红外热波无损检测中材料表面下缺陷类型识别的有限元模拟及分析

Finite element simulation and analysis for type identification of defects under material surfaces in infrared thermal wave nondestructive detection

鉴于红外热波无损检测中被检测物的形状、尺寸、材料和缺陷类型的不同,为给红外热波无损检测提供前期实验结果的预演,利用大型有限元分析软件ANSYS选择3种热特性差异较大的均匀材料,设计了三维模型。利用软件的前处理器和通用后处理器,绘出不同时刻模型表面的温度场分布,以此确定温度分布材料缺陷的类型。通过对模拟数据进行分析,绘出不同缺陷的温度变化曲线。根据曲线斜率的不同,可定性确定缺陷的类型。模拟结果说明:大型有限元分析软件ANSYS可用于红外热波无损检测实验过程的模拟,模拟结果与实验结果相符。该方法可用于其他不同缺陷类型的模拟及定量识别。

Since the shape, size, material and defect of UUT in the infrared thermal wave nondestructive detection are different, three types of uniformity materials with different characteristics were selected by means of the finite element analyze software （ANSYS）, and a 3-D sample model was designed to provide the detection with preview of the previous experiment result. The temperature field profiles of the model surface are drawn at different times with the preprocessor and general postprocessor of the software, and then the defect types are confirmed according to the given temperature distribution diagrams. The curves of temperature variation of different defects are drawn based on the analysis of the simulated data. The defect types are determined according to the different slope of the curves. The simulation result indicates that the finite element analyze software can be used for nondestructive evaluation, the simulation result matches with the experiment one. The method can be extended to the detection and the quantitative identification for other kinds of defects under material surfaces.