• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.3
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• pp.430-442
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• 1992

본 연구에서는 자동차의 여러 모드 사이에 존재하는 연성항의 비연성을 위한 능동 제어력을 계산하여 연성항이 승차감에 미치는 영향을 살펴보고, 이 연성항을 비 연성화하기 위한 제어력을 계산하였으며, 현가장치의 반능동 제어에 적용하였다. 또 한 새로운 민감도 이론식을 제안하여 7자유도 현가계에 적용하고 시뮬레이션을 통하여 특성변화예측을 하였다.

• 한국방재학회:학술대회논문집
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• 2010.02a
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• pp.83.1-83.1
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• 2010

본 연구는 고강도 강재를 적용한 연속교 형식의 강교량에 대하여 연구를 수행하였다. 교량에 사용되는 주구조의 고강도화에 따로 연속교의 교각 부근 부모멘트부에는 정모멘트부에 비하여 큰 모멘트가 작용하게 된다. 또한 정모멘트 구간과 달리 상부플랜지에 인장력이 작용하게 되어 완공 후에도 극한 하중 상태에서 콘크리트 데크가 응력을 부담할 수 없게 된다. 이에 따라 하부 플랜지에 불안정 파괴가 발생할 가능성이 있으며 비합성 단면과 같은 방법으로 설계하게 된다. 또한 모멘트 재분배를 고려한 설계를 하기 위해서는 부모멘트부에 충분한 휨 연성이 필요하다. 고강도 강재를 적용한 교량은 일반강재를 적용한 교량에 비하여 휨연성이 감소하게 되므로 휨연성 확보를 위한 보강방안이 필요하다. 본 연구는 부모멘트부의 휨연성 향상을 휘하여 가로보의 부등 배치를 제안하였으며, 유한요소해석 결과 휨연성이 향상되었다.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2010.04a
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• pp.508-511
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• 2010

본 논문에서는 정상상태 유체-구조 연성문제를 연속체 기반으로 정식화하고 유한요소법을 이용하여 완전 연성된 해를 구하였다. 대 변형을 고려하기 위하여 토탈 라그란지안 정식화를 사용하였으며 유체 및 구조의 비선형성이 고려되었다. 유체와 구조 영역의 형상을 NURBS 곡면을 이용하여 매개화하여 표현하였으며, 형상 최적화를 위해 효율적인 설계민감도 해석법인 애조인 기법을 이용하여 압력, 속도, 변위 등에 대한 설계민감도를 구하였다. 이를 이용하여 최소 컴플라이언스를 갖게 하는 구조물 내부의 유체영역의 설계 등의 수치예제를 통하여 개발된 방법론의 타당성을 확인하였다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.6 s.177
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• pp.1479-1490
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• 2000

The design process of the motor driven tilt/telescopic steering column is established by axiomatic design approach in conceptual design stage. By selecting independent design variables for improvin g performance of the steering system, each detailed design can be carried out independently. In the detailed design, the safety in crash environment and vibration reduction are considered. An occupant analysis code SAFE(Safety Analysis For occupant crash Environment) is utilized to simulate the body block test. Segments, contact ellipsoids and spring-damper elements are used to model the steering column in SAFE. The model is verified by the result of the body block test. After the model is validated, the energy absorbing components are designed using an orthogonal array. Occupant analyses are performed for the cases of the orthogonal array. Final design is determined for the minimum occupant injury. For vibrational analysis, a finite element model of the steering column is defined for the modal analysis. The model is validated by the vibration experiment. Size and shape variables are selected for the optimization process. An optimization is conducted to minimize the weight subjected to various constraints.

• Journal of the KSME
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• v.23 no.3
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• pp.186-190
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• 1983

파괴역학 연구를 대상재료에 의해 구분하면 선형파괴와 탄소성재료의 파괴로 나눌 수 있다. 취 성파괴(brittle fracture)를 다루는 선형타성 파괴역학연구는 주로 여러가지 크랙의 모양, 시편모양, 부하형태에 따른 탄성응력분포 혹은 은력확대계수를 구하거나 에너지방법에 의해 안정비안정 크랙전파를 연구한다. 대개의 경우 취성파괴는 전체 구조물에 치명적이 되기 쉽다. 따라서 구조물 설계시에 취성파괴의 가능성을 배제하기 위해 재료의 적절한 선택과 같은 대책을 강구하는 것이 바람직하다. 다시 말해, 구조물 재료는 강도와 연성의 상황에 따른 적절한 조합을 필요로 한다. 오늘날 특수합금과 같은 고강도 금속에서의 취성화 경향이 증가하나 합금설계시 강도와 아울러 연성을 증가시키기 위한 여러 대책이 파괴역학 연구의 중요한 부분을 차지한다.

• Journal of the Earthquake Engineering Society of Korea
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• v.3 no.2
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• pp.55-66
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• 1999

Eight RC bridge plers have been made on a 1/3.4 scale model and have been tested in a quasi-static cyclic load so as to investigate their seismic performance. The ultimate objective of this experimental study is to investigate the hysteretic behavior of reinforced concrete plers, which have been widely used for urban transportation facilities in Korea. Improtant test parameters are hoop ratio, axial load, load pattern, and etc. And noninear behaviors of test columns have been evaluated through their yield and ultimate strength, energy dissipation, ductility and load-deflection characteristics under quasi-static cyclic loads. From the quasi-static tests on 8 bridge piers, it is concluded that energy dissipation, ultimate strength and curvature for a given displacement factor ${\mu}={\Delta}/{\Delta}_y$ are higher for the seismically designed columns than for the nonseismically designed columns.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.684-688
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• 1997

The human species has been able to fly for about a century - with the help of aircraft of various kinds. Recently. air vehicles which are like an insect or a bird with flapping wings have been appeared, although many of them are experimental flight vehicle. However, the rubber-powered flapping vehicle is put to practical use such as toy, which flies for some seconds. In this paper, we analyze and evaluate above the rubber-powered flight vehicle using axiomatic design and will present new four flapping wing model.

• Journal of Ocean Engineering and Technology
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• v.18 no.4 s.59
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• pp.59-64
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• 2004

Functional requirements and design parameters were not clarified in the early design process. Design axiom shows some difficulty for larger system designs, such as the butterfly valve, which is basically carried out by an incremental and iterative process. A numerical analysis was carried out on fluid flows in a butterfly valve, by using ANSYS-FLOTRAN. Characteristics of the butterfly flows at different valve disk opening angles, with a uniform incoming velocity, were investigated. The entire analysis is decomposed to satisfy the independence axiom. This paper resolves the problems associated with the establishment of a systematic design process.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.13 no.3
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• pp.246-251
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• 2008

The conceptual design evaluation of Deep-Sea Manganese Nodule Miner(DSNM) based on Axiomatic Design was preformed. Functional Requirements(FRs) in functional domain and Design Parameters(DPs) in physical domain were embodied for the given concept design of DSNM. Interactions between FRs and DPs were sequentially analyzed from the first level hierarchy to the lower level hierarchy. The interactions were expressed as design matrices which showed the dependence or independence between FRs and DPs. The results showed that the design of DSNM was not a coupled one, but a decoupled. Finally, it was conceptually verified that DSNM was a good design satisfying the independence axiom of the Axiomatic Design.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.8
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• pp.1426-1435
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• 2003

Design goal is to find the one that has the highest probability of success and the smallest variation. A robustness index has been proposed to satisfy these conditions. The two-step optimization process of the target problem requires a scaling factor. The search process of a scaling factor is replaced with the making of the decoupled design between the mean and the standard deviation. The decoupled design matrix is formed from the sensitivity or the sum of squares. After establishing the design matrix, the robust design process has a new three-step one. The first is ″reduce variability,″ the second is ″make the candidate designs that satisfy constraints and move the mean on the target,″ and the final is ″select the best robust design using the proposed robustness index.″ The robust design process is verified by three examples and the results using the robustness index are compared with those of other indices.