"Seismology" for granular particles under shear

Cheng-En Tsai^2,1*, Jih-Chiang(JC) Tsai¹

¹Institute of Physics, Academia Sinica, Taipei, Taiwan
²Department of Physics, National Taiwan University, Taipei, Taiwan

* Presenter:Cheng-En Tsai, email:danner04290429@gmail.com

Intermittency in granular matter, a burst of particle displacements and sudden release of stress, sets the flow of such material apart from that of ordinary fluids. Through numerical methods, we have established a state diagram for a shear flow of soft particles, with the speed-dependence of interparticle friction taken into account. The two-parameters state diagram spans over the packing fraction and a dimensionless shearing rate, and exhibits two types of intermittency that we called quaking[arXiv:2211.14187]. Here we extend our numerical experiments and draw an analogy to Seismology: Each quake is characterized by the abrupt change of the force moment enclosing the “fault”. Such analogy allows us to establish a landscape of the magnitude over the state diagram, and to seek potential connection between our numerical experiments and the studies of earthquake.

Keywords: Granular flow, Intermittency , Earthquakes, Seismology