Method of Depth Detection and Correction of Thermal Proof Tile Structural Defects Based on CW-THz
Terahertz detection imaging technology has an important application prospect in the field of aerospace nondestructive testing,the use of nondestructive testing methods to detect thermal protective materials is of great significance to ensure the quality of materials and improve their reliability.The frequency modulation continuous terahertz acquisition signal is limited by the operating bandwidth of the system,resulting in low test accuracy.In order to improve the measurement accuracy,this paper introduces different discrete spectrum correction and thinning methods to compare and analyze.Based on the thermal protection ceramic tiles,the hole defects of different depths in the tiles were detected.The position and size of the defects were obtained by analyzing the two-dimensional terahertz images of the samples and comparing the typical signals,and the depth information was corrected from the point of view of signal processing.The results show that the frequency-modulated continuous THZ detection system can clearly identify the hole defects in the thermal protection structure,and the discrete spectrum thinning and correction processing algorithm can accurately locate the defect depth,and the correction error is within 1mm.
万方数据
维普
