• Journal of the Korean Society for Precision Engineering
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• v.18 no.9
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• pp.204-209
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• 2001

The finite element model for automotive muffler analysis is improved by modifying the boundary condition of outlet and the mesh of finite element model. The model minimizes the difference between transmission loss from analysis and that from experiment. Four different boundary conditions and the four types of finite element model are tested to find out the best one of those. From the case study it is verified that the bevel of transmission loss can be changed by the variation of radiation impedance value. Also the resonance or anti-resonance frequencies of transmission loss can be shifted by the variation of finite element mesh. An improved finite element model of muffler is proposed in consideration with the accuracy and the computing time of analysis.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.25 no.4
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• pp.290-294
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• 2016

A finite element method (FEM) study was performed on micro-scale blanking of an AL6061-T6 foil with negative clearance. ABAQUS/explicit was used to prepare a simulation model of negative clearance blanking with tools having an edge radius comparable to the foil thickness. The Johnson-Cook plastic flow model was used in the simulations for the material flow. The FEM model was used to study the effects of various blanking parameters on the negative clearance blanking process and quality of the blank. In particular, the projecting edge on the bottom of the blank was observed. Research on negative blanking at the micro-scale is summarized and discussed.

• Computers and Concrete
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• v.7 no.6
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• pp.497-510
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• 2010

For better estimation of elastic property of concrete composites, the effect of Interfacial Transition Zone (ITZ) has been found to be significant. Numerical concrete composites models have been introduced using Finite Element Method (FEM), where ITZ is modeled as a thin shell surrounding aggregate. Therefore, difficulties arise from the mesh generation. In this study, a numerical concrete composites model in 3D based on FEM and random unit cell method is proposed to calculate elastic modulus of concrete composites with ITZ. The validity of the model has been verified by comparing the calculated elastic modulus with those obtained from other analytical and numerical models.

• Transactions of Materials Processing
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• v.31 no.4
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• pp.194-199
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• 2022

In finite element method (FEM) simulations, constitutive models are widely used and developed to represent a wide range of true stress-strain curves using a small number of modeling parameters. Nevertheless, many studies has been conducted to find a suitable constitutive model and optimal modeling parameters to represent experimentally obtained true stress-strain curves. Therefore, in this study, a new constitutive modeling approach using the combined Swift and Voce model is suggested, and confirmed through comparisons of the experimental results with the FEM simulation results.

• Journal of the Korean Ceramic Society
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• v.27 no.1
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• pp.23-26
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• 1990

A model is developed based on the Finite Element Method (FEM) which provides a more accurate prediction of the hydrostatic piezoelectric coefficient of 1-3 or 3-1 PZT-Polymer composites than does the series/parallel model.

• Journal of The Korean Society of Agricultural Engineers
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• v.46 no.5
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• pp.61-68
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• 2004

Methodologies of the finite element and boundary element are combined to achieve an efficient and accurate analysis model of frame structure containing shear wall. This model analyzes the frame by employing the finite element method and the shear wall by boundary element method. This study is applicable to a specific situation, where the boundary element is surrounded by finite elements. By employing FE dominant method in which boundary stiffness matrix is transformed into finite element stiffness matrix, boundary element and finite element method are combined to analyze frame structure with walls.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11a
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• pp.401.2-401
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• 2002

An unconstrained tuning fork with a 3-D model has been numerically analyzed by Finite Element Method (FEM) and Boundary Element Method (BEM). The first three natural frequencies were calculated by the FEM modal analysis. Then the change of the modal frequencies was examined with the variation of the tuning fork length and width. (omitted)

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.13 no.2
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• pp.99-107
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• 2003

The finite element method(FEM) is the most widely used and powerful method for structural analysis. In general, in order to analyze complex and large structures, we have used the FEM. However, it is necessary to use a large amount of computer memory and computation time for solving accurately by the FEM the dynamic problem of a system with many degree-of-freedom, because the FEM has to deal with very large matrices in this case. Therefore, it was very difficult to analyze the vibration for plate structures with a large number of degrees of freedom by the FEM on a personal computer. For overcoming this disadvantage of the FEM without the loss of the accuracy, the finite element-transfer stiffness coefficient method(FE-TSCM) was developed. The concept of the FE-TSCM is based on the combination of modeling technique in the FEM and the transfer technique in the transfer stiffness coefficient method(TSCM). The merit of the FE-TSCM is to take the advantages of both methods, that is, the convenience of the modeling in the FEM and the computation efficiency of the TSCM. In this paper, the forced vibration analysis algorithm of plate structures is formulated by the FE-TSCM. In order to illustrate the accuracy and the efficiency of the FE-TSCM, results of frequency response analysis for a rectangular plate, which was adopted as a computational model, were compared with those by the modal analysis method and the direct analysis method which are based on the FEM.

• Journal of Power System Engineering
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• v.11 no.4
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• pp.78-85
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• 2007

In order to analyze accurately the vibration of a structure by using the finite element method (FEM), we have to model a analytical structure as a numerical model with many degrees-of-freedom. However, in this case, the FEM needs much computation time and storage. The authors developed the finite element-transfer stiffness coefficient method (FE-TSCM) for overcoming the drawback of the FEM. In this paper, the authors apply the FE-TSCM to the in-plane vibration analysis of general plates with various shapes. Two numerical examples, a rectangular plate and a triangular plate, are used to compare the results of the FE-TSCM and the FEM. Through the numerical calculation, we confirm that the FE-TSCM can be applied to the in-plane free or forced vibration analysis of the general plates with various shapes and is effective to in-plane vibration analysis of general plates.

• 한국방재학회:학술대회논문집
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• 2007.02a
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• pp.49-52
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• 2007

Terrestrial Laser Scanning(TLS) was developed at the mid-to-late 1990s. This technique enables to perform reconnaissance surveying of regions or structures hard to access. Besides, TLS has been extended its application gradually such as preservation of historical remains, underground surveys, slopes, glaciers monitoring and so on. However, though the technique has a lot of advantages, an application for structural health and safety monitoring is a beginning stage and it need much research. Therefore in this study, as a groundwork, the estimation model on stress of structures using TLS and Finite Element Method(FEM) applied by the Digital Elevation Model(DEM) technique of geoinformatics is proposed. For the verification of this model, experiments were performed with a continuous steel beam subjected to point loads and outputs were compared with those of electrical strain sensors.