  Infrared pulse thermography non-destructive testing (NDT) method is developed
based on the difference in the infrared radiation intensity emitted by
defective and non-defective areas of an object. However, when the radiation
intensity of the defective target is similar to that of the non-defective area
of the object, the detection results are poor. To address this issue, this
study investigated the polarization characteristics of the infrared radiation
of different materials. Simulation results showed that the degree of infrared
polarization of the object surface changed regularly with changes in thermal
environment radiation. An infrared polarization imaging-based NDT method was
proposed and demonstrated using specimens with four different simulated
defective areas, which were designed and fabricated using four different
materials. The experimental results were consistent with the simulation
results, thereby proving the effectiveness of the proposed method. Compared
with the infrared-radiation-intensity-based NDT method, the proposed method
improved the image detail presentation and detection accuracy.
