ESPCI web site
Le séminaire hebdomadaire du laboratoire PMMH a lieu tous les vendredis à 11h, au premier étage Barre Cassan, campus Jussieu (plan).
Stéphane Perrard
Etienne Reyssat
Virgile Thiévenaz
PMMH
BARRE CASSAN
BAT A 1ER ETAGE CASE 18
7 QUAI SAINT BERNARD
75005 PARIS
France
Tel : (33) 1 40 79 45 22
Hans Herrmann (ETH Zürich)
Packing of wires in cavities and growing surfaces
We investigate the morphologies and maximum packing density of thin wires packed into spherical cavities.
Using simulations and experiments with nylon lines, we find that ordered as well as disordered structures emerge,
depending on the amount of internal torsion. We find that the highest packing densities are achieved in a low torsion
packing for large systems, but in a high torsion packing for small systems. An analysis of both situations is given
in terms of energetics and comparison is made to analytical models of DNA packing in viral capsids. In two dimensions
we also find different morphologies and present the associated morphological phase diagram based on experiments
with metallic wires and confirmed by numerical simulations using discrete elements. During crumpling, the number
of loops increases according to a power-law with different exponents in each morphology. Furthermore,
we observe a power-law divergence of the structure's bulk. We also investigate the morphology of thin discs and rings
growing in circumferential direction. Recent analytical results suggest that this growth produces symmetric excess cones (e-cones).
We study the stability of such solutions considering self-contact and bending stress. Contrary to what was assumed
in previous analytical solutions, beyond a critical growth factor, no symmetric e-cone solution is energetically minimal any more.
Instead, we obtain skewed e-cone solutions having lower energy, characterized by a skewness angle and repetitive spiral winding
with increasing growth. These results are generalized to discs with varying thickness and rings with holes of different radii.
Experiments with cardboard confirm the simulations.
Séminaires (5)
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Séminaire PMMH - Julien Scheibert (LTDS, EC Lyon)
Vendredi 16 mai de 11h00 à 12h00 - Salle réunion PMMH 1
Metainterfaces : how to design a rough contact that obeys a specific friction law ?
Many devices, including touchscreens and robotic hands, involve frictional contacts. Optimizing those devices requires fine control of the interface's friction law. We lack systematic methods to create dry contact interfaces whose frictional behaviour satisfies preset specifications. In this seminar, I will present (…) -
Séminaire PMMH - Francesca Borghi Università degli Studi di Milano
Vendredi 20 juin de 11h00 à 12h00 - Salle réunion PMMH 1
REPROGRAMMABLE HARDWARE FOR DATA PROCESSING AT THE EDGE : A NEW COMPUTING PARADIGM BASED ON NEUROMORPHIC SYSTEMS
The brain's ability to perform efficient and fault-tolerant data processing is strongly related with its peculiar interconnected adaptive architecture, based on redundant neural circuits interacting at different scales. By emulating the brain's processing and learning mechanisms, computing technologies strive to (…) -
Séminaire PMMH - Francesca Borghi Università degli Studi di Milano
Vendredi 20 juin de 11h00 à 12h00 - Salle réunion PMMH 1
REPROGRAMMABLE HARDWARE FOR DATA PROCESSING AT THE EDGE : A NEW COMPUTING PARADIGM BASED ON NEUROMORPHIC SYSTEMS
The brain's ability to perform efficient and fault-tolerant data processing is strongly related with its peculiar interconnected adaptive architecture, based on redundant neural circuits interacting at different scales. By emulating the brain's processing and learning mechanisms, computing technologies strive to (…) -
Séminaire PMMH - Salvatore Federico (University of Calgary, Canada)
Vendredi 4 juillet de 11h00 à 12h00 - Salle réunion PMMH 1
Continuum Mechanics of Hydrated Fibre-Reinforced Soft Tissues
Biological tissues can be represented as bi-phasic continua, with a porous solid phase saturated by an interstitial fluid and reinforced by collagen fibers. This lecture will give an overview of the modelling techniques for fibre-reinforced porous composite materials with statistical orientation of the fibers. Both (…) -
Séminaire PMMH - Salvatore Federico (University of Calgary, Canada)
Vendredi 4 juillet de 11h00 à 12h00 - Salle réunion PMMH 1
Continuum Mechanics of Hydrated Fibre-Reinforced Soft Tissues
Biological tissues can be represented as bi-phasic continua, with a porous solid phase saturated by an interstitial fluid and reinforced by collagen fibers. This lecture will give an overview of the modelling techniques for fibre-reinforced porous composite materials with statistical orientation of the fibers. Both (…)
Instructions générales pour les conférenciers
Le public du séminaire est très hétérogène (rien qu’au PMMH nous travaillons sur des thématiques très diverses, mécanique des fluides, des milieux granulaires, des solides, physique statistique, physique du mouillage, micro-fluidique, biophysique,...) l’objectif est donc de ne pas faire un séminaire trop spécialiste : au moins la première moitié du séminaire à un niveau accessible pour celui qui ne connaît rien sur le sujet.
Le séminaire a lieu à 11h. rendez-vous 15 minutes avant pour installer et tester la projection.
Le séminaire dure environ 45 minutes pour laisser un peu de temps pour discuter à la fin.
- Séminaires ESPCI-ENS de biophysique
- Séminaires du Département de Physique de l’ENS
- Séminaires du Laboratoire d’Hydrodynamique de l’X
- Séminaire de Mécanique d’Orsay (page web FAST)
- Séminaire de Mécanique d’Orsay (page web LIMSI)
- Séminaire de Mécanique des Fluides de l’Institut Jean le Rond d’Alembert
- Séminaires du laboratoire MSC, Paris VII
- Séminaires Gulliver
Lien vers séminaires café (internes, tous les jeudis)
