Experimental characterization of meso-scale deformation mechanisms and the RVE size in plastically deformed carbon steel

The local deformation response of low carbon steel subjected to uniaxial tensile loading is investigated, and the local strain field at sub-grain scale is obtained using high-spatial-resolution digital image correlation. The implemented digital image correlation method enables the observation and study of inhomogeneous deformation response at microstructural levels. Detailed local deformation mechanisms including mesoscopic slip bands are captured. Furthermore, the local information is used for the determination of representative volume element size in polycrystalline low carbon steel. To obtain the representative volume element size, we proposed and successfully implemented a strain variation method. Further, the influence of global strain on the local deformation mechanisms and representative volume element size is discussed. The challenges associated with the local strain measurement using digital image correlation are also discussed.