K.
Kawashima
,
R.
Yamada
and
H.
Horio
, “
Evaluation of amorphous diffusion bonding by nonlinear ultrasonic method
,”
Review of Progress QNDE (Vol. 23
),
AIP Conf. Proc.
,
944
951
, (
2004
).
12.
J.
Frouin
,
T.
Matikas
,
J.
Na
and
S.
Sathish
, “
In-Situ Monitoring of Acoustic Linear and Nonlinear Behavior of Titanium Alloys during Cycling Loading
,”
Proc. of SPIE Conf. on NDE of Aging Materials
,
Newport Beach, California
,
3585
(
1999
).
13.
C.
Pruell
,
J.
Kim
,
J.
Qu
and
L.
Jacobs
, “
Evaluation of fatigue damage using nonlinear guided waves
,”
Smart Mater Struct
,
18
(
3
)
035003
(
2009
).
14.
A.
Viswanath
,
B.
Rao
,
S.
Mahadevan
,
P.
Parameswaran
,
T.
Jayajumar
and
B.
Raj
, “
Nondestructive assessment of tensile properties of cold worked AISI type 304 stainless steel using nonlinear ultrasonic technique
,”
J Mat Proc Tech
,
211
,
538
544
, (
2011
).
15.
J.
Kim
,
L.
Jacobs
,
J.
Qu
and
J.
Littles
, “
Experimental characterization of fatigue damage in nickel-base superalloy using nonlinear ultrasonic waves
,”
J. Acoust. Soc. Am.
,
120
,
1266
, (
2006
).
16.
K.
Kawashima
,
R.
Imanishi
,
F.
Fujita
and
T.
Aida
, “Imaging of Partial Plastic Deformation in Thin Metal Plates by Immersion Nonlinear Ulrasonic Local resonance,”
AIP Conf. Proc. Nonlinear Acoustics
,
Tokio, Japan
, pp.
207
210
(
2012
).
17.
K.
Kawashima
,
T.
Aida
and
H.
Yasui
, “
Higher-harmonic imaging of the plastic zone in front of a fatigue crack tip
,”
Jap J Appl Phys
,
53
, (
2014
).
18.
A.
Yee
,
D.
Stewart
,
G.
Bunget
,
P.
Kramer
,
K.
Farinholt
,
F.
Friedersdorf
,
M.
Pepi
and
A.
Ghoshal
, “
Nonlinear ultrasonics measurements based on cross-correlation filtering techniques
,”
Review of Progress in QNDE (Vol. 36
),
AIP Conference Proceedings
1806
,
060004
,
Atlanta, Georgia
, (
2017
).
19.
A.
Hikata
,
B.
Chick
and
C.
Elbaum
, “
Dislocation Contribution to the Second Harmonic Generation of Ultrasonic Waves
,”
J. Appl. Phys.
,
36
,
229
, (
1965
).
20.
J.
Cantrell
, “
Generalized Gruneisen tensor from solid nonlinearity parameters
,”
Phys Rev B
,
21
:
10
,
4191
5
, (
1980
).
21.
D.
Joharapurkar
and
M.
Breazeale
, “
Nonlinear parameter, nonlinearity constant, and frequency dependence of ultrasonic attenuation in GaAs
,”
J Appl Phys
,
67
:
1
,
76
80
, (
1990
).
22.
D.
Joharapurkar
,
D.
Gerlich
and
M.
Breazeale
, “
Temperature dependence of elastic nonlinearities in single-crystal gallium arsenide
,”
J Appl Phys
,
72
:
6
,
2002
8
, (
1992
).
23.
H.
Mohrbacher
,
D.
Lee
,
E.
Schneider
and
K.
Salama
, “Acoustic nonlinearity in metal-matrix composites,”
Review of Prog. in QNDE
,
10B
, pp.
1821
1828
, (eds)
D.O.
Thompson
and
D.E.
Chimenti
,
Plenum Press
,
New York
(
1991
).
24.
A.
Hikata
and
C.
Elbaum
, “
Generation of Ultrasonic Second and Third Harmonics Due to Dislocations. I
,”
Phys Rev
,
144
:
2
,
469
77
, (
1966
).
25.
A.
Hikata
,
F.
Sewell
and
C.
Elbaum
, “
Generation of Ultrasonic Second and Third Harmonics due to Dislocations. II
,”
Physical Rev
,
151
:
2
,
442
9
, (
1966
).
This content is only available via PDF.