Displacement-based design procedure for the seismic retrofit of existing buildings with self-centering dissipative braces

Structures, Journal Year: 2024, Volume and Issue: 62, P. 106174 - 106174

Published: March 13, 2024

Existing framed buildings, especially those designed according to outdated seismic codes, often offer inadequate protection levels due material degradation, low amount of reinforcement and poor construction details. Among the possible retrofit strategies, elasto-plastic dissipative braces (EPDBs) can be installed provide supplemental stiffness energy dissipation in main resisting frame. Since they are based on plastic deformation sacrificial steel components, EPDBs inherently affected by scarce recentering capability, i.e., presence residual at end mainshock that could impair their effectiveness for aftershock events. As demonstrated recent sequences, there might not enough time restore (e.g., though hydraulic actuators a reaction frame) undeformed configuration structure before subsequent shock. This issue overcome through self-centering (SCDBs), equipped with dampers characterized "flag-shaped" hysteretic behavior, which facilitates immediate re-centering Despite this evident benefit, is still lack practical design procedures buildings SCDBs. To fill gap, direct displacement-based procedure SCDBs tailored building frames here conceived illustrated. The proposed method aims achieving simultaneously two performance requirements: (i) target maximum roof displacement under ultimate-limit-state event; (ii) absence significant inter-storey drifts shaking. implementation described applications reinforced concrete case-study building. Nonlinear time-history analyses carried out prove method, along comparison offered versus traditional implemented same buildings.

Language: Английский

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Optimum tuned tandem mass dampers for suppressing seismic-induced vibrations considering soil-structure interaction

Structures, Journal Year: 2023, Volume and Issue: 52, P. 1146 - 1159

Published: April 26, 2023

Language: Английский

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Effectiveness and robustness of braced‐damper systems with adaptive negative stiffness devices in yielding structures

Earthquake Engineering & Structural Dynamics, Journal Year: 2022, Volume and Issue: 51(11), P. 2648 - 2667

Published: June 2, 2022

Abstract This study applied adaptive negative stiffness devices in the application of braced‐damper systems to propose an amplifying damper (NSAD), and investigated its effectiveness robustness for controlling inelastic seismic responses yielding structures. The behavior proposed NSAD perform damping magnification effect within a certain displacement threshold, thus both structural acceleration drift at elastic stage; when subjected strong earthquakes, would adaptively develop positive stiffness, which limits deformation A set nonlinear spectra are established including acceleration, ductility, energy dissipation, residual deformation. Numerical results validated that is effective In addition, influences key parameters like flexible support, ratio, threshold ratio (ratio displacement), carefully studied. From point ductility demands structures, recommended have value close unit; typically, reasonable upper limit be lower than 1.5 avoid

Language: Английский

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Study on the Influence and Optimization Design of Viscous Damper Parameters on the Damping Efficiency of Frame Shear Wall Structure

Buildings, Journal Year: 2024, Volume and Issue: 14(2), P. 497 - 497

Published: Feb. 10, 2024

This study investigates the influence of viscous damper parameters on damping efficiency frame shear wall structures. Taking a specific structure as background, three-dimensional finite element model is established using nonlinear dynamic time–history analysis method. The ratio, reduction in vertex displacement, base shear, and inter-story drift utilization rate are selected performance indicators. Firstly, sensitivity conducted to different these Then, relationship models between indicators fitted response surface method, fitting effect evaluated through an F-test determination coefficient R2. Finally, objective function based key solve for optimal parameters. results show that traditional method unable comprehensively consider combined effects has high accuracy good predictability can serve optimization model. Considering stiffness supporting components matched with parameters, feasibility demonstrated from engineering application perspective. A simple easy-to-operate design flowchart proposed, providing important guidance reference designers future.

Language: Английский

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Multi-objective optimization for probabilistic performance-based design of buildings using FEMA P-58 methodology

Engineering Structures, Journal Year: 2022, Volume and Issue: 254, P. 113856 - 113856

Published: Jan. 22, 2022

Language: Английский

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Metallic Yielding Dampers and Fluid Viscous Dampers for Vibration Control in Civil Engineering: A Review

International Journal of Structural Stability and Dynamics, Journal Year: 2022, Volume and Issue: 22(16)

Published: July 5, 2022

Structural vibration is a widespread issue occurred in the field of civil engineering. The passive energy dissipation devices are being increasingly popular for protecting structures from external excitations due to their high performance and no need energy. They can be divided into displacement-dependent dampers velocity-dependent dampers, among which metallic yielding (MYDs) fluid viscous (FVDs) most representative. This paper presents an overview MYD FVD, aiming reveal defects provide suggestions future development. basic concept, mechanical models, design approaches, applications engineering two reviewed. In particular, obstacles application preference research these summarized, merits drawbacks further discussed. Emphatically, strategies improvement development trends explored.

Language: Английский

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Experimental Characterization, Modeling, and Numerical Evaluation of a Novel Friction Damper for the Seismic Upgrade of Existing Buildings

Materials, Journal Year: 2023, Volume and Issue: 16(5), P. 1933 - 1933

Published: Feb. 26, 2023

The paper presents the experimental characterization, formulation of a numerical model, and evaluation, by means non-linear analyses, new friction damper conceived for seismic upgrade existing building frames. dissipates energy through force triggered between steel shaft lead core prestressed within rigid chamber. is adjusted controlling prestress core, allowing achievement high forces with small dimensions, reducing architectural invasiveness device. has no mechanical parts subjected to cyclic strain above their yield limit, thereby avoiding any risk low-cycle fatigue. constitutive behavior was assessed experimentally, demonstrating rectangular hysteresis loop an equivalent damping ratio more than 55%, stable over repeated cycles, low dependency axial on rate displacement. A model formulated in OpenSees software rheological comprising in-parallel system spring element Maxwell element, calibrated data. To assess viability rehabilitation buildings, investigation conducted performing dynamic analyses two case-study structures. results highlight benefits PS-LED dissipating largest part energy, limiting lateral deformation frames, increase structural accelerations internal at same time.

Language: Английский

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Energy dissipation demand and distribution for multi-story buildings with fluid viscous dampers

Engineering Structures, Journal Year: 2022, Volume and Issue: 253, P. 113813 - 113813

Published: Jan. 10, 2022

Language: Английский

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Optimal distribution of friction dampers to improve the seismic performance of steel moment resisting frames

Structures, Journal Year: 2022, Volume and Issue: 37, P. 624 - 644

Published: Jan. 20, 2022

This study aims to develop a low computational cost framework optimize the seismic performance of steel moment-resisting frames (SMRFs) equipped with friction dampers at different levels. To achieve optimal design in structure, novel approach called adaptive optimisation technique (AOT) is adopted. The basis this method uniform distribution damage (UDD) structure exploit maximum energy dissipation capacity dampers. objective obtain best position and minimize their slip-threshold force satisfy predefined inter-story drift (i.e. selected target). efficiency proposed demonstrated through optimum 4, 8, 16-story SMRFs subjected set strong natural earthquake records. unique features AOT are examined including high convergence rate, independence solution from an arbitrary starting point, also ability perform multi-level optimisation. Finally, dependency methods acceleration record, as challenge practical process, addressed by proposing modification formula. In addition, results compared iterative, non-iterative, some metaheuristic such genetic algorithm (GA), particle swarm (PSO), simulated annealing (SA). It shown that can lead solutions significantly less costs (up 98%) conventional techniques.

Language: Английский

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A decoupled double-loop method with the adaptive allowable limits for probabilistic performance-based design optimization

Engineering Structures, Journal Year: 2023, Volume and Issue: 279, P. 115634 - 115634

Published: Jan. 20, 2023

Language: Английский

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