Publications associées à Low energy impact damage monitoring of composites using dynamic strain signals from FBG sensors - Part I: Impact detection and localization

Optothermal shaping of lamb waves with square and spiral phase fronts

Romain Christophe Rémy Fleury, Aleksi Antoine Bossart, Janez Rus

We introduce a Lamb-wave medium with tunable propagation velocities, which are controlled by a two-dimensional heating pattern produced by a laser beam. We utilized it to demonstrate that waves in an appropriately designed medium can propagate in the form ...

2024

Automatic and high-precision microseismic monitoring of progressive failure prior, during, and after tunnel excavation

Brice Tanguy Alphonse Lecampion, Christophe Nussbaum, Seyyedmaalek Momeni

Acoustic emission (AE) monitoring is commonly used to inspect the health of a structure continuously. During fracture processes elastic waves of AE are created and emitted, and sensors can capture these waves. The acquired signals can be processed to track ...

2023

Optimization of elastic wave propagation in a reconfigurable medium by genetic algorithms with adaptive mutation probability

Romain Christophe Rémy Fleury, Janez Rus

We introduce a reconfigurable medium for the manipulation of elastic propagation properties of Lamb waves. It is based on a shape memory polymer (SMP) with temperature-dependent Young's modulus. Waves are excited by a laser pulse and detected by a laser vi ...

IOP Publishing Ltd2023

Fluid flow through microcracked and fractured granitic reservoirs

Marie Estelle Solange Violay, Michael Heap, Lucille Jocelyne Nadine Carbillet

The permeability of crustal rocks and rock-masses dictates the efficiency of hydrothermal circulation and therefore the productivity of geothermal resources. In this study, we find by monitoring P-wave velocity that thermal microcracking in Lanhélin granit ...

2023

Integrated production of urea and nitric acid in the pulp industry: techno-economic and environmental analysis of black liquor gasification-based processes

François Maréchal, Shivom Sharma, Daniel Alexander Florez Orrego, Meire Ellen Gorete Ribeiro Domingos

The pursuit of alternative energy sources for the nitrogen fertilizers sector has recently earned renewed interest due to increasing concerns regarding the world dependence on non-renewable energy resources and also motivated by the more stringent environm ...

2022

cRacklet: a spectral boundary integral method library for interfacial rupture simulation

Jean-François Molinari, Fabian Barras, Thibault Didier Roch

The study of dynamically propagating rupture along interfaces is of prime importance in various fields and system sizes, including tribology (nm to m), engineering (mm to m) and geophysics (m to km) (Armstrong-Hélouvry et al., 1994; Ben-Zion, 2008; Vanossi ...

2022

Origin of the Co‐Seismic Variations of Elastic Properties in the Crust: Insight From the Laboratory

Marie Estelle Solange Violay, Mateo Alejandro Acosta, François Xavier Thibault Passelègue, Federica Paglialunga

Seismological observations highlighted that earthquakes are often followed by changes in elastic properties around the fault zone. Here, we studied the origin of these variations using stick-slip experiments on saw-cut granite samples presenting different ...

2021

Study on the Performances of AlScN based SAW/BAW Hybrid Resonators A Parametric Analysis of Acoustic Wave Resonators with Large Figure of Merit

Luis Guillermo Villanueva Torrijo, Guilain Lionel Germain Lang, Soumya Yandrapalli

In this study, we analyze a 3rd type of FBAR's fundamental mode by finite element method. We show the importance of the substrate's wave velocity and conductivity on the electromechanical coupling efficiency. Then we demonstrate that etching traditional SA ...

IEEE2021

An Extension of the Guided Wave M‐Component Model Taking Into Account the Presence of a Tall Strike Object

Farhad Rachidi-Haeri, Marcos Rubinstein, Mohammad Azadifar, Mi Zhou, Qi Li

We present in this paper an extension of the guided-wave M-component model of Rakov et al. considering the presence of a vertically elevated strike object. The tall object is represented as a lossless, uniform transmission line. Expressions for the current ...

2021

Mechanical and hydraulic transport properties of transverse-isotropic Gneiss deformed under deep reservoir stress and pressure conditions

Marie Estelle Solange Violay, Mateo Alejandro Acosta

In central Europe, many geo-energy reservoirs have revealed to be hosted in transverse isotropic crystalline rock, where the rock's mechanical and hydraulic transport properties are poorly constrained. Here, we performed triaxial experiments on Cresciano G ...

2020

Amplitude analysis of the B+ -> pi(+)pi(+)pi(-) decay

Christoph Frei, Peter Clarke, Jean Wicht, Aurelio Bay, Minh Tâm Tran, Marc-Olivier Bettler, Cédric Potterat, François Fleuret, Tatsuya Nakada, Guido Haefeli, Niko Neufeld, Olivier Schneider, Hans Dijkstra, Frédéric Teubert, Gerhard Raven, Mingkui Wang, Chitsanu Khurewathanakul, Frédéric Blanc, Matthew Needham, Axel Kuonen, Olivier Göran Girard, Liang Sun, Maxime Schubiger, Brice Emile Maurin, Thibaud Humair, Hang Yin, Xiaoxue Han, Greig Alan Cowan, Paolo Durante, Jessica Prisciandaro, Guillaume Max Pietrzyk, Matthieu Philippe Luther Marinangeli, Vladislav Balagura, Lino Ferreira Lopes, Albert Puig Navarro, Zhirui Xu, Mark Tobin, Victor Coco, Violaine Bellée, Mirco Dorigo, Yu Zheng, , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ,

Experimental study of impulse waves generated by viscoplastic fluid

Zhenzhu Meng

Landslide-generated waves, also called impulse waves, occur as a result of the intrusion of landslides (such as rock falls, debris flows, and avalanches) into bodies of water (such as lakes, reservoirs, and seas). The objective of this thesis was to study ...

EPFL2020

Crack front waves: A 3D dynamic response to a local perturbation of tensile and shear cracks

Jean-François Molinari, Fabian Barras, Damien Spielmann, Fatima-Ezzahra Fekak

Crack front waves are long-lived perturbations propagating along the crack front. They are triggered by heterogeneities on the crack plane, as for instance tough asperities, which disturb the crack front shape. Crack front waves are thought to leave a trac ...

PERGAMON-ELSEVIER SCIENCE LTD2020

Life cycle assessment integration into energy system models: An application for Power-to-Methane in the EU

François Maréchal, Victor Codina Gironès, Alexis Laurent

As the EU energy system transitions to low carbon, the technology choices should consider a broader set of criteria. The use of Life Cycle Assessment (LCA) prevents burden shift across life cycle stages or impact categories, while the use of Energy System ...

2020

Measurement and Modeling of Both Distant and Close Electric Fields of an M‐Component in Rocket‐Triggered Lightning

Farhad Rachidi-Haeri, Marcos Rubinstein, Mohammad Azadifar, Mi Zhou, Amirhossein Mostajabi, Qi Li

Simultaneous measurements of current and multiple‐station electric fields associated with a 5.4‐kA‐peak M‐component in rocket‐triggered lightning are presented in this study. A close‐range electric field measurement site was located northeast of the trigge ...

2020

Influence of the stacking sequence on the low-energy impact resistance of flax/PA11 composite

Yann Albert Gérard Lebaupin

In this paper, the low-energy impact behavior of a fully biobased composite made of bio-sourced polyamide 11 resin reinforced with flax fibers was investigated. Different composite laminates were studied in order to determine the stacking sequence effects ...

SAGE PUBLICATIONS LTD2019

Effect of bed roughness on tsunami-like waves and induced loads on buildings

Anton Schleiss, Michael Pfister, Davide Wüthrich

Tsunami, impulse-waves and dam-break waves afflict humanity with casualties and damages. An insight into the flow mechanisms of these waves is important to provide safety and reduce reconstruction costs. This experimental study focuses on the effect of bed ...

2019

Environmental impact assessment of Swiss residential archetypes: a comparison of construction and mobility scenarios

Emmanuel Rey, Sophie Lufkin, Sergi Aguacil Moreno, Thomas Bernard Paul Jusselme, Endrit Hoxha, Judith Elisa Drouilles

Environmental performance assessment of the built environment tends to focus mostly on operational final energy consumption of buildings located within a specific context. Such a limited scope prevents broader usability of findings in practice. In Switzerl ...

2019

Cavitation induction by projectile impacting on a water jet

Mohamed Farhat

The present paper focuses on the simulation of the high-velocity impact of a projectile impacting on a water-jet, causing the onset, development and collapse of cavitation. The simulation of the fluid motion is carried out using an explicit, compressible, ...

PERGAMON-ELSEVIER SCIENCE LTD2019

Extreme Hydrodynamic impact onto buildings

Davide Wüthrich

Dam failures, impulse waves, tsunamis and storm surges are disasters that challenge humanity, often leading to massive casualties and important economic losses. These events generate highly unsteady flow conditions in the form of surges or turbulent bores, ...

EPFL2018