Composite Material Defect Detection

• The objective of this test is to verify whether the DEEPSOUND equipment can successfully detect underlying defects within the composite material.

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Test Samples

• Front Side

• Back Side

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Measuring Method

• Measurements are conducted by placing the probe directly onto the sample without a wedge. The goal is to determine if points of varying sizes (Point #1 to Point #3) can be distinctly identified in the PAUT S-scan.

• Equipment: 2.25 MHz PAUT Probe

• Marking Each Signal Point

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Inspection Point #1

• Actual Thickness of Point #1: Approximately 7.00 mm
• Detected Position of the Reflected Signal: 6.13 mm
• Observation: The S-scan clearly displays the ultrasonic signal reflecting off the intermediate rubber layer.

• S-Scan Image of Point #1

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Inspection Point #2

• Actual Thickness of Point #2: Approximately 11.00 mm
• Detected Position of the Reflected Signal: 10.38 mm
• Observation: A clear reflected signal is visible at the designated depth.

• S-Scan Image of Point #2

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Inspection Point #3

• Actual Thickness of Point #3: Approximately 23.00 mm
• Detected Position of the Reflected Signal: 22.31 mm
• Observation: The S-scan clearly displays the ultrasonic signal reflecting off the intermediate rubber layer at its maximum thickness.

- S-Scan Image of Point #3

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Evaluation & Conclusion

• The test successfully confirmed that explicit reflected signals could be detected at each designated inspection point within the composite specimen.
• The inspection was conducted using a probe with a frequency of 2.25 MHz. For optimal results in highly attenuating materials, we recommend utilizing a probe with a frequency lower than 2.25 MHz.
• Because composite specimens inherently cause severe attenuation of ultrasonic waves, images can appear somewhat blurred. Measuring alongside a known defect-free reference sample is strongly advised for comparative analysis.
• When inspecting the maximum thickness at Point #3, identifying the signal reflecting off the far back-wall proved challenging. (Recommendation: Increase the transmission voltage of the probe to proactively compensate for severe signal attenuation.)
• Ultimately, this ultrasonic testing comprehensively verified the presence of internal structural changes. Employing a lower frequency probe is expected to yield noticeably sharper and cleaner images.