玻纤复合材料分层缺陷太赫兹无损检测技术

Terahertz Nondestructive Test of Delamination Defects in Glass-Fiber-Reinforced Composite Materials

利用时域有限差分法和太赫兹时域光谱技术对玻纤复合材料分层缺陷进行研究。首先,基于透射式太赫兹时域光谱系统获得玻纤复合材料在太赫兹波段的光学参数,并用时域有限差分法对缺陷进行数值仿真;其次,利用太赫兹时域光谱系统对提前预制的缺陷样件进行实际检测;最后,对比理论和实际检测获得的时域波形数据,对缺陷进行成像分析,发现两种方法均实现了在距离材料上表面3 mm和5 mm处对0.3 mm厚度分层缺陷的检测。结果表明:时域有限差分法可为利用太赫兹时域光谱系统检测复合材料缺陷提供理论支撑,减小对标准件的依赖性;太赫兹时域光谱系统可有效检测材料内部缺陷,可通过检测结果判断材料整体性能。

Finite-difference time-domain and terahertz time-domain spectroscopy are used to study the internal delamination defects in glass-fiber-reinforced composite materials.First,the optical parameters of the glass-fiber-reinforced composite material in the terahertz frequency band are obtained using transmission terahertz time-domain spectroscopy;the finite-difference time-domain method is used to simulate the defects.Second,a terahertz time-domain spectroscopy system is used to inspect the prefabricated sample.Finally,the defects are imaged and analyzed for comparison to the time-domain waveform data determined theoretically and through actual detection.It is found that both methods can detect delamination defects with a thickness of 0.3 mm at a distance of 3 and 5 mm from the upper surface of the materials.These results show that the finite-difference time-domain method can provide theoretical support for detecting defects in composite materials by using terahertz time-domain spectroscopy while reducing the dependence on standard components;the terahertz time-domain spectroscopy system can effectively detect internal defects of materials and assess their overall performance through the detection results.