三维试件固定深度内热源几何分布识别研究

Geometry Identification of Fixed-depth Internal Heat Sources in Three-dimensional Test-piece Based on Surface Temperature Measurement

基于表面测温技术的传热反问题研究是红外无损检测技术从定性到定量发展的理论基础,同时也是其中一个重点和难点问题。为了研究三维试件固定深度上内热源的几何分布问题,通过将三维试件简化为一维模型,建立了一维问题中检测表面温度和内部固定深度的内热源的解析解关系。然后利用改进的一维修正算法对内热源不断进行修正,在给定的收敛条件下得到三维试件固定深度上的内热源的分布,使得计算温度的分布和检测温度的分布吻合得最好。数值实验结果表明,该方法具有有效性和简便性。

The inverse heat conduction problem based on surface temperature measurement is not only the key theoretical basis for the quantitative development of thermographic nondestructive techniques, but also an important and difficult issue. To identify the geometry of fixed-depth internal heat sources in a three-dimensional test-piece, the three-dimensional test-piece is simplified to a one-dimensional model so that establishing the relationship between the measured temperature and the internal heat sources in one-dimensional problem. The internal heat sources obtained can be corrected by the modified one- dimensional correction method until reaching the stopping criterions thus the result identified can make the error between the calculation temperature distribution and measured temperature distribution to be minimum. Numerical test cases show that the method is effective and simple.