Comparative study of active infrared thermography, ultrasonic laser vibrometry and laser ultrasonics in application to the inspection of graphite/epoxy composite parts

Three nondestructive testing techniques, namely, optically- and ultrasonically stimulated infrared thermography, ultrasonic laser vibrometry and laser ultrasonics, have been comparatively investigated in the inspection of a graphite-epoxy sample characterized by a complicated geometry to demonstrate advantages and drawbacks of each technique in the detection of different types of defects.