Damage evolution in marble under uniaxial compression monitored by Pressure Stimulated Currents and Acoustic Emissions

Ilias Stavrakas,Stavros Kourkoulis,Dimos Triantis

doi:10.3221/igf-esis.50.48

Abstract

The spatiotemporal evolution of damage in marble specimens under uniaxial compression is monitored using Pressure Stimulated Currents (PSCs) and Acoustic Emissions (AEs). The novelty of the study is the use of an integrated grid of sensors (instead of a single pair of electrodes) to detect the weak electrical signals, emitted during loading. The use of such a grid of sensors does indeed enhance the capabilities of the PSC technique providing valuable information about the initiation and propagation of micro-fracturing at the interior of the specimens. The experimental results indicate that both the improved b-value of the AE hits and the energy of the PSCs offer information about the proximity of the applied stress to that causing fracture. It is thus concluded that both quantities could be considered as pre-failure indicators.

Highlights

E nlightening the spatiotemporal evolution of damage at the interior of structural elements under mechanical load is an interesting, though demanding, task of Mechanics of Materials and Engineering
ISpatiotemporal variation of the Pressure Stimulated Currents (PSCs) n previously published studies, in which the PSC technique was employed, a single pair of electrodes was used as sensing tool
The fact that during the loading branch of the first loading loop the PSC emission is initially recorded stronger by channels 1, 2 and 3 indicates that for the specific specimen mechanical damage starts in the vicinity of its central cross section and it is gradually developed towards its bases

Summary

Introduction

E nlightening the spatiotemporal evolution of damage at the interior of structural elements under mechanical load is an interesting, though demanding, task of Mechanics of Materials and Engineering. The two sensing techniques mentioned above (AE, PSC) are here employed in a combined manner in order to monitor damage evolution within Dionysos marble specimens subjected to uniaxial compression until fracture.

Results

Conclusion