基于微波平面传感器的碳纤维复合材料表面薄涂层厚度测量方法

Thickness Measurement for the Surface Thin Coatings of Carbon Fiber Composites Using a Microwave Planar Sensor

碳纤维增强复合材料已经广泛用于航空航天制造,其表面涂层厚度直接影响部件性能,因此准确测量涂层厚度至关重要。基于材料微扰原理,提出一种利用微带线平面谐振器测量碳纤维增强复合材料表面涂层厚度的方案,该传感器具有尺寸小、成本低等优点。电磁仿真结果表明,谐振频率随着涂层厚度的增加而增大。试验在复合材料表面放置薄膜来模拟涂层,结果与仿真一致,且谐振频率偏移与厚度之间的关系可以用二次多项式进行表征。利用拟合曲线对覆盖层厚度进行预测,误差在实际厚度的±3%以内,而且对较厚覆盖层的预测也比较准确,表明所提出的传感器用于厚度测量的适用性较广。

Carbon fiber-reinforced composites(CFRP)have been widely used in aerospace manufacturing.The coating thickness of CFRP direct affects the component performance.So,accurate measurement of coating thickness is essential.A scheme for measuring the surface coating thickness of CFRP is proposed,which uses a microstrip line planar resonator based on material perturbation.This sensor has the advantages of small size and low cost.In electromagnetic simulations,the resonance frequency increases with increasing coating thickness.In experiments,thin films are placed on the surface of CFRP to simulate the coating.The experimental results are consistent with that in simulations and the relationship between the resonance frequency offset and the thickness can be well characterized by a quadratic polyno-mial.The thickness of the overburden layer is predicted by the fitted curve obtained from the experiment,with an error within±3%.Also,the prediction for thick coating is accurate,which shows that the proposed sensor has wide applicability in thickness measurement.