新型光束匀化激光红外热成像检测系统及应用

激光红外热成像检测方法具有检测距离远、检测速度快、检测结果可视化等优点,在纤维增强复合材料缺陷检测领域具有广阔的应用前景。为消除由于激光加热不均造成的检测能力较低等问题,本文提出和研究了一种基于衍射分束原理的激光光束整形和匀化方法,在此基础上开发了便携式光纤耦合光束匀化激光红外热成像检测系统,并将其应用于航空碳纤维增强复合材料结构快速检测上的应用研究,计算及实验结果表明该方法及系统大幅提升了激光光束的均匀度,有效消除了由于加热不均造成的背景噪声,提高了缺陷的检出率,可以实现对纤维增强复合材料内部分层脱粘缺陷和冲击损伤等的有效检测。与现有商用红外热成像检测系统相比,所开发系统具有更高的检测性能。

Study on new beam homogenization laser infrared thermography system and applications

Laser infrared thermography testing method has the advantages of long detection distance,fast detecton speed and visualization detection results,etc.It has a broad application prospect in the field of fiber reinforced composite defect inspection.In order to overcome the low detection ability due to the uneven laser heating,a laser beam shaping and homogenizing method based on the principle of diffraction beam splitting is proposed and studied in this paper.Based on that,a portable optical fiber coupled beam homogenization laser infrared thermography testing system is developed and applied on the research of the rapid detection of aviation carbon fiber reinforce composte structures.The calculation and experimental results show that the proposed method and devloped system can greatly improve the uniformity of the laser beam,and effectively eliminate the background noise caused by uneven laser heating.The detection rate of defects is significanly increased.The delamination defects and impact damages in both the carbon fiber laminate and carbon fiber honeycom sandwich pannel can be effectively detected.Comparing with the existing commercial infrared thermalgraphy testing system,the devloped system has higher detection performance.