**3.2 Digital image correlation**

For mode I, a series of images is taken with a CCD camera and digitalized and then compared to the reference image. It has been verified that in Mode I loading, the crack surfaces separate symmetrically and the crack front propagates in the direction of the crack plane (**Figure 7**).

*Combination of Numerical, Experimental and Digital Image Correlation for Mechanical… DOI: http://dx.doi.org/10.5772/intechopen.99357*
