1. NONDESTRUCTIVE INSPECTION
OF COMPOSITE STRUCTURES
Presented by:-
Rohit Goyal
14MMT0068

2. • Composite materials are widely used in a number of
industrial sectors from aviation, space, to boat
building, automotive, and sports goods.
• The various forms of composite materials, with their
advantages of light weight, design flexibility, and high
specific stiffness and specific strength, are widely
used as structural materials in the aviation, space,
marine automobile, and sports industries.
• composites is a crucial component in critical
structures on airplanes, space vehicles, and boats

3. AIRCRAFT ANALYSIS:
• Nondestructive testing is used extensively during the
manufacturing ,in-service of aircraft.

4. AIRCRAFT ANALYSIS:
• Carbon graphic composite materials are now being
used in the latest generation of commercial aircraft
such as the Boeing 787 and the Airbus A350
• Classical inspection methods such as the tap-hammer
or ultrasound are still widely used for the inspection
of composite structures on aircraft
Limitation
• Dependency of the inspection results on the experience of the
inspector
• Do not allow for the scanning of large areas in an economically
efficient manner.

5. Active thermography
• Active thermography is a non-destructive inspection
systems are used to verify the Structural integrity of
composite materials.
• active thermography enables large-area measurements
to be performed and results presented as images that
can be easily interpreted.
• active inspection systems are relatively easy to
operate and do not necessarily require an experienced
inspector to perform.
• a single measurement can cover an area of from a few
millimeters to several square meters

6. Active Thermography
What is active thermography?
•Active thermography system is an automated image
scanning unit designed to detect defects in advanced
composite structures designed and built for high
performance aircraft.
How it works?
•Based on inducing a heat flow in the part to be
inspected
•The propagation of the heat flow inside the object
directly affects the temporal behavior of the surface
temperature
•By imaging the object with an infrared camera, captured
data can be analsed to show the internal structure of the
part and any defects

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• Automation AT system consists of a measuring head
and a tablet computer.
• measuring head contains an IR Smart Eye 320 GEV
infrared Ethernet camera with integrated control
electronics and a halogen lamp heat source with
integrated power electronics.
• these components are mounted on a frame that
contains three legs with vacuum-driven suction
cups .suction cups are used for fixing the measuring
head to the surface of the object to be inspected

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Benefits
•required inspection can be done in a series of tests by
personnel without a NDT background.
•Detection of hidden defects like cracks, disbondings or
delaminations in metal or plastic materials
•No system calibration required
•Inspect most parts in minimum time.
•the complete side of an A320 rudder could be checked
in 2.5 hours.

11. Laser Ultrasonic Systems
• Laser ultrasonic non-destructive inspection systems
are used to verify the structural integrity of composite
materials
• Laser Ultrasound (LUS) is a method to generate and
detect ultrasonic signals remotely with the aid of
lasers, without requiring direct physical contact
between probe and samples
• What is LaserUT®
?
• LaserUT®
system is an automated ultrasonic scanning
unit designed to detect defects in advanced composite
structures designed and built for high performance
aircraft.

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How it Works?
• LaserUT® uses pulse-echo ultrasound and requires
only single-sided access to a structure.
• Laser beams that generate and detect ultrasound are
scanned across the testing surface.
•Ultrasound generation works by a mechanism called
thermo-elastic expansion
•In this process, a pulse generation laser is directed at the
surface of the material under test.
•The beam is absorbed into a shallow volume of the
material

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• The rapid absorption of the pulse laser energy creates
a localized heating, which results in expansion of the
materials, inducing a stress wave.
• This stress wave is also an ultrasonic wave

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• The ultrasonic signal is detected using another
pulsed laser whose wavelength is scattered from
the surface of the material .
• The light scattered off the surface is collected
and inserted into an interferometer to “strip off”
the ultrasonic signal
• Once the signal is “stripped off” by the
interferometer, it is sent to silicon detectors that
convert the light signals to electrical signals
• The signal from each detection point on the
surface of the part is collected by a computer,
filtered, processed, stored, and displayed.

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Block Diagram of LaserUT® System

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• Completed LaserUT® scans of composite skins are
displayed in the User Interface
LaserUT® Scan of a Typical Composite Showing A, B, and C-Scan Images

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Benefits
•Significantly reduces setup time (typically 5 minutes or
less)
•No special tooling or fixtures required for each part
•Minimal training requirements - results are operator
invariant
•No system calibration required
•No special foundation required
• Requires no couplant of any kind .
•No direct contact between probe and surface
•Scan surface of complex shaped parts at speeds on the
order of ten-times faster than conventional ultrasonic
systems.

18. References
• David K. Hsu, "Nondestructive Evaluation of Damage in
Composite Structures," Proceedings of the 21st Technical
Conference of the American Society for Composites, September
17-20, 2006, Dearborn, Michigan, pp. 1-14.
• A. Pasztor, “Older Airbus Jets Get High-Tech Rudder Check,”
Wall Street Journal, December 19, 2006. p.41 F. Fiorino,
“Rudder Alert”, Aviation Week and Space Technology, April 3,
2006, p.41
• NTSB website http://www.ntsb.gov/AA587/default.html
• J. S. Sandhu, H. Wang, M. M. Sonpatki, and W. J. Popek, “Real
time full field ultrasonic inspection of composites using
acoustography,” NDE and Health Monitoring of Aerospace
Materials and Composites II, edited by A. L. Gyekenyesi and P.
J. Shull, Proc. SPIE, Vol. 5046, 00-104 (2003).
• M. Lasser and G. Harrison, “High speed high resolution
ultrasound imaging system for composite inspection,” 29th
International SAMPE Conference, 1997.

19. Thanks
Any questions?