• 한국공간구조학회논문집
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• 제16권3호
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• pp.99-106
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• 2016

The proposed hybrid damper installs at a coupling beam and consists of a high-damping rubber (HDR) and steel pin. The proposed hybrid damper adopted a pin-lock system acts as a viscoelastic damper under wind load (small displacement) while it behaves as a hysteretic damper under earthquake load (large displacement). In this paper, the pin-lock mechanism and structural performance of the proposed hybrid damper is evaluated through experiment. Experiments were carried out with the variables which displacement, loading frequency and steel pin quantities were used. Test results showed that the pin-lock mechanism and the performance of the hybrid damper under a large displacement were verified. Also equivalent damping ratios of HDR were increasing at a small displacement as displacement amplitudes were increasing. However HDR did not depend on frequency.

• 한국구조물진단유지관리공학회 논문집
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• 제7권4호
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• pp.201-208
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• 2003

철근콘크리트 코어 벽체와 외부 철골골조로 구성된 복합벽체시스템은 중앙 코아 전단벽 주변의 오픈공간을 갖는다. 이와 같은 복합 벽체시스템은 연결된 벽체가 대부분의 횡하중에 저항하고 벽체저면과 커플링 보에서 대부분의 에너지를 소산할 수 있는 설계기법을 개발하는 것이 필요하다. 본 연구논문은 커플링 보의 접합방식 및 층규모를 주변수로 수직하중 및 풍하중과 지진하중을 받는 복합 벽체시스템에 대하여 전단력, 전도모멘트, 최대 횡변위, 층간변위비 및 동적특성을 규명하였다.

• Structural Engineering and Mechanics
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• 제73권3호
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• pp.239-257
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• 2020

In the present study, an innovative steel bracket and haunch hybrid scheme is devised, for retrofitting of earthquake damaged deficient beam-column sub-assemblages. Formulations are presented for evaluating haunch force factor under combined load case of lateral and gravity loads for the design of double haunch retrofit. The strength hierarchies of control and retrofitted beam-column sub-assemblages are established to showcase the efficacy of the retrofit in reversing the undesirable strength hierarchy. Further, the efficacy of the proposed retrofit scheme is demonstrated through experimental investigations carried out on gravity load designed (GLD), non-ductile and ductile detailed beam-column sub-assemblages which were damaged under reverse cyclic loading. The maximum load carried by repaired and retrofitted GLD specimen in positive and negative cycle is 12% and 28% respectively higher than that of the control GLD specimen. Further, the retrofitted GLD specimen sustained load up to drift ratio of 5.88% compared with 2.94% drift sustained by control GLD specimen. Repaired and retrofitted non-ductile specimen, could attain the displacement ductility of three during positive cycle of loading and showed improved ductility well above the expected displacement ductility of three during negative cycle. The hybrid haunch retrofit restored the load carrying capacity of damaged ductile specimen to the original level of control specimen and improved the ductility closer to the expected displacement ductility of five. The total cumulative energy dissipated by repaired and retrofitted GLD, non-ductile and ductile specimens are respectively 6.5 times, 2.31 times, 1.21 times that of the corresponding undamaged control specimens. Further, the damage indices of the repaired and retrofitted specimens are found to be lower than that of the corresponding control specimens. The novel and innovative steel bracket and haunch hybrid retrofit scheme proposed in the present study demonstrated its effectiveness by attaining the required displacement ductility and load carrying capacity and would be an excellent candidate for post-earthquake retrofit of damaged existing RC structures designed according to different design evolutions.

• 한국생산제조학회지
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• 제22권5호
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• pp.871-878
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• 2013

Roll-to-roll (R2R) hot embossing systems have been developed and are widely used in various industrial domains. These systems press and heat flexible films between a press roll and a back-up roll, as said films pass through the two rolls. In previous studies, a heating roll was used for heating. However, in this study, a hybrid roll for R2R hot embossing is conceptualized and developed. This R2R system can be used for generating fine patterns on large and continuous films. The hybrid roll of our system can cool and heat the films simultaneously, thus affording greater flexibility in process design. Thermal and structural analyses were performed for developing the hybrid roll. In addition, a hybrid roll was designed based on analytical results. Experiments were conducted for measuring the performance of the developed hybrid roll.

• Structural Engineering and Mechanics
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• 제70권1호
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• pp.81-96
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• 2019

In this paper, a hybrid uncertain model is applied to system reliability based design optimization (RBDO) of trusses. All random variables are described by random distributions but some key distribution parameters of them which lack information are defined by variation intervals. For system RBDO of trusses, the first order reliability method, as well as monotonicity analysis and the branch and bound method, are utilized to determine the system failure probability; and Improved (${\mu}+{\lambda}$) constrained differential evolution (ICDE) is employed for the optimization process. System reliability assessment of several numerical examples and system RBDO of different truss structures are proposed to verify our results. Moreover, the effect of different classes of interval distribution parameters on the optimum weight of the structure and the reliability index are also investigated. The results indicate that the weight of the structure is increased by increasing the uncertainty level. Moreover, it is shown that for a certain random variable, the optimum weight is more increased by the translation interval parameters than the rotation ones.

• 한국기계가공학회지
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• 제16권6호
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• pp.75-80
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• 2017

The use of optical fiber makes it possible to transfer a large amount of data, thereby enabling a high-speed image transmission with a high response speed and a large number of frames. The need for an optical fiber HDMI System has grown in importance due to the rapid development of displays with large sizes and high-resolution images. In this paper, we have studied the structural design and FEM analysis of a 4C fiber guide for hybrid interconnection implementation. According to the structural analysis of the fiber guide, we have confirmed the safety of the design and we will make additional design changes to minimize the optical loss and fabricate a fiber guide for photoelectric composite HDMI in the future.

• 한국전산구조공학회논문집
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• 제18권3호
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• pp.227-243
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• 2005

본 논문에서는 지진하중을 받는 사장교에 납고무받침과 유압식 가력기를 결합한 복합제어 시스템을 적용하였다. 복합제어 시스템은 다중의 제어장치로 인해 제어성능의 향상을 기대할 수 있지만 추가적으로 사용되는 능동제어 장치로 인하여 전체 제어시스템의 강인성이 저하될 수 있다. 따라서 본 연구에서는 복합제어 시스템의 강인성을 향상시키기 위해 기존의 LQG 알고리즘에 납고무받침의 응답에 따른 on-off 형태의 알고리즘을 결합하였다. 수치해석 결과 on-off 형태의 LQG 알고리즘을 사용한 복합제어 시스템은 납고무받침을 사용할 수동제어 시스템이나 유압식 가력기만을 사용한 능동제어 시스템과 비슷한 최대제어력이나 평균제어력을 사용하면서 제어성능이 향상되었으며, 기존의 성능에 초점을 둔 LQG 알고리즘만을 사용한 복합제어 시스템과 유사한 제어성능을 나타냈다. 또한 제안된 제어시스템은 구조물의 강성행렬에 교란이 있을 때 기존의 LQG 알고리즘만을 사용한 복합제어 시스템에 비해 강인성이 향상되었으며 교란된 시스템에 대해 불안정성을 보이지 않았다. 제안된 제어시스템은 설계지진뿐만 아니라 다른 입력지진에 대해서도 제어성능을 유지하였다. 따라서 On-Off 형태의 LQG 알고리즘을 사용한 복합제어 시스템은 불확실성이 많은 지진하중을 받는 사장교에 개선된 제어기법으로 제안될 수 있다.

• Steel and Composite Structures
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• 제48권4호
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• pp.475-483
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• 2023

In this paper, a new energy-efficient semi-active hybrid bulk damper is developed that is cost-effective for use in structural applications. In this work, the possibility of active and semi-active component configurations combined with suitable control algorithms, especially vibration control methods, is explored. The equations of motion for a container bridge equipped with an MDOF Mass Tuned Damper (M-TMD) system are established, and the combination of excitation, adhesion, and control effects are performed by a proprietary package and commercial custom submodel software. Systematic methods for the synthesis of structural components and active systems have been used in many applications because of the main interest in designing efficient devices and high-performance structural systems. A rational strategy can be established by properly controlling the master injection frequency parameter. Simulation results show that the multiscale model approach is achieved and meets accuracy with high computational efficiency. The M-TMD system can significantly improve the overall response of constrained structures by modestly reducing the critical stress amplitude of the frame. This design can be believed to build affordable, safe, environmentally friendly, resilient, sustainable infrastructure and transportation.

• 한국구조물진단유지관리공학회 논문집
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• 제19권3호
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• pp.48-54
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• 2015

본 연구에서는 수평변위와 횡력의 저감을 위해서 빌딩외부의 빌딩간 변형차이와 단면2차 모멘트의 최대화를 이용하여 다수의 빌딩으로 구성된 빌딩시스템의 빌딩간 협업제어 방식의 횡력분배 및 변위감소를 제안하였다. 제안된 복합빌딩 시스템의 안전설계를 위한 방안으로 케이블 파단시의 연속붕괴방지를 위한 연결부 정착판의 추가배치와 대공간구조 자체의 질량과 강성 및 공간을 활용한 동조질량감쇠장치의 설계에 대하여 제안하였다. 도심지 인구집중과 지가상승의 필연적 결과에 대한 해결방안으로 제안된 초고밀도 복합빌딩 시스템의 설계 최적화를 위하여, 3차원 빌딩구조시스템의 2축 대칭조건과 경계조건을 이용하여 2차원 모델을 구성하고 1차부정정구조를 이루는 2차원 모델의 중요설계변수를 검토하였다. 제안된 복합빌딩구조 시스템은 인구밀도와 지가가 상승하는 도심내 최대밀도구역에서 토지이용의 효율성을 극대화시키고, 새로운 빌딩 또는 기존빌딩구조의 안전성을 증대할 것으로 기대한다.

• 복합신소재구조학회 논문집
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• 제6권1호
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• pp.14-20
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• 2015

In this study, we propose an innovative lateral force distribution building system between tall buildings by utilizing the difference of moment of inertia, as the alternative design for highly integrated city area. Considering a tri-axial symmetric conditions and boundary conditions for the three-dimensional building structure system, a two-dimensional model is composed. In the proposed indeterminate structural model, important design variables are determined for obtaining minimum horizontal deflections, reactions and bending moments at the ground level of the buildings. Regarding a case of the provided two spatial structures connected to 4 buildings, the optimum location of middle located spatial structure is 45% from the top of the building, which minimize the end moments at the bottom of the buildings. In the considered verification examples, reduced drifts at the top location of the building systems are validated against static wind pressure loads and static earthquake loads. The suggested hybrid building system will improve the safety and reliability of the system due to the added internal truss-dome structures in terms of more than 30% reduced drift and vibration through the development of convergence of tall buildings and spatial structures.