Publications associées à A total fatigue life model for the prediction of the R-ratio effects on fatigue crack growth of adhesively-bonded pultruded GFRP DCB joints

Numerical investigation of two-dimensional Mode-II delamination in composite laminates

Thomas Keller, Anastasios Vassilopoulos, Congzhe Wang

Existing standards for delamination tests on composite materials typically employ one-dimensional (1D) beam specimens. However, such specimens may not represent real delamination scenarios in composite structures, where cracks tend to propagate in two dime ...

Elsevier Sci Ltd2024

Novel multi-crack damage approach for pultruded fiber-polymer web-flange junctions

Thomas Keller

This paper aims to propose a novel approach to assess the multi-crack behavior of layered fiber-polymer composites. The Compliance and R-curves generated from this novel approach were useful to understand the multiple delamination process, enabling to eval ...

Elsevier Sci Ltd2023

Determining crack kinematics from imaged crack patterns

Katrin Beyer, Amir Rezaie, Bryan German Pantoja Rosero, Ketson Roberto Maximiano Dos Santos

Determining the relationship between the cause of damage and the subsequent structural behavior of infrastructure systems requires an accurate characterization of the propagation of cracks, which represents the evolution of the damage state. When no inform ...

2022

Experimental investigation of hydraulic fracture growth in an anisotropic rock with pre-existing discontinuities under different propagation regimes

Brice Tanguy Alphonse Lecampion, Seyyedmaalek Momeni, Guanyi Lu

Laboratory experiments have been carried out to investigate the growth of hydraulic fracture (HF) in an anisotropic rock with pre-existing discontinuities such as bedding planes and veins. The experiments are designed in light of scaling relationships that ...

2022

Predicting damage in aggregates due to the volume increase of the alkali-silica reaction products

Jean-François Molinari, Barbara Lothenbach, Emil Gallyamov

Volume increase between the reactants and the products of alkali silica reaction could reach up to 100%. Taking place inside the aggregates, ASR imposes internal pressure on the surrounding material. In the current paper, we study the possibility of crack ...

Pergamon-Elsevier Science Ltd2022

Fatigue examination of reinforced-concrete bridge slabs using acoustic emission and strain monitoring data

Imane Bayane

The examination of bridges under service loading is key for understanding their condition and thus for their sustainable and efficient use. The need to extend the service duration of existing bridges is increasing, and therefore, efficient tools for examin ...

EPFL2021

Experiments and numerical modelling on angle-ply laminates under remote mode II loading

John Botsis, Charlie Joseph Simon Blondeau, Georgios Pappas

Delamination is a very frequent damage mechanism that affects the integrity of laminated composites. In this study, the effect of ply orientation on crack growth resistance was analyzed for three different anti-symmetric interfaces (+/- 30 degrees, +/- 45 ...

ELSEVIER SCI LTD2020

A decohesion pathway for hydrogen embrittlement in nickel: Mechanism and quantitative prediction

Xiaoqing Zhou, William Curtin, Ali Tehranchi

Hydrogen embrittlement (HE) is a ubiquitous and catastrophic mode of fracture in metals. Here, embrittlement is considered as an intrinsic ductile-brittle transition at the crack tip, where H at the crack tip can reduce the stress intensity K-Ic for cleava ...

PERGAMON-ELSEVIER SCIENCE LTD2020

Time-lapse reconstruction of the fracture front from diffracted waves arrivals in laboratory hydraulic fracture experiments

Brice Tanguy Alphonse Lecampion, Thomas Emmanuel Blum, Dong Liu

4-D acoustic imaging via an array of 32 sources/32 receivers is used to monitor hydraulic fracture (HF) propagating in a 250 mm cubic specimen under a true-triaxial state of stress. We present a method based on the arrivals of diffracted waves to reconstru ...

2020

On the benefits of a stress criterion for the simulation of cup drawing process

Roland Logé

Experimental and numerical cup drawing process has been investigated on 0.65 mm zinc sheets. The cup exhibits anisotropic earrings due to the material microstructure. The material formability is studied through elliptical bulge tests in the rolling, diagon ...

Springer France2018

Out-of-plane instability of thin reinforced concrete walls under seismic loading

Angelica Rosso

Out of plane instability of reinforced concrete walls is a failure mechanism observed rather recently following the earthquakes in Chile (2010) and New Zealand (2011). Global out of plane instability is a phenomenon that may occur in thin walls, subjected ...

EPFL2018

Numerical simulation of two-dimensional crack propagation

Thomas Keller, Anastasios Vassilopoulos, Aida Cameselle Molares

A numerical investigation was carried out to simulate the experimental results previously obtained concerning two-dimensional in-plane crack propagation in laminated glass fiber-reinforced polymer (GFRP) plates. The plates were designed with an embedded ci ...

2018

Physical Phenomena in Dynamic Failure of Concrete at the Mesoscale

Okan Yilmaz

The aim of the present thesis is to model numerically the dynamic failure behavior of concrete at the mesoscale. Concrete is the world's most widely used construction material and the structures made of it are subjected to dynamic loads during their long s ...

EPFL2017

Experiments versus theory for the initiation and propagation of radial hydraulic fractures in low permeability materials

Brice Tanguy Alphonse Lecampion

We compare numerical predictions of the initiation and propagation of radial fluid-driven fractures with laboratory experiments performed in different low permeability materials (PMMA, cement). In particular, we choose experiments where the time evolution ...

2017

An efficient method for fiber bridging traction identification based on the R-curve: Formulation and experimental validation

Joël Cugnoni, Thomas Gmür, John Botsis, Guillaume Frossard

Fiber bridging is one of the main toughening mechanisms in mode I interlaminar and intralaminar fracture of laminated composites. Intact fibers exert closing forces on both faces of the crack, restraining crack propagation. An effective identification proc ...

Elsevier2017

Influence of Lap Splices on the Deformation Capacity of RC Walls. I: Database Assembly, Recent Experimental Data, and Findings for Model Development

Katrin Beyer, João Saraiva Esteves Pacheco de Almeida, Danilo Tarquini, Ovidiu Prodan

Recent postearthquake missions have shown that reinforced concrete (RC) wall buildings can experience critical damage owing to lap splices, which led to a recent surge in experimental tests of walls with such constructional details. Most of the 16 wall tes ...

Asce-Amer Soc Civil Engineers2017

Dynamic crack propagation with a variational phase-field model: limiting speed, crack branching and velocity-toughening mechanisms

Jean-François Molinari, Clément Pierre Mathieu Roux-Langlois, Jérémy Bleyer

We address the simulation of dynamic crack propagation in brittle materials using a regularized phase-field description, which can also be interpreted as a damage-gradient model. Benefiting from a variational framework, the dynamic evolution of the mechani ...

2017

Punching strength of continuous flat slabs

Jürgen Einpaul

Reinforced concrete slabs with uniform thickness are common in residential and commercial buildings but can also be found in other types of structures. Such slabs are susceptible to punching shear failures, where a supporting column penetrates through the ...

EPFL2016

Architecture-based Design: A Satellite On-board Software Case Study

Anton Ivanov, Simon Bliudze, Joseph Sifakis, Anastasia Mavridou

In this case study, we apply the architecture-based design approach to the control software of the CubETH satellite. Architectures are a means for ensuring global coordination properties and thus, achieving correctness of complex systems by construction. T ...

Springer2016

Creep-fatigue interaction in composite materials

Thomas Keller, Anastasios Vassilopoulos, Abdolvahid Movahedirad

A novel phenomenological model taking into account the creep-fatigue interaction in composite materials’ fatigue performance is introduced in this paper. The model is based on the derivation of a master curve by using existing experimental fatigue data fro ...

2016