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Nondestructive Testing to Detect
Delamination Between Plies in
Composite Laminated Plates
Under Dynamic Loading
By:
Jason C. Starnes
Outline of Study
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Introduction
What I am doing?
Why I am doing it?
Test process and analysis expected
Expectations/hypothesis
Questions
Introduction
• Most common NDT detection methods are visual,
ultrasonic, x-ray, tap test, thermography, and
Shearography.
• Things I wanted to try was using a 3D laser
vibrometer, but source fell though.
• Plan B, use accelerometer grid over face of plate.
What I am doing…
• Use nondestructive test methods to detect
delamination in [0,90,0,90]s cross-ply composite
laminate plates.
• 11 plates total, 10 having known delaminated area.
• Shaker table will excite plates, while accelerometers
will be used to detect delamination.
Delamination zones per test specimen.
Why I am doing it…
• Overtime, composite materials can begin
to delaminate starting from small areas
and lead to bigger.
• Early intervention in determining
delamination will aid in cost savings
during manufacturing process.
• Determine sound FEA analysis model for
future use.
• Discover new methods to finding
delamination's on a small scale.
• Interesting.
Test Process and Analysis
Expected
Test Process
• Material Properties
– M46J/TC250 Unidirectional
• Use built vibration fixture
• Accelerometers over grid
– 3x9 per plate
• FEA
• Correlate all data
Expectations
• Degradation in mat. Prop.
Comparatively (Exp. Mat.)
• Fixture will be well above
plate resonance
• Painstaking, but worth it
• Once process is
discovered, should have
minimal error
• Overall, delamination’s
will be found
Expectations/Hypothesis
• Expectations:
– Delamination's will be
found.
– Modal analysis will
correlate
• Hypothesis
– Will see dampening
effect.
– FEA will show possible
delamination/crack
propagation.
Manufactured Test Specimens
Questions/Comments
Thanks