• 한국강구조학회 논문집
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• 제20권2호
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• pp.303-312
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• 2008

본 논문에서는 초고층 전단벽-골조 아웃리거 구조시스템의 지진하중에 대한 시간이력해석을 수행하였다. 전단벽과 골조를 전단변형과 휨변형이 모두 고려된 (티모센코) 보 이론을 기본으로 하여 개발되었으며, 개발된 해석모델은 일차원 유한요소로 정식화되어 다양한 수치해석 예제들의 거동 분석을 하였다. 해석모델은 아웃리거 트러스의 강성을 회전 스프링 강성으로 치환하여 적용한 것으로 아웃리거 트러스의 형태나 위치에 의한 구조물의 거동 효과를 쉽게 알 수 있다. 앞선 연구를 바탕으로 전단벽-골조 시스템과 전단벽-골조에 아웃리거 시스템을 결합한 건물의 지진해석모델을 개발하고자 하였다. 전단벽-골조 구조는 전단벽과 골조의 전단변형과 휨병형을 동시에 고려한 해석모델을 기반으로 하였으며, 아웃리거 트러스의 강성 해석 역시 전단변형과 휨변형을 모두 고려한 해석 모델을 기반으로 지진해석모델을 개발하였다. 개발되어진 해석 모델의 정확성을 입증하기 위해서 3차원 해석 프로그램인 MIDAS GEN을 이용하여 그 해석결과를 비교하였다. 그 결과 초고층건물의 초기설계단계에서 많은 시간이 소요되는 지진하중에 대한 시간이력해석을 효율적이며 또한 비교적 정확히 수행할 수 있을 것으로 기대된다.

• Smart Structures and Systems
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• 제20권2호
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• pp.127-137
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• 2017

Identification of damping characteristics is of significant importance for dynamic response analysis and condition assessment of structural systems. Damping is associated with the behavior of the energy dissipation mechanism. Identification of damping ratios based on the sensitivity of dynamic responses and the model updating technique is investigated with numerical and experimental investigations. The effectiveness and performance of using the sensitivity-based model updating method and vibration monitoring data for damping ratios identification are investigated. Numerical studies on a three-dimensional truss bridge model are conducted to verify the effectiveness of the proposed approach. Measurement noise effect and the initial finite element modelling errors are considered. The results demonstrate that the damping ratio identification with the proposed approach is not sensitive to the noise effect but could be affected significantly by the modelling errors. Experimental studies on a steel planar frame structure are conducted. The robustness and performance of the proposed damping identification approach are investigated with real measured vibration data. The results demonstrate that the proposed approach has a decent and reliable performance to identify the damping ratios.

• KIEAE Journal
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• 제15권5호
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• pp.35-46
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• 2015

Purpose: This study is to research how New-Hanok R&D technologies of first stage are appearing and adapted to the New-Hanok style public buildings, especially in Daycare Center in Sunchang-gun, Korea. Unlike Hanok houses, public buildings which has special needs for the public and restricted by laws and regulations need not only new system of law incentives but also new components of New-Hnaok R&D technologies used only in Hanok house. Method: For this purpose, we checked the drawings for Daycare Center in Sunchang-gun. The drawings have been changed 6 times for the purpose of adopting New-Hanok R&D technologies of first stage and actual needs for current laws and regulations for public buildings and it reveals not only the possibilities for adapting new technologies in New-Hanok but also meetings the current and public needs for public buildings. Result: The result of this study as follows. Approximately 40-50 percent of New-Hanok R&D technologies in the first stage are adapted in Daycare Center in Sunchang-gun, and this means there are limitations in adapting New-Hanok R&D which are mainly for the Korean style houses. The main reasons are the costs still remaining high and lacking in confidence for using traditional structures and materials still under verification. Some are changed and proposed in another solutions suitable for public buildings as like truss structure system in roof.

• Computers and Concrete
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• 제25권1호
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• pp.67-73
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• 2020

Traditionally used analytical approach to predict the fatigue failure of reinforced concrete (RC) structure is generally conservative and has certain limitations. The nonlinear finite element method (FEM) offers less expensive solution for fatigue analysis with sufficient accuracy. However, the conventional implicit dynamic analysis is very expensive for high level computation. Whereas, an explicit dynamic analysis approach offers a computationally operative modelling to predict true responses of a structural element under periodic loading and might be perfectly matched to accomplish long life fatigue computations. Hence, this study simulates the fatigue behaviour of RC beams with finite element (FE) assemblage presenting a simplified explicit dynamic numerical solution to show computer aided fatigue behaviour of RC beam. A commercial FEM package, ABAQUS has been chosen for this complex modelling. The concrete has been modelled as a 8-node solid element providing competent compression hardening and tension stiffening. The steel reinforcements are simulated as two-node truss elements comprising elasto-plastic stress-strain behaviour. All the possible nonlinearities are duly incorporated. Time domain analysis has been adopted through an automatic Newmark-β time incremental technique. The program consists of twelve RC beams to visualize the real behaviour during fatigue process and to obtain the reliability of the study. Both the numerical and experimental results indicate a redistribution of stresses along the time and damage accumulation of beam which severely affect the serviceability and ultimate capacity of RC beam. The output of the FEM analysis demonstrates good match with the experimental consequences which affirm the efficacy of the computer aided model. The controlled fatigue damage evolution at service fatigue load limits makes the FE model an efficient tool in predicting high cycle fatigue behaviour of RC structures.

• Structural Engineering and Mechanics
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• 제31권5호
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• pp.507-526
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• 2009

Based on numerical and experimental methods, a systematic structural evaluation of a steel natatorium in service was carried out in detail in this paper. Planning of inspection tasks was proposed firstly according to some national codes in China in order to obtain the economic and reliable results. The field visual inspections and static computation were conducted in turn under in-service environmental conditions. Further a three-dimensional finite element model was developed according to its factual geometry properties obtained from the field inspection. An analytical modal analysis was performed to provide the analytical modal properties. The field vibration tests on the natatorium were conducted and then two different system identification methods were used to obtain the dynamic characteristics of the natatorium. A good correlation was achieved in results obtained from the two system identification methods and the finite element method (FEM). The numerical and experimental results demonstrated that the main structure of the natatorium in its present status is safe and it still satisfies the demand of the national codes in China. But the roof system such as purlines and skeletons must be removed and rebuilt completely. Moreover the system identification results showed that field vibration test is sufficient to identify the reliable dynamic properties of the natatorium. The constructive suggestion on structural evaluation of the natatorium is that periodic assessment work must be maintained to ensure the natatorium's safety in the future.

• 한국공간구조학회논문집
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• 제9권3호
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• pp.75-82
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• 2009

본 연구에서는 선형이론을 바탕으로 한 이산계열 대공간구조물의 크기최적화에 따른 후좌굴 거동의 변화에 대하여 조사하고 그 결과를 기술하였다. 먼저 공간구조물의 최적의 부재크기 패턴을 조사하기 위하여 수학적 프로그래밍 기법을 도입하였다. 이때 최소화 해야하는 공간구조물의 전체 부재의 중량을 목적함수로 이용하고 절점에서 발생하는 변위 값과 각 부재에서 발생하는 응력 값을 허용치 이하로 제한하는 제약조건으로 사용하였다. 크기최적화를 통하여 도출된 최적 부재패턴을 가지는 공간구조물의 후좌굴 거동을 통합 비선형해석기법으로 해석하고 그 결과를 분석하였다. 수치해석을 통하여 크기최적화에 따른 공간구조물의 후좌굴 거동의 변화는 매우 큰 것으로 나타났으며 이러한 후좌굴 거동의 변화에 대한 예측과 분석결과가 공간 구조물의 설계에 고려되어야 할 것으로 판단된다. 또한 본 연구에서 제시한 수치해석 결과는 이산계열 대공간구조물의 설계에 기본 데이터로 제시하였다.

• KIEAE Journal
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• 제12권6호
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• pp.77-84
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• 2012

The current architectural design of unit modular has been based on 2D of CAD program, so unit modular character which needs unit information management, as a dried-member system, has no effect on design process. The purpose of this study is We have developed a suitable BIM design process, according to various works of construction, then tried to contribute to supply and activation of the urban-life-housing based on unit modular. The BIM modeling process based on unit modular has been in order of unit combination with preparing manual classification, and, it has been constructed, at construction site, from housing foundation to roof finish by Bottom-up method. At a manufacturing factory, it has been produced in order of 1) grouping materials and parts, 2) fabricating unit boxes, and 3) interference examination of unit boxes, and each order has been classified as housing structure, architecture, plumbing process separately. At a construction site, the fabrication has been done in order of, like as a real housing construction scenario, 1) RC foundation work 2) unit module job-site-fabrication work, 3) roof truss work, 4) plumbing and HVAC work, and 5) housing interior finish work. After modeling process, the interference examination on each work of construction has finally completed modeling. The Unit modular utilizing BIM modeling can make easy housing maintenance through systematic control with preparing manual of unit module information, and securing accurate and speedy construction information. And it will promote design credibility and create maximum effect of unit modular construction method, such as construction period reduction and upgrade of construction quality, etc., through the computer simulation as real as construction environment in cyber space, and with the interfering examination.

• 건축역사연구
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• 제19권6호
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• pp.121-135
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• 2010

This study was to analyze the architectural characteristics and facade construction of brick masonry auditorium through the Auditorium of Namsan Primary School in 1936. The results of this study were described separately as follows. 1. The auditorium is located away from the school buildings, and its plane is a chamber of rectangle type with an entrance installed on each of the four sides. 2. The external appearance is Renaissance eclectic style, laid red bricks on the lower wall of the window and having a mansard roof. The front and the rear are symmetric with respect to the projected wall at the center. 3. As to the structure of the building, a concrete lower wall was built on the concrete continuous footing, and the brick wall was constructed on the lower wall. The roof is queen post roof truss, and the wall girders were installed on the brick wall. 4. The auditorium has had a number of repairing and maintenance works, which changed the roof and windows outside and the floor, walls, ceiling, etc. inside. 5. The decorative elements of external appearance include lower wall, brick wall, entrances, windows, roof, and dormer windows. The brick wall gives verticality and solidity to the surface of the wall, and the lower wall and wall girders are connected like a cornice of the wall. The surface of the mansard roof and dormer windows express a stable vertically oriented shape.

• 한국전산구조공학회논문집
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• 제21권1호
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• pp.73-82
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• 2008

본 논문에서는 구조손상 탐색을 위해 매개변수 부 집합 선택에 의한 새로운 정규화 방법을 제안하였다. Residual function을 위해 동적 residual force 벡터를 이용하였다. 과거에는 Residual function으로서 기본 동적 특성치(고유치와 고유모드)를 이용하여 단일구조손상은 탐색할 수 있었지만 다중구조손상 위치를 탐색하기에는 한계가 있었을 뿐 아니라 고유모드와 고유치의 상이한 기여도 때문에 가중치를 적용해야 하는 어려움이 있었다. 본 논문에서 제안된 방법은 고유모드의 불완전한 계측을 보완하기 위하여 모델 확장법을 적용하였다. 제안된 구조손상 탐색법은 다중구조손상 위치를 동시에 찾아 낼 수 있는 장점을 가지고 있다. 2차원 평면 트러스 구조를 이용하여 제안된 방법의 효용성을 검증하였다.

• 한국산학기술학회논문지
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• 제11권7호
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• pp.2341-2348
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• 2010

본 논문에서는 충돌하중 하에서 스페이스 프레임을 사용하는 경주용 차량의 프레임 변형 및 응력을 분석한다. 충돌 시 변형을 최소한으로 줄이고, 취약부분을 파악하여 운전자의 안전을 확보한다. 탄소강의 물성치를 바탕으로 트러스 구조로 설계된 차량 프레임의 유한요소모델을 만들고, ANSYS 프로그램을 이용하여 정면충돌 시 속도 변화에 따른 충격량 증가가 프레임에 미치는 영향을 분석한다. 또한 정면, 측면, 후면 방향에 충돌하중을 적용하여 프레임의\ 변형을 해석한다. 정면 및 후면충돌에서는 운전석에 가해지는 영향이 적지만, 측면충돌 시 충격에 의한 변형이 운전석까지 진행된다. 이러한 변형에 대한 취약부분의 보강을 통하여 프레임의 안전성 설계를 증진시키고 시뮬레이션 해석의 결과를 실제 프레임 제작에 활용한다.