Study on in-plane thermal conduction of woven carbon fiber reinforced polymer by infrared thermography

Infrared thermography (IRT) is introduced to measure the in-plane thermal conduction of woven carbon fiber reinforced polymers (CFRP). According to the principle of modulated laser heating, the relationship between the phase gradient and the in-plane thermal diffusivity has been deduced, and the experimental platform was established to test the 6 groups of CFRP test specimens with varied porosity. The measured infrared radiation signal was normalized by taking glassy carbon as the reference material, and the Gaussian filtering was applied to removing the noise of infrared thermal images. The experiment results show that the in-plane thermal conduction law in various directions is related to its conduction direction owing to the anisotropy of the CFRP. The in-plane thermal diffusivity of test specimens with different levels of porosity in each direction can be measured when the modulated laser frequency is lower than 1 Hz. In addition, the thermal diffusivity in each direction decreases with the increase of test specimens' porosity.