Infrared Damage Detection System (IDDS) for Real-Time, Small-Scale Damage Monitoring

摘要

Macroscopic damage and final failure of components subjected to repeated loading is preceded by microscopic damage accumulation in localized areas of the component material. The microscopic damage accumulation phase often comprises the majority of the life of the component. Thus, a detailed understanding of the processes involved would be invaluable for material design and life prediction. In metals, these localized damage accumulation areas are usually on the scale of the microstructure and the damage is not readily apparent. An infrared camera system has been developed to detect the radiant energy associated with local damage accumulation. This system pinpoints the location of the damage accumulation site and allows the loading to be stopped early in the damage accumulation process. The first goal is to use the system to stop mechanical testing as soon as a local damage area can be detected. This goal has been achieved and the IDDS has been used to support a number of research programs studying crack initiation. The second goal is to develop an understanding of the various phenomena that produce infrared radiation signatures and correlate them with damage accumulation mechanisms. This work is just beginning and this paper discusses our plan to meet this goal.