Title: Repair Process and NDI of Large Carbon Fiber Composite Structures

Authors: Michael Odarczenko, Tien Vo

DOI: 10.33599/nasampe/s.21.0591

Abstract: Ultrasonic techniques (pulse-echo, through transmission) are extremely common in evaluating carbon fiber composites. These techniques are also used to identify defects (i.e. porosity, delamination, foreign objects (FOD)) and monitor the part throughout the repair process. This form of Non-Destructive Inspection (NDI) was used to analyze a large repair in a carbon composite material measuring almost 0.75 m2 (8 square feet) in damage area and with up to 8 defects in one repair. Large repairs such as this have more issues that arise without a perfect damage repair process. Post processing of the NDI repair data from over 6 double scarf repairs showed bondline indications, FOD, and porosity limitations that led to further composite repair and investigation. Different aspects of the repair process and NDI analysis including surface preparation, cure method, porosity standards, NDI baselines, and environmental factors will be discussed as evidence that caused difficulty in the repair process. Separate test panels will be fabricated and cycled through repair cure cycles to determine when internal defects do change and by how much.

References: 1. Composite Materials Handbook-17 (CMH-17). Composite Materials Handbook Vol 6 – Structural sandwich Composites. (pp 7-6 – 7-12). SAE International on behalf of CMH-17, 2013 2. Pethrick, Richard A. Polymer Science and Technology for Scientists and Engineers – 5.12 General Physical Characteristics of Composites. (pp. 142-145). Whittles Publishing, 2010 3. Wegman, R.R. Tullos, T.R. Handbook of Adhesive Bonded Structural Repair – Controlled Atmospheric layup Areas. (pp. 80-93). William Andrew Publishing/Noyes, 1992

Conference: SAMPE NEXUS 2021

Publication Date: 2021/06/29

SKU: TP21-0000000591

Pages: 15

Price: FREE