Publications related to Smart composites with embedded SMA actuators and fibre Bragg grating sensors : activation and control

Strain engineering and strain measurement by spring tethers on suspended epitaxial GaN-on-Si photonic crystal devices

Suspended epitaxial gallium nitride (GaN) on silicon (Si) photonic crystal devices suffer from large residual tensile strain, especially for long waveguides, because fine structures tend to crack due to large stress. By introducing spring-like tethers, des ...

Iop Publishing Ltd2024

Experimental investigation of rotational behavior of pseudo-ductile adhesive angle joints exhibiting variable strain rate

Thomas Keller, Abdolvahid Movahedirad, Ghazaleh Eslami

Pseudo-ductile behavior in composite structural frames can be achieved by enabling their beam-column joints to exhibit nonlinear structural response due to progressive damage, by using pseudo-ductile adhesives. This study investigates the static behavior o ...

2023

Energy dissipation in fiber-polymer composites adhesive joints under cyclic loading

Ghazaleh Eslami

Sustainable development has emerged as a paramount consideration in various fields of industry, including construction, to preserve the environment and its finite resources. Lightweight structures, such as fiber-polymer composite structures, address both s ...

EPFL2023

Multi-scale characterization and modeling of notched strength and translaminar fracture in hybrid thin-ply composites based on different carbon fiber grades

Guillaume Clément Broggi

Owing to their high specific stiffness and strength, Carbon Fiber Reinforced Composites (CFRP) are ideal candidates for the development of lightweight high-performance structures. Within this family, thin-ply composites allow for wider design freedom and p ...

EPFL2023

Atomic-scale Characterization of Strain and Gate effects on Two-dimensional Materials by Scanning Tunneling Microscopy

Jz -Yuan Juo

Strain is an inevitable phenomenon in two-dimensional (2D) material, regardless of whether the film is suspended or supported. Moreover, strain is known to alter the physical and chemical properties, such as the band gap, charge carrier effective masses, d ...

EPFL2023

Drained Clay-Pipe Interface Resistance at Low Normal Stresses and Elevated Temperatures

Roba Houhou

Offshore pipelines that transport hydrocarbons under high pressure and high temperature are usually thermally insulated to maintain an elevated temperature and prevent any heat loss to the surroundings. However, the temperatures at the outer-wall of the pi ...

AMER SOC CIVIL ENGINEERS2023

Strain Gradients and Magnetoresistance in Microstructured 3D Topological Semi-metals

Jonas De Jesus Diaz Gomez

Three-dimensional topological semimetals have emerged as strong candidates to probe new fundamental physical phenomena that could be exploited to develop next generation electronics. However, many aspects of their electronic properties remain unclear. Thi ...

EPFL2023

Deformation twinning mechanism in magnesium at the microscale: strain rate, temperature and orientation effects

Nicolò Maria Della Ventura

The project aims to validate some recent theoretical developments on the deformation twinning nucleation mechanism in HCP metals through small-scale mechanic experiments. To this end, a systematic investigation of the mechanical response of pure magnesium ...

EPFL2022

Scaling Description of Creep Flow in Amorphous Solids

Marko Popovic, Matthieu Wyart, Wencheng Ji, Thomas Willem Jan de Geus

Amorphous solids such as coffee foam, toothpaste, or mayonnaise display a transient creep flow when a stress E is suddenly imposed. The associated strain rate is commonly found to decay in time as gamma_ -t-nu, followed either by arrest or by a sudden flui ...

AMER PHYSICAL SOC2022

Bending strain in 3D topological semi-metals

Amelia Emily-Kay Estry, Xiangwei Huang, Philip Johannes Walter Moll, Jonas De Jesus Diaz Gomez, Matthias Carsten Putzke

We present an experimental set-up for the controlled application of strain gradients by mechanical piezoactuation on 3D crystalline microcantilevers that were fabricated by focused ion beam machining. A simple sample design tailored for transport character ...

IOP Publishing Ltd2022

Controlling superconductivity of CeIrIn5 microstructures by substrate selection

Philip Johannes Walter Moll, Matthias Carsten Putzke, Chunyu Guo, Maja Deborah Bachmann, Maarten Ruud van Delft, Joshua Alan Wolfe Straquadine

Superconductor/metal interfaces are usually fabricated in heterostructures that join these dissimilar materials. A conceptually different approach has recently exploited the strain sensitivity of heavy-fermion superconductors, selectively transforming regi ...

AIP Publishing2022

A Homogenization Model for Soft Magnetic Composites Considering the Effect of Mechanical Stress

Xiaotao Ren

Soft Magnetic Composites (SMC) are an alternative to laminated steels for the design of smaller and lighter electromagnetic devices.Such electromagnetic devices might be subjected to significant mechanical stresses that can alter their electromagnetic prop ...

Institute of Electrical and Electronics Engineers2022

Fatigue of reinforced UHPFRC members and monitoring of fatigue action effects on bridges

Bartlomiej Wojciech Sawicki

The objective of this thesis is to develop knowledge and methods to prevent fatigue failure of bridges. The Fatigue Limit State is investigated from both the demand (S) and resistance (R) side. The S-part focuses on reduction of uncertainties through monit ...

EPFL2021

Particle-size segregation and rheology coupling in dense granular flows

Tomás Alfredo Trewhela Palacios

Dense granular flows -debris or pyroclastic flows, avalanches, granular flows in heaps, silos or rotating drums-are ubiquitous to many natural and industrial processes. Their grain composition is often polydisperse, with particles differing in shape, size ...

EPFL2021

A numerical approach to characterize the viscoelastic behaviour of fibre beds and to evaluate the influence of strain deviations on viscoelastic parameter extraction

Véronique Michaud, Vincent Werlen, Christian Rytka

The development of a robust material model able to accurately describe fibre bed compaction at different strain and strain rates is highly desirable because it is essential for the simulation of many composite manufacturing processes. In this study, we inv ...

2021

Study on Mechanical Performance of Prestressed UHPFRC U-Beam Bridges

Eugen Brühwiler

The forms of U-shaped UHPFRC beams have not been investigated for the highway footbridge. Compared with the traditional section forms, the U-shaped UHPFRC beams can reduce the material consumption under the condition of providing the same bearing capacity. ...

2021

Brittle faulting of ductile rock induced by pore fluid pressure build‐up

Marie Estelle Solange Violay, Corentin Jean-Marie Rémi Noël, François Xavier Thibault Passelègue

Under upper crustal conditions, deformations are primarily brittle (i.e., localized) and accommodated by frictional mechanisms. At greater depth, deformations are ductile (i.e., distributed) and accommodated by crystal plasticity, diffusion mass transfer o ...

2021

Bedload transport assessment on a physical model of a large river widening using ultrasonic Doppler velocity measurements

Giovanni De Cesare, Azin Amini, Jean-Noël Saugy

The 3rd correction of the Rhône River is the largest flood protection project in Switzerland so far. Covering a length of 162 km, it aims to protect some 100,000 people and prevent flood damages, which could raise up to 10 billion Swiss francs for major ev ...

ETH Zurich, Laboratory of Food Process Engineering2021

{10(1)over-bar2} twinning mechanism during in situ micro-tensile loading of pure Mg: Role of basal slip and twin-twin interactions

Johann Michler, Amit Sharma, Daniele Casari, Roland Logé, Xavier Maeder, Nicolò Maria Della Ventura

An SEM in situ uniaxial tensile testing setup allowing HR-EBSD acquisition during deformation was used to study the extension twinning mechanism in magnesium(Mg) at the micron scale. Structures were fabricated with two different crystal orientations, respe ...

2021

Model-Based Interpretation of Measurements for Fatigue Evaluation of Existing Reinforced Concrete Bridges

Eugen Brühwiler, Ian Smith, Sai Ganesh Sarvotham Pai, Imane Bayane

New methods are required for sustainable and economical management of bridges. Efficient management can be achieved by a detailed understanding of bridge behavior through monitoring and model-based data interpretation. This paper presents a methodology to ...

2021