Multimode infrared thermal-wave imaging in non-destructive testing and evaluation (NDT&E): Physical principles, modulated waveform, and excitation heat source

Multimode infrared thermal-wave imaging has the advantages of intuitive, efficient, large detection area, noncontact, and long-distance detection respectively. It has a wide range of applications in the aerospace, nuclear industry, petrochemical, automobile, and energy fields. In this present investigation, the principle of multimode infrared thermal-wave imaging is briefly introduced initially. Subsequently, several typical infrared thermalwave imaging modalities, such as pulse thermography, lock-in thermography, line scanning infrared thermography, and infrared radar thermal-wave imaging, are introduced in detail from the aspects of the excitation source, excitation waveform, feature extraction algorithm, and image processing. Multimode infrared thermalwave imaging based on different heat source triggering modes was also introduced in this paper. The development status and practical application examples of multimode infrared thermal-wave imaging are emphatically introduced, and the problems faced by infrared thermal-wave imaging are analyzed. Finally, the future development trend of multimode infrared thermal-wave imaging is prospected.