线性调频激励的红外无损检测及其数值模拟

Numerical simulation of infrared technology for nondestructive testing under linear frequency modulation excitation

线性调频激励的红外检测是一种新型的红外检测技术,能弥补传统红外检测方法存在的不足,对不同的缺陷都具有较好检测的能力,为了研究相位检测法在线性调频激励下的红外检测中的应用,利用有限体积法数值模拟计算出二维瞬态导热模型,得出所建立模型在线性调频激励条件下的温度场,利用FFT变换法对模拟计算得到的材料表面温度进行信号处理,从而得到相位变化信息,得出了Chirp调制时间、加热强度、材料、缺陷深度、高度、以及宽度等因素对检测结果的影响,为线性调频激励下的红外检测法的应用提供理论支撑。

Infrared technology for nondestructive testing under linear frequency modulated excitation is a new detect technology. The shortcomings of the traditional infrared NDT methods can be avoided and different detects can be defected by this method. In order to research the application of infrared technology for nondestructive testing under linear frequency modulated excitation, a two-dimensional heat conduction model was established by finite volume method. The temperature field of the model was obtained under linear frequency modulated excitation. The FFT algorithm was applied to the surface temperature of the model and then the phase was obtained. The influences of Chirp modulation time, heating intensity, material depth, height and width on the phase difference were respectively revealed. It is important for the application of infrared technology for nondestructive testing under linear frequency modulated excitation.