Assessing the acoustic activity in marble specimens under stepwise compressive loading

The acoustic activity monitored during stepwise compression of prismatic marble specimens is analyzed in terms of an alternative, recently introduced approach (based on the interevent time intervals) denoted as the F-function. Attention is paid to the temporal evolution of this function during the constant-stress phase of the loading scheme, in an attempt to detect entrance of the loaded element to its critical state (ie, to the state of impending fracture). It is proven that the F-function offers valuable information concerning the level of internal damage. Moreover, it is concluded that well before the final fracture of the specimens, the F-function exhibits well distinguishable characteristics that could be considered as reliable prefailure indicators. © 2019 John Wiley & Sons, Ltd.