【摘要】 利用红外热像仪对建筑外墙饰面砖饰面层内部缺陷进行检测试验,研究饰面层在太阳辐射下的表面温度随时间、空间的分布及变化规律,分析内部缺陷的厚度、大小、饰面砖颜色以及红外热像仪的竖向拍摄角度和发射率等因素对红外热成像效果的影响。试验结果表明,厚度越大、面积越大的内部缺陷越容易被检测出;存在内部缺陷的深色饰面砖缺陷部位与完好部位间的表面温差较浅色的明显偏高;沿内部缺陷宽度方向的饰面层表面温度关于其中心最大温度点呈近似对称关系;饰面层表面温度随着红外热像仪竖向拍摄角度和发射率的增大而减小,但不同拍摄角度下同一路径上的表面温度-位置曲线近似平行。基于试验结果,提出红外热像法检测饰面砖饰面层内部缺陷大小的估算方法,并建立了缺陷面积的估算公式,可供后续相关研究及实际工程应用参考。更多还原

【Abstract】 Thermal infrared imager is used to detect the internal defects of exterior wall decoration. The distribution and variation law of surface temperature on finish coat heated by external heating source with time and space are studied,and the influences of thickness and area of defects,tile color,the vertical shooting angel and emissivity of thermal infrared imager on image quality are analyzed. It is shown that thicker and bigger internal defects can be detected more easily.The surface temperature difference between defect area and undamaged area is obvious. The surface temperature at internal defect location is maximum temperature point of approximate symmetry along with width direction. The surface temperature of finish coat decreases with vertical shooting angel and emissivity of thermal infrared imager,but surface temperature-position curves of the same path are parallel approximately under different shooting angels. Based on the test results,estimation method of internal defect size by thermal infrared imager is proposed,and the estimation formula of internal defects area is established. The proposed method and formula can provide reference for future scientific research and engineering application.更多还原