An Approach to Wide Range Strain Measurement by Bi-sensitive Speckle Interferometry and Digital Image Correlation

Abstract

An approach to a wide range strain measurement by combining digital image correlation and bi-sensitive speckle interferometry is proposed. A center notched pure aluminum specimen subjected to a tensile load is used to observe an elastoplastic deformation field. Both the minute strain and the intermediate strain are measured by bi-sensitive speckle interferometry. The large strain is measured by digital image correlation. A data region of the intermediate strain is placed in data regions between the minute strain and the large strain. By combining these data groups using local least squares, a continuous strain distribution of the elastoplastic deformation can be obtained.