Investigations for inclination angle characterization of angular defects using eddy current pulsed thermography

Characterization of Rolling Contact Fatigue Cracks in Rails by Eddy Current Pulsed Thermography

“…However, this location changes at different frames due to measurement errors and uncertainty. Similar to previous work [22], the characteristic location of the maximum thermal pixel is statistically found by repeated tests, as shown in Fig. 5(b).…”

“…These two features are derived from the thermal distribution at the end of the heating stage and denoted as SST and SKT. The detailed calculation process can be found in [22], the only difference is that the thermal responses of the pixels are preprocessed by zero-lag filtering.…”

“…Oswald-Tranta [21] used Fourier transformation to investigate the relation between the phase contrast and the inclination angle for both non-magnetic and ferro-magnetic materials. Liu et al [22] unitized skewness-and kurtosis-based spatial features to characterize inclination angles. Unfortunately, most of the above investigations are based on testing man-made specimens and lack verification on real cracks.…”

Characterization Method of Surface Crack Based on Laser Thermography

“…Active infrared thermography technology is a fast, noncontact detection method. The method can be divided into halogen lamp excitation [12], eddy current excitation [13], laser excitation [14], ultrasonic excitation [15], microwave excitation [16], resistive heating and mechanical vibrations excitation according to different heating excitation. And this method can be divided into reflection type and transmission type due to the different placement of the infrared imager.…”