ANALYSIS OF LOCALIZATION IN BRITTLE MATERIALS THROUGH OPTICAL TECHNIQUES

This paper is devoted to the experimental analysis of strain localizat ion in rock like specimens subjected to uniaxial compression. Two diff erent techniques are involved in this research: stereophotogrammetry a nd laser speckle photography. The strain fields obtained by these tech niques exhibit a homogeneous response followed by a strain localizatio n before the peak of the load verses displacement curve. These observa tions allow one to choose the appropriate mechanical constitutive equa tions to describe the behavior of such materials.