• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.15 no.2
• /
• pp.271-279
• /
• 2002

This study develops the module to find the lateral stiffness influence matrix of each story and performs the displacement sensitivity analysis by virtual load method for the efficiency of optimal design using lateral stiffness influence matrix. Also, resizing technique based on the estimated lateral stiffness increment factors is developed to apply directly the results of optimal design. To this end, resizing technique is divided into the continuous and discrete section design methods. And then the relationships between section properties and section size are established. Specifically, an initial design under strength constraints is first performed, and then the lateral load resistant system is designed to control lateral displacements yet exceeding the drift criteria. Two types of 45-story three dimensional structures we presented to illustrate the features of the lateral drift control and resizing technique for tall buildings proposed in this study.

• The Korean Publising Journal, Monthly
• /
• s.294
• /
• pp.19-19
• /
• 2001

• Journal of the Earthquake Engineering Society of Korea
• /
• v.4 no.2
• /
• pp.73-82
• /
• 2000

본연구의 목적은 반복하중을 받는 철근콘크리트 교량 교각의 비선형 이력거동을 해석적으로 예측하는 것이다 이를 위해서 반복적인 횡하중이 작용하는 경우에 실험결과와 일치하는 교각의 하중-변위 이력곡선을 도출하고자 수정된 trilinar 이력거동모델을 이용하였다 철근과 콘크리트의 비선형 거동특성과 각 하중단계에 따른 교각의 중립축을 구하여 소성힌지부의 모멘트와 변형률을 구하고 반복하중하에서의 강성의 변화를 해석적으로 모형화하기 위하여 각기 다른 강성을 갖는 5가지 지선을 갖춘 형태의 이력거동모델식을 제안하였다 본 연구에서는 실험적으로 구한 하중-변위 이력곡선을 이용하여 축하중비 주철근비 및 구속철근비에 따른 강도감소지수와 강성감소지수의 영향을 회귀분석을 이용하여 일반식으로 제안하였다 새로운 이력거동 해석 모델을 프로그램 SARCF III에 적용함으로써 기존 철근콘크리트 교각에 강도 및 강성감소 현상을 정확하게 예측하였다

• Proceedings of the Korean Information Science Society Conference
• /
• 2004.10b
• /
• pp.787-789
• /
• 2004

본 논문에서는 퍼지 시스템을 이용하여 칼라 패턴으로부터 인간의 강성을 예측하는 텍스타일 인덱싱 시스템을 제안한다. 텍스타일 인덱싱이란 입력받은 직물 영상을 섬유의 영상을 강성 특징으로 색인화 하는 것이다. 제안된 시스템은 입력 영상에 대해 warm-cold, strong-weak, heavy-light특징이 어느 정도 있는지 조사한다. 제안된 시스템은 크게 특징추출 부분과 감성 분류로 구성한다. 특징 추출은 입력 영상에서 컬러 점보와 텍스처 정보를 추출하고, 감성 분류는 특징 추출 부분으로부터 얻어진 정보들을 분석하여 영상 내 포함된 강성을 찾아낸다. 이때 분류를 위해서 본 논문에서는 퍼지 시스템을 사용한다. 퍼지 룰은 80개의 영상에 대하여 70명의 설문조사를 기반으로 하여 경험적으로 얻어졌다. 제안된 시스템은 80개의 영상에 대하여 테스트 해본 결과는 제안된 시스템의 효율성을 보여주었다.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.28 no.4A
• /
• pp.475-485
• /
• 2008

This paper intends to enhance the reliability and performance of domestic elastomeric bearings through the proposal of directions for the improvement of their stiffness regard to the Korean industrial standard KS F 4420 relative to the evaluation of design/fabrication/quality. Therefore, comparative analysis of the compressive elastic modulus, stiffness measurement method and performance evaluation method of KS F 4420 with those of Eurocode, Japanese bearing manual, and ISO code was performed, and measurement tests on the compressive stiffness and shear stiffness of common elastomeric bearings produced in Korea were conducted. The experimental results reveal that differences of about 20% and 13% occurred respectively for the compressive stiffness and shear stiffness according to the definition adopted for the stiffness. The measured values for the stiffness of the domestic elastomeric bearings were also verified to exhibit large deviation from the formula proposed by KS F 4420. Elastomeric bearings that does not have appropriate compressive stiffness required at the design can result in uneven deflection at supports of bridges and excessive stress in girders. Accordingly, the establishment of compressive elastic modulus formula and performance evaluation criteria fitted to the domestic circumstances through the execution of performance evaluation of bearings presenting diversified shapes and shape factors appears to be necessary for the domestic bearings to meet the performance required in design.

• Computational Structural Engineering
• /
• v.8 no.2
• /
• pp.103-113
• /
• 1995

Since the mechanical properties of the rubber connectors used in the vehicle structures are sensitive on the dynamic characteristics of the system, they must be exactly evaluated. In this paper, both finite deformation theory and Hookean model are considered to calculate the stiffness coefficients of rubber connectors. An expert system is developed by using finite element method. When the equivalent stiffness coefficients on the same kinds of isolators used in actual vehicles were emperically examined, the results were largely dispersed due to the lack of the quality control on the material properties. To compensate the errors caused by the mathematical modeling and the mechanical properties, a practical method which identifies the shear and bulk moduli of rubber with the experimented overall force-deformation curves is suggested and applied to the engine isolators of vehicle.

• Journal of Korean Society of Steel Construction
• /
• v.18 no.4
• /
• pp.469-480
• /
• 2006

The goal of this study is to ases the static and dynamic behavior of disk bearings under railway vehicle loadings. Several static tests were conducted in a laboratory t bearings, all having the same kind of polyurethane disk as used in the static tests, were installed under a full-sized railway bridge and tested with a running locomotive, the tests results, the static and dynamic stiffness of the disk bearings were estimated and compared. the deformation of the disk bearings under the bridge was measured at varying disk bearing was almost half of that under dynamic loading. In addition, the dynamic stiffness of the fixed disk bearing was 80% higher than that of an expansion disk bearing, since the PTFE in the expansion bearing is displaced. The deformation of the disk bearing did not vary significantly with changes in locomotive's speed. The results of this study can contribute to fast-tracking the formulation of a design technique for disk bearings for railway bridges.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.19 no.1 s.71
• /
• pp.63-71
• /
• 2006

This study presents the effective stiffness-based optimal technique to control Quantitatively lateral drift for shear wall-frame structure system using sensitivity analysis. To this end, the element stiffness matrices are constituted to solve the compatibility problem of displacement degree of freedom between the frame and shear wall. Also, lateral drift constraint to introduce the approximation concept that can preserve the generality of the mathematical programming and can effectively solve the large scaled problems is established. And, the section property relationships for shear wall and frame members are considered in order to reduce the number of design variables and differentiate easily the stiffness matrices. Specifically, constant-shape assumption which is uniformly varying in size during optimal process is applied in frame structure. The thickness or length of shear wall can be changed depending on user's intent. Two types of 20 story shear wall-frame structure system are presented to illustrate the features of the stiffness-based optimal design technique.

• Proceedings of the Korea Technology Innovation Society Conference
• /
• 2005.10a
• /
• pp.389-402
• /
• 2005

• Proceedings of the KAIS Fall Conference
• /
• 2000.04a
• /
• pp.9-9
• /
• 2000