The novel procedure of active thermal ndt: combining heating and forced cooling

Abstract

A novel technique of active thermal nondestructive testing is proposed. It involves consecutive heating and forced cooling of the surface of test objects. The results of numerical modeling and experiments have demonstrated efficiency of this technique in case of test materials, which are characterized by a high level of emission/absorption noise. Optimization of such test procedure requires correctly choosing power and turn-on time of forced cooling to stimulate increase of temperature contrast over defects at particular times. An additional advantage of forced cooling is decrease of a thermal load on test materials that may be important in case of composites.