• Journal of Biomedical Engineering Research
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• v.27 no.3
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• pp.110-116
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• 2006

Finite element method (FEM) provides several advantages over other numerical methods such as boundary element method, since it allows truly volumetric analysis and incorporation of realistic electrical conductivity values. Finite element mesh generation is the first requirement in such in FEM to represent the volumetric domain of interest with numerous finite elements accurately. However, conventional mesh generators and approaches offered by commercial packages do not generate meshes that are content-adaptive to the contents of given images. In this paper, we present software that has been implemented to generate content-adaptive finite element meshes (cMESHes) based on the contents of MR images. The software offers various computational tools for cMESH generation from multi-slice MR images. The software named as the Content-adaptive FE Mesh Generation Toolbox runs under the commercially available technical computation software called Matlab. The major routines in the toolbox include anisotropic filtering of MR images, feature map generation, content-adaptive node generation, Delaunay tessellation, and MRI segmentation for the head conductivity modeling. The presented tools should be useful to researchers who wish to generate efficient mesh models from a set of MR images. The toolbox is available upon request made to the Functional and Metabolic Imaging Center or Bio-imaging Laboratory at Kyung Hee University in Korea.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.19 no.1
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• pp.42-49
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• 2010

In general, the direct experimental approach to study machining processes is expensive and time consuming, especially when a wide range of parameters are included: tool, geometry, materials, cutting conditions, etc. The aim of this study is to verify the effectiveness of finite element method for orthogonal cutting process by comparing the simulated cutting forces with measured results. Two commercialized finite element codes $AdvantEdge^{TM}$ and Deform-$2D^{TM}$ have been used to simulate the cutting forces in orthogonal cutting process. In this paper, estimated cutting and feed force components are compared with experimental results for different two materials. As a result, it has been found that FEM simulation is effective for understanding and predicting the orthogonal cutting process although some improvements on friction model and remeshing process are needed.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.2
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• pp.171-176
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• 2002

This paper is the study on stress analysis of spur gear using a finite element method. Gear drives constitute very important mechanisms in transmitting mechanical power processes compromising several cost effective and engineering advantages. The load transmission occurred by the contacting surfaces arises variable elastic deformations which are being evaluated through finite element analysis. The automatic gear design program is developed to model gear shape precisely. This gear design system developed was used by pre-processor of FEM packages. The distribution of stresses at contacting surfaces was examined when a pair of gear contact.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.8
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• pp.1253-1260
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• 2001

Transient thermal analysis of a three-dimensional axisymmetric automotive disk brake is presented in this paper. Temperature fields are obtained using a hybrid FFT-FEM scheme that combines Fourier transform techniques and finite element method. The use of a fast Fourier transform algorithm can avoid singularity problems and lead to inexpensive computing time. The transformed problem is solved with finite element scheme for each frequency domain. Inverse transforms are then performed for time domain solution. Numerical examples are presented for validation tests. Comparisons with analytical results show very good agreement. Also, a 3-D simulation, based upon an automotive brake disk model is performed.

• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.6
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• pp.44-52
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• 1997

As part of the effort to reduce the weight of powertrain, a hollow crankshaft has been designed. The mass reduction of the crankshaft changes the dynamic properties of the crankshaft such as moment of inertia, and torsional, bending stiffness. The purpose of this paper is to compare the dynamic behavior of the hollow crankshaft with that of the original, solid crankshaft. Global dynamic behavior of the crankshaft is analyzed bgy the transfer matrix method(TMM). The crankshaft has been modeled by 38 lumped mass and stiffness elements. The dynamic patameters of each lumped element are provided by Finite Element Method(FEM). The responses of the crankshaft from TMM are fed back as loading conditions to the Finite Element model to obtain dynamic stresses for critical areas of the crankshaft.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.780-785
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• 2007

Accurate and fast haptic simulations of deformable objects are desired in many applications such as medical virtual reality. In haptic interactions with a coarse model, the number of nodes near the haptic interaction region is too few to generate detailed deformation. Thus, local refinement techniques need to be developed. Many approaches have employed purely geometric subdivision schemes, but they are not proper in describing the deformation behavior of deformable objects. This paper presents a continuum mechanics-based finite element adaptive method to perform haptic interaction with a deformable object. This method superimposes a local fine mesh upon a global coarse model, which consists of the entire deformable object. The local mesh and the global mesh are coupled by the s-version finite element method (s-FEM), which is generally used to enhance accurate solutions near the target points even more. The s-FEM can demonstrate a reliable deformation to users in real-time.

• Proceedings of the KIEE Conference
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• 2004.07d
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• pp.2568-2570
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• 2004

CEMTool is a command style design and analyzing package for scientific and technological algorithm and a matrix based computation language. In this paper, we present new FEM (Finite Element Method) package in CEMTool environment. In contrast to the existing MATLAB PDE Toolbox, our proposed FEM package can deal with the combination of the reserved words. Also, we can control the mesh in a very effective way With the introduction of new mesh generation algorithm and NDM (Hosted Dissection Method), our FEM package can guarantee the shorter computational time than MATLAB PDE Toolbox. In addition, using the advanced electromagnetics library of CEMTool FEM package, we can analyze the practical problems such as the motor field analysis. Consequently, with our new FEM package, we can overcome some disadvantages of the existing MATLAB PDE Toolbox.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2006.04a
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• pp.373-380
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• 2006

Accurate and fast haptic simulations of deformable objects are desired in many applications such as medical virtual reality. In haptic interactions with a coarse model, the number of nodes near the haptic interaction region is too few to generate detailed deformation. Thus, local refinement techniques need to be developed. Many approaches have employed purely geometric subdivision schemes, but they are not proper in describing the deformation behavior of deformable objects. This paper presents a continuum mechanics-based finite element adaptive method to perform haptic interaction 'with a deformable object. This method superimposes a local fine mesh upon a global coarse model, which consists of the entire deformable object. The local mesh and the global mesh are coupled by the s-version finite element method (s-FEM), which is generally used to enhance accurate solutions near the target points even more. The s-FEM can demonstrate a reliable deformation to users in real-time.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.794-795
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• 2008

In this paper, eddy current compensation method of 2D finite element method(FEM) is studied compared with 3D FEM. The result of eddy current loss of permeant magnet is different from 3D FEM result because current loop of the inside of permanent magnet can not expressed by 2D FEM. In order to reduce the error between 2D and 3D FEM, permanent magnet conductivity is compensated considering current loop of magnet shape according to length and width.

• Steel and Composite Structures
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• v.42 no.2
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• pp.243-256
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• 2022

A coupled finite element method (FEM)-boundary element method (BEM) for analyzing the hydroelastic response of functionally graded carbon nanotube-reinforced composite (FG-CNTRC) floating plates under moving loads is firstly introduced in this article. For that aim, the plate displacement field is described utilizing a generalized shear deformation theory (GSDT)-based FEM, meanwhile the linear water-wave theory (LWWT)-relied BEM is employed for the fluid hydrodynamic modeling. Both computational domains of the plate and fluid are coincidentally discretized into 4-node Hermite elements. Accordingly, the C1-continuous plate element model can be simply captured owing to the inherent feature of third-order Hermite polynomials. In addition, this model is also completely free from shear correction factors, although the shear deformation effects are still taken into account. While the fluid BEM can easily handle the free surface with a lower computational effort due to its boundary integral performance. Material properties through the plate thickness follow four specific CNT distributions. Outcomes gained by the present FEM-BEM are compared with those of previously released papers including analytical solutions and experimental data to validate its reliability. In addition, the influences of CNT volume fraction, different CNT configurations, water depth, and load speed on the hydroelastic behavior of FG-CNTRC plates are also examined.