本文的目的在于探索一种新的适用于红外热波检测技术的热激励方式一太赫兹(THz)热激励.文中介绍了THz波周期性热激励的热传导理论模型;尝试利用返波振荡器(返波管backward wave oscillator,BWO)太赫兹源对一块碳纤维基底吸波涂层板进行周期性THz热激励,红外热像仪连续观测和记录试件表面温场变化,Canny边缘算法处理热图像显示缺陷;检测结果与闪光灯脉冲激励的结果进行比较,讨论了太赫兹波激励红外热波检测技术可能的优势.实现了THz技术与红外热波无损检测技术的结合.
This work aims at developing a new excitation method for thermal wave nondestructive test(NDT)-Terahertz excitation.In the paper we introduce a theoretical model of heat conduction for periodical THz excitation.BWO(backward wave oscillator) terahertz source is employed to heat a carbon fiber plate with wave absorbing coating,surface temperature variations and distributions are captured by an infrared camera,and Canny edge algorithm is used to process thermal images to show the defects.Result of flash pulse thermography serves as comparison,and the advantages of THz thermal wave NDT are discussed.The combination of THz technology and infrared thermal wave NDT is realized.