由于采用红外热源作为激励的无损检测受到材料对热源吸收特性的影响,将材料对红外波长的吸收系数引入到调制加热的红外无损检测研究中,建立并求解含有内热源的热传导方程,得到相位法表达缺陷信息方式,指出材料的吸收系数对温度变化有作用,对相位无影响.用有限元方法进行了三维热传导仿真,讨论了加热周期、调制频率对实验的影响,并给出结果及分析.
Absorption coefficient was used in modulated heating infrared nondestructive testing to denote the infrared absorption of material. Since the absorption of material had impact on the nondestructive testing with the excitation by infrared heating, the heat conduction equation with internal heat source was presented. The information of subsurface defect was described by phase. The surface temperature was influenced by absorption coefficient which had no effects on phase. 3D simulated results with finite element method were shown. The influences of heating periods and modulation frequency were presented. The results and analysis were given.