The ability to understand the overall long‐term damage behaviour of crack patched components is essential to improve methods for the performance prediction. The method of passive infrared thermography comprises great opportunities to support the comprehension of the subsurface damage progress of crack‐patched structures. Quasi‐static and cyclic coupon tests are performed with patched metallic specimens and monitored with qualitative and comparative passive infrared thermography. Different test set‐ups help to differentiate between pure metallic crack growth and adhesive damage on thermal images. Results show that metallic crack growth can be monitored from the patched side, also in combination with local delamination at the patch/metal interface overlaying the crack. Thus, it is possible to evaluate position and size of the different damage types at the same time with a rather simple test set‐up. The information on the degradation progress of the crack patched component under loading conditions can help identify the driving damage mechanism of the particular repair configuration. This knowledge can in return be used in the patch design process.

中文翻译：

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使用光学红外热像仪监测裂缝修补结构中的多种损伤机制

了解裂纹修补组件的整体长期损坏行为的能力对于改进性能预测方法至关重要。被动红外热成像方法为支持理解裂缝修补结构的地下破坏进展提供了巨大的机会。准静态和循环试样测试是通过修补金属样本进行的，并通过定性和比较性被动红外热像仪进行监控。不同的测试设置有助于区分纯金属的裂纹扩展和热图像上的胶粘剂损坏。结果表明，可以从修补的一侧监测金属裂纹的生长，还可以与覆盖裂纹的修补/金属界面处的局部分层相结合。从而，可以通过相当简单的测试设置同时评估不同损坏类型的位置和大小。有关裂纹修补组件在加载条件下的降解进度的信息可以帮助确定特定维修配置的行驶损坏机理。反过来，可以在补丁设计过程中使用这些知识。