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Seminars
PMMH’s weekly seminar is held every Friday at 11 am (map)
Alice Pelosse
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 – Émilien Dilly (LiPhy, Grenoble)
Metabeams with programmable nonlinear bending response
Recent advances in mesoscale material architecture have enabled the design of structures exhibiting nonclassical mechanical responses, including auxetic behavior, mode coupling (e.g., stretching–bending and stretching–twisting), and exceptional stiffness-to-weight ratios. Inspired by the nonlinear bending response of a carpenter's measuring tape and the pronounced drooping of U-shaped plant petioles under water stress, we investigate the bending behavior of rectangular beams decorated with one or more longitudinal vertical fins.
During bending, longitudinal stretching of the fins couples to the beam curvature, inducing transverse compression within the fins. Beyond a critical curvature, this compression triggers fin buckling, which we rationalize in terms of the governing geometric parameters. Fin buckling leads to an abrupt reduction of the beam's effective moment of inertia, giving rise to a non-monotonic moment–curvature relationship closely analogous to that observed in carpenter's tapes.
By incorporating pillars that engage only beyond a prescribed curvature, we introduce curvature-dependent mechanical hardening. When combined with the fins, this strategy enables the programming of rich, highly tunable, and non-monotonic torque–curvature responses. An inverse design framework is developed to achieve on-demand torque profiles and is validated experimentally.
Exploiting this complex torque response, we further show that embedding fin-decorated beams into pneumatic bending actuators induces a snap-through instability, resulting in rapid actuation and a hysteretic mechanical response. This behavior enables fast, programmable motion.
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Seminars (1)
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Séminaire PMMH - Marie Tani (Kyoto University)
Vendredi 25 septembre de 11h00 à 12h00 - Salle réunion PMMH 1
Swarming of Active Filaments and Collective Force Generation
Collective motion is widely observed in nature, from schools of fish to bird flocks and insect colonies, where groups can accomplish tasks beyond the capability of individuals. Such collective behavior raises an interesting question : can a group of active agents also generate force collectively ? Here, we generate (…)
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
PhD defense
Auriane Huyghues-Despointes : 22/09 - 14h30
Sébastien Kuchly : 23/09 - 14h
Juliette Michaud : 28/09 - 14h
Diane Komaroff : 02/10 - 14h
Marc Vacher : 13/10
Jules Tampier : 16/10 - 13h30
Alex Le Guen : 01/12 - 14h
Cofee seminar (internal, every Thursday 1h30pm) Link
