Pulse thermography (PT) is a nondestructive testing method in which an energy pulse is applied to a surface while the surface temperature evolution is measured to detect sub surface defects and estimate their depth. This nondestructive test method was developed on the assumption of instantaneous surface heating, but recent work has shown that relatively long pulses can be used to accurately determine defect depth in polymers. This paper examines the impact of varying input pulse length on the accuracy of defect depth quantification as a function of the material properties. Simulations using both thermoplastics and metals show that measurement error is dependent on a nondimensionalized pulse length. The simulation results agree with experimental results for three-dimensional (3D) printed acrylonitrile butadiene styrene (ABS) and polylactic acid (PLA) components. Analysis and experiments show that defects can be accurately detected with minor modification to the standard methods as long as the pulse ends before the characteristic defect signal is detected.

References

References
1.
Parker
,
W. J.
,
Jenkins
,
R. J.
,
Butler
,
C. P.
, and
Abbott
,
G. L.
,
1961
, “
Flash Method of Determining Thermal Diffusivity, Heat Capacity, and Thermal Conductivity
,”
J. Appl. Phys.
,
32
(
9
), pp.
1679
1684
.
2.
Liang
,
T.
,
Ren
,
W.
,
Tian
,
G. Y.
,
Elradi
,
M.
, and
Gao
,
Y.
,
2016
, “
Low Energy Impact Damage Detection in CFRP Using Eddy Current Pulsed Thermography
,”
Compos. Struct.
,
143
, pp.
352
361
.
3.
Ringermacher
,
H. I.
,
Archacki
,
R. J.
, and
Veronesi
,
W. A.
,
1998
, “
Nondestructive Testing: Transient Depth Thermography
,” U.S. Patent No. 5,711,603.
4.
Sharath
,
D.
,
Menaka
,
M.
, and
Venkatraman
,
B.
,
2013
, “
Defect Characterization Using Pulsed Thermography
,”
J. Nondestr. Eval.
,
32
(
2
), pp.
134
141
.
5.
Shepard
,
S. M.
,
Lhota
,
J. R.
,
Rubadeux
,
B. A.
,
Wang
,
D.
, and
Ahmed
,
T.
,
2003
, “
Reconstruction and Enhancement of Active Thermographic Image Sequences
,”
Opt. Eng.
,
42
(
5
), pp.
1337
1343
.
6.
Sun
,
J. G.
,
2006
, “
Analysis of Pulsed Thermography Methods for Defect Depth Prediction
,”
ASME J. Heat Transfer
,
128
(
4
), pp.
329
338
.
7.
Zhi
,
Z.
,
Ning
,
T.
,
Lichun
,
F.
, and
Cunlin
,
Z.
,
2012
, “
Specified Value Based Defect Depth Prediction Using Pulsed Thermography
,”
J. Appl. Phys.
,
112
(
2
), p.
023112
.
8.
Masamune
,
S.
, and
Smith
,
J.
,
1963
, “
Thermal Conductivity of Beds of Spherical Particles
,”
Ind. Eng. Chem. Fundam.
,
2
(
2
), pp.
136
143
.
9.
Gibson
,
I.
,
Rosen
,
D.
, and
Stucker
,
B.
,
2015
,
Additive Manufacturing Technologies: 3D Printing, Rapid Prototyping, and Direct Digital Manufacturing
,
2nd ed.
,
Springer
,
New York
.
10.
Kim
,
J. W.
,
Yun
,
K. W.
, and
Jung
,
H. C.
,
2013
, “
Investigation of Optimal Thermal Injection Conditions and the Capability of IR Thermography for Detecting Wall-Thinning Defects in Small-Diameter Piping Components
,”
Nucl. Eng. Des.
,
262
, pp.
39
51
.
11.
Almond
,
D. P.
,
Angioni
,
S. L.
, and
Pickering
,
S. G.
,
2017
, “
Long Pulse Excitation Thermographic Non-Destructive Evaluation
,”
NDT E Int.
,
87
, pp.
7
14
.
12.
Pierce
,
J.
,
2018
, “
Defect Detection in Additive Manufacturing Utilizing Long Pulse Thermography
,”
M.S. theses
, University of South Florida, Tampa, FL.https://scholarcommons.usf.edu/etd/7219
13.
Morton
,
K. W.
, and
Mayers
,
D. F.
,
2005
, Numerical Solution of Partial Differential Equations: An Introduction, Cambridge University Press, Cambridge, UK.
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