Publications associées à Empirical and analytical analyses of laboratory granular flows to investigate rock avalanche propagation

A Depth-Averaged Material Point Method for Shallow Landslides: Applications to Snow Slab Avalanche Release

Bertil Trottet, Johan Alexandre Philippe Gaume, Denis Aloyse Joseph Steffen, Lars Kristoffer Uhlen Blatny, Louis Marie Cédric Guillet

Shallow landslides pose a significant threat to people and infrastructure. Despite significant progress in the understanding of such phenomena, the evaluation of the size of the landslide release zone, a crucial input for risk assessment, still remains a c ...

AMER GEOPHYSICAL UNION2023

Effects of resonator geometry and substrate stiffness on the tunability of a deformable microwave metasurface

Taha Goudarzi, Romain Christophe Rémy Fleury, Rayehe Karimi Mahabadi

Tunable metasurfaces can shift their resonant frequency through different approaches, one of which is applying mechanical deformations. Here, we show the effects of two key factors on the tunability of deformable metasurfaces; the resonator geometry and su ...

2022

Analytical Studies in Support of an Improved Approach to the Design of Acceleration-Sensitive Nonstructural Elements

Dimitrios Lignos, Ahmed Mohamed Ahmed Elkady

This paper summarizes a series of analytical studies that were conducted in connection with an improved approach for the design of acceleration-sensitive nonstructural elements. In the new approach, bracing to secure nonstructural elements to the structure ...

Applied Technology Council, Sponse2022

Experimental quantification of 3D deformations in sensitive clay during stress-probing

Edward Carlo Giorgio Andò

Unique four-dimensional (4D) deformation data are collected during drained triaxial tests on intact specimens of a natural sensitive clay. This requires the development of a miniature triaxial cell for advanced stress path testing, specifically designed fo ...

ICE PUBLISHING2022

Strained crystalline nanomechanical resonators with quality factors above 10 billion

Tobias Kippenberg, Sergey Fedorov, Nils Johan Engelsen, Alberto Beccari

In strained mechanical resonators, the concurrence of tensile stress and geometric nonlinearity dramatically reduces dissipation. This phenomenon, called dissipation dilution, is employed in mirror suspensions of gravitational-wave interferometers and at t ...

NATURE PORTFOLIO2022

Numerical investigation of the effect of cohesion and ground friction on snow avalanches flow regimes

Betty Sovilla, Johan Alexandre Philippe Gaume

With ongoing global warming, snow avalanche dynamics may change as snow cohesion and friction strongly depend on temperature. In the field, a diversity of avalanche flow regimes has been reported including fast, sheared flows and slow plugs. While the sign ...

PUBLIC LIBRARY SCIENCE2022

A lubricated tribocorrosion model incorporating surface roughness

Stefano Mischler, Shoufan Cao

This study presents an improvement of an existing tribocorrosion model developed for passive CoCrMo alloys. This model is based on an empirical formalism established by Duncan Dowson in his pioneering works on the relation between wear and elasto-hydrodyna ...

2021

On the effects of fluid pressure variations on rock-mass and fault mechanical behaviour

Corentin Jean-Marie Rémi Noël

In the past 20 years, the growing interest in deep geo-reservoirs for purposes such as carbon storage, waste water disposal, or geothermal energy exploitation have led to large-volume fluid injections into the upper continental crust. These fluid injection ...

EPFL2021

Mean-field dynamics of infinite-dimensional particle systems: global shear versus random local forcing

Elisabeth Agoritsas

In infinite dimensions, many-body systems of pairwise interacting particles provide exact analytical benchmarks for the features of amorphous materials, such as the stress--strain curve of glasses under quasistatic shear. Here, instead of global shear, we ...

2021

Computation of multi-region, relaxed magnetohydrodynamic equilibria with prescribed toroidal current profile

Jonathan Graves, Joaquim Loizu Cisquella, Antoine Baillod, Ajay Kumar

The stepped-pressure equilibrium code (SPEC) (Hudson et al., Phys. Plasmas, vol. 19, issue 11, 2012, 112502) is extended to allow the computation of multi-region, relaxed magnetohydrodynamics (MRxMHD) equilibria at prescribed toroidal current profile. Toro ...

Cambridge University Press2021

Explicit dynamic approach for unbounded domains in frictional contact with Rate and State laws

Jean-François Molinari, Roozbeh Rezakhani

The paper explores the ability of an explicit time integration procedure to simulate the dynamics of shear rupture between unbounded elastic blocks on frictional interface, modeled with the finite element method. The behaviour of the interface is governed ...

ELSEVIER2020

Surface roughness evolution in adhesive wear processes

Enrico Milanese

Geological faults movements generating earthquakes, a vehicles' tyres rolling on the pavement, and a chalk writing on a blackboard are all different examples of frictional systems. In these systems, which are everywhere around us, two separate bodies are i ...

EPFL2020

Modeling snow and avalanches with the Material Point Method and finite strain elastoplasticity

Bertil Trottet, Johan Alexandre Philippe Gaume, Lars Kristoffer Uhlen Blatny, Xingyue Li

Snow is a complex and fascinating material which can sustain stresses like a solid or flow like a fluid depending upon the load it is subjected to. The transition from solid to fluid state can lead to catastrophic snow slab avalanches. Modeling large defor ...

The Alliance of Laboratories in Europe for Education, Research and Technology2020

Device for measuring a force exerted on an object

Simon Nessim Henein, Charles Baur, Mohammad Hussein Kahrobaiyan, Mohamed Gamal Abdelrahman Ahmed Zanaty

The present invention relates to a device for measuring a contact force exerted by an object on a probe comprising a lever and said probe for contacting the object. The lever is pivotably coupled to a body by coupling means. The device comprising a fixed f ...

2020

A detailed view on the rebar–to–concrete interaction based on refined measurement techniques

Aurelio Muttoni, Miguel Fernández Ruiz, Raffaele Cantone

Simplified assumptions have traditionally been made on the rebar–to–concrete interaction in structural concrete to calculate the stress state in rebars. Such assumptions typically consider a uniform stress state in the reinforcement at a given cross sectio ...

2020

Radial-Force-Based Swirling Actuator with Surface-Permanent-Magnet Structure for Low-Speed High-Torque Applications

Adrien Jean-Michel Thabuis

This paper proposes a swirling actuator that utilizes the electromagnetic radial force and a swirling gear to generate rotational torque. This actuator converts the swirling motion to the rotational motion and is suitable for low-speed high-torque applicat ...

IEEE2019

Volume change characteristics of fine-grained soils due to sequential thermo-mechanical stresses

Alessio Ferrari, Rakshith Shetty

Know-how of volume change characteristics, VCC, of the fine-grained soils, exposed to thermal stresses, is essential for design of various thermo-active structures. These stresses are known to induce excess pore-water pressure, Δu θ , in the saturated stat ...

2019

Crack Nucleation in the Adhesive Wear of an Elastic-Plastic Half-Space

Jean-François Molinari, Guillaume Anciaux, Lucas Henri Galilée Frérot

The detachment of material in an adhesive wear process is driven by a fracture mechanism which is controlled by a critical length-scale. Previous efforts in multi-asperity wear modeling have applied this microscopic process to rough elastic contact. Howeve ...

PERGAMON-ELSEVIER SCIENCE LTD2020

Following Microstructures during Deformation: In situ X-ray/Neutron Diffraction and HRDIC

Helena Van Swygenhoven, Efthymios Polatidis

The mechanical behavior of three engineering materials is studied employing in situ deformation methods. The study covers metastable austenitic steels with different stacking fault energies during multiaxial loading, a Ti-6Al-4V alloy processed by electron ...

IOP PUBLISHING LTD2019

Microstructure and flow stress evolution during hot deformation of 304L austenitic stainless steel in variable thermomechanical conditions

Roland Logé, Ke Huang

Most of industrial hot deformation processes are performed in variable conditions where the strain rate and/or deformation temperature are not constant. In this work, hot compression tests in both constant and varying strain rate conditions were performed ...

Elsevier2018