碳纤维智能层在纤维复合材料结构健康监测中的应用

在预制有缺陷的纤维复合材料结构玻璃钢板缺陷表面覆盖碳纤维智能层，将玻璃钢板有缺陷一侧置于弯曲受拉面，对玻璃钢板进行单调弯曲破坏试验和等幅弯曲循环试验。结果表明：在单调弯曲破坏试验过程中，碳纤维智能层电阻的变化存在明显的拐点，该拐点即为玻璃钢板预制缺陷尖端发生开裂形成裂纹的瞬时，裂纹形成前，碳纤维智能层电阻随玻璃钢板表面缺陷张开值线性增加，裂纹形成后，碳纤维智能层电阻随玻璃钢板表面缺陷张开值不再线性变化，呈陡增趋势；在等幅弯曲循环试验过程中，碳纤维智能层电阻变化在玻璃钢板预制缺陷尖端开裂前表现为等幅循环，但开裂后表现为增幅循环；通过对比碳纤维智能层电阻在玻璃钢板预制缺陷尖端开裂前后的不同变化规律，可以实现对玻璃钢构件的健康监测。

Application of Carbon Fiber Smart Layer for FRP Structural Health Monitoring

Carbon fiber smart layer was covered on the lower side surface of a fiber reinforced plastic(FRP) plate where a disfigurement was performed.Through monotonic bending test until damage and constant amplitude cycle bending test,some conclusions were obtained.During the monotonic flexural failure test,the resistance change of carbon fiber smart layer existed knee point,and the appearance of this point marked the disfigurement started cracking.Before cracking,the resistance of carbon fiber smart layer changed linearly versus the disfigurement stretch.While after cracking,the resistance of carbon fiber smart layer increased steeply versus the disfigurement stretch.In the cycle of constant amplitude cycle flexural test,the resistance change of carbon fiber smart layer displayed constant amplitude change before the disfigurement cracking,but amplified change after the disfigurement cracking.The results show that health monitoring of FRP structure could be fulfilled by monitoring the resistance change of carbon fiber smart layer on the surface.