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

Geometric tolerances of welded connections with inelastic panel zones

Dimitrios Lignos, Andronikos Skiadopoulos, Ce Wen

Prequalified beam-to-column connections in steel moment resisting frames usually concentrate inelastic deformations in the steel beam ends. As such, nonlinear geo-metric instabilities (i.e., local buckling) may occur in these regions at modest lateral drif ...

Ernst & Sohn2023

Proposed residual stress model for hot‐rolled wide flange steel cross sections

Albano António De Abreu E Presa De Castro E Sousa, Dimitrios Lignos, Andronikos Skiadopoulos

Residual stresses in hot-rolled wide flange steel cross sections may lead to premature yielding, accelerated corrosion and brittle fracture of steel members. The above phenomena lead to a loss of a steel member's stiffness and resistance under mechanical l ...

Ernst & Sohn2023

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

The new Chapter 9 of Eurocode 8 Part 3 for Seismic Assessment of Existing Steel Structures

Dimitrios Lignos

The seismic assessment of existing steel structures necessitates the development of practice- oriented engineering models for use in nonlinear static and dynamic analysis procedures. These models should encompass the full range of the anticipated nonlinear ...

2023

Towards instability-free welded moment connections

Dimitrios Lignos, Andronikos Skiadopoulos

In capacity-designed steel moment resisting frames (MRFs), inelastic deformations are mostly concentrated in the steel beams and the column fixed ends of the first story, while the participation of the panel zones in energy dissipation is limited. In such ...

2023

Database of Residual Stress Measurements on Hot-rolled Wide Flange Steel Cross Sections

Albano António De Abreu E Presa De Castro E Sousa, Dimitrios Lignos, Andronikos Skiadopoulos

Data_info.csv: Database of 'Residual Stress Measurements on Hot-rolled Wide Flange Steel Cross Sections' including cross-sectional and material characteristics as well as information relevant to ploting the residual stress distributions. Distributions.zip: ...

Zenodo2023

Advancing efficiency and reliability in thermal analysis of laser powder-bed fusion

Christian Leinenbach, Thomas Mayer, Rafal Wróbel

In laser based powder-bed fusion of metals (PBF-LB/M), parts are fabricated by melting layers of powder using a high-intensity laser beam. During this process, the material is exposed to rapid cooling rates and intense thermal gradients, which are the unde ...

2023

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

Experimental Investigation of the Inelastic Cyclic Behavior of Concrete-Filled Double-Skin Tubular Beam-Columns with Corrugated Inner Skins and Ultrahigh-Strength Corner Tubes

Mojtaba Farahi, Dimitrios Lignos

This paper presents the experimental results from nine full-scale concrete-filled double-skin tubular (CFDST) beam-columns. The test specimens exploited two fabrication strategies, featuring either hollow steel inner skins with corrugated geometry or ultra ...

ASCE-AMER SOC CIVIL ENGINEERS2022

Experimental investigation of dowel action using advanced measurement techniques

Aurelio Muttoni, Marko Pejatovic

Existing shear-cracked structures need to be reliably verified in order to avoid redundant interventions. Code provisions often raise shear safety and/or fatigue life concerns of the reinforcement subjected to stress concentrations due to cyclic dowel acti ...

2022

Seismic stability of steel moment resisting frames with inelastic panel zones

Dimitrios Lignos, Andronikos Skiadopoulos

This paper summarizes preliminary findings of nonlinear simulations aiming to quantify the seismic demands of codecompliant steel MRFs with variable panel zone targeted shear distortions, 𝛾!. The probability of beam fractures is explicitly considered in th ...

Earthquake Engineering Research Institute2022

Laser powder-bed fusion of metallic alloys with enhanced microstructures and properties

Navid Sohrabi

Laser powder-bed fusion (LPBF) is an additive manufacturing (AM) process that uses a laser to selectively melt a powder bed. This process can build dense samples with complicated geometries from a wide variety of metallic alloys. In this thesis, LPBF of al ...

EPFL2021

Conceptual design of 1000 m scale steel-UHPFRC composite truss arch bridge

Ping Zhu, Jieping Zhu, Xiujiang Shen

Excessive self-weight and difficulty in construction are the main issues confronted by super-long-span arch bridges. To address these issues, a conceptual design of steel-ultra-high performance fibre-reinforced concrete (UHPFRC) composite truss arch bridge ...

ELSEVIER SCI LTD2021

Reduced-order Models for Simulating Coupled Geometric Instabilities in Steel Beam-columns Under Inelastic Cyclic Straining

Alexander Riley Hartloper

Numerical models that can simulate coupled geometric instabilities in steel beam-columns are required for the seismic assessment of certain steel moment-resisting frames. Reliably simulating coupled instabilities requires that the steel material is precise ...

EPFL2021

Enhancement of riveted steel bridges by adding a trough in UHPFRC acting in composite action

Eugen Brühwiler

Riveted railway bridges are commonly considered as being “old”, having fatigue damage and are therefore replaced. While this practice should be by now obsolete by using novel engineering methods like structural monitoring, prolongation of the service durat ...

Taylor & Francis2021

Generation of elastic geodesic gridshells with anisotropic cross sections

Olivier Baverel, Corentin Jean Dominique Fivet, Nicolas Robin Montagne

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

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

A parametric neutron Bragg edge imaging study of additively manufactured samples treated by laser shock peening

Christian Leinenbach, Roland Logé, Nikola Kalentics, Markus Strobl

Laser powder bed fusion is an additive manufacturing technique extensively used for the production of metallic components. Despite this process has reached a status at which parts are produced with mechanical properties comparable to those from conventiona ...

Nature Portfolio2021

Experimental Evaluation of Steel Columns under Seismic Hazard-Consistent Collapse Loading Protocols

Dimitrios Lignos

This paper presents results from 21 large-scale experiments on steel columns that examined their collapse behavior as related to steel moment resisting frames (MRFs). The test specimens included wide-flange and square hollow structural shapes (HSS) and wer ...

2021