石英纤维增强复合材料内部孔洞缺陷的红外热成像检测有限元分析研究

Finite Element Analysis of Infrared Thermography Testing for Blind Holes of Quartz Fiber Reinforced Composite Materials

在石英纤维增强树脂基复合材料平板上钻直径和深度不同的盲孔,模拟材料内部的孔洞缺陷。采用数值模拟方式,建立了石英纤维增强复合材料盲孔缺陷平板试样三维实体模型,对盲孔缺陷平板试样红外热成像检测过程进行模拟计算,重点研究了盲孔缺陷大小、深度、分布等以及脉冲热源强度和加热时间对红外热成像检测信号的影响规律。结果表明,在一定范围内,缺陷径深比越大,最大温差越大,最大温差对比度越大,越容易被检出;脉冲热源强度越大和加热时间越长,最大温差越大,缺陷越容易被检出;最大温差对比度不随热源强度和加热时间的改变而改变,增加热源强度和加热时间并不能提高红外热成像图像上缺陷的清晰程度。

Quartz fiber reinforced resin matrix composites drilled with the blind holes of various diameters and various depths were prepared in order to simulate defects of air voids or delaminations under the surface of the material.The three-dimensional model of quartz fiber reinforced resin matrix composite plate sample with blind hole defects was established by numerical simulation.The infrared thermal imaging detection process of the plate sample with blind holes was simulated and calculated.The influence of the size,depth and distribution of blind holes,the intensity of pulse heat source and heating time on the infrared thermal imaging detection signal was mainly studied.The results indicate that increasing in a certain range,the larger the defect diameter depth ratio is,the larger the maximum temperature difference is,the easier it is to be detected,and the larger the maximum temperature difference contrast is,the clearer it is displayed in the infrared thermal imaging.The greater the intensity and heating time of the pulse heat source,the easier the defects are detected.Increasing the intensity and heating time of the pulse heat source cannot improve the clarity of defects in the infrared thermal imaging.