The Experts below are selected from a list of 4557 Experts worldwide ranked by ideXlab platform
Gloria Terenzi - One of the best experts on this subject based on the ideXlab platform.
-
shaking table and numerical seismic performance evaluation of a fluid viscous dissipative Bracing System
Earthquake Spectra, 2012Co-Authors: Stefano Sorace, Gloria Terenzi, Fabio FadiAbstract:A shaking table campaign was carried out on a 2:3-scale, two-story steel frame structure retrofitted by a dissipative Bracing System incorporating pressurized fluid viscous spring-dampers. Up to 1....
-
fluid viscous damper based seismic retrofit strategies of steel structures general concepts and design applications
2009Co-Authors: Stefano Sorace, Gloria Terenzi, S MartaAbstract:Two advanced seismic protection technologies, represented by a dissipative Bracing System and a damped cable System, both incorporating fluid viscous dampers as passive control devices, are examined with special reference to their use in retrofitting steel structures. The essential characteristics and performance of the dampers and the two technologies, along with their analytical and computational modelling criteria, are recalled in the first part of this paper. A demonstrative design study concerning the application of both Systems to an Italian pre-normative steel school building is then presented, by discussing the mechanical parameters, dimensions, layouts and locations selected for the relevant constituting elements. The advantages of the two rehabilitation hypotheses are assessed in terms of the mutual performance objectives formulated at a preliminary design stage, based on the results of the modal and non-linear dynamic analyses carried out during the final verification phase. Structural implementation and technical installation details are finally provided for both retrofit solutions.
-
seismic protection of frame structures by fluid viscous damped braces
Journal of Structural Engineering-asce, 2008Co-Authors: Stefano Sorace, Gloria TerenziAbstract:A research study on a damped Bracing System incorporating pressurized silicone fluid viscous devices for seismic protection of frame structures is presented in this paper. This technology features an inverse-chevron brace configuration, where a pair of interfaced devices are placed, parallel with the floor-beam axis, at the tip end of each couple of supporting steel braces. The experimental section of this study consisted of a pseudodynamic testing campaign on a 2:3-scale three-story steel frame and a full-scale three-story reinforced concrete frame seismically retrofitted by the technology considered. Test results were elaborated to evaluate: the improvement of seismic response of both structures after retrofit, also assessed through a formal performance-based evaluation analysis; the capabilities of the assumed analytical and numerical models in reproducing the observed structural response; and the feasibility of a methodology previously formulated to select the damping coefficient of fluid viscous devices, herein implemented with further details for practical use. This methodology was applied to the design of the protection Systems of the two test structures, and checked by comparing the target and experimentally obtained values of the governing energy-ratio coefficients.
Stefano Sorace - One of the best experts on this subject based on the ideXlab platform.
-
shaking table and numerical seismic performance evaluation of a fluid viscous dissipative Bracing System
Earthquake Spectra, 2012Co-Authors: Stefano Sorace, Gloria Terenzi, Fabio FadiAbstract:A shaking table campaign was carried out on a 2:3-scale, two-story steel frame structure retrofitted by a dissipative Bracing System incorporating pressurized fluid viscous spring-dampers. Up to 1....
-
fluid viscous damper based seismic retrofit strategies of steel structures general concepts and design applications
2009Co-Authors: Stefano Sorace, Gloria Terenzi, S MartaAbstract:Two advanced seismic protection technologies, represented by a dissipative Bracing System and a damped cable System, both incorporating fluid viscous dampers as passive control devices, are examined with special reference to their use in retrofitting steel structures. The essential characteristics and performance of the dampers and the two technologies, along with their analytical and computational modelling criteria, are recalled in the first part of this paper. A demonstrative design study concerning the application of both Systems to an Italian pre-normative steel school building is then presented, by discussing the mechanical parameters, dimensions, layouts and locations selected for the relevant constituting elements. The advantages of the two rehabilitation hypotheses are assessed in terms of the mutual performance objectives formulated at a preliminary design stage, based on the results of the modal and non-linear dynamic analyses carried out during the final verification phase. Structural implementation and technical installation details are finally provided for both retrofit solutions.
-
seismic protection of frame structures by fluid viscous damped braces
Journal of Structural Engineering-asce, 2008Co-Authors: Stefano Sorace, Gloria TerenziAbstract:A research study on a damped Bracing System incorporating pressurized silicone fluid viscous devices for seismic protection of frame structures is presented in this paper. This technology features an inverse-chevron brace configuration, where a pair of interfaced devices are placed, parallel with the floor-beam axis, at the tip end of each couple of supporting steel braces. The experimental section of this study consisted of a pseudodynamic testing campaign on a 2:3-scale three-story steel frame and a full-scale three-story reinforced concrete frame seismically retrofitted by the technology considered. Test results were elaborated to evaluate: the improvement of seismic response of both structures after retrofit, also assessed through a formal performance-based evaluation analysis; the capabilities of the assumed analytical and numerical models in reproducing the observed structural response; and the feasibility of a methodology previously formulated to select the damping coefficient of fluid viscous devices, herein implemented with further details for practical use. This methodology was applied to the design of the protection Systems of the two test structures, and checked by comparing the target and experimentally obtained values of the governing energy-ratio coefficients.
Constantin Christopoulos - One of the best experts on this subject based on the ideXlab platform.
-
application of hybrid simulation to fragility assessment of the telescoping self centering energy dissipative Bracing System
Earthquake Engineering & Structural Dynamics, 2014Co-Authors: Viswanath Kammula, Jeffrey Erochko, Ohsung Kwon, Constantin ChristopoulosAbstract:SUMMARY Substructure hybrid simulation has been the subject of numerous investigations in recent years. The simulation method allows for the assessment of the seismic performance of structures by representing critical components with physical specimens and the rest of the structure with numerical models. In this study the System level performance of a six-storey structure with telescoping self-centering energy dissipative (T-SCED) braces is validated through pseudo-dynamic (PsD) hybrid simulation. Fragility curves are derived for the T-SCED System. This paper presents the configuration of the hybrid simulation, the newly developed control software for PsD hybrid simulation, which can integrate generic hydraulic actuators into PsD hybrid simulation, and the seismic performance of a structure equipped with T-SCED braces. The experimental results show that the six-storey structure with T-SCED braces satisfies performance limits specified in ASCE 41. Copyright © 2013 John Wiley & Sons, Ltd.
-
cast steel yielding brace System for concentrically braced frames concept development and experimental validations
Journal of Structural Engineering-asce, 2014Co-Authors: Michael Gray, Constantin Christopoulos, Jeffrey A PackerAbstract:AbstractThe Yielding Brace System is a highly ductile Bracing System in which seismic energy is dissipated by the yielding fingers of a specially engineered cast steel connector. When the brace is severely loaded in tension and compression, the fingers yield in flexure, thus providing a full, symmetric hysteresis. Second-order geometric effects result in an increase in postyield stiffness at large displacements. The mechanics of the System are first presented, including several first principle equations used to predict a connector’s response. These equations are then used to design a prototype connector. The geometry of this prototype is evaluated using nonlinear finite element analysis. Following this analysis, the results of full-scale axial component testing of the prototype are discussed. These results include tensile coupon tests from material taken directly from unyielded portions of the test specimens. The prototype design and testing program presented demonstrate that the Yielding Brace System is ...
-
self centering energy dissipative Bracing System for the seismic resistance of structures development and validation
Journal of Structural Engineering-asce, 2008Co-Authors: Constantin Christopoulos, Robert Tremblay, Martin LacerteAbstract:Buildings designed according to modern seismic codes are expected to develop a controlled ductile inelastic response during major earthquakes, implying extensive structural damage after a design level earthquake, along with possibly substantial residual deformations. To address this drawback of traditional yielding Systems, a new Bracing System that can undergo large axial deformations without structural damage while providing stable energy dissipation capacity and a restoring force has recently been developed. The proposed Bracing member exhibits a repeatable flag-shaped hysteretic response with full recentering capabilities, therefore eliminating residual deformations. The mechanics of this new System are first explained, the equations governing its design and response are outlined, and one embodiment of the System, which combines a friction dissipative mechanism and Aramid tensioning elements, is further studied. Results from component tests, full-scale (reduced length) quasi-static axial tests, and quasi-static and dynamic seismic tests on a full-scale frame System are presented. Experimental results confirm the expected self-centering behavior of the self-centering energy dissipative (SCED) Bracing System within the target design drift. Results also confirm the validity of the design and behavior equations that were developed. It is concluded that the proposed SCED concept can represent a viable alternative to current braced frame Systems because of its attractive self-centering property and because the simplicity of the System allows it to be scaled to any desired strength level.
A. Q. Bhatti - One of the best experts on this subject based on the ideXlab platform.
-
Performance evaluation of retrofitting strategies for non-seismically designed RC buildings using steel braces
Bulletin of Earthquake Engineering, 2013Co-Authors: Humberto Varum, A. V. Pinto, F. Teixeira-dias, P. Marques, A. Q. BhattiAbstract:Recent major earthquakes around the world have evidenced that research in earthquake engineering must be directed to the vulnerability assessment of existing constructions lacking appropriate seismic resisting characteristics. Their retrofit or replacement should be made in order to reduce vulnerability, and consequent risk, to currently accepted levels. In this work, the efficiency of ductile steel eccentrically-braced Systems in the seismic retrofitting of existing reinforced concrete (RC) buildings is studied. The retrofit technique studied consists in a Bracing System with an energy dissipation device, designed to dissipate energy by shear deformation. The numerical model was calibrated with cyclic test results on a full-scale structure. The models used for the RC frame and masonry represent their real behavior and influence in the global structural response. The steel Bracing System was modeled with strut rigid elements. The model for the energy dissipater device reproduces rigorously the behavior of the shear-link observed in the cyclic tests, namely in terms of shear, drift and energy dissipation. With the calibrated numerical model, a series of non-linear dynamic analyses were performed, for different earthquake input motions, intending to study: the influence of the retrofitting System in the response of bare and infilled structures; the influence of the location and strength of the retrofitting System.
Martin Lacerte - One of the best experts on this subject based on the ideXlab platform.
-
self centering energy dissipative Bracing System for the seismic resistance of structures development and validation
Journal of Structural Engineering-asce, 2008Co-Authors: Constantin Christopoulos, Robert Tremblay, Martin LacerteAbstract:Buildings designed according to modern seismic codes are expected to develop a controlled ductile inelastic response during major earthquakes, implying extensive structural damage after a design level earthquake, along with possibly substantial residual deformations. To address this drawback of traditional yielding Systems, a new Bracing System that can undergo large axial deformations without structural damage while providing stable energy dissipation capacity and a restoring force has recently been developed. The proposed Bracing member exhibits a repeatable flag-shaped hysteretic response with full recentering capabilities, therefore eliminating residual deformations. The mechanics of this new System are first explained, the equations governing its design and response are outlined, and one embodiment of the System, which combines a friction dissipative mechanism and Aramid tensioning elements, is further studied. Results from component tests, full-scale (reduced length) quasi-static axial tests, and quasi-static and dynamic seismic tests on a full-scale frame System are presented. Experimental results confirm the expected self-centering behavior of the self-centering energy dissipative (SCED) Bracing System within the target design drift. Results also confirm the validity of the design and behavior equations that were developed. It is concluded that the proposed SCED concept can represent a viable alternative to current braced frame Systems because of its attractive self-centering property and because the simplicity of the System allows it to be scaled to any desired strength level.