109 citations · 597 across the 40 of their papers we have counts for
40 papers
Weakly Nonlinear Dynamics of Unstable Modes in Jammed Amorphous Solids
Kota Noto, Harukuni Ikeda, Kuniyasu Saitoh +1
We investigate the structural evolution in jammed amorphous solids by analyzing the eigenmodes of a generalized Hessian matrix that incorporates spatial modulation via wave numbers…
Anomalous phonon dispersion near yielding in athermal crystals
Fumiaki Nakai, Michio Otsuki, Kuniyasu Saitoh +1
Vibrational properties of ordered athermal solids near yielding remain poorly understood. We show that yielding in a sheared crystal is governed not by a single localized instabili…
Jamming transition and normal modes of polydispersed soft particle packing
Kuniyasu Saitoh, Brian P. Tighe
The jamming transition of soft particles characterized by narrow size distributions has been well studied by physicists. However, polydispersed systems are more relevant to enginee…
Unified study of viscoelasticity and sound damping in hard and soft amorphous solids
Hideyuki Mizuno, Kuniyasu Saitoh, Yusuke Hara +1
Recent research has made significant progress in understanding the non-phonon vibrational states present in amorphous materials. It has been established that their vibrational dens…
Scaling relations between viscosity and diffusivity in shear-thickening suspensions
Abhinendra Singh, Kuniyasu Saitoh
Dense suspensions often exhibit a dramatic response to large external deformation. The recent body of work has related this behavior to transition from an unconstrained lubricated…
The role of microscopic friction in statistics and scaling laws of avalanches
Kuniyasu Saitoh
We investigate statistics and scaling laws of avalanches in two-dimensional frictional particles by numerical simulations. We find that the critical exponent for avalanche size dis…
Eigenvalue analysis of stress-strain curve of two-dimensional amorphous solids of dispersed frictional grains with finite shear strain
Daisuke Ishima, Kuniyasu Saitoh, Michio Otsuki +1
The stress-strain curve of two-dimensional frictional dispersed grains interacting with a harmonic potential without considering the dynamical slip under a finite strain is determi…
Theory of rigidity and numerical analysis of density of states of two-dimensional amorphous solids with dispersed frictional grains in the linear response regime
Daisuke Ishima, Kuniyasu Saitoh, Michio Otsuki +1
Using the Jacobian matrix, we obtain theoretical expression of rigidity and the density of states of two-dimensional amorphous solids consisting of frictional grains in the linear…
Relaxation dynamics and long-time tails explain shear-induced diffusion of soft athermal particles near jamming
Kuniyasu Saitoh, Takeshi Kawasaki
We numerically study shear-induced diffusion of soft athermal particles in two dimensions. The Green-Kubo (GK) formula is applicable to the shear-induced diffusion coefficient, whe…
Localized and extended dynamical correlation lengths in jammed packings of soft athermal disks under slow shear
Shoichi Takahata, Norihiro Oyama, Kuniyasu Saitoh
Dynamics of jammed packings of soft athermal disks under finite-rate shear are studied by means of molecular dynamics simulations. Particularly, we investigate the spatial structur…
Dynamic susceptibilities in dense soft athermal spheres under a finite-rate shear
Norihiro Oyama, Takeshi Kawasaki, Kuniyasu Saitoh
The mechanical responses of dense packings of soft athermal spheres under a finite-rate shear are studied by means of molecular dynamics simulations. We investigate the volume frac…
Structural and mechanical characteristics of sphere packings near the jamming transition: From fully amorphous to quasi-ordered structures
Hideyuki Mizuno, Kuniyasu Saitoh, Leonardo E. Silbert
Mechanically stable sphere packings are generated in three-dimensional space using the discrete element method, which span a wide range in structural order, ranging from fully amor…
Sound damping in frictionless granular materials: The interplay between configurational disorder and inelasticity
Kuniyasu Saitoh, Hideyuki Mizuno
We numerically investigate sound damping in a model of granular materials in two dimensions. We simulate evolution of standing waves in disordered frictionless disks and analyze th…
Critical scaling of diffusion coefficients and size of rigid clusters of soft athermal particles under shear
Kuniyasu Saitoh, Takeshi Kawasaki
We numerically investigate the self-diffusion coefficient and correlation length of the rigid clusters (i.e., the typical size of the collective motions) in sheared soft athermal p…
Stress relaxation above and below the jamming transition
Kuniyasu Saitoh, Takahiro Hatano, Atsushi Ikeda +1
We numerically investigate stress relaxation in soft athermal disks to reveal critical slowing down when the system approaches the jamming point. The exponents describing the diver…
Universal relaxation dynamics of sphere packings below jamming
Atsushi Ikeda, Takeshi Kawasaki, Ludovic Berthier +2
We show that non-Brownian suspensions of repulsive spheres below jamming display a slow relaxational dynamics with a characteristic time scale that diverges at jamming. This slow t…
Transition rates for slip-avalanches in soft athermal disks under quasi-static simple shear deformations
Kuniyasu Saitoh, Norihiro Oyama, Fumiko Ogushi +1
We study slip-avalanches in two-dimensional soft athermal disks by quasi-static simulations of simple shear deformations. Sharp drops in shear stress, or slip-avalanches, are obser…
Elastic wave propagation in dry granular media: effects of probing characteristics and stress history
Hongyang Cheng, Stefan Luding, Kuniyasu Saitoh +1
Elastic wave propagation provides a noninvasive way to probe granular materials. The discrete element method using particle configuration as input, allows a micromechanical interpr…
Rotational sound in disordered granular materials
Kuniyasu Saitoh, Rohit K. Shrivastava, Stefan Luding
We employ numerical simulations to understand the evolution of elastic standing waves in disordered frictional disk systems, where the dispersion relations of rotational sound mode…
Non-local effects in inhomogeneous flows of soft athermal disks
Kuniyasu Saitoh, Brian P. Tighe
We numerically investigate non-local effects on inhomogeneous flows of soft athermal disks close to but below their jamming transition. We employ molecular dynamics to simulate Kol…
Avalanche Interpretation of the Power-Law Energy Spectrum in Three-Dimensional Dense Granular Flow
Norihiro Oyama, Hideyuki Mizuno, Kuniyasu Saitoh
Turbulence is ubiquitous in nonequilibrium systems, and it has been noted that even dense granular flows exhibit characteristics that are typical of turbulent flow, such as the pow…
A microscopic theory for discontinuous shear thickening of frictional granular materials
Kuniyasu Saitoh, Hisao Hayakawa
We extend a recent theory for the rheology of frictionless granular materials [K. Suzuki and H. Hayakawa, Phys. Rev. Lett. 2015, 115, 098001] to the case of frictional disks in two…
Elastic Moduli and Vibrational Modes in Jammed Particulate Packings
Hideyuki Mizuno, Kuniyasu Saitoh, Leonardo E. Silbert
When we elastically impose a homogeneous, affine deformation on amorphous solids, they also undergo an inhomogeneous, non-affine deformation, which can have a crucial impact on the…
A master equation for force distributions in soft particle packings - Irreversible mechanical responses to isotropic compression and decompression
Kuniyasu Saitoh, Vanessa Magnanimo, Stefan Luding
Mechanical responses of soft particle packings to quasi-static deformations are determined by the microscopic restructuring of force-chain networks, where complex non-affine displa…