Quantitative analysis of the fibre content distribution in CFRP composites using thermal non-destructive testing

Purpose: The primary purpose of present study was to determine the fibre content distribution in CFRP composites using thermal non-destructive testing. Design/methodology/approach: The experiments have been performed using transient thermography to obtain the thermograms for CFRP and neat resin specimens. From recorded thermograms, the thermal diffusivity values were determined for all materials under investigation and for two different preheating conditions to verify the effect of preheating conditions on obtained results. Findings: It was found from obtained results that composites with different carbon fibre content had different values of thermal diffusivity. Relationship showed that the thermal diffusivity was a linear function of fibre content in considered materials. It was also found from investigated neat resin specimens that the thermal diffusivity measurement was affected by specimen thickness. Research limitations/implications: Developed relationships between thermal diffusivity and carbon fibre content is not generalized for all types of CFRP composites (manufactured using a different technology or of different thickness), such specific relationships should be determined for any other composite. Practical implications: The results obtained from present experiment would be of great importance in the industrial or laboratory applications to evaluate the fibre content distribution in carbon/epoxy composites. Originality/value: Originality of the present paper is about applying the thermal non-destructive testing to determine the fibre content distribution in CFRP composites.