• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1999.06a
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• pp.73-79
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• 1999

Finite element equations by using fast Fourier transformation were formulated for studying temperatures resulting from frictional heating in sliding systems. The equations include the effect of velocity of moving components. The program developed by using FFT-FEM that combines Fourier transform techniques and the finite element method, was applied to the sliding bearing system. Numerical prediction obtained by FFT-FEM was in an excellent agreement of experimental temperature measurements.

• Transactions of the Korean Society of Automotive Engineers
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• v.4 no.2
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• pp.183-188
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• 1996

The compressive stress-strain response of Low Density Polyurethane foam material is modeled using the finite element method. A constitutive equation which include experimental constants based on quasi-static and dynamic uniaxial compression test is proposed. Impact test with different impactor masses and velocities are performed to verify the proposed model. The comparison between impact test and finite element analysis shows good agreements.

• Tribology and Lubricants
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• v.16 no.3
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• pp.218-222
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• 2000

Finite element equations by using fast Fourier transformation were formulated for studying temperatures resulting from frictional heating in sliding systems. The equations include the effect of velocity of moving components. The program developed by using FFT-FEM that combines Fourier transform techniques and the finite element method, was applied to the sliding bearing system. Numerical prediction obtained by FFT-FEM was in an excellent agreement of experimental temperature measurements.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.724-729
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• 2007

The study is a structure analysis by applying the output torque and tangential force on 47 ton excavator drive motor gear carrier. The finite element analysis for 3D model is performed by ABAQUS/Standard. We made an estimate by evaluating the results of the finite element analysis.

• Journal of Korean Association for Spatial Structures
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• v.3 no.4 s.10
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• pp.85-92
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• 2003

In this work, a finite element model is presented for geometrically non-linear analysis of shell structures. Finite element by using a three-node flat triangular shell element is formulated. The non-linear incremental equilibrium equations are formulated by using an updated Lagrangian formulation and the solutions are obtained with the incremental/iterative Newton-Raphson method and arc length method. Some of results are presented for shell structures. The obtained results are in good agreement with the results available in existing literature.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.2
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• pp.271-277
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• 1994

The fatigue crack opening behavior is analyzed using finite element method. Because extremely fine mesh subdivision is required when using constant stress constant strain triangular element, this study uses conventional two dimensional eight node isoparametric elements. Since plasitc zone size is similar to crack propagating length per each load cycle because of relatively large element size, a new analysis model that a crack propagates every two load cycle is suggested. the opening load and crack opening displacement can be obtained accurately by this method.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.10
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• pp.1049-1056
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• 2008

A method for the vibration analysis of curved beam conveying fluid with uniform velocity was presented. The dynamics of curved beam is based on the inextensible theory. Both in-plane motion and out-of-plane motion of curved beam were discussed. The finite element method was formulated to solve the governing equations. The natural frequencies calculated by the presented method were compared with those by analytical solution, straight beam theories and Nastran. As the velocity of fluid becomes larger, the results by straight beam model became different from those by curved beam model. And it was shown that the curved beam element should be used to predict the critical velocity of fluid exactly. The influence of fluid velocity on the frequency response function was also discussed.

• Transactions of Materials Processing
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• v.5 no.4
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• pp.343-352
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• 1996

One of the preferred methods that can be used to verify the results of finite element analysis is to measure surface strains of the deformed part for purpose of direct comparison with simulation results. Instead of using the usual manual method the vision-based measurement method is capable of determining surface geometry and strain from the deformed grid pattern automatically with the help of a computer. To obtain strain distribution over an area, the coordinates of such a surface grid are determined from the multiple video images by applying the photogrammetry principle. Methods to improve the overall accuracy of the vision-based strain measurement system are explored and the possible accuracies that can be attained by such a measurement method are discussed. A major emphasis is placed on the initial grid application method its accuracy and ease of subsequent image processing. Finite element analyses of limiting dome height(LDH) test are carried out and the results of them are compared with exsperimen-tal data.

• Coupled systems mechanics
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• v.2 no.4
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• pp.389-410
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• 2013

Three-dimensional Lagrangian fluid finite element is applied to seismic response analysis of an oil storage tank with a floating roof. The fluid element utilized in the present analysis is formulated based on the displacement finite element method considering only volumetric elasticity and its element stiffness matrix is derived by using one-point integration method in order to avoid volumetric locking. The method usually adds a rotational penalty stiffness to satisfy the irrotational condition for fluid motion and modifies element mass matrices through the projected mass method to suppress spurious hourglass-mode appeared in compensation for one-point integration. In the fluid element utilized in the present paper, a small hourglass stiffness is employed. The fluid and structure domains for the objective oil storage tank are modeled by eight-node solid elements and four-node shell elements, respectively, and the transient response of the floating roof structure or the free surface are evaluated by implicit direct time integration method. The results of seismic response analyses are compared with those by other method and the validation of the present analysis using three-dimensional Lagrangian fluid finite elements is shown.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.9
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• pp.972-981
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• 2008

The blower which is installed in a FCEV(fuel cell electric vehicle) may cause noise due to misalignment and unbalance of mechanical components that rotate at high speed. One of the key points in efforts to minimize the noise radiation from a blower is the knowledge of the main radiating component and the relation between the surface vibration of a blower and the sound pressure. In this research, the blower model is developed based on FEM(finite element method). FE(finite element) model is reliable by correlation of frequencies and MAC(modal assurance criterion) values between EMA(experimental modal analysis) and FEA(finite element analysis). This model is applied to predict the vibration of a blower by using inverse force identification method and predict the radiating noise by using BEM(boundary element method). Comparing the frequencies of resonance and those mode shapes between EMA and FEA, a structural modification of the FE model is evaluated for reducing the parameters of the blower noise.