应用量纲分析与热图像的板缺陷深度检测

Detection of Depth Plate Defect Based on Dimensional Analysis and Thermal Image

利用量纲分析与板的红外热图像相结合,提出板缺陷深度的定量检测方法.建立了缺陷板的热分析有限元模型,并由已知实验数据对模型进行验证.在此基础上,分析缺陷与完好处峰值温差时间的影响因数,采用量纲分析推导影响因数与峰值温差时间的对应关系,利用热分析有限元模型仿真数据进行拟合,获得板缺陷深度和半径与峰值温差时间之间的函数关系式,相比于其他定义温差法,提出的方法以峰值温差时间为缺陷特征,更具全面性.结果表明,提出的方法能较为准确地检测板的缺陷深度.

A method combining dimensional analysis with thermal image is proposed to quantitatively detect the defect depth of plates. The thermal analysis model of defective plates is built with the finite element method and verified by the known experimental data. Then,the influence factors of the time of maximum temperature difference between the defective and intact parts are analyzed and the corresponding relationship between the time and the factors is derived by means of dimensional analysis. The corresponding relationship is formulated by fitting the simulation data of the thermal analysis model. Compared with the other defined temperature difference methods,the proposed method is more comprehensive,which could detect the defect depth of plates more accurately,as the result shows.