• 제목/요약/키워드: Elastic sheet

검색결과 178건 처리시간 0.025초

탄소섬유쉬트로 전단보강한 RC 기둥의 이력성능평가에 관한 실험적 연구 (An Experimental Study on the Hysteretic Capacity Evaluation of the Shear-Strengthened RC Column with Carbon Fiber Sheet)

  • 이현호;구은숙
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1999년도 봄 학술발표회 논문집(I)
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    • pp.750-755
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    • 1999
  • When the RC frame structures subjected to the seismic load, brittle shear failure of vertical members induces brittle collapse of whole structures. Failure mechanism like this is not desirable. So shear strengthening method to avoid this failure mechanism is needed. Recently, strengthening method using continuous fiber sheet is studied and used widely which have high elastic and high strength characteristics. In this study, RC columns which is strengthened by carbon fiber sheet in the form of tape or whole sheet were tested under the cyclic load. The parameter of this test is the amount of strengthening. As the amount of strengthening increase, strength, ductility and energy capacity increase. The failure mode of test results are shear and bond-split failure.

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전단띠 형성에 의한 원형접합판의 변형한계 해석 (Analysis of Forming Limit for Circular Bonded Sheet Metals by Shear Band Formation)

  • 정태훈
    • 한국공작기계학회논문집
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    • 제10권1호
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    • pp.127-132
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    • 2001
  • By the use of a similar numerical method as the forming limit strain by coating method of coated sheet metals is investigated, in which the FEM is applied and J2G(J2-Gotohs Corner Theory) is utilized as the plasticity constitutive equa-tion. Circular bonded sheet metals with dissimilar sheets on both surface planes are stretched in a plane -strain state, with various work-hardening exponent n-values and thicknesses of each layer. Processes of shear-band formation in such com-posite sheets are clearly illustrated. It is concluded that, it the bonded state, the higher limiting strain of one layer is reduced due to the lower limiting strain of the other layer and vice versa, and does not necessarily obey the rule of linear combination of the limiting strain of each layer weighed according thickness.

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분기좌굴이론을 이용한 박판성형공정에서의 주름발생해석 (An analysis of the wrinkling initiation in sheet metal forming using bifurcation theory)

  • 김종봉;양동렬;윤정환
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 1998년도 춘계학술대회논문집
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    • pp.28-31
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    • 1998
  • Wrinkling is one of the major defects in sheet metal products and may be also attributable to the wear of the tool. The initiation and growth of the wrinkles are influenced by many factors such as stress state, mechanical properites of the sheet material, geometry of the body, and contact condition. It is difficult to analyze the wrinkling initiation and growth considering the factors because the effects of the factors are very complex and the wrinkling behavior may show wide variation for small deviation of the factors. In this study, the bifurcation theory is introduced for the finite element analysis of wrinkling initiation and growth, All the above mentioned factors are conveniently considered by finite element method. The finite element formulation is based on the incremental deformation theory and elastic-plastic material modeling. The finite element analysis is carried out using the continuum-based resultant shell elements considering the planar anisotropy of the sheet metal. The proposed method is verified by employing to column buckling problem. And then, the initiation and growth of wrinkling in deep drawing of cylindrical cup are analyzed.

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Structural Behavior of a RC Bridge Slab Retrofitted with Carbon Fiber Sheet under Large Repeated Load

  • Park, Hae-Geun
    • KCI Concrete Journal
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    • 제14권2호
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    • pp.61-68
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    • 2002
  • An experimental investigation on the flexural fatigue behavior of a RC bridge slab retrofitted with Carbon Fiber Sheet (CFS) is presented. The test slab was almost identical to the slab of a highway viaduct in terms of the amount of reinforcement, quality of concrete and thickness of the slab, which was 18cm. Repeated load corresponding to 3.0, 4.5 or 6.0 times of the design load was applied to the test slab. Normal type and high-elastic modulus type of CFS were used for strengthening. The test slabs were loaded in dry or wet condition. Two different types of an-choring system were adapted. Some of the test slabs were damaged by the repeated load and retrofitted by CFS, then loaded again to see the improvement of the fatigue life. Infrared Thermography was also performed to investigate the debonding condition of CFS. From the test results, Carbon Fiber Sheet can be applied to the RC bridge slabs as a feasible retrofitting material.

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박판 성형공정에서의 등가 경계조건 계산을 위한 드로우비드 성형의 탄소성 유한요소 해석 - PartI: 등가 경계조건 계산 (Elastic-plastic Finite Element Analysis of Drawbead Forming for Evaluation of Equivalent Boundary Conditions in Sheet Metal Forming - Part I : Evaluation)

  • 박종세;김승호;허훈
    • 소성∙가공
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    • 제11권6호
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    • pp.503-512
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    • 2002
  • The drawbead is used to control material flow into the die during the binder wrap process and the stamping process in the sheet metal forming process. Since the dimension of drawbead is relatively small in comparison with the typical dimensions, it is difficult to include drawbeads in finite element analysis of the sheet metal forming process. It is because the mesh system has to be fine enough to describe the drawbead and the computation time is drastically increased. In this paper, simulation of drawbead forming has been carried out to obtain the equivalent boundary conditions in the binder wrap process and the stamping process. In order to investigate the effect of various die geometries, parameter studies are performed with the variation of parameters such as the blank length, the drawbead depth, the drawbead radius, the inclination of die and the friction coefficient.

디텐트 스프링 교정시스템 구축을 위한 박파해석 (Sheet Analysis for Construsion of the Correction System on Detent Spring)

  • 권혁홍;김선호;박경택;정용헌
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1995년도 추계학술대회 논문집
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    • pp.1150-1153
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    • 1995
  • This paper describes that study which construct a theoretic and experimental algorithm in order to make the automatic correction system od detent spring, and when load for correction pressed at spring, it can be found elastic and plastic deformation quantities by Finite Element Analysis. As a result, it has been found that the simulation datas are in good agreement with experimental results.

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탄소섬유쉬트로 보강된 철근콘크리트보의 계면박리해석 (An Analysis of Interface Debonding Failure on Reinforced Concrete Beams Strengthened with Carbon Fiber Sheet)

  • 심종성;배인환
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1998년도 가을 학술발표대회 논문집(III)
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    • pp.839-844
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    • 1998
  • The purpose of this study is to analyze the interface debonding failure on RC beams strengthened with carbon fiber sheet(CFS). The behavior of damaged RC beams strengthened with CFS is analytically investigated using both linear elastic fracture mechanics (LEFM) approach and the finite element method. This study includes the investigation of the separation mode by interface fracture of the strengthening materials due to the interfacial shear and normal stresses.

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유한요소법에 의한 드로오비드 인출특성 연구 (A study on the drawing characteristics of drawbead by F.F.M)

  • 신양호
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 1997년도 춘계학술대회 논문집
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    • pp.42-47
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    • 1997
  • In this study, the drawing characteristics of circular drawbead are examined with the plane strain elastic-plastic FE Method by varying the process variables such as friction coefficient, drawbead radius, and closing depth. Numerical analysis are carried out by 2-D elastic-plastic F.E.M. The results are compared with the existing experimental results about the drawing force, the die clamping force, and the strain distribution of upper and lower sheet faces

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마그네슘의 결정립 성장과 집합조직: 상장모델 계산 (Grain Growth and Texture Evolution of Mg: Phase Field Modeling)

  • 김동욱;차필령
    • 한국분말재료학회지
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    • 제18권2호
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    • pp.168-171
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    • 2011
  • We investigate grain growth behavior of poly-crystalline Mg sheet having strong basal fiber texture using phase field model for grain growth and micro-elasticity. Strong initial basal texture was maintained when external load was not imposed, but was weaken when external biaxial strain was imposed. Elastic interaction between elastic anisotropy of Mg grain and external load is the reason why texture evolution occurs.

고정형 조건에서의 스테인레스 강판의 충격 특성 (Impact characteristics of the stainless sheet on the fixed boundary condition)

  • 안동규;문경제;정창균;한길영;양동열
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2007년도 춘계학술대회A
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    • pp.48-53
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    • 2007
  • The objective of this paper is to investigate the influence of impact conditions on the impact characteristics of the stainless sheet for the case of the fixed boundary conditions. In order to examine impact characteristics of the sheet, three-dimensional finite element analyses and impact tests have been performed. High speed tensile tests have been carried out to obtain strain-stress relationships including the effects of the strain rate. In order to improve an accuracy of the FE analysis, the hyper-elastic model and the damping factor have been introduced. The results of the FE analyses and the impact tests have been shown that the diameter of the impact head does not affect the absorption energy of the stainless sheet. In addition, it has been shown that the absorption rate of energy maintains almost $82.5\;\sim\;83.5\;%$ irrespective of the impact energy level and the diameter of the impact head. From the results of FE analyses, the variation of stress and strain energy in the stainless sheet has been quantitatively examined.

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