Electric circuit modeling of ultrasound-excited thermo-image technique
Ultrasound-excited thermo-image is a new method of NDE/T technology, in which a high-power ultrasonic transducer excites high ultrasonic energy pulses into the tested sample. While the defects(e.g. cracks) exist in the sample, the propagation of wave should cause the frictional interaction of the crack area, therefore, the local temperature increases. By an IR camera monitoring this kind of local transient temperature increase, the surface and subsurface cracks in the sample can be detected. The related experiments show that, under the intensive ultrasonic excitation, the non-linear vibration phenomena, such as harmonics, sub-harmonics, quasi-sub-harmonics or chaotic, may appear in the system. The transient temperature increase of the defective area is more significant then other parts, so the detection of cracks is very sensitive.