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
Séminaire PMMH - Gergely Molnár (Laboratory 3SR, Univ. Grenoble Alpes)
Multiscale methods for the analysis of plastic deformation of amorphous materials
Silicate glasses are used for many technical purposes, especially where stiffness and transparency are required. These glasses are brittle on the macroscopic scale but ductile at the micron level. The study deals with the analysis of the elasto-plastic response of sodium silicate glasses. We propose a new method using atomistic simulations combined with coarse-grained analysis to calculate structural and mechanical properties at different scales.
The numerical simulations were performed on large samples, and the results were ompared to experiments (neutron scattering, NMR, Brillouin scattering). The systems were tested by deforming the periodic simulation box in a homogeneous way. During compression or tension the dimensions of the simulation box was reduced by a constant displacement step while the positions of the particles were rescaled in a homogeneous way. After the box displacement a new equilibrium position was searched using the Polak-Ribiere conjugate gradient algorithm. Combining quasi static shear and compressive mechanical deformation, we were able to reconstruct hardening yield surfaces in the 3D stress space, parameterized by the residual shear strain and densification.
After identifying the smallest scale where the material could be considered homogeneous and isotropic we were able to develop continuum based material models. The observed mechanical response was described using a pressure dependent, hydrostatic hardening yield surface. The functions were then implemented in a finite element code. The continuum models made possible to compare atomistic results to real life experiments. We have used the results of micropillar, microsphear and nanoindentation to fine-tuned and verify our model.
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)
