• The Transactions of the Korean Institute of Electrical Engineers B
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• v.48 no.4
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• pp.187-193
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• 1999

This study investigates the hysteresis phenomena of a Synchronous Reluctance Motor (SynRM) using coupled FEM and Preisach modeling. Preisach's model, which allows accurate prediction of hysteresis, is adopted in this procedure to provide a nonlinear solution. the computer simulation and experimental result for the i$\lambda$loci show the propriety of the proposed method.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.11a
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• pp.89-90
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• 2007

• Journal of the Korea Institute of Building Construction
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• v.14 no.5
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• pp.379-388
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• 2014

The purpose of this study is to investigate the effect of capsulated slurry phase change material (PCM) on the thermal crack in mass concrete by experimental work and FEM analysis. In this study, three conditions of samples were prepared for evaluating the level of hydration heat, i.e., a material condition, a cement paste condition and a concrete condition. Also, a compressive strength test was conducted for FEM inverse analysis. Based on the results of the experiment, exothermic function coefficients of concrete with encapsulated slurry PCM were deducted by the inverse analysis. After that, they applied to FEM analysis of the mass scale concrete structures. From the results of this experiment, $31^{\circ}C$ capsulated slurry PCM had no super cooling phenomenon in the material condition. In the cement condition, hydration heat decreased by 34.61J when PCM of 1g was mixed. In the concrete condition, PCM of 6% was deducted as the best level in hydration heat absorption. In FEM inverse analysis, rate coefficient of reaction gradually decreased when PCM mixing ratio increased. But, temperature-rise coefficient increased when PCM mixing ratio exceeded 6%. For the inversed exothermic function coefficients applying to large scale concrete structures, a thermal cracking index increased by 0.05 when PCM of 1% was mixed.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.9
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• pp.81-86
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• 2000

This paper was carried out to investigate the characteristics of interlaminar fracture toughness of foam core sandwich structures under opening loading mode by using the double cantilever beam (DCB) specimens in Carbon/Epoxy and foam core composites. instead of using symmetric geometry of DCB specimen non-symmetric DCB specimen was used to calculate the interlaminar fracture toughness. Three approaches for calculating the energy release rate({{{{ {G }_{IC } }}}}) were compared. Fracture toughness of foam core sandwich structures by autoclave vacuum bagging and hotpress were compared and analyzed. Experiment nonlinear beam bending FEM method were performed. Suggested bonding surface compensation and equivalent area inertia moment was used to calculate the energy release rate in nonlinear analytical results. The conclusions among experimental nonlinear analytical and FEM results was observed. The vacuum bagging method was shown to be able to substitute method in stead of autoclave without serious loss of Mode I energy release rate({{{{ {G }_{IC }}}}}) to be able to substitute method in stead of autoclave without serious loss of Mode I energy release rate({{{{ {G }_{IC }}}}}).

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.690-692
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• 2001

A FEM model of the remote-field eddy current effect is presented for zirconium-2.5percent niobium(Zr-2.5%Nb) nuclear reactor pressure tubes to demonstrate the important electromagnetic field. Phenomena that describe this effect. This model is applied to evaluate the optimal operating frequency and detector position. There are many ambiguous experimental results connected with this technique. Finite element calculations can be used in the interpretation of these experimental results even though the electromagnetic fields measured in the remote-field technique are very small.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.2 no.2
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• pp.45-51
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• 2003

The multi-piloting type progressive die for U-bending sheet metal production part is a very specific division. This study reveals the sheet metal forming process with multi-forming die by center carrier type feeding system. Through the FEM simulation by DEFORM, it was accepted to u-bending process as the first performance to design of strip process layout. The next process of die development was studied according to sequence of die development, i.e die structure, machining condition for die making, die materials, heat treatment of partially die components, know-how and so on. The feature of this study is the die development of scrapless progressive die of multi-stage through the modeling on the I-DEAS program, components drawing on the Auto-LISP, CAD/CAM application, ordinary machine tool operating and revision by tryout.

• Proceedings of the KIEE Conference
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• 1995.07a
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• pp.56-58
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• 1995

Dynamic characteristics of the vector controlled induction motor has been analysed using d-q equivalent circuit. However, for the design of the induction motor, the analysis of an accurate response characteristic are needed. In this paper, dynamic characteristic analysis method using 2-D Finite Element Method (FEM), which takes the motion equation of the rotor into account and considers the physical motion of the rotor by an automatic subdivision of mesh, are explained.

• Journal of the Korean Society for Heat Treatment
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• v.10 no.1
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• pp.40-46
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• 1997

Although functionally gradient materials(FGM) has been developed so as to decrese the thermal stress induced by the high temperature difference between metal and ceramic, it is necessary to analyze the residual thermal stress for the fabrication of FGM. In order to reduce the residual thermal stress, compositional profile of SUS/PSZ(FGM) was suggested using finite element method(FEM). The stress analysis was made on the shape of cylinder with axial symmetry using two dimensional triangular element. For the case of various cylinder with different compositional gradient, calculated stress components were in reasonably good agreement with the expected ones. And the qualitative profile was suggested.

• Journal of the Korean Magnetics Society
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• v.5 no.5
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• pp.631-635
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• 1995

Longitudinal magnetic recording process of thin film media was simulated by the 2-D finite element method (FEM). To describe precisely the hysteresis behavior of thin film media, scalar Preisach model was used. In this paper, we discussed the formation of bit patterns and importance of modeling of minor loops in high density recording. The effects of the media coercivity and film thickness on the remanent magnetization and transition shape were investigated.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.216-218
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• 1996

In this paper, it is treated the design and characteristics analysis of the voice coil type LOA which is composed of a voice coil type mover and permanent magnets. The design is acomplished using FEM analysis to make up the magnetic circuit. And the characteristics of LOA are analyzed to be used on the control system for the earthquake-proof experiments.