碳纤维树脂基复合材料电热损伤机理研究

Composite aircraft structural damage and failure assessment has always been the focus of the aviation industry. The electro-thermal damage caused by low intensity current is unique to the structure of carbon fiber reinforced polymer (CFRP) in aircrafts. Former studies have shown that electro-thermal damage has significant influence on CFRP performance, the damaging behavior has much uncertainty. With the significant application of CFRP in main load-bearing structures of civil airliners, the electro-thermal damage is becoming a potential threat against aviation safety, the mechanism study is calling for continued airworthiness amongst global academic circles. Considering the electro-thermal properties of CFRP, electro-thermal loading tests with fine control of the electric current parameters is compiled in this project, and evolution of the interface micro-nano structures and the matrix polymer is observed, in order to investigate the damaging behavior thoroughly. Then, CFRP electro-thermal response and temperature field is gained, the association analysis among current-temperature field-damage characteristics is developed, the CFRP damage mechanism and the and performance will be revealed. Furthermore, damage process simulation method is established. Finally, this project will provide scientific basis and technology support for systematic electro-thermal damage assessment and sustained aviation safety.

复合材料结构损伤失效评估一直是航空工业关注的重要问题。电磁感应引起的低强度电流导致的电热损伤是碳纤维复合材料（CFRP）飞机结构特有的、尚未引起足够关注的损伤形式。已有研究表明，电热损伤对CFRP性能影响显著，损伤行为具有很强不确定性。在CFRP在民航飞机主承力结构上的大量应用的背景下，电热损伤已成为航空安全的潜在威胁，其损伤机理研究在国际上已成为CFRP领域的新热点。本项目针对CFRP的电热特性，通过精细控制电流参量的电热载荷加载试验，复合材料界面微纳结构和树脂基体对电热作用的响应观测，深入研究低强度电流导致的电热损伤行为，获取CFRP电热响应及温度场特性，发展电流-温度场-损伤特征参量三者间关联分析方法，揭示损伤机制，建立损伤过程仿真方法，为发展CFRP飞机结构的电热损伤风险评估方法、保障航空安全提供科学依据和技术支撑。

复合材料结构损伤失效评估一直是航空工业关注的重要问题。由电磁感应等原因引起的低强度电流导致的电热损伤是碳纤维复合材料（CFRP）飞机结构特有的、尚未引起足够关注的损伤形式。电热损伤对CFRP性能影响显著，损伤行为具有很强不确定性，电热损伤已成为航空安全的潜在威胁。本项目针对CFRP的电热特性，通过精细控制电流参量的电热载荷加载试验，复合材料界面微纳结构和树脂基体对电热作用的响应观测，深入研究低强度电流导致的电热损伤行为，获取CFRP电热响应及温度场特性，发展电流-温度场-损伤特征参量三者间关联分析方法，揭示损伤机制，建立损伤过程仿真方法。经研究，明确了通过安培级电流时，碳纤维环氧复合材料宏观尺寸试样的力学性能随电流密度增大先增强后减弱的行为规律。揭示了在电-热效应作用后，碳纤维的表面形貌、表面元素组成和官能团、纤维上浆剂和界面区树脂都存在变化，对电热效应的机理有协同性支撑。提出了基于电学量，包括碳纤维导电网络的电阻变化率，和复合材料整体的介电性质在内的特征量，发现了电学特征量与弯曲性能之间的关联关系，并利用有限元方法计算了通过一定特征的电流时，在复合材料内部建立的稳态温度场。这些成果为发展CFRP飞机结构的电热损伤风险评估方法、保障航空安全提供科学依据和技术支撑。