Temperature distribution analysis of carbon fiber reinforced polymer composites during self-resistance electric heating process

Abstract

Self-resistance electric (SRE) heating for carbon fiber reinforced plastics (CFRP) is an alternative out-of-autoclave curing methodology that has high efficiency and low energy consumption. However, thanks to the heating mechanism of inside-out conduction, which is significantly different from that of the traditional outside-in heating process, the temperature distribution and its homogenization strategy still need further investigation. This work focuses on analyzing the affecting factors of the temperature uniformity of CFRP laminates during the SRE curing process utilizing a multi-physical numerical computation model and experimental verification. It is found that mold sizes have the most significant impact due to the non-uniform center-to-edge heat absorption of the mold. The maximum temperature difference during the untreated process could be lower than 20 K if the excess size proportion of the mold is smaller than 10%. Thermal barriers made of aerogel homogenize the temperature distribution during the dwell stage, reducing the maximum temperature difference by 84.18%. Considering that the mold size is sometimes unchangeable, the existence of auxiliary heating elements compensates the heat dissipation from the self-heated laminate and reduces the maximum temperature difference by 79.81%. Based on analysis results, a temperature homogenization strategy is proposed, where the maximum temperature difference is reduced by 86.15%.