• Proceedings of the Computational Structural Engineering Institute Conference
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• 2001.10a
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• pp.67-74
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• 2001

In domestic, irregular walls such as T, L, H and Box shapes are considered as rectangular wall in the design of bearing wall apartment building. The strengths of walls, therefore, can be underestimated in case of using the current design process. Irregular walls are connected to each other as rigid joint so that part of the load can be resisted by the wall perpendicular to the load direction. This resistance can be caused by the effective width of perpendicular wall. This additional resistance by the perpendicular wall increases the strength of structural walls. The objective of this study is to evaluate the effective widths of flanged walls with different aspect ratios by using FEM analyses. the results from finite element method are compared with effective flange widths of some code provisions.

• Journal of the Korean Society of Safety
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• v.12 no.2
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• pp.37-44
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• 1997

Composite materials have various complicated characteristics depending on the ply materials, ply orientations, ply stacking sequences and boundary conditions. Therefore, it is difficult to analyze composite materials. For efficient use of composite materials in engineering applications, the dynamic behavior such as natural frequencies and nodal patterns should be identified. This study presents FEM results for the free vibration of symmetrically and antisymmetrically laminated composite and hybrid composite rectangular plates. The natural frequencies of laminated composite rectangular plates having the various boundary conditions (completely clamped, 2-edge clamped, cantilevered) are experimentally obtained. In order to demonstrate the validity of the experiment, FEM analysis using ANSYS was performed and natural frequencies experimentally obtained is compared with that calculated by FEM analysis. The results obtained from both experiment and FEM analysis show a good agreement.

• Transactions of Materials Processing
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• v.5 no.2
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• pp.130-137
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• 1996

The sheet formability can be improved by the optimum drawbeads installation because draw-beads can control the flow of the metal into the die cavity when the punch enters into the die opening, In this study the drawing characteristics for step drawbead are analyzed by 2-D rigid -plastic FEM and also are measured experimentally. In addition for the validity of FEM theoretical results are compared with the experimental results. Especially the draw bead restrain-ing forces and the strain distributions of drawn specimens are obtained in both FEM and experiment. Also the effects of the drawbead dimensions drawing angles and blank holding forces on the drawing characteristics are investigated.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.18 no.1
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• pp.21-28
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• 2005

This study tries to analyzes the torque and engaging time generated in a micro-electromagnetic clutch by using FEM. For the purpose of design change and optimization of the micro-electromagnetic clutch, the torque prediction is very important. We employ a mathematical approach based on the electromagnetic principle. For torque prediction, real material properties are substituted to the constructed axi-symmetric FEM model to obtain the analytical torque and engaging time. The predicted torque and engaging time are compared with those obtained by experiments to discuss the validity of torque and engaging time analysis. The analytical results agrees well with experimental data, therefore explaining the validity of the torque and engaging time prediction method.

• Proceedings of the KSME Conference
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• 2001.06c
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• pp.146-151
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• 2001

This study is an investigation for the ADS optimum design by using FEM. We write out program which express ADS perfectly and reduce the required time for correcting of model to the minimum in solution and manufacture result. We complete algorithm which can plan optimum forming of model by feedback error information in CAE. For that, we draw up ADS program which modeling rachet wheel by using visual LISP and telegraph to ANSYS, structural solution program, we can solve stress solution. Then we correct model by feedback date obtaining in solution process, repeat course following stress solution again and do modeling rachet wheel for optimum forming. That is our aim. As a result of experience, we can develope automatic design program using Visual LISP and exhibit ADS as modeling third dimension CAD for optimum design. Also, we develop optimum design algorithm using ADS and FEM. In rachet wheel, greatest equivalence stress originates in key groove comer and KS standard is proved the design for security.

• Journal of the Korean Geotechnical Society
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• v.19 no.4
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• pp.65-74
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• 2003

This paper presents the results of a comparative study between FEM and LEM on slope stability analysis. For validation, factors of safety were compared between FEM and LEM. The results from the two methods were in good agreement. This suggests that the FEM with the shear strength reduction method can be effectively used on slope stability analyses. A series of analyses were then performed using the FEM for various constitutive laws, slope angles, flow rules, and the finite element discretizations. Among the findings, the finite element method in conjunction with the shear strength reduction method can provide reasonable results in terms of safety. Also revealed is that the results of FEM can be significantly affected by the way in which the type of constitutive law and flow nile we selected.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.05a
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• pp.36-37
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• 2019

In domestic construction industry progress, construction and quality control of large structures are considered to be important as the superstructure and mass scale of structures. In the case of mass concrete, high hydration heat caused by cement hydration generates temperature stress by generating internal temperature difference with the concrete surface. These temperature stresses cause cracks to penetrate the concrete structure. A method of lowering the heat generation by incorporating Urea in order to reduce the concrete temperature crack has been proposed. In this study, the heat function coefficient for the FEM temperature crack analysis of the mass concrete containing the element was derived and the adiabatic temperature rise test was carried out according to the incorporation of the element. As a result of this experiment, the maximum temperature of 41 ± 1℃ was obtained irrespective of the amount of urea, and the maximum temperature decreased by 16.9℃ in concrete containing 40kg/㎥ of urea.

• Geomechanics and Engineering
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• v.9 no.4
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• pp.415-426
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• 2015

Researches have been done to discover ways to strengthen peat soil deposits. In this model study, fibrous peat that is the most compressible types of peat has been reinforced with precast peat columns stabilized with ordinary Portland cement and polypropylene fibres. Rowe cell consolidation tests as well as plate load tests (PLTs) were conducted on various types of test samples to evaluate the strength and deformation of untreated peat and peat reinforced by various types of columns. PLTs were conducted in a specially designed and fabricated circular steel test tank. The compression index ($C_c$) and recompression index ($C_r$) of fibrous peat samples reduced considerably upon use of precast columns. Also, PLT results confirmed the results obtained from Rowe cell tests. Use of polypropylene fibres added to cement further decreased ($C_c$) and ($C_r$) and increased load bearing capacity of untreated peat. Finite element method (FEM) using Plaxis 3D was carried out to evaluate the stress distributions along various types of tested samples and also, to compare the deformations obtained from FEM analysis with the actual maximum deformations found from PLTs. FEM results indicate that most of the induced stresses are taken on the upper portion of tested samples and reach their maximum values below the loading plate. Also, a close agreement was found between actual deformation values obtained from PLTs and values resulted from FEM analysis for various types of tested samples.

• Composites Research
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• v.16 no.4
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• pp.59-65
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• 2003

FEM analysis of the smart skin structure, and application of the sandwich structures investigated. The honeycomb manufactures only provide stillness of thickness direction and transverse shear modulus. Although these are dominant mechanical properties. the other mechanical properties are needed in FEM analysis. Hence, this work shows procedures of obtaining those mechanical properties. Honeycomb material was assumed to be ar, isotropic material and properties are estimated by its dominant honeycomb properties. The other honeycomb properties are then obtained by mechanical properties of Nomex. Buckling test and three point bending test were simulated by ABAQUS. Both the shell and solid element models were used. The results were compared with experimental results and analytical approaches. They showed good agreements. This study shows a guideline of FEM analysis of smart skin structure using commercial a FEM package.

• Proceedings of the KIEE Conference
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• 2000.11c
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• pp.565-567
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• 2000

In this paper, the discharge characteristics of AC PDP, one of the leading technologies currently under development for large-area flat displays, is computed by using Finite Element Method(FEM) combined with Flux-corrected Transport(FCT) algorithm. Up to now, many simulations of AC PDP have been mainly done by Finite Difference Method(FDM). But we simulated the AC PDP by using FEM-FCT method which discretizes the region of interest with unstructured grids. FEM-FCT method can reduce the computational cost because of refining locally where the physical quantities have steep gradients and is more efficient in solving discharge problems, such as a AC PDP. Results are presented in Ne-Xe(4%) gas mixture for a gas pressure of 400 Torr and as the discharge proceeds, the space and time variations of the electron and ion densities, potential and wall charges on the dielectric are described. Results from our simulation by FEM-FCT are similar to those from simulation by FDM and are more efficient in computational cost reduction.