• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2001년도 춘계학술대회 논문집(한국공작기계학회)
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• pp.22-27
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• 2001

Cochlea is well known to have the ability to analyze a wide frequency and this ability seems to be caused to the Basilar Membrane(BM) configuration. However, the relationship between the Cochlea frequency-position map is not clear. In this paper, the three-dimensional BM Model was made using the Finite Element method. Then, an attempt was made to examine the influence of the BM configuration on the Cochlea frequency-position map. Theoretical consideration reveals that the wide frequency-position of Cochlea is achieved by not only the BM configuration change along the length of the Cochlea but also the change of the Young's module of the BM along the length of the Cochlea.

• 한국공작기계학회논문집
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• 제11권1호
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• pp.114-119
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• 2002

Cochlea is well known to have the ability to analyze a wide frequency and this ability seems to be caused to the Basilar Membrane(BM) configuration. However, the relationship between the Cochlea frequency-position map is not clear. In this paper, the three-dimensional BM Model was made using the Finite Element Method. Then an attempt was made to examine the influence of the BM configuration on the Cochlea frequency-position map. Theoretical consideration reveals that the wide frequency-position of Cochlea is achieved by not only the BM configuration change along the length of the Coohlea but also the change of the Young's module of the BM along the length of the Cochlea.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1999년도 가을 학술발표회 논문집
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• pp.67-74
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• 1999

Self-Boring Pressuremeter Test(SBPT) is known to be the most effective in-situ test method which can reliably determine consolidation characteristics as well as deformation modules and untrained shear strength. In order to derive the coefficient of consolidation using SBPT results it is necessary to obtain the dissipation behavior from the pore pressure change with time during constant radial strain(generally 10%) and to derive the reliable time factor(Τ) from the analytical method which considers the real in-situ conditions. As previous studies on time factor are based on the assumptions of plane strain condition that the membrane of SBP is infinite, of untrained condition during the expansion of the probe and of elastic soil behavior during consolidation, these analyses can't consider the real boundary conditions and the real soil behaviour. In this study, consolidation analysis similar to real in-situ conditions including test procedure is conducted using finite element program which employs MCC model and Biot theory. Time factor considering the effects of finite membrane length, the total pressure change during consolidation and partial drainage is proposed and compared with previous results.

• 한국가스학회지
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• 제3권3호
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• pp.58-64
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• 1999

멤브레인 방식의 저장탱크 제작에서 가장 중요한 설계 파라메타인 멤브레인 유니트의 피치에 관한 응력거동 문제를 유한요소법을 사용하여 해석하였고, 이 결과를 기존의 피치설계치수와 비교 검토하였다. 본 연구에서 고려한 링 마디식 멤브레인의 경우 피치의 길이를 어떻게 설정하든지 초대형 탱크의 경우에서는 안전성 문제가 발생하지 않았다. 그러나 반복하중에 의한 피로강도가 문제되는 선박용 멤브레인의 경우에는 피치를 짧게 설계하는 것이 유리하다는 것을 보여주고 있다. 멤브레인 주름의 변형거동을 보면 주름의 높이 방향 변형이 폭에 비하여 $15{\~}50\%$ 정도 더 크게 발생하고, $-162^{\circ}C$의 초저온에 의한 변형은 액압에 의한 변형과 비교할 때 그리 크지는 않음을 보여준다.

• 한국생산제조학회지
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• 제7권6호
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• pp.36-41
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• 1998

The objective of this study is to investigate effects of prebuckling on the buckling of laminated composite cylindrical shells. axial compression is considered for laminated composite cylindrical shells with length to radius ratios. The shell walls are made of a laminate with several symmetric ply orientations. This study was made using finite difference energy method, utilizing the nonlinear bifurcation branch with nonlinear prebuckling displacements. The results are compared to the buckling loads determined when membrane prebuckling displacements are considered.

• 한국생산제조학회지
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• 제6권2호
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• pp.49-58
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• 1997

The objective of this study is to investigate effects of prebuckling on the bucking of laminated compostie cylindrical shells, Both axial compression and lateral pressure are considered for laminated composite cylindrical shells with length to radius ratios. The shell walls are made of a laminate with several symmetric ply orientations. The study was using finite difference energy method, utilizing the nonlinear bifurcation branch with nonlinear prebuckling displacements. The results are compared to the buckling loads determined when membrane prebuckling displacements are considered.

• 대한기계학회논문집
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• 제11권5호
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• pp.800-809
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• 1987

본 연구에서는 원통에 대하여는 Donnel 식과 Flugge식을 사용하여 원통의 유 한길이에 대한 일반적인 해를 구하였고, 평판에 대하여는 막이론과 굽힘이론을 사용하 여 일반해를 구한 후 중첩하였다. 평판과 원통에 발생하는 미정력계를 구하기 위하 여 가장 합리적이라고 생각되는 접합부에 모든 미정력계가 집중하여 작용한다고 가정 하고, 이 부분에서 평판과 원통의 각각에 대한 하중, 모우멘트, 기울기, 변위 등이 연 속하도록 접한조건식을 세웠다.그리고 이론해석의 타당성을 알아보기 위하여 S 45C 강재로 플러시타잎의 모델을 제작하여 실험을 행하였다.

• Structural Engineering and Mechanics
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• 제12권3호
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• pp.313-328
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• 2001

A multi-span bridge has the peak value of resultant girder moment or membrane stress at the interior support. In this paper, the spline finite strip method (FSM) is modified to obtain the more appropriate solution at the interior support where the peak values of solution exist. The modification has been achieved by expressing the shape function with non-periodic B-splines which have multiple knots at the boundary. The modified B-splines have the useful feature for interpolating the curve with sudden change in curvature. Moreover, the modified spline FSM is very efficient in analyzing multi-span box girder bridges, since a bridge can be modeled by an assembly of strips extended along the entire bridge length. Numerical examples of the bridge analysis have been performed to verify the efficiency and accuracy of the new spline FSM.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1998년도 춘계학술대회 논문집
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• pp.112-116
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• 1998

The objective of this study is to investigate effects of prebuckling on the buckling of laminated composite cylindrical shells. Axial compression is considered for laminated composite cylindrical shells with length to radius ratios. The shell walls are made of a laminate with several symmetric ply orientations. This study was made using finite difference energy method, utilizing the nonlinear bifurcation branch with nonlinear prebuckling displacements. The results are compared to the buckling loads determined when membrane prebuckling displacements are considered.

• 오토저널
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• 제12권6호
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• pp.48-59
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• 1990

A finite element program was developed using line elements for simulating the stretch/draw forming operation of an arbitrarily-shaped plane-strain section. An implicit, incremental, updated Lagrangian formulation is employed, introducing a minimum plastic work path assumption for each time step. Geometric and material nonlinearities are also considered within each time step. The finite element equation is based on the mesh-normal, which compatibly describes arbitrary tool surfaces and FEM meshes without depending on the explicit spatial derivatives of tool surfaces. The membrane approximation is adopted under the plane stress assumption. The sheet material is assumed to obey a rigid-viscoplastic constitutive law. The developed program was tested in the die-tryout of typical automotive inner panels. In order to determine a single friction coefficient and boundary length, FEM results and measurements of thinning for a stretched section of final die were compared. After finding analysis parameters, the sheet forming operations of original and final die designs were simulated. Excellent agreement between measured and computed thickness strains was obtained and the developed program was able to identify die designs which were rejected during die tryout.