复合材料蜂窝板脉冲热像检测和调制热像检测的比较研究

Comparative study on pulsed thermography and modulated thermography of composite honeycomb panels

为了探索适合复合材料蜂窝板缺陷检测的红外热像检测法及热像信号处理方法,对蜂窝板的脉冲热像检测(PT)、调制热像检测(MT)及几种热像信号处理方法的缺陷检测能力进行了比较。在脉冲热像检测中,用脉冲相位法进行热像序列处理,并与最佳原始热像进行比较。在调制热像检测中,提出用离散傅里叶级数法和相关系数法进行热像序列处理,并与经典的四点法进行比较。研究结果表明,在蜂窝板脱粘缺陷的检测中,调制热像法的检测效果好于脉冲热像法。在调制热像法的信号处理中,离散傅里叶级数法和相关系数法的应用效果均好于四点法。在最佳调制频率下,以"调制热像-离散傅里叶级数"法进行蜂窝板脱粘缺陷的检测具有最大的缺陷探测能力。

To investigate the optimal infrared thermography testing technique and thermographic data processing methods for the flaw inspection of composite honeycomb panels,the defect detection capabilities of pulsed thermography（PT）,modulated thermography（MT） and several thermographic data processing algorithms were compared.In PT,pulsed phase thermography（PPT） was applied to the thermographic signal processing,and compared with the best raw image.In MT,discrete Fourier series（DFS） and correlation coefficient（CC） algorithm were newly proposed to process the experimental data,and compared with the classical Four-point method.The obtained results indicate that,MT is better than PT for debonding inspection of honeycomb panels.The effects of both DFS and CC are better than Four-point method for signal processing of MT.At the best modulation frequency,the MT-DFS method shows the maximum detection capability for debondings in honeycomb panels.