[SCG66-P07] Study of deformation mechanism(s) of sandstones by parallel AE signal measurement and neutron diffraction technique
Keywords:neutron diffraction, acoustic emission, rock, strain
In situ neutron diffraction measurements were undertaken using the Engineering Materials Diffractometer “TAKUMI” at J-PARC (Japan Proton Accelerator Research Complex). AE signals were measured using a PCI-2 (PHYSICAL ACOUSTIC CORP.). Three types of sandstone were tested: Berea, Tomita, and Izumi. Macroscopic strain values were recorded using a strain gauge.
The macroscopic strain of each sandstone was larger than the lattice strain. The macroscopic strain exhibited plastic deformation behavior, whereas the lattice strain exhibited elastic deformation behavior. AE signals were detected as the applied load was increased. These AE events might be related to internal structural changes. These dynamic phenomena may also explain the discrepancy between the macroscopic and lattice strain values. The characteristics of the measured AE signals varied with rock type, indicating that the deformation mechanism is a function of rock type.
In this presentation, I will provide further details of the experimental methods and present some of the more interesting data obtained from these measurements.