粘钢加固混凝土脱粘缺陷的红外相位检测

Infrared Phase Detection of Debonding Defect of Concrete Strengthened by Bonded Steel Plate

为了实现对粘钢加固混凝土脱粘缺陷的红外相位检测,依据传热学原理建立了相应的检测模型,利用有限体积法得到了检测表面温度,然后通过快速傅里叶变换(Fast Fourier Transform,FFT)获得了相位分布数据,并研究了检测表面相位差与钢材厚度、缺陷宽度、缺陷厚度以及热流强度的关系。结果表明,在一定的缺陷大小下,当钢材厚度增大时,检测表面相位差的最大值将减小;在一定的钢材和缺陷厚度下,当缺陷宽度增加时,检测表面相位差的最大值将增大;在一定的钢材厚度和缺陷宽度下,当缺陷高度增大时,检测表面相位差的最大值会有一定程度的增大,但是增加量较小;在一定的钢材厚度和缺陷大小下,当热流强度增大时,检测表面的相位差基本无变化。研究结果为粘钢加固混凝土脱粘缺陷的红外相位检测提供了理论依据。

In order to realize the infrared phase detection of debonding defects of concrete strengthened by bonded steel plate,the detection model is established according to the theory of heat transfer.The surface temperature is obtained by using the finite volume method,and the phase distribution is obtained by FFT.The relationship between phase difference and steel thickness,defect width,defect thickness as well as heat flux intensity is studied.The results show that the maximum value of phase difference decreases when the steel thickness increases with a certain defect size.For a given thickness of the steel plate and defect,the maximum value of phase difference increases with the increase of defect width.With a certain thickness of steel plate and defect width,when the defect height increases,the maximum value of detected surface phase difference increases to a certain extent,but the increase is small.Under certain steel thickness and defect size,the phase difference of the detected surface is almost unchanged when the heat flux increases.The results provide a theoretical basis for infrared phase detection of debonding defects of concrete strengthened by bonded steel plate.