• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1633-1637
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• 2008

In this study, we developed 3D MLS-based variable-node elements for easy meshing. These elements should be derived from 2D MLS-based variable-node elements and would be utilized as key elements of easy meshing technique we proposed. Using developed 3D MLS-based variable-node elements, we demonstrated several examples having complex configuration compared with conventional meshing technique. Moreover, we compared with the stress results of our model and conventional one.

• Advances in aircraft and spacecraft science
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• v.6 no.2
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• pp.169-187
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• 2019

This work presents a practical detailed finite element (FE) approach for the three-dimensional (3D) free-vibration analysis of actual aircraft and spacecraft-type lightweight and thin honeycomb sandwich panels. It consists of calling successively in $MATLAB^{(R)}$, via a developed user-friendly GUI, a detailed 3D meshing tool, a macrocommands language translator and a commercial FE solver($ABAQUS^{(R)}$ or $ANSYS^{(R)}$). In contrary to the common practice of meshing finely the faces and core cells, the proposed meshing tool represents each wall of the actual hexagonal core cells as a single two-dimensional (2D) 4 nodes quadrangularshell element or two 3 nodes triangular ones, while the faces meshes are obtained simply using the nodes at the core-faces interfaces. Moreover, as the same 2D FE interpolation type is used for meshing the core and faces, this leads to an automatic handling of their required FE compatibility relations. This proposed approach is applied to a sample made of very thin glass fiber reinforced polymer woven composite faces and a thin aluminum alloy hexagonal honeycomb core. The unknown or incomplete geometric and materials properties are first collected through direct measurements, reverse engineering techniques and experimental-FE modal analysis-based inverse identification. Then, the free-vibrations of the actual honeycomb sandwich panel are analyzed experimentally under different boundary conditions and numerically using different mesh basic cell shapes. It is found that this approach is accurate for the first few modes used for pre-design purpose.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.6
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• pp.63-68
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• 2015

Recently, 3D printer technologies have been used in many research efforts for high precision manufacturing. In particular, the rapid prototyping technology has been developing rapidly, because it can be manufactured in a short time with a 3D designed shape. This paper relates to the production characteristics of the straight bevel gear designed using a 3D print using the PolyJet method. The characteristics of a 3D printed straight bevel gear were compared with a machined straight bevel gear. The accuracy of the produced straight bevel gear was evaluated by backlash, meshing pattern, face angle, root angle, and surface roughness.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.1 s.173
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• pp.196-205
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• 2000

Computed Tomography (CT), Nuclear Magnetic Resonance Imaging (MR1) and some ultrasound techniques make it possible to obtain cross sections of human body or mechanical parts. In CAD system, a series of sectional surfaces can also be obtained from solid models of 3D objects. In this paper we introduce a tetrahedral meshing algorithm from these series of general sections using basic operators. In this scheme. general sections of three-dimensional object are triangulated first and side surfaces between two sections are triangulated by the use of tiling process. Finally tetrahedral meshing process is performed on each layer of 3D objects, which is composed of two general sections and one side surface.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.1419-1424
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• 2003

Impact analysis of TFT-LCD module is very complicated because the structure is assisted with thin, small and non-uniform geometry. Especially, finite element modeling is more difficult and need time-consuming efforts. In this study, we developed LCD Impact Analysis System (LIAS) for the purpose of reducing the analysis time without accuracy reduction. This system contains pre-meshing data, material database, shock condition, auto-reporting etc. PATRAN and DYNA3D is used for meshing and solving. Previously, we performed impact test and reviewed the accuracy of analysis results. Simply we can control design parameters, the procedure such as meshing, running and reporting which are partially auto-prepared. By adopting proposed system, it is expected to achieve efficient impact analysis of LCD module.

• Design & Manufacturing
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• v.6 no.2
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• pp.31-36
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• 2012

Now days CAE has been used for almost all injection molding designs in order to find the best injection conditions. Almost all CAE use 2-D mesh, but the CAE with 2-D mesh can't indicate such as jetting, flow-mark and filling imbalance in multi cavity mold. In this study, we suggested a new 3D meshing. the method which can indicate the filling imbalance in geometrically balanced runner system with Mold Flow MPI 6.1 and we found out that the calculation times are saved. As a feasibility study, we verified that Melt Flipper, RC Pin etc appeared the balanced filling behaviors. of geometrically balanced runner system and Melt Flipper, filling imbalance was indicated more accurately.

• 한국금형공학회:학술대회논문집
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• 2008.06a
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• pp.121-127
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• 2008

Nowdays CAE has been used for almost all injection molding designs in order to find the best injection conditions. Almost all CAE use 2-D mesh, but the CAE with 2-D mesh can't indicate such as jetting, flow-mark and filling imbalance in multi cavity mold. In this study, we suggested a new 3D meshing. the method which can indicate the filling imbalance in geometrically balanced runner system with Mold Flow MPI 6.1 and we found out that the calculation times are saved. As a feasibility study, we verified that Melt Flipper, RC Pin etc appeared the balanced filling behaviors. of geometrically balanced runner system and Melt Flipper, filling imbalance was indicated more accurately.

• Journal of Korean Society for Quality Management
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• v.22 no.2
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• pp.154-165
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• 1994

A new criterion, the solid angle, is introduced to measure the Quality of tetrahedral mesh. This criterion is compared with the existing Delaunay triangulation criterion. The properties of solid angles have been studied and are proposed for utilization in 3-D meshing algorithms. Furthermore, difficulties of developing a 3-D algorithm that provides a lower bound on the smallest angle have been discussed.

• 한국전산유체공학회:학술대회논문집
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• 2000.10a
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• pp.86-91
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• 2000

Automatic method for generation of mesh and three dimension natural convection flow result adapted by this method are presented in this paper. It lake long time to meshing com plex 3-D geometries, and It's difficult to clustering grid at surface boundary. Octree structure resolve this difficulty.

• Journal of the Korean Geotechnical Society
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• v.23 no.1
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• pp.67-76
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• 2007

Flat DMT penetration was analyzed using a finite element model based on a large strain formulation. The ABAQUS/Explicit, a commercial finite element method, was used to study the flat DMT penetration in soils. Then, because the very large mesh distortion occurred due to the penetration of flat DMT, the adaptive meshing technique was utilized to maintain a high quality mesh configuration. The undrained shear strength obtained from the flat DMT is estimated using only the horizontal stress index ($K_{D}$) and so it became necessary to examine using the analysis results obtained from the penetration of the flat DMT. Analysis results show that in normally consolidated region of $K_{D}=2$, the results obtained from the correlations proposed by Marchetti show good agreement with those estimated from the finite element method. The present analysis also shows that in overconsolidated region of $K_{D}>2$, the results obtained from the relationships proposed by Kamei and Iwasaki show good agreement with those provided by the penetration analysis.