• 한국전산구조공학회논문집
• /
• 제15권4호
• /
• pp.727-739
• /
• 2002

강자성 판의 자기-열-탄성 상호작용을 고찰하기 위하여 자기-열-탄성에 관한 일반화된 변분원리에 기초한 이론적인 모델이 제안되었다. 자탄성 선형화이론과 섭동법을 사용하여, 온도장과 자기장으로 재하된 단순지지 강자성 평판의자-탄성 좌굴과 자기-열-탄성 좌굴거동을 해석하였다. 또한 해석적인 고찰이 어려운 보다 복잡한 강자성 판의 자기-열-탄성 거동을 모사하기 위하여 비선형 유한요소 모형을 개발하였다. 이 유한요소모형을 이용하여 유한한 강자성 판의 자기-열-탄성 ？과 좌굴거동 그리고, 이에대한 온도장과 자기장의 영향에 대하여 고찰하였다.

• Steel and Composite Structures
• /
• 제5권2_3호
• /
• pp.193-202
• /
• 2005

This paper describes recent developments in composite construction and their effect on codified design procedures in the UK. Areas of particular interest include: rules on shear connection, design of beams with web openings, serviceability limits, such as floor vibrations, and fire safe design. The design of cellular beams with regular circular openings now includes generalized rules for web-post buckling, and for the development of in-plane moment in the web-post for asymmetric sections. Closed solutions for the maximum shear force due to limits on web-post bending or buckling are presented. The fire resistance of cellular beams is also dependent on the temperature of the web-post, and for closely spaced openings. It is necessary to increase the thickness of fire protection to the web. For serviceability design of beams, deflection limits and natural frequency and response factor for vibration are presented. It may be necessary to use stricter limits for certain applications.

• 국제초고층학회논문집
• /
• 제1권4호
• /
• pp.247-254
• /
• 2012

In order to improve the seismic behaviors of traditional steel-concrete mixed structure, a novel steel concrete mixed structure consisting of steel frames braced with buckling restrained braces (BRBs) and a concrete tube is proposed. Based on several assumptions, the simplified mechanical model of the novel mixed structure is established, and the shear and bending stiffness formulas of the steel frames, BRBs and concrete tube are respectively introduced. The equilibrium differential equation of the novel mixed structure under horizontal load is developed based on the structural elastic theory. The simplified algorithms to determine the lateral displacement and internal forces of the novel mixed structure under the inverted-triangle distributed load, uniformly load and top-concentrated load are then obtained considering several boundary conditions and compatible deformation conditions. The effectiveness of the simplified algorithms is verified by FEM comparison.

• 대한기계학회논문집
• /
• 제18권4호
• /
• pp.958-966
• /
• 1994

The postbuckling compressive strengths of $[0/90/\pm\theta]_s$ composite laminated cylindrical panels with various fiber angles and width-to-length ratios are characterized by the nonlinear finite element method. For the iteration and load-increment along the postbuckling equilibrium path a modified arc-length method in which the effect of failure can be considered is introduced. In the progressive failure analysis the maximum stress criterion and complete unloading model are used. Present finite element results show good agreement with experiments for $[0_3/90]_s$ cylindrical panel and $[0/\pm45/90/]_s$ plate. The postbuckling compressive strength of $[0/90/\pm\theta]_s$ composite laminated cylindrical panel is independent of the initial buckling stress but high in the panel with large value of the bending stiffness in axial direction. In the several cylindrical panels, it is observed that the prebuckling compressive failures occur and result into the collapse before the buckling.

• 한국전산구조공학회:학술대회논문집
• /
• 한국전산구조공학회 1998년도 봄 학술발표회 논문집
• /
• pp.449-456
• /
• 1998

A consistent finite element formation and analytic solutions are presented for spatial stability of thin-walled circular arch. The total potential energy is derived by applying the principle of linearized virtual work and including second order terms of finite semitangential rotations. As a result the energy functional corresponding to the semitangential rotation is obtained, in which the elastic strain energy terms are considered restrained warping effects. We have obtained analytic solution for the lateral buckling of monosymmetric thin-walled curved beam subjected to pure bending or uniform compression and it's boundary conditions are simply supported. For finite element analysis, the two node cubic Hermitian polynomials are utilized as shape Auctions. In order to illustrate the accuracy of this study, parameter studies for lateral buckling problems of circular arch are presented and compared with available solutions and numerical results analyzed by the FEM using straight beam element.

• 한국자동차공학회논문집
• /
• 제16권2호
• /
• pp.114-119
• /
• 2008

The modern automotive industry develops innovative vehicle designs to meet increasing stability of car and performance demands of their customers. The improvement of frame rigidity by the structural foam is thought to be an effective means to improve the performance because of high applicability and minimum weight. The object of this paper is to examine the use of structural foam in a hat section as an optimum reinforcing means, to compare the reinforcing performance of structural foam versus a plastic reinforcement. The result of this paper indicated that reinforcing efficiencies are achieved by structural foam and plastic reinforcement shape.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 1997년도 추계학술대회 논문집
• /
• pp.702-705
• /
• 1997

Sandwich plate structure is widely used in various fields of industry due to its excellent strength and stiffness compared with weight. In this paper, the mechanical behavior of sandwich plate structure with honeycomb core considering buckling is investigated in detail. The focus of the analysis is to evaluate strength and stiffness of the plate structure with critical stress, natural frequency, and mode shapes. The results of this investigation are obtained from detailed finite element analysis for various parameters, such as length, height ratio, and thickness ratio of honeycomb core

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2002년도 추계학술대회 논문집(I)
• /
• pp.709-714
• /
• 2002

Recently, the applications of corrugated plates(or folded plates) are increasing due to economic and structural advantages in certain situations. And, because of the higher strength of corrugated plates than flat plates, the usage of the corrugated plates is increasing. So there are many necessities for specifications of corrugated plates. For flat plates, there are many design details in almost specifications. However, there are no detail design guides such as shear strength except the bending strength and the normal strength. So, it is difficult for engineers to design structures consist of corrugated plates. Therefore, a provision is necessary for engineers to refer for designing corrugated plates. The conclusion of this study shows a formula that helps to determine the shear strength of corrugated plates under various geometric conditions ; the size of corrugation ; the curvature of corrugation and ; the thickness of the corrugated plate. Also, it shows that corrugated plates have higher shear buckling strength than flat plates.

• 전산구조공학
• /
• 제11권1호
• /
• pp.251-259
• /
• 1998

개구부를 갖는 콘크리트 전단벽을 두께가 얇은 직사각형 평판으로 모델화하였다. 판의 두가지 경계조건에 대한 안정해석 결과를 판좌굴계수 k로 표시하였다. 경계조건이 다른 변수로는 휨으로 인한 힘/연직하중비 .alpha., 수평 전단력/연직하중비 .betha. 및 개구부의 위치 및 크기 변화이다. 유한요소법에 의한 결과를 얻기 위하여 예제의 판을 27*9의 정사각형 요소로 분할하였으며 node에서 3가지 자유도를 갖는 c.deg. 유한요소를 택하였다. 일반적으로 개구부의 크기가 증가함에 따라 판 개구부가 판 중앙에서 자유연(free edge)으로 접근할수록 좌굴계수는 감소하는 현상을 보이고 있다.

• 항공우주기술
• /
• 제4권1호
• /
• pp.129-142
• /
• 2005

KSLV-I의 위성 어댑터의 구조 형식으로 결정된 세미 모노코크 형식의 잘려진 원뿔형 구조체를 제작하고, 정적 구조 시험을 수행하였다. 설계 하중에 따라 순수 압축, 순수 굽힘, 순수 전단, 복합 하중을 가하여 변형률 및 변위를 측정하고, 구조의 건전성을 확인하였다. 최종적으로 파괴 시험을 수행하여, 국부 좌굴 모드 및 파괴 형상을 관찰하였으며, 파괴하중 및 모드를 유한 요소법으로 해석하여 비교한 결과 정확한 파괴 하중의 예측이 가능하였다.