• 한국건설순환자원학회논문집
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• 제5권4호
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• pp.382-388
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• 2017

본 연구에서는 공공건물에 보강이 가능하도록 건물 외부에 록킹 월을 설치하고 이를 본 구조에 강재댐퍼로 연결하는 외부 보강 내진공법에 대한 기초 연구를 시행하였다. 2개의 실험체를 제작하였으며, 댐퍼 비보강 실험체는 기존 결과를 활용하였다. 포락선, 강도, 강성저하 및 에너지 소산능력을 평가한 결과, 플레이트 댐퍼를 외부 보강한 RW_P 실험체의 강도 증진이 우수한 것으로 평가되었다. 또한 S형 댐퍼를 외부 부착한 RW_S 실험체는 최대하중 이후에 완만한 포락곡선을 보여 댐퍼가 하중을 적절히 소산하는 것을 확인할 수 있었다.

• 한국강구조학회 논문집
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• 제24권4호
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• pp.371-382
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• 2012

기존의 전단벽 시스템은 커플링보를 강하게 설계하는 경우가 많아 상대적으로 내력 및 강성이 낮은 콘크리트 코어와 특정층에 손상이 발생되기 쉬워 건물의 연성이 저하된다. 전단벽 시스템의 연성능력 및 내진성능을 향상시키기 위해 본 연구에서 강성은 기존의 커플링보 이상으로 발휘되면서 설계하중에 따라 내력을 용이하게 변화시킬 수 있는 강재이력댐퍼를 커플링보에 적용하였다. 강재이력댐퍼는 2단으로 직렬 연결된 형상으로 제안하였고, 제안된 강재이력댐퍼의 구조성능을 검증하기 위하여 정적실험을 수행하였다. 또한 FEM 해석결과를 실험결과와 비교 검증하고 강재이력댐퍼의 초기강성, 에너지 흡수능력, 변형능력 등을 분석하여 설계 근사식을 제안하였다.

• 융복합기술연구소 논문집
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• 제4권2호
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• pp.17-21
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• 2014

This paper presents the effects of the time delay on the stability of the haptic system that includes a virtual wall and a first-order-hold method. The model of a haptic system includes a haptic device model with a mass and a damper, a virtual wall model, a first-order-hold model and a time delay model. In this paper, the time delay is considered as the computational time delay that is assumed to be as much as the sampling time. As the time delay increases, the maximal available stiffness of a virtual wall model is reduced reversely. The relation among the time delay and the maximum available stiffness, the mass and the damper of the haptic device are analyzed using the MATLAB simulation.

• Structural Engineering and Mechanics
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• 제64권2호
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• pp.183-194
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• 2017

This paper presents the experimental investigation into a new type of steel-concrete hybrid outrigger system developed for the high-rise building structure. The steel truss is embedded into the reinforced concrete outrigger wall, and both the steel truss and concrete outrigger wall work compositely to enhance the overall structural performance of the tower structures under extreme loads. Meanwhile, metal dampers of low-yield steel material were also adopted as a 'fuse' device between the hybrid outrigger and the column. The damper is engineered to be 'scarified' and yielded first under moderate to severe earthquakes in order to protect the structural integrity of important structural components of the hybrid outrigger system. As such, not brittle failure is likely to happen due to the severe cracking in the concrete outrigger wall. A comprehensive experimental research program was conducted into the structural performance of this new type of hybrid outrigger system. Studies on both the key component and overall system tests were conducted, which reveal the detailed structural response under various levels of applied static and cyclic loads. It was demonstrated that both the steel bracing and concrete outrigger wall are able to work compositely with the low-yield steel damper and exhibits both good load carrying capacities and energy dispersing performance through the test program. It has the potential to be applied and enhance the overall structural performance of the high-rise structures over 300 m under extreme levels of loads.

• 한국기계가공학회지
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• 제14권1호
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• pp.21-28
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• 2015

A Tsunami damper, which is installed on the outer wall of a nuclear power plant, is usually used as a ventilation window of the machine room, but can serve as a device for preventing flooding of the machine room when large waves flow over the outer wall. The sealing strip, which is inserted between the casing and the blades, plays an important role in maintaining a watertight environment. In this study, in order to ensure an effective watertight performance of the tsunami damper, FE analysis is conducted to compare the contact characteristics of sealing strips with three different section shapes. In the analysis, the casing and the blade of Tsunami damper are assumed to be rigid bodies; the sealing strip is assumed to be a flexible body. The stress, the strain, and the contact pressure are investigated to examine the sealing performance of each model.

• 한국공간구조학회논문집
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• 제17권4호
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• pp.77-84
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• 2017

As an alternative to coupling beam in shear wall system, application of the damper which can dissipate energy is increasing. In this study, lintel beam type steel damper which is simple to construct and change depending on design load was proposed. Cyclic loading test was conducted to compare reinforced concrete coupling beam and lintel beam type steel damper. The test results showed that lintel beam type steel damper has higher initial stiffness and energy dissipation capacity than reinforced concrete coupling beam.

• 한국구조물진단유지관리공학회 논문집
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• 제24권6호
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• pp.1-9
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• 2020

본 연구에서는 벽체의 록킹 거동을 고려한 내진보강 기법을 개발하였다. 록킹 거동은 벽체 수직 축을 중심으로 좌우로 회전하는 것으로, 개발 시스템은 변위 큰 부분에 댐퍼 등을 설치하여 에너지를 소산 시키는 방법이다. 댐퍼는 강봉 댐퍼를 사용하였으며, 강봉 지름 및 길이(형상비)를 변수로 선정하였다. 실험결과 댐퍼길이 260mm 경우 우수한 내진 성능을 보유한 것으로 평가되었다.

• 한국지진공학회논문집
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• 제27권2호
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• pp.91-99
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• 2023

Structural vibration induced by earthquake hazards is one of the most significant concerns in structure performance-based design. Structural hazards evoked from seismic events must be properly identified to make buildings resilient enough to withstand extreme earthquake loadings. To investigate the effects of combined earthquake-resistant systems, shear walls and five types of dampers are incorporated in nineteen structural models by altering their arrangements. All the building models were developed as per ACI 318-14 and ASCE 7-16. Seismic fragility curves were developed from the incremental dynamic analyses (IDA) performed by using seven sets of ground motions, and eventually, by following FEMA P695 provisions, the collapse margin ratio (CMR) was computed from the collapse curves. It is evident from the results that the seismic performance of the proposed combined shear wall-damper system is significantly better than the models equipped with shear walls only. The scrutinized dual seismic resisting system is expected to be applied practically to ensure a multi-level shield for tall structures in high seismic risk zones.

• 한국지진공학회논문집
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• 제18권5호
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• pp.241-251
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• 2014

In this study, shaking table test was carried out to evaluate the seismic behavior and performance of low-rise reinforced concrete (RC) piloti structures with and without retrofit. The specimens were designed considering the characteristics of existing building with pilotis such as natural period, distribution factor of strength and stiffness between columns and core wall on the first soft story. The test for the non-retrofit specimen showed that damage was concentrated on the stiffer member on the same floor as the core wall failed by shear fracture whereas columns experienced slight flexural cracks. Considering the failure mode of the non-retrofit specimen, the retrofit method using steel rod damper was presented for improving the seismic performance of piloti structures. The results of the test for retrofit specimen revealed that the retrofit method was effective for controlling the damage as the main RC structural members were not destroyed and most of input energy was dissipated by hysteretic behavior of the damper.

• Smart Structures and Systems
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• 제14권6호
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• pp.1031-1054
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• 2014

Real-time hybrid simulation (RTHS) of a stacked wood shear wall retrofitted with a rate-dependent seismic energy dissipation device (viscous damper) was conducted at the newly constructed Structural Engineering Laboratory at the University of Alabama. This paper describes the implementation process of the RTHS focusing on the controller scheme development. An incremental approach was adopted starting from a controller for the conventional slow pseudodynamic hybrid simulation and evolving to the one applicable for RTHS. Both benchmark-scale and full-scale tests are discussed to provide a roadmap for future RTHS implementation at different laboratories and/or on different structural systems. The developed RTHS controller was applied to study the effect of a rate-dependent energy dissipation device on the seismic performance of a multi-story wood shear wall system. The test specimen, setup, program and results are presented with emphasis given to inter-story drift response. At 100% DBE the RTHS showed that the multi-story shear wall with the damper had 32% less inter-story drift and was noticeably less damaged than its un-damped specimen counterpart.