• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.10
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• pp.1237-1242
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• 2011

The A detailed 3D finite-element analysis model of a human foot has been developed by converting CT scan images to 3D CAD models in order to analyze the distribution of plantar pressure. The 3D foot model includes all muscles, bones, and skin. On the basis of this model and the pressure distribution results, shoes for diabetes patients, which can make the plantar pressure distribution uniform, may be designed through finite-element contact analysis.

• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.3
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• pp.771-788
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• 1991

본 연구에서는 편심된 강성 강화 부재가 붙어 있는 얇은 판 또는 얇은 셸에 대해 유한 요소 해석을 할 때, 편심된 강성 강화 부재를 개별된 요소로서 정확히 묘사 할 수 있도록, 일반적인 보 이론을 기초로 하여 2개의 절점을 갖고, 각 절점당 6자유 도를 갖는 3차원 편심 보 요소(offset beam element)에 대하여 수식화하여 변위와 응 력을 계산한다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.3A
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• pp.439-445
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• 2006

Analysis problems of tunnels whose geometrical dimensions are very small compared with surrounding media can be treated as infinite region problems. In such cases, even if finite element models can be applied, excessive number of elements is required to obtain satisfactory accuracy. However, inaccurate results may be produced due to assumed artificial boundary conditions. To solve these problems, a hybrid model, which models the region of interest with finite elements and the surrounding infinite media with infinite elements, is introduced for the analysis of infinite region. Three-dimensional isoparametric infinite elements with various decay characteristics are formulated in this paper and the corresponding parameters are presented by means of parametric studies. Three-dimensional tunnel analysis performed on a representative example verifies the applicability of hybrid model using infinite elements.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.12
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• pp.1021-1030
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• 2017

This paper describes the algorithm of computing thermal contact conductance between unmatched grid interfaces for finite element thermal analysis. Because grid interfaces should be coincident with adjacent meshes for finite element method, large amount of man hours and huge computations are required to match interfaces between many numbers of complex subdomains. A novel method that distributes feasibly the conductances to interface nodes is proposed. The aims of the method are described, and details of the nodal conductance distribution algorithm with less dependency on meshes are represented. The algorithm can be applied both the flat and curved interfaces in 3 dimensional space, and proposed method can combined with many finite element application including thermal analysis.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.22 no.6
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• pp.549-555
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• 2009

Based on three-dimensional(3-D) finite element limit analyses, this paper provides limit and TES (Twice-Plastic Load) loads for mitred pipe bends under bending and pressure. The plastic limit loads are determined from FE limit analyses based on elastic-perfectly-plastic materials using the small and large geometry change option. A wide range of parameters related to the mitred bend geometry is considered. Based on the finite element results, closed-form approximations of plastic limit and TES plastic load solutions for mitred pipe bends under bending are proposed.

• Journal of Power System Engineering
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• v.16 no.1
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• pp.78-83
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• 2012

The authors suggest the algorithm for the static analysis of a three dimensional solid structure by using the finite element-transfer stiffness coefficient method (FE-TSCM) and the hexahedral element of the finite element method (FEM). MATLAB codes were made by both FE-TSCM and FEM for the static analysis of three dimensional solid structure. They were applied to the static analyses of a very thick plate structure and a three dimensional solid structure. In this paper, as we compare the results of FE-TSCM with those of FEM, we confirm that FE-TSCM introducing the hexahedral element for the static analysis of a three dimensional solid structure is very effective from the viewpoint of the computational accuracy, speed, and storage.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.6
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• pp.491-497
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• 2017

In recent years, 3D printing has received increasing attention due to its potential for direct fabrication beyond the traditional rapid prototyping. 3D printing has the advantage of being able to manufacture complicated shapes that were thought impossible to produce by traditional manufacturing processes. This advantage has driven applications of 3D printing to direct manufacturing of functional parts, such as lightweight structures and component integration. In this study, a porous shell structure is designed for the purpose of weight reduction and ventilation. Finite element (FE) analyses are performed to compare the effective stiffness of the porous structure with the conventional solid structure. Structural reinforcements are also considered in order to make up the stiffness reduction due to the porosity, and the relevant FE analyses are performed to investigate the effect of the reinforcement design on the bending stiffness. The optimized reinforced structure is then proposed through response surface analysis.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.3D
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• pp.435-444
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• 2006

This paper investigates the effect of 3-dimensional FE models to evaluation results of jointed concrete pavements which is back-calculated by AREA method. Sensitivity of 3-dimensional FE models developed to simulate the behavior of real jointed concrete pavement are analyzed after compared with 2-dimensional FE models using ILLISLAB. In comparison with 2-dimensional models, influence of concrete contraction under loading plate and base layer on surface deflections is more than that of loading configuration. Deflections at 3-dimensional model between linear and nonlinear temperature distribution under same temperature difference are similar, but noticeable differences are investigated in low elastic modulus of foundations. Dynamic deflections under loading plate are larger than static deflections in high elastic modulus of foundation, but smaller in low elastic modulus. Lower dynamic modulus of subgrade reactions are backcalculated by dynamic deflections than by static deflections. But reverse trend is investigated in the backcalculated elastic modulus of concrete which describes trends of the field backcalculation values calculated from AREA method.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.20 no.6
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• pp.691-697
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• 2007

Numerical eigen analysis of beam-like structure can be easily and effectively done by various conventional beam theory-based methods. However, in case of the structures composed of composite-sectioned beams, the application of conventional numerical methods requires one to derive both equivalent material and geometry properties. In the present paper, these equivalent properties are derived by the transformed section method and the test FEM program is coded. The numerical accuracy of the proposed method is verified through the comparison with the ANSYS 3-D model.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.33 no.3
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• pp.201-207
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• 2020

In this study, various types of porous beams were designed and analyzed to examine the relationship between the behavior of a porous beam and certain nonlocal parameters. The nonlocal parameters were defined as functions of the conditions of defects in the porous material. Finite element analysis was conducted on the beams under typical boundary and loading conditions. Beams with stiffeners having the same dimensions as the defects in the porous beams were also analyzed. The deformation tendency of these beams was determined and described in terms of the nonlocal parameters. The deformation of a porous beam was linearly proportional to the square of the diameters of the defects, whereas that of a beam with a stiffener was linearly proportional to the cube of the diameter of the stiffener. Furthermore, for a stiffened beam with axial loading, the results derived from a 3D solid element and those under 2D plane stress conditions were different.