Measurements of time-dependent stress distribution on material after HP impact

Kawai, Masayoshi*; Futakawa, Masatoshi  ; Naoe, Takashi   ; Xu, C.-N.*; Yamada, Hiroshi*

We have proposed a sophisticated novel method of the SHB experiment to measure the time-dependent local strain distributions on a surface of the specimen by using mechanoluminescent materials combined with a high-speed camera and an image intensifier. The feasibility study was made for the aluminum specimens pasted with a typical mechanoluminescent material -Eu doped SrAlO film, in order to obtain the fundamental data for the method. Our results showed that SrAlO: Eu emitted lights as a response to the strain. Rise up of the light intensity was swift enough to follow the strain change due to HP impact. The luminescence intensity was experimentally verified and expressed as product of strain and strain rate. Accordingly, it can be said that this method gives a good tool for measuring time variation of local strain distributions.