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

摘要

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 degrees C, and the L-SRE process that had an optimized thickness of each sub-layer achieved the minimum mean temperature deviation of 2.1 degrees 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 degrees C (32.5 degrees 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.