• Journal of the Korea Concrete Institute
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• v.27 no.6
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• pp.625-632
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• 2015

In this study, a comparative analysis have been conducted to examine seismic reinforcement effect of a school building that is designed with a CBD (Channel Beam Damper) system supported by H-frame with existing non-seismic RC frame. As a result of experiment, seismic reinforcement specimen with CBD system showed hysteretic characteristics of a large ellipse with great energy dissipation ability and increased strength and stiffness, while non-seismic design specimen showed rapid reduction in strength and brittle shear failure at top and bottom of the left and right column. In addition, comparing the stiffness reduction between the two specimens, CBD system was effective in preventing the reduction of stiffness. Energy dissipation ability of specimen reinforced by CBD system was about 4.0 times higher than the non-reinforced specimen. Such enhancement in energy dissipation ability could be considered as the result of improved strength and deformation for further application in designing of seismic reinforcement.

• Journal of Korean Association for Spatial Structures
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• v.13 no.3
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• pp.45-55
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• 2013

The core aim of this paper is to empirically scrutinize a strength characteristic and ductility of the beam-column frame of reinforced with steel subjected to the cyclic lateral load. First and foremost, I the author embarks upon making four prototypes vis-$\grave{a}$-vis this research. Through this endeavour, the author has analysed cyclic behavior, fracture shape, ductility and energy dissipation of the normal beam-column frame and a beam-column frame of reinforced with steel. In addition, the survey has revealed the exact stress transfer path and the destructive mechanism in order to how much a beam-column frame of reinforced with steel has resistance to earthquake regarding all types of building, as well as school construction. To get the correct data, the author has compared the normal beam-column frame and three types of the beam-column frame of reinforced with steel following these works, the characteristic of cyclic behavior, destructive mechanism, ductility, and Energy dissipation of normal beam-column frame and a beam-column frame of reinforced with steel have been examined clearly.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.2
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• pp.148-153
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• 2018

In this study, the nonlinear time history analysis of seismic retrofitted structures with TS damper for seven ground motion records was conducted for the purpose of verifying the seismic strengthening effect of TS seismic retrofitting method. Through comparison of the interstory drift ratio and the energy dissipation amount of the non - reinforced structure obtained and those of retrofitted structures with TS damper from the nonlinear time history analysis, the interstory drift ratio was reduced by about 30% and the amount of energy dissipation through the structure was halved. As a result, it was confirmed that the damping performance of the TS seismic retrofitting method is excellent.

• Earthquakes and Structures
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• v.25 no.6
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• pp.443-454
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• 2023

Steel shear walls are used to strengthen steel and concrete structures. One such system is Partial Attached Steel Shear Walls (PASSW), which are only connected to frame beams. This system offers both structural and architectural advantages. This study first calibrated the numerical model of RC frames with and without PASSW using an experimental sample. The seismic performance of the RC frame was evaluated by 30 non-linear static analyses, which considered stiffness, ductility, lateral strength, and energy dissipation, to investigate the effect of PASSW width and column axial load. Based on numerical results and a curve fitting technique, a lateral stiffness equation was developed for frames equipped with PASSW. The effect of the shear wall location on the concrete frame was evaluated through eight analyses. Nonlinear dynamic analysis was performed to investigate the effect of the shear wall on maximum frame displacement using three earthquake records. The results revealed that if PASSW is designed with appropriate stiffness, it can increase the energy dissipation and ductility of the frame by 2 and 1.2 times, respectively. The stiffness and strength of the frame are greatly influenced by PASSW, while axial force has the most significant negative impact on energy dissipation. Furthermore, the location of PASSW does not affect the frame's behavior, and it is possible to have large openings in the frame bay.

• Steel and Composite Structures
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• v.51 no.1
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• pp.93-101
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• 2024

This paper presents an experimental and analytical study on a steel slit damper designed as an energy dissipative device for earthquake protection of structures considering soil-structure interaction. The steel slit damper is made of a steel plate with a number of slits cut out of it. The slit damper has an advantage as a seismic energy dissipation device in that the stiffness and the yield force of the damper can be easily controlled by changing the number and size of the vertical strips. Cyclic loading tests of the slit damper are carried out to verify its energy dissipation capability, and an analytical model is developed validated based on the test results. The seismic performance of a case study building is then assessed using nonlinear dynamic analysis with and without soil-structure interaction. The soil-structure system turns out to show larger seismic responses and thus seismic retrofit is required to satisfy a predefined performance limit state. The developed slit dampers are employed as a seismic energy dissipation device for retrofitting the case study structure taking into account the soil-structure interaction. The seismic performance evaluation of the model structure shows that the device works stably and dissipates significant amount of seismic energy during earthquake excitations, and is effective in lowering the seismic response of structures standing on soft soil.

• Journal of KIISE:Computer Systems and Theory
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• v.32 no.6
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• pp.324-332
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• 2005

In general, bus system consumes a very significant portion of power in a chip. Bus splitting can be used to reduce the energy dissipation and to reduce the Propagation delay on the bus by lowering the parasitic load of each bus segment. Data exchange probability distribution between a set of interconnected processing elements affects the average energy dissipation of the splitted bus architectures. In this research, we have developed tree-based bus splitting techniques and design methodologies, as an extension of horizontally aligned bus splitting. We have developed the methodology to select near-optimal bus architectures for low energy dissipation when data exchange probability distribution of a system is given. Experimental results show that the proposed techniques can reduce energy dissipation on the bus by up to 83$\%$.

• Smart Structures and Systems
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• v.4 no.2
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• pp.137-152
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• 2008

The work presented in this paper includes material characterisation and an investigation of suitability in seismic dampers for two commercially available NiTi-alloys, along with a numerical analysis of a new damper system employing composite NiTi-wires. Numerical simulations of the new damper system are conducted, using Brinson's one-dimensional constitutive model for shape memory alloys, with emphasis on the system's energy dissipation capabilities. The two alloys tested showed some unwanted residual strain at temperatures higher than $A_f$, possibly due to stress concentrations near inclusions in the material. These findings show that the alloys are not ideal, but may be employed in a seismic damper if precautions are made. The numerical investigations indicate that using composite NiTi-wires in a seismic damper enhances the energy dissipation capabilities for a wider working temperature range.

• International Journal of High-Rise Buildings
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• v.3 no.2
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• pp.107-120
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• 2014

A Reinforced concrete (RC) shear wall system with coupling beams has been known as one of the most promising structural systems for high-rise buildings. However, significantly large flexural and/or shear stress demands induced in the coupling beams require special reinforcement details to avoid their undesirable brittle failure. In order to solve this problem, one of promising candidates is frictional hysteretic energy dissipating devices (HEDDs) as an alternative to the coupling beams. The introduction of frictional HEDDs into a RC shear wall system increases energy dissipation capacity and maintains the frame action after their yielding. This paper investigates the strength demands (specifically yield strength levels) with a maximum allowable ductility of frictional HEDDs based on comparative non-linear time-history analyses of a prototype RC shear wall system with traditional RC coupling beams and frictional HEDDs. Analysis results show that the RC shear wall systems coupled by frictional HEDDs with more than 50% yield strength of the RC coupling beams present better seismic performance compared to the RC shear wall systems with traditional RC coupling beams. This is due to the increased seismic energy dissipation capacity of the frictional HEDD. Also, it is found from the analysis results that the maximum allowable ductility demand of a frictional HEDD should increase as its yield strength decreases.

• Ocean Systems Engineering
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• v.11 no.1
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• pp.1-16
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• 2021

Experimental and numerical investigations were conducted to study the performance of a surface-fixed horizontal porous wave barrier in regular waves. The characteristics of the reflection and transmission coefficients, energy dissipation, and vertical wave force were examined versus different porosities of the barrier. Numerical simulations based on 3D Reynolds Averaged Navier-Stokes equations with standard low-Re k-ε turbulent closure and volume of fluid approach were accomplished and compared with the experimental results conducted in a 2D wave tank. Experimental measurements and numerical simulations were shown to be in satisfactory agreement. The qualitative wave behavior propagating over a horizontal porous barrier such as wave run-up, wave breaking, air entrapment, jet flow, and vortex generation was reproduced by CFD computation. Through the discrete harmonic decomposition of the vertical wave force on a wave barrier, the nonlinear characteristics were revealed quantitatively. It was concluded that the surface-fixed horizontal barrier is more effective in dissipating wave energy in the short wave period region and more energy conversion was observed from the first harmonic to higher harmonics with the increase of porosity. The present numerical approach will provide a predictive tool for an accurate and efficient design of the surface-fixed horizontal porous wave barrier.

• Journal of Korean Society of Steel Construction
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• v.25 no.1
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• pp.81-92
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• 2013

The objective of conventional seismic design is to ensure an acceptable safety level while avoiding catastrophic failures of structures and loss of life. Over the last many years, a large amount of research has been devoted into developing effective earthquake resistant systems in order to raise the seismic performance level of structures. The purpose of this study is to propose a new damping system, which realize not only increasing seismic performance but also easy repairing after an earthquake. The proposed damping system is slit in the bottom of wall with damping devices installed in the slit horizontally aiming to dissipate energy during earthquakes. Cyclic loading tests were conducted to investigate hysteretic behavior and energy dissipation capacity. Test results show that the proposed systems exhibit a stable hysteretic response and the energy dissipation in this system is concentrated on the damping devices.