Low-cost two-dimensional digital image correlation system

A low-cost digital image correlation (DIC) system for measuring two-dimensional displacement fields is described. Using an off-the-shelf camera, lens, and open-source DIC analysis software, displacement fields in aluminum and steel dog-bone tensile specimens were measured. Correction for out-of-plane motion is used to obtain strains from the displacement fields. Proposed DIC strain measurement system is validated using conventional thin-film strain gauges for strains below 1%. Average strain measurements from the DIC system were found to be within 1% of the measurement obtained using strain gauges. For strains between 1% and 10%, strain histories from the DIC systems displayed excellent correlation with strain measurements obtained using an extensometer.