757 パルス加熱後の時系列温度場解析による宇宙構造複合材料の非破壊評価法の開発  [in Japanese] Development of Thermographic NDT Based on Sequential Temperature Data after Pulse Heating and Its Application for Space Structure  [in Japanese]

A new thermographic NDT technique was developed based on data processing of transient temperature descent curve after pulse heating. Temperature distribution after pulse heating using xenon flash lamp was measured by high-speed infrared camera. The shape of transient temperature descent curve, which reflects defect parameters such as depth, shape and size, was analyzed by the Fourier series analysis. Experimental investigation was carried out on identification of flat-bottom hole defects. It was found that the 1st order coefficients of the Fourier series were effectively used to determine depth and shape of the defects. The present technique was applied for measurements of impact delamination damage introduced in CFRP plates used for structural members of H-IIA launch vehicle. It was found that shape and depth of the delamination damage were successfully determined.