• 대한기계학회논문집A
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• 제21권3호
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• pp.378-384
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• 1997

In curing process of tire, contact and slip occurs between green tire and curing bladder. The curing process is a critical step in the manufacture of tires. In this investigation, curing bladder shaping is examined using a finite element method. Specifically, a finite element model between the inner part of green tire and the outer part of curing bladder is generated using contact element and curing bladder is generated using incompressible element. Numerical analysis are performed on two different bladder types, different overall outer diameters of curing bladder and different heights of curing bladder. Numerical results show that contact pressure is increased by using toroidal type of curing bladder, increasing overall diameter and increasing height of curing bladder. To obtain natural equilibrium carcass line, there is a requirement in increasing contact pressure of the section between side and bead.

• Tribology and Lubricants
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• 제26권5호
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• pp.263-271
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• 2010

The rollers of cylindrical roller bearing are axially profiled to relieve high edge stress concentration caused by mainly their finite length and by misalignment. In this paper, a numerical analysis is carried to study the EHL of misaligned (tilted) rollers with axially profiled ends. Using a finite difference method with non-uniform grids and the Newton-Raphson method, the highly nonlinear EHL problems are systematically solved. Physically consistent solutions are obtained for moderate load, material parameters and very small misalignment. For different misalignment angles, contours and sectional plots of pressure and film shape near both edge regions are compared. The asymmetric pressure distributions and film shapes show that the EHL results of finite line contacts are highly dependent upon very small amounts of roller misalignment. Especially, the effect of misalignment on the EHL pressure distribution is much higher than the film shapes.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.1874-1880
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• 2011

In this paper, sensitivity analysis of the pantograph for the high-speed Train was conducted using finite element analysis method. Dynamic interaction of catenary-pantograph model was simulated by using a commercial finite element analysis software, SAMCEF. Pantograph was assumed to be three degree of freedom mass-spring-damper model and the pre-sag of the contact and messenger wire was implemented due to gravity. The span data of the actual high-speed line and specification of pantograph for high-speed train was applied in the analysis model, respectively. The reliability of the simulation model is verified by comparing the contact force results of simulation and test. Through the simulation, mean contact force and its deviation was evaluated and then sensitivity of the pantograph was analyzed.

• 소성∙가공
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• 제5권1호
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• pp.37-46
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• 1996

Superplastic forming/diffusion bonding (SPF/DB) processes were analyzed using a rigid visco-plastic finite element method. The optimum pressure-time relationship for a target strain rate and thickness distributions were predicted by two-node line elements based on the membrane approximation for plane strain. Material behavior during SPF/DB of the integral structures having complicated shapes was investigated. The tying condition is employed for the analysis of inter-sheet contact problems. A movement of rib structure is successfully predicted during the forming.

• International Journal of Precision Engineering and Manufacturing
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• 제6권1호
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• pp.36-41
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• 2005

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 춘계 학술발표회 논문집
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• pp.735-738
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• 2005

The purpose of this study is the infiltration characteristics of soil cut-slope by rainfall. Stability analysis of soil cut-slopes has been conducted by limit equilibrium method on Seep/w and finite element method on Slope/w. Result is same as following. First. the hour when seepage line and groundwater in contact is proportionate from rainfall rate condition and upper natural slope gradient condition which is identical. Second, when seepage line and groundwater is contact, seepage line moves gradually at soil cut-slope surface. Finally, seepage line is formed similarly with soil cut-slope gradient. Third, when rainfall is ended, from the recording upper natural slope where the hour will pass it is stabilized

• Steel and Composite Structures
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• 제29권3호
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• pp.333-348
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• 2018

An analytical method is developed for analysing the contact buckling response of infinitely long, thin corrugated plates and flat plates restrained by a Winkler tensionless foundation and subjected to linearly varying in-plane loadings, where the corrugated plates are modelled as orthotropic plates and the flat plates are modelled as isotropic plates. The critical step in the presented method is the explicit expression for the lateral buckling mode function, which is derived through using the energy method. Simply supported and clamped edges conditions on the unloaded edges are considered in this study. The acquired lateral deflection function is applied to the governing buckling equations to eliminate the lateral variable. Considering the boundary conditions and continuity conditions at the border line between the contact and non-contact zones, the buckling coefficients and the corresponding buckling modes are found. The analytical solution to the buckling coefficients is also expressed through a fitted approximate formula in terms of foundation stiffness, which is verified through previous studies and finite element (FE) method.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1999년도 춘계학술대회논문집
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• pp.22-25
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• 1999

A dynamic explicit finite element code for simulating sheet forming processes has been developed The code utilises the discrete Kirchhoff shell element and contact force is treated by a conventional penalty method. In order to reduce the computational cost a new and robust contact searching algorithm has been developed and implemented into the code. in the method a hierarchical structure of tool segments called a tree structure is built for each tool at the initial stage of the analysis Tree is built in a way to divide a trunk to 8 sub-trunk 2 in each direction until the lowest level of the tree(leaf) contains exactly one segment of the tool. In order to have a well-balanced tree each box on each sub level contains one eighth of the segments. Then at each time step contact line from a node comes out of the surface of the tool. Simulation of various sheet forming processes were performed to verify the validity of the developed code with main focus on he usefulness of the developed contact searching algorithm.

• Tribology and Lubricants
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• 제28권4호
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• pp.153-159
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• 2012

Tapered roller bearings are widely used in high axial-load and radial-load applications. In this study, a numerical analysis is performed to study a finite line contacts EHL problem between a tapered roller and raceway in tapered roller bearings. Converged solutions are obtained for moderate load and material parameters using a finite difference method with non-uniform grids and the Newton-Raphson method. The contours and sectional plots of pressure distribution and film shape are compared. The pressure distribution and film shapes near both ends of the roller are very different from those in the central part and are transversely asymmetric. The maximum pressure and absolute minimum film thickness always occur at the small end of the roller.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2009년도 제7회 압연 심포지엄
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• pp.19-22
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• 2009

It is essential to predict the deformed roll profile for the prediction of the strip profile in rolling process. The work roll of the Sendzimir mill has a small diameter in comparison to a barrel length, so that it is well deformed by the rolling pressure. Also it has a complex roll system, so it is difficult to analyze the roll deflection. In this paper, 3D finite element method is used for the analysis of the roll deflection of the Sendzimir due to the contact between rolls. But it takes much time to get the results, so that the on-line model to evaluate the radial deformation of a roll is developed on the basis of the finite element method.