Abstract
A dynamic process in tensile experiment of austenitic stainless steel was observed by digital speckle pattern interferometry (DSPI) which enables us to observe entire process of whole field deformation. In plastic deformation state, localized deformation appeared as concentrated correlation fringes in a narrow band, which run over the specimen repeatedly. Correspondingly, a stress curve took some hills. In microscopic surface observation of a fractured specimens, martensite were found together with collapsed grain. It means that strain-induced martensitic transformation generates in part in heterogeneous structure of the material. These phenomena vary depending on carbon content. Dynamic DSPI presented here is expected as a new tool to invenstigate dynamic behavior of plastic deformation and fracture.
