VISUALIZATION METHOD FOR DEBONDING DEFECTS IN A HEAT-SHIELDING STRUCTURE USING THZ WAVES

This paper presents the development of an advanced non-destructive inspection system utilizing terahertz (THz) waves to detect debonding defects in adhesive layers of heat-resistant composite structures. Such structures are commonly used in aerospace, energy, and transportation industries, where adhesive layer integrity is critical for performance and safety. The proposed system analyzes THz waveforms transmitted through the structure to detect differences in reflection signals caused by adhesive separation or other defects. The system visualizes these variations using A, B, and C-Scan images, enabling precise identification of defect locations, sizes, and material thickness distributions. The inspection process can also calculate defect area ratios, offering a comprehensive view of structural integrity. To evaluate the system's effectiveness, tests were conducted on heat-resistant composite structures. The THz signals were visualized in a three-dimensional matrix, and areas showing anomalous signal characteristics were flagged as potential defects. These suspected defect regions were compared to actual defects observed upon disassembly. The comparison demonstrated a high degree of correlation between the identified defect areas and those found in the physical inspection, confirming the reliability and accuracy of the THz-based method for detecting debonding defects. This study highlights the potential of THz wave-based non-destructive testing for enhancing the quality control and reliability of heat-resistant composite structures used in critical industries.