• 한국구조물진단유지관리공학회 논문집
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• 제5권2호
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• pp.175-182
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• 2001

Five reinforced concrete frames were constructed and tested to study the structural performance of retrofitting effect reinforced concrete frame during and load revesals simultaneously. All specimens were modeling in one-third scale size. Experimental research was carried out to develop and evaluate the hysteretic behavior of reinforced concrete frame designed by high performance techniques, using carbon fiber plate, ALC panel, steel plate system with or without stiffener. Experimental programs wore carried to evaluate the structural performance of such test specimens, such as the hysteretic behavior, the maximum horizontal strength, crack propagation, and ductility etc. Specimens(RFCP, RFAR, RFSR, RFSR-S), designed by the improvement of earthquake-resistant performance, were attained more load-carrying capacity, energy dissipation capacity, and stable hysteretic behavior.

• Architectural research
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• 제2권1호
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• pp.61-69
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• 2000

This research focused on the hysteretic energy performance of 12 steel moment-resisting frames, which were intentionally designed by three types of design philosophies, strength control design, strength and drift control design, and strong-column and weak-beam control design. The energy performances of three designs were discussed In view of strength increase effect, stiffness increase effect, and strong-column and weak-beam effects. The mean hysteretic energy of the 12 basic systems were statically processed and compared to that of single-degree-of-freedom systems. Hysteretic energy was not always increased with an increase of strength and stiffness in the steel moment-resisting frames. Hysteretic energy between strong-column and weak-beam design and drift control design with the same stiffness was not sensitive each other for these types of mid-rises of steel moment-resisting frames.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계학술발표회 논문집(I)
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• pp.206-209
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• 2006

This study presents the performance evaluation of a tuned mass damper (TMD) for controlling seismic responses of the nonlinear hysteretic structure represented by a Bouc-Wen model, considering that the general reinforce concrete building structures subject to earthquake load show nonlinear hysteretic behavior. Numerical analysis result indicates that the performance of a passive TMD of which design parameters are optimized for a elastic structure deteriorates when the hysteretic portion of the structural responses increases, while a semi-actively operated TMD shows about 15-40% more response reduction than the TMD.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2001년도 봄 학술발표회 논문집
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• pp.406-413
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• 2001

The energy dissipation or damage prevention capability of structure can be greatly enhanced by employing hysteretic dampers. According to recent studies by the authors, the ratio of hysteretic damper stiffness to structural story stiffness has been identified as one of the most important parameters for characterizing the performance of this damper In this study the method for determining appropriate properties of hysteretic dampers to satisfy the given performance objectives is developed based on the concept of capacity spectrum method. The comparison with the results from inelastic time history analysis proves that the hysteretic dampers designed from the proposed method restrains the displacement well within the target displacement.

• Structural Engineering and Mechanics
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• 제38권1호
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• pp.39-63
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• 2011

Referring to the formulation of physical stochastic optimal control of structures and the scheme of optimal polynomial control, a nonlinear stochastic optimal control strategy is developed for a class of structural systems with hysteretic behaviors in the present paper. This control strategy provides an amenable approach to the classical stochastic optimal control strategies, bypasses the dilemma involved in It$\hat{o}$-type stochastic differential equations and is applicable to the dynamical systems driven by practical non-stationary and non-white random excitations, such as earthquake ground motions, strong winds and sea waves. The newly developed generalized optimal control policy is integrated in the nonlinear stochastic optimal control scheme so as to logically distribute the controllers and design their parameters associated with control gains. For illustrative purposes, the stochastic optimal controls of two base-excited multi-degree-of-freedom structural systems with hysteretic behavior in Clough bilinear model and Bouc-Wen differential model, respectively, are investigated. Numerical results reveal that a linear control with the 1st-order controller suffices even for the hysteretic structural systems when a control criterion in exceedance probability performance function for designing the weighting matrices is employed. This is practically meaningful due to the nonlinear controllers which may be associated with dynamical instabilities being saved. It is also noted that using the generalized optimal control policy, the maximum control effectiveness with the few number of control devices can be achieved, allowing for a desirable structural performance. It is remarked, meanwhile, that the response process and energy-dissipation behavior of the hysteretic structures are controlled to a certain extent.

• 대한토목학회논문집
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• 제28권5A호
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• pp.685-690
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• 2008

최근 대규모의 지진피해로 인해 내진설계에 대한 관심이 높아지면서, LRB(Lead Rubber Bearing), FPS(Friction Pendulum System) 등 다양한 지진격리장치에 대한 연구가 진행되고 있다. 본 연구에서 E-Shape 강재이력댐퍼를 이용한 지진격리장치의 성능 평가를 위해 E-Shape 댐퍼의 동적거동 실험을 수행하였으며, 이를 바탕으로 해석적 연구를 위한 수치모델을 제안하였다. 또한, 제안된 E-Shape 강재이력댐퍼의 수치모델을 6자유도를 가진 5층 건물에 적용하여 LRB 시스템과 이력거동을 비교하여 지진격리성능 평가를 수행하였다. 본 연구를 통하여 제안된 수치모델은 실제 E-Shape 강재이력댐퍼의 동적거동을 적절히 묘사할 수 있으며, E-Shape 강재이력댐퍼는 비선형 거동을 통한 에너지를 적절히 소산시킴으로서 기존 시스템과 비교하여 충분히 지진격리성능을 발휘할 수 있을 것으로 사료된다.

• Steel and Composite Structures
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• 제18권3호
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• pp.739-756
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• 2015

This paper presents investigations on the hysteretic behavior of concrete-filled circular tubular (CFCT) T-joints subjected to axial cyclic loading at brace end. In the experimental study, four specimens are fabricated and tested. The chord members of the tested specimens are filled with concrete along their full length and the braces are hollow section. Failure modes and load-displacement hysteretic curves of all the specimens obtained from experimental tests are given and discussed. Some indicators, in terms of stiffness deterioration, strength deterioration, ductility and energy dissipation, are analyzed to assess the seismic performance of CFCT joints. Test results indicate that the failures are primarily caused by crack cutting through the chord wall, convex deformation on the chord surface near brace/chord intersection and crushing of the core concrete. Hysteretic curves of all the specimens are plump, and no obvious pinching phenomenon is found. The energy dissipation result shows that the inelastic deformation is the main energy dissipation mechanism. It is also found from experimental results that the CFCT joints show clear and steady stiffness deterioration with the increase of displacement after yielding. However, all the specimens do not perform significant strength deterioration before failure. The effect of joint geometric parameters ${\beta}$ and ${\gamma}$ of the four specimens on hysteretic performance is also discussed.

• Steel and Composite Structures
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• 제8권6호
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• pp.441-455
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• 2008

This paper presents an effective hysteretic model for the prediction and evaluation of steel reinforced concrete member seismic performance. This model adopts the load-deformation relationship acquired from monotonic load tests and incorporates the double-pivot behavior of composite members subjected to cyclic loads. Deterioration in member stiffness was accounted in the analytical model. The composite member performance assessment control parameters were calibrated from the test results. Comparisons between the cyclic load test results and analytical model validated the proposed method's effectiveness.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 추계학술대회논문집
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• pp.257-262
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• 2003

Base isolation bearings are known as an effective system to Protect bridges from the earthquake damage. There are many types of base isolation bearings in the market. Among them, steel hysteretic damper, made of mild steel and one of the oldest ones, has some good features. Since steel hysteretic damper is made of steel and has simple structure, it is cheeper and easier to maintain than other types. Despite the advantages, steel hysteretic damper with pin-type elements has no application in Korea. The steel hysteretic damper with pin-type elements are tested to examin the basic characteristics and to evaluate antiseismic performance. In this paper, the results of the test are presented.

• Structural Engineering and Mechanics
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• 제84권3호
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• pp.345-360
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• 2022

In this paper, the impact on seismic performance of an economical effective technique for retrofitting reinforced concrete (RC) columns using high-strength steel strips under high axial compression ratios was presented. The experimental program included a series of cyclic loading tests on one nonretrofitted control specimen and three retrofitted specimens. The effects of the axial compression ratio and spacing of the steel strips on the cyclic behavior of the specimens were studied. Based on the test results, the failure modes, hysteretic characteristics, strength and stiffness degradation, displacement ductility, and energy dissipation capacity of the specimens were analyzed in-depth. The analysis showed that the transverse confinement provided by the high-strength steel strips could effectively delay and restrain diagonal crack development and improve the failure mode, which was flexural-shear failure controlled by flexural failure with better ductility. The specimens retrofitted using high-strength steel strips showed more satisfactory seismic performance than the control specimen. The seismic performance and deformation capacity of the retrofitted RC columns increased with decreasing axial compression ratio and steel strip spacing. Based on the test results, a hysteretic model for RC columns that considers the transverse confinement of high-strength steel strips was then established. The hysteretic model showed good agreement with the experimental results, which verified the effectiveness of the proposed hysteretic model. Therefore, the aforementioned analysis can be used for the design of retrofitted RC columns.