碳纤维复合材料电导率-温度特性测量及其在预测雷击热效应中的应用

飞机的碳纤维复合材料（carbon fiber reinforced polymer，CFRP）蒙皮在遭受雷击时将经受急剧的温升效应，对材料电导率造成重要影响，而这一影响又反作用于焦耳热产生过程.文章通过直接加热和电加热两类实验分别测量了ZT7H/5229D碳纤维/树脂层合板在升降温过程中的电导率温度特性；开展了脉冲大电流试验，测量了模拟雷击情况下材料表面的瞬时温度.将实测的电导率温度参数应用到仿真模型中，仿真分析了脉冲注入实验的瞬时温度，结果表明:两类实验的电导率温度特性有着良好的一致性，CFRP在升降温过程中的回滞环现象、热解及基体热固性变化，会影响加温前后及升降温过程中的电导率；基于实验测量规律的仿真模型能够更准确预测雷电流注入时CFRP的温度场.

Measurement of the conductivity temperature dependence of CFRP and its application in anticipating lightning strike thermal effect

The carbon fiber reinforced polymer (CFRP) of aircraft skin structure suffers from a sharp temperature rise which is induced by lightning strikes. The temperature rise has an important influence on the electrical conductivity of composites which in turn affects the generation process of Joule heat. In this paper, two kinds of heating experiments, using hot air gun to directly heat one surface of specimen and conducting direct current into the material, were carried out to unidirectional ZT7H/5229D carbon fiber/epoxy laminates. In the two heating experiments, the temperature-dependent conductivity during heating-cooling cycle (thermal cycle) were measured, respectively. A high pulse current injection experiment was carried out. The instantaneous temperature of the material surface during the current action was measured firstly using an all-fiber transient high temperature probe. The measured temperature-dependent conductivity were applied to the simulation model, and the instantaneous temperature of the high pulse current injection experiment was simulated. The results show that the temperature-dependent conductivity of the two kinds of heating experiments have a good consistency. The electrical conductivity before and after heating and during the whole thermal cycle are influenced by the hysteresis loop, decomposition and matrix thermoset. The temperature field of CFRP under lightning current injection can be predicted accurately through the simulation model on the basis of measured temperature-dependent conductivity.