Publications related to Gas tungsten arc welding

Experimental Investigation of Instability-Free Welded Moment Connections With Simplified Weld Details

Dimitrios Lignos, Andronikos Skiadopoulos

In capacity designed steel moment resisting frames, inelastic deformations are mostly concentrated in the steel beams and the column fixed ends of the first story. This design concept limits the participation of the column web’s panel zone in the energy di ...

2023

Control of intermetallics in the interface in directed energy deposition of titanium on stainless steel 316L

Di Cui

Application of a single metal or alloy is often restricted by its properties from optimal combination of performance and cost. Therefore, there is a vast need of joining dissimilar metals for various applications in biomedical, aerospace, automobile and ma ...

EPFL2023

Laser powder bed fusion of Fe-based shape memory alloys for novel structural metamaterials and "smart" structures

Irene Ferretto

Laser powder bed fusion (LPBF) is a powder-based additive manufacturing (AM) technique, which shows great potential in the production of complex-shaped parts with unprecedented design freedom. In addition, it allows for an active manipulation of the micros ...

EPFL2023

Full-scale testing of European steel beams with reduced beam section under reversed cyclic loading

Dimitrios Lignos, Hiroyuki Inamasu

Steel beams with reduced beam section (RBS) are often used as part of prequalified connections in seismic regions. However, RBS connections are not as common in Europe. Reasons relate to easiness in fabrication, which requires on-site welding, and the seis ...

Springer Nature2022

In situ work function measurements of W, WO3 nanostructured surfaces

Francisco Sanchez

Surface nanostructuring enables the fabrication of materials with highly desirable properties. Nanostructured tungsten surfaces have potential applications in solar water splitting. Exposing a polished tungsten surface to helium plasma induces various surf ...

ELSEVIER SCIENCE SA2022

Realistic Modelling of Dynamics at Nanostructured Interfaces Relevant to Heterogeneous Catalysis

Kevin Rossi

The focus of this short review is directed towards investigations of the dynamics of nanostructured metallic heterogeneous catalysts and the evolution of interfaces during reaction-namely, the metal-gas, metal-liquid, and metal-support interfaces. Indeed, ...

MDPI2022

Generation of elastic geodesic gridshells with anisotropic cross sections

Corentin Jean Dominique Fivet, Nicolas Robin Montagne, Olivier Baverel

Geodesic gridshells are shell structures made of continuous elements following geodesic lines. Their properties ease the use of beams with anisotropic cross-sections by avoiding bending about their strong axis. However, such bending may arise when flatteni ...

2021

Development of Lamb wave resonators in thin film X-cut lithium niobate

Muhammad Faizan

Microelectromechanical systems (MEMS) is among the most revolutionary technologies of 21st century, with the applications ranging from industrial systems to consumer electronics. Using MEMS in battery-powered wireless devices has long been seen as the evol ...

EPFL2021

Gas-puff induced cold pulse propagation in ADITYA-U tokamak

Harshita Raj, Ankit Kumar, Abhijit Sen, Rohit Kumar

Short bursts (similar to 1 ms) of gas, injecting similar to 10(17)-10(18) molecules of hydrogen and/or deuterium, lead to the observation of cold pulse propagation phenomenon in hydrogen plasmas of the ADITYA-U tokamak. After every injection, a sharp incre ...

IOP Publishing Ltd2021

Adaptive Laser Welding Control: A Reinforcement Learning Approach

Silvio Zanoli, Giulio Masinelli

Despite extensive research efforts in the field of laser welding, the imperfect repeatability of the weld quality still represents an open topic. Indeed, the inherent complexity of the underlying physical phenomena prevents the implementation of an effecti ...

2020

Recommendations for Improved Welding Procedures for Thick Steel Plates Through Thermo-Mechanical Analysis

Dimitrios Lignos

Welding of steel plates is accompanied by residual stresses that increase as the constraint provided by the welded components becomes greater. Consequently, crack initiation has been reported after welding thick plates due to the high residual stresses dev ...

2019

Residual stresses of friction melt bonded aluminum/steel joints determined by neutron diffraction

Jean-Marie Drezet

Near interfacial residual stresses are investigated in a joint composed of aluminum alloy and dual phase steel. A small step neutron diffraction scan was initially performed to determine the weld interface position along the measured transverse cross secti ...

ELSEVIER SCIENCE SA2019

Folded-Tube Soft Pneumatic Actuators for Bending

Wyatt Marshall Felt

This article presents a model and experimental results for a new class of bending soft pneumatic actuators (SPAs) made from a single section of thin-walled flexible tubing. The actuator is formed by creasing the tubing into fin-like rectangular folds and i ...

MARY ANN LIEBERT, INC2019

Healing cracks in selective laser melting by 3D laser shock peening

Roland Logé, Jamasp Jhabvala, Christian Leinenbach, Nikola Kalentics, Navid Sohrabi, Hossein Ghasemi Tabasi, Andreas Burn

Selective Laser Melting (SLM) of Ni-based superalloys such as CM247LC is prone to weld-cracking. This paper investigates how to suppress cracks by repeatedly applying Laser Shock Peening (LSP) during the building phase of SLM. Samples made of CM247LC were ...

ELSEVIER2019

Basic creep of cement paste at early age - the role of cement hydration

Karen Scrivener, Pietro Lura

In this work, the uniaxial creep in compression during the first days of hydration is studied experimentally on cement pastes with w/c of 0.50. to order to assess the effect of the evolving microstructure on creep, the so-called equivalent systems are empl ...

Pergamon-Elsevier Science Ltd2019

Strain-based approach to fatigue crack initiation on high-strength-steel welded joints under multiaxial loading

Alain Nussbaumer, Martin Antonio René Garcia, Heikki Tapani Remes

A recently novel strain-based approach recently proposed by Remes (Remes 2013) for the fatigue strength modelling of welded steel joints is extended here to consider multiaxial loading conditions and three dimensions finite element models. Only the first s ...

CRC Press (Taylor & Francis)2019

Determination of tungsten sources in the JET-ILW divertor by spectroscopic imaging in the presence of a strong plasma continuum

Olivier Sauter, Ambrogio Fasoli, Basil Duval, Stefano Coda, Duccio Testa, Jonathan Graves, Jonnathan Cesar Hidalgo Acosta, Yves Martin, Li Shuai, Alberto Hernando de Castro, Patrick Blanchard, Alessandro Pau, Cristian Sommariva, Henri Weisen, Richard Pitts, Yann Camenen, Jan Horacek, Javier García Hernández, Marco Wischmeier, Nicola Vianello, Mikhail Maslov, Federico Nespoli, Yao Zhou, David Pfefferlé, Davide Galassi, Antonio José Pereira de Figueiredo, Jonathan Marc Philippe Faustin, Liang Yao, Dalziel Joseph Wilson, Hamish William Patten, Samuel Lanthaler, Bernhard Sieglin, Otto Asunta

The identification of the sources of atomic tungsten and the measurement of their radiation distribution in front of all plasma-facing components has been performed in JET with the help of two digital cameras with the same two-dimensional view, equipped wi ...

Elsevier2019

Modelling of tungsten erosion and deposition in the divertor of JET-ILW in comparison to experimental findings

Olivier Sauter, Ambrogio Fasoli, Basil Duval, Stefano Coda, Duccio Testa, Jonathan Graves, Sun Hee Kim, Yves Martin, Daniel Scott Alessi, Julio Rodriguez, Patrick Blanchard, Alberto Hernando de Castro, Alessandro Pau, Cristian Sommariva, Henri Weisen, Richard Pitts, Yann Camenen, Jan Horacek, Javier García Hernández, Marco Wischmeier, Nicola Vianello, Mikhail Maslov, Federico Nespoli, Yao Zhou, David Pfefferlé, Davide Galassi, Antonio José Pereira de Figueiredo, Jonathan Marc Philippe Faustin, Liang Yao, Dalziel Joseph Wilson, Hamish William Patten, Samuel Lanthaler, Bernhard Sieglin, Otto Asunta

The erosion, transport and deposition of tungsten in the outer divertor of JET-ILW has been studied for an H-Mode discharge with low frequency ELMs. For this specific case with an inter-ELM electron temperature at the strike point of about 20 eV, tungsten ...

Elsevier2019

Fatigue Strength Upgrading of Cover Plate Ends by Welded Extensions in Existing Steel Bridge Girders

Alain Nussbaumer, Dimitrios Lignos, Vasileios Grigoriou

This paper investigates the fatigue upgrading of typical cover plate joint connections in existing steel bridge girders through cover plate extension. The upgraded detail is created by removing the existing transverse end weld, then welding the extension t ...

2018

Mechanical properties of MC multimetallic carbides in steel

Lionel Michelet

Carbides constitute a class of materials used for many applications, where excellent mechanical properties, such as stiffness, hardness and fracture toughness, are required. The machining industry is a typical example where carbide are crucial materials. W ...

EPFL2018