In this paper, shearography and thermography have been used in detecting inner defects of the fiber reinforced resin matrix composite fairing shell. Shearography and infrared thermography are contactless nondestructive testing methods based on distinct disciplines. Under the same thermal excitation, these two methods are able to be applied to nondestructive testing. In this study, an image fusion technique has been proposed to expand the dynamic range of digital camera to meet the requirement for smooth surface of the fairing shell. Based on a low-cost thermography setup, a phase enhancement scheme has also been developed for on-situ nondestructive evaluation. Shearography and infrared thermography have been conducted on the fairing by means of thermal excitation. The experimental results show that the proposed fusion method is helpful in dealing with the uneven distribution of light intensity due to laser illumination and surface condition; and the infrared phase enhancement scheme greatly improves the visibility of defects. These two methods possess individual advantages. Based on the experiment, an assessment about these two optical methods is conducted, which provides valuable experiences in subsequent defect detections.
张东升,罗永健,廖日程,叶益民,张涛,叶成炯. 激光散斑和红外在整流罩无损检测中的应用研究[J]. 航空制造技术, 2022, 65(20): 63-69,91.
ZHANG Dongsheng, LUO Yongjian, LIAO Richeng, YE Yimin, ZHANG Tao, YE Chengjiong. Study on Shearography and thermography in Nondestructive Testing for Fairing Parts[J]. Aeronautical Manufacturing Technology, 2022, 65(20): 63-69,91.