[S-CG49] Innovation through the Integration of Solid Earth Science and Materials Science

[SCG49-02] Oscillation properties of microcrack-bearing α-quartz derived from molecular dynamics simulations

*Ikuchi Funahashi¹, Ryo Kobayashi², Satoshi Ohmura³, Kenji Kawai¹ (1.University of Tokyo, 2.Nagoya Institute of Technology, 3.Hiroshima Institute of Technology)

Keywords:microcrack, molecular dynamics, simulation

Microcracks in rock affect the physical properties of the rock, such as elastic wave velocity and attenuation. Although crack face movement is considered a fundamental source of such an effect, observing it in situ is still difficult. The classical molecular dynamics (MD) method, which computationally investigates the time evolution of atom systems regarding them as classical particle systems, makes it possible to simulate microscopic processes concealed from observation and is widely used to discuss their effects. As for cracks, a sufficient number of crack growth simulations have been conducted, making use of MD’s relative ease in handling bond breakage, while fewer focused on the kinematics of pre-existing crack faces. In our research, we observe the behavior of an α-quartz sample bearing a cavity that imitates a microcrack in MD simulations and explore the oscillation phenomenon which takes place there. Oscillation properties of the microcrack-bearing sample derived from simulation results are expected to be closely related to elastic waves emitted from or scattered at cracks. We will show the simulation results and discuss their relationships with experimentally observed phenomena.