Evaluation of an open source digital image correlation program for surface strain field measurement

The accuracy of an open source Digital Image Correlation (DIC) program namely Ncorr program for 2-D strain measuretnent was investigated. An experimental programwas carried out in order to characterize the mechanical properties of a carbon/epoxy composite laminate. Unidirectional standard specimens under monotonic tension uniaxial loading employed for derivation of strain- stress curves. Digital images and axial strain using an extensometer were recorded during the monotonic testing.The strain-stress curves resulted from application of the investigating DIC program were evaluated using the experimental data collected from the extensometer. As well, the strain-stress curves were compared with curves computed using a commercial software. Also the influence of one of the DIC setting parameters that usually impacts the calculation error. known as the subset radius size. on the accuracy of results was studied. The good correlation of results confirmed the reliability of the program for 2-D surface strain measurements in solid mechanics applications.