Advanced automated detection of foreign object debris (FOD) in woven and uni-directional composite laminates.

Carbon fiber laminates are popular in the manufacturing industry for their advantageous characteristics, including good vibration damping, high strength-to-weight ratio, toughness, high dimensional stability, low coefficient of thermal expansion, etc. To get optimal results from these properties, the fibers need to be aligned, straight and well bonded. During the manufacturing process, undesirable foreign objects, including peel-ply strips, gloving material, Kapton film, etc. can be introduced into the part, resulting in localized weakness that degrades the desirable properties of the composite. Manufacturing defects can act as stress concentration points, potentially causing catastrophic failure. This study used pulse-echo ultrasound testing for the detection and quantification of the dimensions of foreign object debris (FOD) within carbon fiber laminates. This study presents a method to create high-resolution c-scans, and from the full-waveform dataset extract the FOD depth and planar dimensions with an automatic edge detection technique. Variable material inserts of various dimensions were embedded into both unidirectional and woven carbon fiber laminates at different depths. The samples for environmental effect study are conditioned and investigated in several different environmental conditions. CT imaging is used to verify that the FOD remained unaltered during manufacturing, and the as manufactured FOD dimensions were equal to the as designed FOD dimensions within the resolution of the CT configuration utilized. Again, in every case there is a 100% probability of detection and the identification of the layer depth for the FOD. To show the effect of FOD inclusion in CFRP laminates, preliminary studies with mechanical testing and FEA have been done. The work is further expanded by inserting FODs of different materials, sizes, shapes, depths in both the unidirectional and woven CFRP and comparing the results. In total over 900 individual FODs are studied covering the above conditions and parameter sets, with a typical error of 0.07 inches observed. The error varies with conditions, with small circular FODs averaging 0.06 inches and large circular FODs averaging 0.05 inches, whereas small triangular FODs averaging 0.09 inches and large triangular FODs averaging 0.10 inches. Furthermore, FOD detection results from laboratory immersion tank system are compared to a novel portable inspection station.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Doctoral

Grantor

Baylor University.

Year dc:date.issued

2024

Author dc:creator

• Nargis, Rifat Ara, 1994-

Advisor dc:contributor.advisor

• Jack, David Abram, 1977-

• Nondestructive testing.
• Composite.
• Ultrasound.
• X-ray computed tomography (CT)
• Carbon fiber laminates.
• Automatic detection.
• Foreign object debris.
• Finite element analysis (FEA) modeling.
• Mechanical testing.

Statement dc:rights

• Baylor University works are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. Contact libraryquestions@baylor.edu for inquiries about permission.

Language dc:language.iso

en

Handle dc:identifier.uri

https://hdl.handle.net/2104/13564

OAI identifier oai:identifier

oai:baylor-ir.tdl.org:2104/13564