Quantitative study of local heat sources by Ultrasonic Infrared Thermography: An approach for estimating total energy released by low energy impact damage in C/C composite

An approach intended for the evaluation of total energy released in multi-component defects subjected to ultrasonic stimulation is described. Experimental research was conducted on carbon/carbon composite containing a 25 J impact damage defect. The test sample was ultrasonically stimulated at the frequency of 22 kHz by using a magnetostrictive device. The impact damage was modelled as a pyramid-like set of six single delaminations, and each of them represented an independent heat source. The calculated temperature response was matched to the experimental temperature profile by shape and amplitude thus allowing the evaluation of energy release within the defect.