Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : October 08, 2016 - October 10, 2016
In recent years, fatigue limit estimation based on dissipated energy measurement has been attracting considerable attention. In this study, a system for microscopic measurements of dissipated energy was developed and this system was applied to a specimen whose grain size was greater than spatial resolution of the system to investigate the relationship between dissipated energy and microstructure in grain scale. It was revealed that measured dissipated energies were influenced by differences in emissivity due to unevenness of the black body coating on the specimen and the displacement of the specimen. Then, image process technique including a position correction of the specimen and an averaging filter was developped and its usefulness was demonstrated for reduction of the influence. The dissipated energy showed characteristic distribution for the specimen. Especially, the location where the highest dissipated energy was measured coincided with a crack initiation point. The area where high dissipated energy was measured corresponded to the area where a large number of slip bands was observed. Therefore, it was found that the system with the image process technique was able to evaluate the more detailed fatigue damage.
