“…As done in the numerical example, the deformation gradient F was computed applying the gradient function to the displacement field obtained by DIC, afterwards, all the other quantities were derived from F (i.e., ϵ , Δ ϵ , , , , and ). More advanced derivation functions could be used to evaluate the deformation gradient and the strain field, for example, using polynomials or other approaches . However, in the present application, the gradient function is satisfactory and produce accurate strain field maps, as illustrated in Figure .…”