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Comparative Study on Effect of Metallic Yield Dampers and Friction Devices on Response of Steel Structure
, M.Sc. Thesis Sharif University of Technology ; Kazemi, Mohammad Taghi (Supervisor)
Abstract
Passive energy dissipation systems are mechanical devices which could spread input energy, reduce response and decrease possible damage of the structure. Dampers were identified as a strong energy dissipation devices with cost efficiency and easy installation and maintanance. In this study, effects of using friction and metallic yield dampers to reduce structural responses are investigated. In addition, a comparison between these devices for reducing responses are conducted. Two 5 and 10 stories buildings with intermediate steel moment frames with and without damper are modeled and designed. It is seen, using of dampers could be reduce sections’ sizes. Seven pairs of earthquake records...
Numerical Simulation of a Telescopic Metallic Yielding Damper
, M.Sc. Thesis Sharif University of Technology ; Eskandari, Morteza (Supervisor)
Abstract
In this study, a new type of metallic yielding damper called Telescopic damper is proposed and analyzed numerically. The damper comprises of three concentric steel tubes connected together by lead shear keys. The relative axial deformation of steel tubes under axial forces results in shear deformation and yielding in lead shear keys and dissipates energy. The inner steel tube has a lock which limits its movement to some certain extent and beyond this limit the outer tube activates. Therefore, a multi-linear force-deformation behavior with two different yield plateaus is expected for the introduced telescopic damper. The multi-level yield plateaus of damper makes it effective in both low and...
On the Assessment of a Novel Exemplary Metallic Yielding Damper
,
M.Sc. Thesis
Sharif University of Technology
;
Mofid, Massood
(Supervisor)
;
Khezrzadeh, Hamed
(Co-Advisor)
Abstract
One of the passive control systems that are used widely in today’s buildings are metallic yielding dampers. Metallic yielding dampers by absorbing earthquake input energy, prevent inelastic defromations form in beams and columns. In this research, the behavior of an innovated metallic yielding damper, named pistonic damper is investigated. This damper consists of a number of circular parallel plates with constant or variable thickness that dissipate seismic input energy by flexure yielding in small displacements. at large displacements stress field in plates is changed and this caused the stiffness and strength of damper are increased and show shell behavior. this kind of behavior...
Analytical and Parametric Study of Telescopic Lead Shear Damper
, M.Sc. Thesis Sharif University of Technology ; Eskandari, Morteza (Supervisor) ; Arghavani, Jamal (Supervisor)
Abstract
This research studies behavior and implementing of telescopic lead shear damper in structures. Telescopic lead shear damper (TLSD) is a type of metallic yielding dampers that can dissipated energy with usage of shear yielding of lead. TLSD is made from behind act of two lead shear damper (LSD) like a telescope. Lead shear damper composed of two coaxial steel pipes where their interfacial gap is filled with pure lead. The interface of lead and steel pipes are roughened in a threaded form to guarantee the no-slip condition across the interface. Due to stable and fat force displacement hysteresis loops of TLSD, this device can be used in structures subjected to wind, seismic, and other dynamic...
Performance Based Analysis of Steel Bridges with Telescopic Dampers
, M.Sc. Thesis Sharif University of Technology ; Eskandari, Morteza (Supervisor)
Abstract
The main purpose of this study is Performance Based Analysis of steel bridges equipped with Telescopic Dampers and also to design a suitable damper in order to improve the behavior of the structural system and, consequently, reduce the damage to the structure after the earthquake. Different models of dampers such as Buckling Restrained Braces (BRB’s), Hydraulic Dampers, Viscous Dampers, Shear Panel Dampers, Visco-Elastic Dampers, etc., are used according to their specifications along with Laminated Rubber Bearings (LRB’s) to control the structural behavior of bridge, reduce deck displacement and base shear. The result of this project is the design of a special type of telescopic dampers,...
Comparison between uniform deformation method and Genetic Algorithm for optimizing mechanical properties of dampers
, Article Earthquake and Structures ; Volume 14, Issue 1 , February , 2018 , Pages 1-10 ; 20927614 (ISSN) ; Mirjalaly, M ; Mirtaheri, M ; Nazeryan, M ; Sharif University of Technology
Techno Press
2018
Abstract
Seismic retrofitting of existing buildings and design of earth-quake resistant buildings are important issues associated with earthquake-prone zones. Use of metallic-yielding dampers as an energy dissipation system is an acceptable method for controlling damages in structures and improving their seismic performance. In this study, the optimal distribution of dampers for reducing the seismic response of steel frames with multi-degrees freedom is presented utilizing the uniform distribution of deformations. This has been done in a way that, the final configuration of dampers in the frames lead to minimum weight while satisfying the performance criteria. It is shown that such a structure has an...
Experimental and Numerical Modeling of Telescopic Damper
, M.Sc. Thesis Sharif University of Technology ; Eskandari, Morteza (Supervisor)
Abstract
This study proposes a new metallic yielding damper for seismic applications. First, considering the damper proposed by curadelli in 2009 a simple lead yielding damper was manufactured to determine its maximum allowable axial deformation showing that it cannot tolerate suitable axial deformations. To solve this problem a telescopic damper with curadelli damper’s descriptions was manufactured and tested which increased the last damper’s allowable deformation 100%. Although new damper’s allowable deformation is twofold the old one, it was not enough for seismic applications. In the next step 6 dampers called lead shear dampers (LSD) with modified lead section were tested. LSD deformation...
Parametric Study of Telescopic Metallic Yielding Dampers
, M.Sc. Thesis Sharif University of Technology ; Eskandari, Morteza (Supervisor)
Abstract
The parametric study of a new introduced metallic yielding damper called telescopic damper is addressed. The telescopic damper comprises of three concentric steel pipes connected together by lead shear keys. The inner and outer steel pipes are subjected to axial loading which results in the shear yielding of the embedded lead cylinders. The inner steel pipe has a lock which limits its movement to some certain extent and beyond this limit the outer tube activates. Employing ABAQUS software, the behavior of damper under cyclic loading is studied numerically. The finite element model is verified by available results in the literature. The effects of inner and outer steel pipes thickness,...
Seismic Analysis of Multi-Degree Freedom Structures Equipped with Telescopic Metallic Yield Dampers (TLYD)
, M.Sc. Thesis Sharif University of Technology ; Eskandari, Morteza (Supervisor)
Abstract
Ordinary structures absorb a large amount of input energy by structural elements whereas failure in these elements causes a huge loss in structure and it’s really difficult to repair or unrepairable. Nowadays a wide range of metallic dampers is used in structures as fuse elements. this research evaluates the response of structures that are equipped with a novel steel damper named Telescopic Lead Yield Damper (TLYD) which was introduced by Eskandari in 2018. As TLYD has a different yielding plateau it can tolerate large deformations. In this research firstly this novel damper was introduced and the performance of the damper under cyclic loading was demonstrated. Then a numerical model of 6,...
Experimental and numerical evaluation of piston metallic damper (PMD)
, Article Journal of Constructional Steel Research ; Volume 154 , 2019 , Pages 99-109 ; 0143974X (ISSN) ; Khezrzadeh, H ; Mofid, M ; Jafari, K ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
In this paper, a metallic yielding damper, called piston metallic damper (PMD) is introduced for the first time. The PMD is comprised of a set of parallel hollow circular plates that interconnect inner shaft of the PMD to its outer pipe. Experiments and numerical models are used to examine its applicability as a seismic energy dissipating device. In this novel damper seismic input energy will be dissipated through flexural yielding of circular steel plates when system experiences small to medium displacements. At large displacements, tensile behavior will dominate and causes significant increase in stiffness of the system. In experimental program, different specimens were tested and the...
Life-Cycle Cost-Based Seismic Retrofit of Steel Frame with Dual Pipe Damper
, M.Sc. Thesis Sharif University of Technology ; Maleki, Shervin (Supervisor)
Abstract
Nowadays seismic designs of building structures are based on a life-safety criterion that made the structures do not collapse to compromise safety of human life in the structure, but they can be designed to experience some damage. However, this design method has permitted large economic losses due to the damage to the structural and non-structural components at rather moderate levels of seismic intensities. This led to a new concept about design approach called performance-based design that satisfies the life-safety objective at the same time, reduces the economic loss to an acceptable level. In this study, the use of energy dissipating damping devices to improve the performance of a...
Experimental and analytical study of telescopic lead yielding damper
, Article Journal of Constructional Steel Research ; Volume 150 , 2018 , Pages 371-383 ; 0143974X (ISSN) ; Pournamazian Najafabadi, E ; Sharif University of Technology
Abstract
In this study, a novel type of passive energy dissipation device called a Telescopic Lead Yielding Damper (TLYD) is proposed and analyzed. This device comprises co-axial steel cylinders and lead rings, such that these rings act as shear locks between the steel cylinders. TLYDs dissipate energy through the plastic shear deformation of lead metal. The telescopic mechanism used in TLYDs allows these small-sized dampers to tolerate large axial displacements with low fatigue. For each telescopic level, a yield plateau is added to the hysteresis behavior of TLYD devices. Each yield plateau resists a different performance level, namely design-based and maximum credible earthquakes. Seven...
Performance-based seismic design and assessment of low-rise steel special moment resisting frames with block slit dampers using endurance time method
, Article Engineering Structures ; Volume 224 , 2020 ; Pournamazian Najafabadi, E ; Esmailpur Estekanchi, H ; Ozbakkaloglu, T ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
Block Slit Dampers (BSDs) are recently developed metallic yielding dampers for passive structural control. This type of damping devices can provide designers with an option of using highly ductile systems, such as steel special moment resisting frames (steel SMRFs), in important structures located in regions of high seismicity. The aim of this study is to obtain a performance-based seismic design (PBSD) procedure for these devices, and to assess the seismic performance levels of low-rise steel SMRF equipped with BSDs using the endurance time (ET) dynamic analysis method. For this purpose, first, the simplified behavioral model of these devices was established based on the analysis of...