501 citations · 2k across the 54 of their papers we have counts for
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Structural transitions in jammed asymmetric bidisperse granular packings
Juan C. Petit, Matthias Sperl
We study the local structural changes along the jamming transitions in asymmetric bidisperse granu\-lar packings. The local structure of the packing is assessed by the contact orie…
Granular piston-probing in microgravity: powder compression, from densification to jamming
Olfa D'Angelo, Anabelle Horb, Aidan Cowley +2
The macroscopic response of granular solids is determined by the microscopic fabric of force chains, which, in turn, is intimately linked to the history of the solid. To query the…
Dynamical yield criterion for granular matter from first principles
O. Coquand, M. Sperl
We investigate, using a recently developed model of liquid state theory describing the rheology of dense granular flows, how a yield stress appears in granular matter at the yieldi…
Bulk Modulus along Jamming Transition Lines of Bidisperse Granular Packings
Juan C. Petit, Nishant Kumar, Stefan Luding +1
We present 3D DEM simulations of bidisperse granular packings to investigate their jamming densities, , and dimensionless bulk moduli, , as a function of the size ratio, $δ…
Granular rheology: a tale of three time scales
Olivier Coquand, Wolf Till Kranz, Matthias Sperl
We adapt statistical models of the physics of complex fluids to study the rheology of granular liquids. This allows us to provide laws of granular rheology based on first principle…
Velocity Distribution of a Homogeneously Cooling Granular Gas
Peidong Yu, Matthias Schröter, Matthias Sperl
In contrast to molecular gases, granular gases are characterized by inelastic collisions and require therefore permanent driving to maintain a constant kinetic energy. The kinetic…
Persistent anti-correlations in Brownian dynamics simulations of dense colloidal suspensions revealed by noise suppression
Suvendu Mandal, Lukas Schrack, Hartmut Löwen +2
Transport properties of a hard-sphere colloidal fluid are investigated by Brownian dynamics simulations. We implement a novel algorithm for the time-dependent velocity-autocorrelat…
Acoustic Waves in Granular Packings at Low Confinement Pressure
Karsten Tell, Christoph Dreißigacker, Alberto Chiengue Tchapnda +2
Elastic properties of a granular packing show nonlinear behavior determined by its discrete structure and nonlinear inter-grain force laws. Acoustic waves show a transition from co…
Additional transition line in jammed asymmetric bidisperse granular packings
Juan C. Petit, Nishant Kumar, Stefan Luding +1
We present numerical evidence for an additional discontinuous transition inside the jammed regime for an asymmetric bidisperse granular packing upon compression. This additional tr…
Temperature Expansions in the Square Shoulder Fluid II: Thermodynamics
O. Coquand, M. Sperl
In a companion paper, we derived analytical expressions for the structure factor of the square-shoulder potential in a perturbative way around the high- and low-temperature regimes…
Distinguishing noisy crystalline structures using bond orientational order parameters
Jan Haeberle, Matthias Sperl, Philip Born
The bond orientational order parameters originally introduced by Steinhardt \emph{et. al.} [Phys. Rev. B \textbf{28}, 784 (1983)] are a common tool for local structure characteriza…
Double origin of stochastic granular tribocharging
Jan Haeberle, André Schella, Matthias Sperl +2
The mechanisms underlying triboelectric charging have a stochastic nature. We investigate how this randomness affects the distributions of charges generated on granular particles d…
Kinetic theory for strong uniform shear flow of granular media at high density
W. Till Kranz, Matthias Sperl
We discuss the uniform shear flow of a fluidized granular bed composed of monodisperse Hertzian spheres. Considering high densities around the glass transition density of inelastic…
Rheology of inelastic hard spheres at finite density and shear rate
W. Till Kranz, Fabian Frahsa, Annette Zippelius +2
Considering a granular fluid of inelastic smooth hard spheres we discuss the conditions delineating the rheological regimes comprising Newtonian, Bagnoldian, shear thinning, and sh…
Glassy Dynamics of Brownian Particles with Velocity-Dependent Friction
Anoosheh Yazdi, Matthias Sperl
We consider a two-dimensional model system of Brownian particles in which slow particles are accelerated while fast particles are damped. The motion of the individual particles are…
Enhanced granular medium-based tube press hardening
Hui Chen, Sigrid Hess, Jan Haeberle +5
Active and passive control strategies of internal pressure for hot forming of tubes and profiles with granular media are described. Force transmission and plastic deformation of gr…
Probing density waves in fluidized granular media with diffusing-wave spectroscopy
Philip Born, Steffen Reinhold, Matthias Sperl
Density waves are characteristic for fluidized beds and affect measurements on liquid-like dynamics in fluidized granular media. Here, the intensity autocorrelation function as obt…
Drop tower setup for dynamic light scattering in dense gas-fluidized granular media
Philip Born, Johannes Schmitz, Michael Bussmann +1
Investigation of dynamics in dense granular media is challenging. Here we present a setup that facilitates gas fluidization of dense granular media in microgravity. The dynamics is…
Cut-off nonlinearities in the low-temperature vibrations of glasses and crystals
Hideyuki Mizuno, Leonardo E. Silbert, Matthias Sperl +2
We present a computer simulation study of glassy and crystalline states using the standard Lennard-Jones interaction potential that is truncated at a finite cut-off distance, as is…
Thinning and thickening in active microrheology
Ting Wang, Matthias Sperl
When pulling a probe particle in a many-particle system with fixed velocity, the probe's effective friction, defined as average pulling force over its velocity, $γ_{eff}:=\langle F…
Spatial Distributions of Local Elastic Moduli Near the Jamming Transition
Hideyuki Mizuno, Leonardo E. Silbert, Matthias Sperl
Recent progress on studies of the nanoscale mechanical responses in disordered systems has highlighted a strong degree of heterogeneity in the elastic moduli. In this contribution,…
Multiple higher-order singularities and iso-dynamics in a simple glass-former model
Nicoletta Gnan, Gayatri Das, Matthias Sperl +2
We investigate the slow dynamics of a colloidal model with two repulsive length scales, whose interaction potential is the sum of a hard-core and a square shoulder. Despite the sim…
Granular Structure Determined by Terahertz Scattering
Philip Born, Nick Rothbart, Matthias Sperl +1
Light-scattering in the terahertz region is demonstrated for granular matter. A quantum-cascade laser is used in a benchtop setup to determine the angle-dependent scattering of sph…
Active Microrheology of Driven Granular Particles
Ting Wang, Matthias Grob, Annette Zippelius +1
When pulling a particle in a driven granular fluid with constant force , the probe particle approaches a steady-state average velocity . This velocity and the correspond…