电-湿耦合作用下碳纤维增强树脂基复合材料损伤机制

Damage mechanism of carbon-fiber-reinforced polymeric composites under electric-wet coupling action

针对航空结构碳纤维增强树脂基复合材料(CFRP)在电-湿耦合多场作用下的损伤机制进行研究,采用复合材料电-湿耦合环境测试平台对CFRP试样进行电-湿耦合处理,对试样表面温度进行实时监测,获得试样表面温度随电流强度大小与通电时间的变化规律,以及不同电流强度下CFRP试样的失重率变化;对不同环境条件处理后的CFRP试样进行弯曲性能测试,并对其断口形貌与表面形貌进行观测和分析。结果表明,通电电流强度越大,CFRP试样的表面稳定温度越高,同一电流值处理下CFRP试样表面稳定温度随通电时间的增加呈上升趋势;经9 A电-湿耦合处理24 h后的试样,其试样吸湿开始大于脱湿,经10 A电-湿耦合处理96 h后的试样达到吸湿-脱湿平衡,经12 A、15 A电-湿耦合处理后的试样出现不同程度的质量损失;不同电流强度电-湿耦合处理后,对界面均有一定程度损伤,使得弯曲强度下降,下降幅度与电流强度呈正相关。

In this paper,the damage mechanism of carbon-fiber-reinforced polymeric composites with an aviation structure was studied under the electro-wet coupling multiple fields.The electro-wet coupling environment-test platform was used to perform an electro-wet coupling treatment for the composites.The surface temperature of the composite samples was monitored in real time,and the evolution rule of the surface temperature with current intensity and electrification time was obtained.Moreover,a change in weightlessness rate under different current intensity was also obtained for the composite samples.The bending properties of the composite samples treated with different environmental conditions were measured,and their fracture morphology and surface morphology were observed and analyzed.The results indicated that the higher the energization current intensity,the higher is the stable surface temperature of the composite samples.The surface stable temperature of the composite samples increased with an increase in energization time at the same current value,and the moisture absorption tended to be greater than the dehumidification.After the 10 A electric-wet coupling treatment for 96 h,the composite samples reached the equilibrium of moisture absorption and dehumidification,and the samples after 12 A and 15 A electric-wet coupling treatment presented different mass losses.After the electro-wet coupling treatment at different current intensities,the sample interface was damaged to a certain extent.This makes the bending strength decrease,and the decrease range is positively correlated with the current intensity.