Structural health monitoring and material safety with multispectral technique: A review

Structural health monitoring is the technique which evaluate and analyze materials in the production and service process. In this paper, the basic principles and characteristics of terahertz, infrared, visible-multispectral and X-ray nondestructive testing technologies with different penetration rates, spectral energy, detection accuracy and system complexity are reviewed. Based on the types and causes of defects in aerospace materials, the corresponding testing techniques and nondestructive testing technology for different defects are also summarized. Finally, the image processing technology of each detection technology is analyzed. In practice, it is usually necessary to select one or more test methods according to the material properties and damage types. The differences in imaging techniques and processing algorithms are the major obstacles to joint multispectral detection. Although there have been preliminary studies on the methods of combining and associating image data under different spectra, further research is needed on how to integrate more spectra for new, more complex applications.