针对人工编程数值建模进行缺陷识别反问题求解存在编程复杂、分析效率低的局限性, 提出了采用通用有限元数值计算软件Ansys结合共轭梯度算法进行二次开发对复合材料内壁不规则缺陷进行红外诊断定量识别的方法, 并引入了相对敏感系数的概念用于比较评估试件检测状态对缺陷边界形状定量识别的影响。通过相对敏感系数分析发现, 不同检测状态下内壁不规则缺陷的可检测性并不相同, 采用检测面达到最大温差时刻点的瞬态检测比稳态检测更具优越性。数值试验验证了Ansys二次开发红外诊断识别的可行性和相对敏感系数比较评估的有效性。

As to the complexity and low analysis efficiency of defect identification inverse problem solution by manual programming model, with the conjugate gradient algorithm, a method for the secondary development of the universal finite element numerical computation software Ansys was put forward in this paper, which is successfully applied to the diagnosis of the irregular inner-wall surface defect by infrared inspection. And a new concept of relative sensitivity was introduced here in order to assess the influence of inspection state to the quantitative identification of defect boundary shape. Through analyzing the relative sensitivity, it was found that the inspectability of the irregular inner-wall surface defect was different in the different inspection states, and the inspection carried out at the time with maximum inspection surface temperature difference was more desirable than that in the steady heat transfer state. Both of the feasibility of the infrared diagnosis with Ansys secondary development and the validity of the relative sensitivity assessment were verified by the numerical experiment.