The interlaminar interface of a carbon fiber polymer-matrix composite as a resistance heating element

The interface between two crossply laminae of a continuous carbon fiber epoxy-matrix composite is an effective resistance heating element. For an interface of area 5 × 5 mm² and resistance 0.25 Ω, a DC electrical power input of 1.1 W (2.1 A, 0.53 V) results in a maximum temperature of 85 °C (initial temperature = 19 °C). The time to reach half of the maximum temperature is 10 s. The efficiency of energy conversion reaches 100% after about 47 s of heating, when the heat power output is about 2 × 10⁴ W/m² of the interlaminar interface. In case that the volume resistance of the laminae dominates the resistance, the response time is longer. An additional advantage of the use of the interlaminar interface as the resistance heating element is that the interface area can be divided to provide a two-dimensional array of heating elements for the purpose of spatially distributed heating.