Assessing Impact Damage In Thermoplastic Composites Using Maximum Contrast Approach

Background: With the widespread use of carbon fiber reinforced polymers (CFRP) in the aerospace industry, detecting damage or defects has become crucial in preserving the structural integrity of these systems. Materials and Methods: This research aims to explore the effectiveness of thermography non-destructive evaluation (TNDE) in assessing impact damage in structural components of carbon/thermoplastic composites. Several coupons of carbon/thermoplastic composites impact damaged with a range of impact energy were inspected using active flash thermography. Thermal data obtained from thermography was processed using thermographic signal reconstruction, and the defect depth and size were estimated using a calibration profile and the maximum contrast approach. These results were also compared with results from ultrasonic C-scan. Results: The results from thermography were found to be consistent with those from the C-scan. Furthermore, damage progression in impacted tensile specimens was also evaluated under increasing loads, with areas of damage being measured using a pixel-count method. Conclusion: The depth and area measurements evaluated from TNDE were consistent with the C-scan analysis, which confirms a high degree of agreement.