On the Meso-Macro Scale Deformation of Low Carbon Steel

Abstract

The multiscale deformation response of low carbon steel is investigated. The meso and macro scale displacement and strain fields for specimen subjected to pure tension are measured using in-situ multiscale digital image correlation technique. The specimen is specked with different scale pattern ranging from 5 to 500 μm size. The smallest scale, 5 μm, speckles are used for local meso-scale deformation measurement. In this case an optical microscope is used to record the local information within 1 mm square field of view. On the other hand, the larger size, 500 μm, speckles are used to measure the continuum level deformation. In this case two digital cameras with 5 megapixel resolution are used in 3D arrangement by considering the entire width of the specimen inside the field of view. Both the optical microscope and the digital camera systems are triggered simultaneously to acquire the deformation at the same time scale. The displacement and strain fields are extracted using digital image correlation. The effect of local deformation on the overall displacement and strain of low carbon steel is presented by comparing with the macro scale deformation and strain fields. Furthermore, microstructure images are obtained by optical microscope and used for the analysis of local strain field coupled with the strain field from digital image correlation.