碳纤维混凝土电热红外无损检测的灵敏性分析

Sensitivity Analysis for the Infrared Non-destructive Inspection of Electro-thermal Carbon Fiber Reinforced Concrete

利用碳纤维混凝土的电热效应,在电致发热的情况下,对含预制裂纹的碳纤维混凝土缺陷体进行红外无损检测,检测的灵敏性在于缺陷体被检表面上的最大温差。在建立了有内热源的热传导理论分析模型的基础上,采用有限元的方法计算得到了电热碳纤维混凝土缺陷体的表面温度分布及其最大温差,分析表明随材料电阻率的降低和裂纹逐步加深,检测灵敏性显著提高,为优化和评估电热红外检测方案提供了重要的数值依据。

By making use of the electro-thermal effect of the material, cracks in carbon fiber-reinforced concrete can be inspected with infrared thermal image system. The inspection sensitivity relies on the maximum difference of temperature on the observed surface. A heat-transfer theoretical model for this electro-thermal analysis is developed involving internal heat sources. Based on the model, finite element method is adopted to compute the surface temperature distribution of the defective body and the corresponding difference of the surface temperature. The numerical results show that the sensitivity increases with the electrical resistivity of the material reduced. Also the sensitivity increases with the crack deepened. These results are helpful to evaluate and optimize the inspection.