Digital image correlation for large strain

Abstract

Due to their high deformability, the elastomers are widely used in various fields of applications. Their hyper-elastic behavior requires means of characterization adapted to contactless, high strain as well as heterogeneous strain field. Digital Image Correlation (DIC) have been used to characterize such material. In case of large strain it might be necessary to re-actualize the reference image to compute the displacement field on every images of the test. Different strategy to apply DIC in large strain are presented. The direct addition of the successive calculated displacement leads to inconsistent results, it is required to make a composition of the successive calculated displacements. Some artefacts due to the multiple interpolation are highlighted and may leads to filter the results. In case of high strain gradients, a method with very small element size and median filter applied directly in correlation process has been used highlighting the ability of large strain DIC in heterogeneous media.