Publications associées à Mouvement à la Poinsot

Design of a Flexure-Based Flywheel for the Storage of Angular Momentum and Kinetic Energy

Simon Nessim Henein, Florent Cosandier, Hubert Pierre-Marie Benoît Schneegans, Patrick Robert Flückiger

The flywheel is a widespread mechanical component used for the storage of kinetic energy and angular momentum. It typically consists of cylindrical inertia rotating about its axis on rolling bearings, which involves undesired friction, lubrication, and wea ...

2024

Rapid motion estimation and correction using self-encoded FID navigators in 3D radial MRI

Tobias Kober, Davide Piccini

Purpose: To develop a self-navigated motion compensation strategy for 3D radial MRI that can compensate for continuous head motion by measuring rigid body motion parameters with high temporal resolution from the central k-space acquisition point (self-enco ...

Wiley2023

Chaotic microcomb inertia-free parallel ranging

Tobias Kippenberg, Anton Stroganov, Anton Lukashchuk

Ever growing pixel acquisition rates in the fields of augmented reality, autonomous driving and robotics have increased interest in solid state beam scanning without moving parts. Modern photonic integrated laser ranging advances towards passive beam steer ...

AIP Publishing2023

Buoyancy-driven convection of droplets on hot nonwetting surfaces

François Gallaire, Eunok Yim

The global linear stability of a water drop on hot nonwetting surfaces is studied. The droplet is assumed to have a static shape and the surface tension gradient is neglected. First, the nonlinear steady Boussinesq equation is solved to obtain the axisymme ...

AMER PHYSICAL SOC2021

Topology design of general tensegrity with rigid bodies

Yafeng Wang

This study presents a general approach to the topology design of tensegrities with rigid bodies. To the best of the authors' knowledge, all existing topology design methods of tensegrities focus on tensegrities that only consist of members carrying axial f ...

2020

Inkjet Printing of Complex Soft Machines with Densely Integrated Electrostatic Actuators

Herbert Shea, Samuel Rosset, Samuel Schlatter, Giulio Grasso

A multimaterial inkjet printing method for integrated soft multifunctional machines is reported, combining dense arrays of electrostatic actuators, multilayer electrical routing, and complex networks of microfluidic channels in one printing process. Most a ...

2020

A priori error for unilateral contact problems with Lagrange multipliers and isogeometric analysis

Annalisa Buffa, Pablo Antolin Sanchez, Mathieu Jonathan Fabre

In this paper, we consider unilateral contact problem without friction between a rigid body and deformable one in the framework of isogeometric analysis. We present the theoretical analysis of the mixed problem. For the displacement, we use the pushforward ...

2019

Head motion measurement and correction using FID navigators

Tobias Kober, Maryna Volodimirivna Waszak

Purpose: To develop a novel framework for rapid, intrinsic head motion measurement in MRI using FID navigators (FIDnavs) from a multichannel head coil array. ...

WILEY2019

Mechanical Model for Drift-Induced Punching of Slab-Column Connections without Transverse Reinforcement

Aurelio Muttoni, Katrin Beyer, Ioannis Sokratis Drakatos

A mechanical model is presented for predicting the momentrotation relationship of interior slab-column connections without transverse reinforcement when subjected to seismically induced drifts. The model accounts explicitly for the three load-transfer acti ...

2018

Prospective head motion correction using FID-guided on-demand image navigators

Rolf Gruetter, Tobias Kober, Gunnar Krüger, Tom Hilbert, Bénédicte Marie Maréchal, Pavel Falkovskiy, Reto Meuli, Maryna Volodimirivna Waszak, Guillaume Bonnier

PURPOSE: We suggest a motion correction concept that employs free-induction-decay (FID) navigator signals to continuously monitor motion and to guide the acquisition of image navigators for prospective motion correction following motion detection. METHODS: ...

Wiley-Blackwell2017

The isostatic 3-body problem: a complete solution

Simon Nessim Henein, Florent Cosandier, Ilan Vardi, François Barrot, Johannes Richard Cornelis Geerit Kruis

Kinematic couplings are used when two rigid bodies need to be repeatedly and accurately positioned with respect to each other. They allow for sub-micron positioning repeatability by suppressing play and reducing strains in the bodies. Typical applications ...

2017

Ion heating and flows in a high power helicon source

Ivo Furno, Alan Howling, Rémy Jacquier, Riccardo Agnello, Gennady Plyushchev

We report experimental measurements of ion temperatures and flows in a high power, linear, magnetized, helicon plasma device, the Resonant Antenna Ion Device (RAID). Parallel and perpendicular ion temperatures on the order of 0.6 eV are observed for an rf ...

Amer Inst Physics2017

The Geometric Nature of the Flaschka Transformation

Tudor Ratiu, François Gay-Balmaz

We show that the Flaschka map, originally introduced to analyze the dynamics of the integrable Toda lattice system, is the inverse of a momentum map. We discuss the geometrical setting of the map and apply it to the generalized Toda lattice systems on semi ...

Springer Verlag2017

Effect of static and kinematic boundary conditions on the out-of-plane response of brick masonry walls

Katrin Beyer, Filippo Lucca

The Unreinforced Wall (URM) elements that are most susceptible to out-of-plane failure are wall elements of the upper storeys where the accelerations are largest. In modern URM buildings with reinforced concrete slabs, the out-of-plane mechanism involves t ...

Taylor and Francis Group2016

Design, analysis, testing and applications of two-body and three-body kinematic mounts

Johannes Richard Cornelis Geerit Kruis

Kinematic couplings are used when two rigid bodies need to be repeatedly and accurately positioned with respect to each other. They allow for sub-micron positioning repeatability by suppressing play and reducing strains in the bodies. Typical applications ...

EPFL2016

Seismic behaviour of slab-column connections without transverse reinforcement

Ioannis Sokratis Drakatos

Reinforced concrete (RC) flat slabs supported by slender columns are often used as gravity load resisting system for buildings in regions of moderate and high seismicity. Such buildings are typically braced by RC walls, which carry the largest portion of t ...

EPFL2016

Muscle Moment-Arms: A Key Element in Muscle-Force Estimation

Alexandre Terrier, Philippe Müllhaupt, Alain Farron, Christoph Anselm Engelhardt, David Ingram

A clear and rigorous definition of muscle moment-arms in the context of musculoskeletal systems modelling is presented, using classical mechanics and screw theory. The definition provides an alternative to the tendon excursion method, which can lead to inc ...

Taylor & Francis2015

Closed-loop magnetic bearing and angular velocity control of a reaction sphere actuator

Yves Perriard, Leopoldo Rossini

This article presents the first closed-loop magnetic bearing and angular velocity experimental results of a reaction sphere actuator for satellite attitude control. The proposed reaction sphere is a permanent magnet spherical actuator whose rotor is suppor ...

Pergamon-Elsevier Science Ltd2015

The U (n) free rigid body: Integrability and stability analysis of the equilibria

Tudor Ratiu

A natural extension of the free rigid body dynamics to the unitary group U (n) is considered. The dynamics is described by the Euler equation on the Lie algebra u(n), which has a bi-Hamiltonian structure, and it can be reduced onto the adjoint orbits, as i ...

Elsevier2015

Soft tissue artifact distribution on lower limbs during treadmill gait: Influence of skin markers' location on cluster design

Kamiar Aminian, Arnaud Barré

© 2015 Elsevier Ltd. Segment poses and joint kinematics estimated from skin markers are highly affected by soft tissue artifact (STA) and its rigid motion component (STA. RM ). While four marker-clusters could decrease the STA non-rigid motion d ...

Elsevier2015