Terahertz Non-destructive Testing Technology for Glass Fiber Honeycomb Composites

The terahertz time domain waveform was optimized with double Gaussian filtered inverse filtering technology. A terahertz reflection tomography technique based on terahertz time-domain spectroscopy nondestructive testing was proposed to analyze the bonding quality of glass fiber honeycomb composites. Combined with the characteristics of the glass fiber honeycomb composite structure, circular and trapezoidal debonding defects with different diameters were designed in the upper and lower layer of the honeycomb film. On this basis, the fabrication of the debonding defect honeycomb structure samples were completed. The proposed terahertz reflection tomography and B-scan imaging methods are suitable for the analysis of debonding defects of glass fiber honeycomb composites. Aiming at the problem of poor contrast of reflective tomography image, combined with the characteristics of terahertz time domain waveform data at the debonding defect, the defect feature time domain imaging optimization technology is used to improve the detection ability and recognition accuracy of debonding defects and realize the terahertz nondestructive testing of glass fiber honeycomb composite with its upper debonding thickness as 50 mu m and lower debonding thickness as 50 mu m.