Notched marble plates under tension: Detecting prefailure indicators and predicting entrance to the 'critical stage'

摘要

The potentialities of the pressure stimulated currents technique to be used as a continuous structural health monitoring tool in applications related to stone monuments are assessed experimentally. The data gathered by this technique from experiments with notched marble plates submitted to direct tension are considered in juxtaposition to the respective ones provided by the acoustic emissions technique, a well-founded and widely used sensing tool. The time evolution of the pressure stimulated currents produced provides clearly distinguishable fingerprints of upcoming fracture well before visible cracking is macroscopically observed. These fingerprints are in good qualitative agreement with similar ones provided by the acoustic emissions, and therefore, they can be considered as safe prefailure indicators designating entrance to a "critical stage." Thus, the use of the pressure stimulated currents technique as an alternative structural health monitoring system appears quite promising, taking also into account the low cost and the small size of the respective sensors.