Layered self‐resistance electric heating to cure thick carbon fiber reinforced epoxy laminates

Abstract

Abstract Curing of thick carbon fiber reinforced thermosetting composite laminates has been a major challenge due to the undesired through‐thickness temperature gradient. In this paper, a novel layered self‐resistance electric heating (L‐SRE) method to cure thick laminates was proposed. The thick laminate was divided into multiple independent sub‐layers, and the temperature of each sub‐layer was controlled individually. The experiment's results revealed that L‐SRE was able to achieve highly homogeneous temperature distribution filed through‐thickness both in rapid heating and exothermic reaction stages. The maximum temperature difference of dwell stage for L‐SRE process was less than 4.0°C, and the L‐SRE process that had an optimized thickness of each sub‐layer achieved the minimum mean temperature deviation of 2.1°C, which was 88.46% lower than that of the oven process. By using the optimized L‐SRE method, the maximum value of crosslink thermal overshoot was 12.2°C (32.5°C for oven curing). Different layered temperature control strategies were explored, and the lowest energy consumption of 309.7 Wh (19.82% of oven process) was achieved by using the single‐power pulsed heating. The method proposed in this paper provided a new solution for high‐quality and energy‐efficient curing of thick laminates.