LAUSR

Defect depths are estimated in the basalt fiber reinforced composite using long pulse infrared thermography in the transmission mode. Defects of different sizes and depths are induced in the basalt fiber composite using flat bottom holes and their thermograms are analyzed. Contrast derivative and parker's method are used to predict the defect depths. The proportionality factor between peak contrast time and defect depth is determined analytically for contrast derivative method. It is observed that the contrast derivative method predicts the defect depths and is independent of the defect sizes, whereas the Parker's method predicts higher depth. The experimental results are in good agreement with numerical results.