| Abstrakt: |
Infrared thermography is a common technique for nondestructive evaluation. In active infrared thermography privileged here, a thermal stimulation is required to generate relevant thermal contrasts on specimens. Among stimulation techniques, pulse heating is one of the most common along with lock-in thermography. In this article, a technique is discussed that shows that by modifying the pulse heating shape, higher thermal contrasts are generated (for a given level of energy injection). In fact, it was found that ideally, it is better to use two pulses separated by a short Δ time interval. Variation of Δ directly influences the thermal contrast. By increasing Δ, the thermal contrast first improves up to a certain level before to reduce below the reference value (single pulse case). This was tested on several materials of low, medium, and high thermal conductivity. Moreover, this was also confirmed by an appropriate thermal model (not discussed in the article). In the text, a theory and experiments are provided. [ABSTRACT FROM AUTHOR] |
