FRLP - I+D+i - GRUPOS UTN
http://hdl.handle.net/20.500.12272/1744
2024-03-28T23:56:41ZSelf-assembly of self-propelled magnetic grains
http://hdl.handle.net/20.500.12272/10110
Self-assembly of self-propelled magnetic grains
In this work, we study bidisperse mixtures of self-propelled magnetic particles of di erent shapes
via discrete element method simulations. We show how these particles self-assemble into clusters and how these clusters depend on the ratio of the mixture, the magnetic interaction, and the shape of the grains. It is found that the mix ratio of the system controls the cluster size. Besides, the intensity of the magnetic dipoles and the shape of the grains in the mixture rule the average number of neighbors in contact and the shape of the clusters. By varying the intensity of the interactions, globular, linear and branched clusters were obtained.
2021-01-01T00:00:00ZOn the use of magnetic particles to enhance the flow of vibrated grains through narrow apertures
http://hdl.handle.net/20.500.12272/10108
On the use of magnetic particles to enhance the flow of vibrated grains through narrow apertures
The ow of grains through narrow apertures posses an extraordinary challenge: clogging. Strategies to alleviate the effect of clogging, such as the use of external vibration, are always part of the design of machinery for the handling of bulk materials. It has recently been shown that one way to reduce clogging is to use a small fraction of small particles as an additive. Besides, several works reported that self-repelling magnetic grains can
ow through narrow apertures with little clogging, which suggest these are excellent candidates as \lubricating" additives for other granular materials. In this work, we study the effect of adding self-repelling magnetic particles to a sample of grains in two-dimensions.
We find that, in contrast with intuition, the added magnetic grains not necessarily aid the
ow of the original species.
2021-06-28T00:00:00ZIntruder in a two-dimensional granular system: effects of dynamic and static basal friction on stick-slip and clogging dynamics
http://hdl.handle.net/20.500.12272/10090
Intruder in a two-dimensional granular system: effects of dynamic and static basal friction on stick-slip and clogging dynamics
We discuss the results of simulations of an intruder pulled through a two-dimensional granular system
by a spring, using a model designed to lend insight into the experimental findings described by Kozlowski
et al. [Phys. Rev. E 100, 032905 (2019)]. In that previous study the presence of basal friction between
the grains and the base was observed to change the intruder dynamics from clogging to stick–slip. Here
we first show that our simulation results are in excellent agreement with the experimental data for a variety of experimentally accessible friction coefficients governing interactions of particles with each other and with boundaries. Then, we use simulations to explore a broader range of parameter space, focusing on the friction between the particles and the base. We consider a range of both static and dynamic basal friction coefficients, which are difficult to vary smoothly in experiments. The simulations show that dynamic friction strongly affects the stick–slip behaviour when the coefficient is decreased below 0.1, while static friction plays only a marginal role in the intruder dynamics.
2019-10-15T00:00:00ZTwo approaches to quantification of force networks in particulate systems
http://hdl.handle.net/20.500.12272/10089
Two approaches to quantification of force networks in particulate systems
The interactions between particles in particulate systems are organized in ‘force networks’,
mesoscale features that bridge between the particle scale and the scale of the system as a whole.
While such networks are known to be crucial in determining the system wide response, extracting
their properties, particularly from experimental systems, is difficult due to the need to measure
the interparticle forces. In this work, we show by analysis of the data extracted from simulations
that such detailed information about interparticle forces may not be necessary, as long as the
focus is on extracting the most dominant features of these networks. The main finding is that a
reasonable understanding of the time evolution of force networks can be obtained from incomplete information such as total force on the particles. To compare the evolution of the networks based on
the completely known particle interactions and the networks based on incomplete information (total
force each grain) we use tools of algebraic topology. In particular we will compare simple measures
defined on persistence diagrams that provide useful summaries of the force network features.
2021-02-24T00:00:00Z