Abstract:
InfraRed Thermography is an expeditiously growing non-destructive testing and evaluation technique widely
used to estimate the subsurface defect details in fibre reinforced polymer materials due to its remote, fast, easy,
safe and wide area monitoring abilities. In order to explore the details of subsurface anomalies in active infrared
thermography, a modulated heat flux with a predefined intensity and bandwidth is employed to excite the test
sample. Among various widely used active infrared thermographic techniques for non-destructive testing and
evaluation applications, pulse based and modulated lock-in thermography are predominantly in use. However,
these conventional techniques limits their applicability due to high peak power heat source requirements (pulse
based techniques) and poor resolution (modulated lock-in thermography) for detecting the defects located at
various depths of different lateral dimensions. The present paper highlights a pulse compression favourable
frequency modulated thermal wave imaging which can be carried out with moderate peak power heat sources in
a limited span of time with improved test resolution and sensitivity. Further the proposed experimentation is
validated with the analytical as well as numerical simulations on glass fibre reinforced polymer samples having
flat bottom hole defects.
