Publication

Characterization of natural sand under complex dynamic loading

Publications associées (30)

Stability: a search for structure

In this thesis we study stability from several viewpoints. After covering the practical importance, the rich history and the ever-growing list of manifestations of stability, we study the following. (i) (Statistical identification of stable dynamical syste ...

EPFL2024

Role of Minimum Adhesive Wear Particle Size in Third-Body Layer Properties

Jean-François Molinari, Son-Jonathan Pham-Ba

We employ a novel discrete element method (DEM) force formulation to simulate adhesive wear and assess the effects of material and loading parameters on the properties of the third-body layer (TBL) formed during sliding motion. The study emphasizes the rol ...

2023

Unsupervised Electrofacies Clustering Based on Parameterization of Petrophysical Properties: A Dynamic Programming Approach

François Fleuret, Karthigan Sinnathamby

Electrofacies using well logs play a vital role in reservoir characterization. Often, they are sorted into clusters according to the self-similarity of input logs and do not capture the known underlying physical process. In this paper, we propose an unsupe ...

SOC PETROPHYSICISTS & WELL LOG ANALYSTS-SPWLA2023

Self-sustained dynamics and forced resonant oscillations in flows: cross-junction jets and sloshing liquids

Alessandro Bongarzone

In engineering, oscillatory instabilities and resonances are often considered undesirable flow features and measures are taken to avoid them. This may include avoiding certain parametric regions or implementing control and mitigation strategies. However, t ...

EPFL2023

The challenges of quasi-static and fatigue experiments of structural adhesives

Anastasios Vassilopoulos, Valentin Perruchoud

This paper presents the results of an experimental campaign designed specifically to investigate unexpected and unwanted failures observed during the quasi-static and fatigue tensile loading of structural adhesives. Simple finite element models were also d ...

ELSEVIER SCI LTD2022

EMC Impact of Disturbances Generated by Multiple Sources

Farhad Rachidi-Haeri, Marcos Rubinstein, Hamidreza Karami

In this paper, the impact of an increasing number of arbitrary electrical/electronic devices on the overall radiated emissions is investigated. Understanding and quantifying such an impact are prerequisites to the proper evaluation of electromagnetic compa ...

2022

Determination of Parameters Characteristic of Dynamic Weakening Mechanisms During Seismic Faulting in Cohesive Rocks

Marie Estelle Solange Violay, Chiara Cornelio, François Xavier Thibault Passelègue

While sliding at seismic slip-rates of ∼1 m/s, natural faults undergo an abrupt decrease of shear stress called dynamic weakening. Asperity-scale processes related to flash heating and weakening and, meso-scale (mm-cm) processes involving shear across the ...

AGU2022

Step Change Detection for Improved ROCOF Evaluation of Power System Waveforms

Mario Paolone, Asja Derviskadic, Guglielmo Frigo, Alexandra Cameron Karpilow

In the analysis of power grid waveforms, the presence of amplitude or phase steps can disrupt the estimation of frequency and rate-of-change-of-frequency (ROCOF). Standard methods based on phasor-models fail in the extraction of signal parameters during th ...

IEEE2022

A mechanical approach for the maximum punching resistance of shear-reinforced slab-column connections

Aurelio Muttoni, Miguel Fernández Ruiz, João Tiago Ramos Bernardo de Santa Rita Simões, Diego Hernández Fraile

The use of punching shear reinforcement is currently considered as one of the most convenient practices to enhance the punching shear strength and deformation capacity of slab-column connections in flat slabs. Intensive research has been performed in the l ...

Fédération Internationale du Béton (fib)2021

Optimization Method for Extracting Stabilizer Geometry and Properties of REBCO Tapes

Bertrand Dutoit, Bertrand Dutoit, Francesco Grilli, Arooj Akbar, Nicolo' Riva

A good knowledge of material properties is a critical aspect for modeling high-temperature superconductor (HTS) devices. However, the electrical resistivity of coated conductors above the critical current is limited. The major challenge in characterizing t ...

2021

Hybrid hydrogels for load-bearing implants

Céline Samira Wyss

Load-bearing tissues such as articular cartilage or meniscus are not infallible. They might fail due to trauma, over-solicitations, or diseases, which could subsequently alter the mobility of the patient. Repairing these damaged tissues in a minimally inva ...

EPFL2021

Laser-induced liquid micro-jets for drug delivery

Jan Krizek

Jet injection devices have been studied and developed for transdermal drug delivery to avoid the use of needles. Such contact-less devices provide several advantages such as better dose control, lateral and depth localisation, lower collateral damage than ...

EPFL2021

A methodology to design measurement systems when multiple model classes are plausible

Ian Smith, Numa Joy Bertola, Sai Ganesh Sarvotham Pai

The management of existing civil infrastructure is challenging due to evolving functional requirements, aging and climate change. Civil infrastructure often has hidden reserve capacity because of conservative approaches used in design and during constructi ...

2021

Automatic locking of a parametrically resonating, base-excited, nonlinear beam

Amit Yedidia Dolev

Described is a closed-loop control scheme capable of stabilizing a parametrically excited nonlinear structure in several vibration modes. By setting the relative phase between the spatially filtered response and the excitation, the open-loop unstable solut ...

SPRINGER2021

Cyclic metal plasticity model parameters with limited information: a constrained optimization approach

Albano António De Abreu E Presa De Castro E Sousa, Dimitrios Lignos, Alexander Riley Hartloper

Tensile test data for structural steels are ubiquitous. Yet, the information monotonic loading provides with respect to the material's characteristics is limited. Notably, features of inelastic response to cyclic loading, such as the Bauschinger eect, can ...

2021

Investigation of fatigue damage in a RC deck slab due to moving loads through long-term monitoring of a road viaduct

Eugen Brühwiler, Imane Bayane

The behavior of reinforced-concrete structural elements under moving loads involves many complex parameters related to material properties, vehicle loading, environmental changes and structural response. It is difficult to generate the real conditions of l ...

Taylor & Francis2021

Swirl number based transposition of flow-induced mechanical stresses from reduced scale to full-size Francis turbine runners

François Avellan, Christian Landry, Joao Gomes Pereira Junior, Arthur Tristan Favrel, Keita Yamamoto

At part load conditions, Francis turbines are subject to the emergence of a hydrodynamic instability in their draft tube, referred to as precessing vortex rope. It induces pressure pulsations in the water passages at the precession frequency of the vortex, ...

2020

A New Evaluation Criterion for Optimizing the Mechanical Properties of Toughened Polypropylene/Silica Nanocomposites

Hossein Pourrahmani

This study aims to experiment with the mechanical properties of polypropylene (PP)/thermoplastic elastomer/nano-silica/compatibilizer nanocomposite using the melt mixing method. The addition of polyolefin elastomers has proved to be an approachable solutio ...

SPRINGER2020

Window Size Effects on Subjective Impressions of Daylit Spaces: Indoor Studies at High Latitudes Using Virtual Reality

Marilyne Andersen, Kynthia Chamilothori, Jan Wienold

Daylight provision to the indoor space is affected by different building elements that cannot be fully controlled by the users, such as the window size of a space. The dimensions of the fenestration not only affect the lighting levels, but they also affect ...

2021

Smart Contract With Secret Parameters

Serge Vaudenay

By design, smart contracts' data and computations are public to all participants. In this paper, we study how to create smart contracts with parameters that need to stay secret. We propose a way to keep some of the parameters off-chain, while guaranteeing ...

2020