ESPCI web site
PMMH’s weekly seminar is held every Friday at 11 am (map)
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
Lucas Goehring (Max Planck Institute Goettingen)
Evolving crack patterns : mud cracks, columnar joints, and polygonal terrain
Contraction cracks can form captivating patterns, such as the artistic
craquelure sometimes found in pottery glazes, to the cracks in dried mud,
or the polygonal networks covering the polar regions of Earth and Mars.
Two types are frequently encountered : those with irregular rectilinear
patterns, such as that formed by an homogeneous slurry when dried (or
cooled) uniformly, and more regular hexagonal patterns, such as those
typified by columnar joints. Once cracks start to form in a thin
contracting layer, they will sequentially break the layer into smaller and
smaller pieces. A rectilinear crack pattern encodes information about the
order of cracks, as later cracks tend to intersect with earlier cracks at
right angles. In this manner they relieve the stresses perpendicular to
the pre-existing crack. In a hexagonal pattern, in contrast, the angles
between all cracks at a vertex are near 120°. In this presentation it
will be shown how both types of pattern can arise from identical forces,
and that a rectilinear, T-junction dominated pattern will develop into to
a hexagonal pattern, with Y-junctions, if allowed to. The ordering of
crack patterns are seen in a number of systems : columnar joints in starch
and lava ; desiccation cracks in clays that are repeatedly wetted and
dried ; cracks in eroding gypsum-cemented sand layers ; and the cracks in
permafrost known as polygonal terrain. These patterns will each be briefly
explored, in turn, and shown to obey the above principles of crack pattern
evolution.
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Seminars (4)
-
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 (…)
The audience is composed of people with rather heterogeneous backgrounds including specialists in solids, fluids, granular flows, statistical physics... so the idea is to keep your talk understandable by people not necessarily working in your field... The seminar time slot runs from 11am to noon so the best is to make the talk last around 45 minutes to leave some time for discussion.
- 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
Link to cofee seminar (internal, every Thursday)
