| 要旨 |
The authors have developed a nondestructive measurement method for internal defects using optical excited thermography. In order to find optimal measurement conditions, experiments have been carried out under different light irradiation cycles and times. Furthermore, the authors have proposed a method for quantitatively estimating the size of internal defects by differential processing of the phase difference distribution of surface temperature variation. From the experimental results, it has been found that there exists an optimal irradiation cycles and times, and that these depend on specimen. Also, it has been recognized that internal defect size can be quantitatively estimated from differential processing of the phase difference distribution of surface temperature variation, that estimation accuracy is related to the thermal conductivity of materials and materials with lower thermal conductivity show higher estimation accuracy. |
