Recording the mechanical response and fracture of marble DENT specimens using modern sensing techniques

The mechanical response and fracture of Double Edged Notched Tensile (DENT) specimens, made of Dionysos marble, is studied in an effort to enlighten the mechanisms activated before and during catastrophic crack initiation and propagation in pre-cracked structures. The innovation of the study is that four modern sensing techniques, both contact and non-contact, are used simultaneously to monitor the response of the specimens, in the direction of pumping real-time data from both the surface and the interior of them. The analysis of these data, permitted comparative assessment of the efficiency of the techniques used and indicated that they provide clear and in mutual agreement signs, which precede the onset of crack initiation and can be considered as pre-failure indicators.