Publication

Rate-dependent model for simulating the hysteretic behavior of low-yield stress buckling-restrained braces under dynamic excitations

Publications associées (21)

A Softening Constitutive Law and Gradient-Inelastic Fiber-Based Element for 3-Dimensional Frame Simulations Under Seismic Excitations

Steel frame structures are essential components of modern infrastructure. Understanding their behavior under seismic loading is critical for ensuring public safety and minimizing damage that occurs during earthquakes. To accurately predict the response of ...

EPFL2024

Seismic Assessment and Retrofit of Pre-Northridge High Rise Steel Moment Resisting Frame Buildings with Bilinear Oil Dampers

Dimitrios Lignos

This paper presents quantitative information on the effectiveness of seismic retrofit solutions using bilinear oil dampers for seismically deficient existing tall steel buildings. For this purpose, a benchmark 40-story steel space moment-resisting frame bu ...

MDPI2023

Modelling of in-plane seismic behaviour of one-way steel or timber jack arch floors in existing buildings

Savvas Saloustros

The type of floor system has a decisive role in the seismic performance of unreinforced masonry buildings. The in-plane stiffness of the floors has to be adequately represented in the numerical modelling of existing buildings, as it can influence their sei ...

2022

Could building replacements significantly contribute to seismic vulnerability mitigation at urban scale? Case studies of two typical swiss cities

Pierino Lestuzzi

This paper contains an investigation on the potential decrease of seismic vulnerability related to building replacements for the cities of Sion and Martigny in Switzerland. Those two cities were identified for the present research based on the accuracy of ...

FRONTIERS MEDIA SA2022

Experimental investigation of steel building gravity framing systems under strong earthquake shaking

Dimitrios Lignos

Hybrid simulations were conducted to evaluate the system-level seismic response of a 4-story steel moment frame building and its gravity framing system through various levels of ground motion shaking. The experimental substructure examined in detail corres ...

2019

A practical method for seismic retrofit of tall buildings with supplemental damping

Dimitrios Lignos

Current simplified design methods for buildings with supplemental damping devices are mainly based on single-degreefreedom (SDF) shear-models. Common errors of such methods are attributed to the linearization of nonlinear damping and stiffness, higher buil ...

CEI / SCE2019

Equivalent frame models for in-plane and out-of-plane response of unreinforced masonry buildings

Francesco Vanin

The seismic assessment of masonry buildings, both modern unreinforced masonry (URM) buildings and historical heritage constructions, is a complex task, characterised by a several sources of uncertainty, which regard the appropriate modelling of strategy th ...

EPFL2019

Application of Association Rules to Determine Building Typological Classes for Seismic Damage Predictions at Regional Scale: The Case Study of Basel

Pierino Lestuzzi, Yves Sylvain Gilles Reuland, Lorenzo Diana

Assessing seismic vulnerability at large scales requires accurate attribution of individual buildings to more general typological classes that are representative of the seismic behavior of the buildings sharing same attributes. One-by-one evaluation of all ...

2019

Sensitivity of Simulated Steel Column Instabilities to Plasticity Model Assumptions

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

Current experimental studies on the seismic behavior of steel wide-flange columns under multi-axis cyclic loading reveal that these members, depending on their geometric characteristics, may be susceptible to axial shortening, out-of-plane deformations and ...

2019

The Deformation Capacity of Lap Splices in RC Walls: From Experimental Testing to Numerical Modelling

Danilo Tarquini

Field observations as well as experimental tests have shown that both the strength and displacement capacity of reinforced concrete (RC) members might be significantly reduced by the presence of lap splices. This degradation applies in particular if the lo ...

EPFL2019

Pricing interest rate, dividend, and equity risk

Sander Félix M Willems

This thesis studies the valuation and hedging of financial derivatives, which is fundamental for trading and risk-management operations in financial institutions. The three chapters in this thesis deal with derivatives whose payoffs are linked to interest ...

EPFL2019

Adaptive numerical method algorithms for nonlinear viscous and bilinear oil damper models subjected to dynamic loading

Dimitrios Lignos

Adaptive numerical method algorithms are presented for the numerical simulation of the hysteretic behaviour of nonlinear viscous and bilinear oil dampers within a finite element program for nonlinear dynamic analysis of frame structures under earthquake ex ...

2018

Application of a Point Estimate Method for incorporating the epistemic uncertainty in the seismic assessment of a masonry building

Katrin Beyer, Francesco Vanin

Several sources of uncertainty affect the assessment of existing buildings, including uncertainties associated with the material properties and the displacement capacity of the elements. In engineering practice, Monte Carlo simulations of the nonlinear sei ...

2018

Modelling of the Cyclic Response of an Unreinforced Masonry Wall through a Force Based Beam Element

Katrin Beyer, João Saraiva Esteves Pacheco de Almeida, Francesco Vanin

The seismic assessment of existing masonry buildings is based on the prediction of their nonlinear response under lateral loading. This requires a reliable estimation of the force and displacement demand. For this purpose, modelling strategies using struct ...

2017

Methods and Approaches for Blind Test Predictions of Out-Of-Plane Behavior of Masonry Walls: A Numerical Comparative Study

Katrin Beyer, Andrea Penna

Earthquakes cause severe damage to masonry structures due to inertial forces acting in the normal direction to the plane of the walls. The out-of-plane behavior of masonry walls is complex and depends on several parameters, such as material and geometric p ...

2017

Utilization of wavelet-based damage-sensitive features for structural damage assessment of steel braced frames

Dimitrios Lignos, Seong-Hoon Hwang

Rapid structural damage assessment methodologies for engineered facilities are essential in order to properly allocate and ensure efficient use of emergency rescue forces, minimize business interruption and perform effective repairs in damaged infrastructu ...

EMPA2017

Seismic performance of a steel moment frame subassembly tested from the onset of damage through collapse

Dimitrios Lignos

A series of seismic tests were conducted on a 1½-bay by 1½-story special steel moment-resisting frame subassembly from the onset of damage through incipient collapse. These tests were conducted using hybrid simulation with substructuring as a mean to demon ...

Wiley-Blackwell2016

Multi-Directional Structural Component Hybrid Testing System for the Assessment of the Seismic Response of Steel I-Shaped Columns

Ali Imanpour, Dimitrios Lignos, Ahmed Mohamed Ahmed Elkady

The Multi-Directional Hybrid Testing System (MDHTS) at Polytechnique Montreal is an advanced structural testing system that can be used to study the response of large-scale structural components such as columns, walls, or bridge piers subjected to any comb ...

2016

Elemento de Viga Baseado em Formulação de Rigidez Enriquecido com Funções de Forma Adaptativas para Garantir Equilíbrio Axial

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

In the framework of Performance Based Earthquake Engineering (PBEE), assessing the inelastic behaviour of structures both at the global (force-displacement) and local (stress-strain) level is of priority importance. This goal is typically achieved by advan ...

2016

Dynamic performance comparison between buckling-restrained braced frames with concentric and eccentric configurations

Gary Scott Prinz

Buckling-restrained braced frames (BRBFs) are often used in steel buildings to resist seismic loads; however, BRBF ductility can be limited by poor performance of the beam-column-gusset regions. Additionally, the concentric brace configuration in BRBFs can ...

2012