• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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• pp.517-519
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• 2007

We report our study on the implementation of Q tensor approach into three-dimensional finite element method (FEM) numerical solver. The comparative simulation results demonstrated the possibility of a different director configuration in between Q tensor method and vector method. The comparative study confirmed that Q Tensor implementation is more appropriate for OCB analysis than the vector method.

• 한국산학기술학회논문지
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• 제14권10호
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• pp.4713-4718
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• 2013

플라스틱 사출성형은 원재료를 한 번의 가공으로 최종 제품을 만들 수 있는 장점을 가지고 있다. 사출성형을 위해서는 금형의 설치, 플라스틱 수지의 용융, 용융수지의 사출, 성형품의 취출 등을 위하여 사출성형기는 반드시 필요하다. 사출성형기는 여러 가지 방법으로 구분되는데, 본 연구는 현재 국내 A사에서 생산되고 있는 토글식 사출성형기를 대상으로 한다. 연구내용으로는 사출성형기의 여러 부품 및 주요한 플레이트에 대하여 3차원 모델링을 실시하고, 3차원 캐드상에서 조립하여 사출성형기의 전체 구조를 파악하였다. 그리고 에너지 및 생산비 절감을 위하여 주요 플레이트에 대하여 유한요소법을 이용하여 사출압력과 형체력 적용시의 플레이트에 발생하는 스트레스와 변위를 분석하고, 그 결과를 토대로 플레이트를 개선하였다. 개선된 플레이트를 대상으로 유한요소 재해석을 통하여 고정플레이트는 약 2.7%, 이동 플레이트는 약 3.5%, 테일 스톡은 약 6.9%의 중량 감소 결과를 확인하였다.

• 한국정밀공학회지
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• 제29권10호
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• pp.1043-1049
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• 2012

The FEM analysis of machine tools is the general analysis process to evaluate machine performance in the industry for a long time. Despite advances in FEM software, because of difficult simplicity of CAD drawing, little experience of joints stiffness modeling and troublesome manual contact area divide for bindings, the industry designers think the FEM analysis is still an area of FEM analysis expert. In this paper, the automation of modeling process with simplicity of drawing, modeling of joints and contact area divide is aimed at easy FEM analysis to enlarge utilization of a virtual machine tools. In order to verify the effects of modeling automation, a slant bed type model with tilting table is analyzed. The results show FEM modeling automation method only needed 45 minutes to complete the whole modeling process, while manual modeling method requires almost one month with 8200 calculations for coordinate transformations and stiffness data input.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2003년도 봄 학술발표회 논문집
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• pp.663-670
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• 2003

Urban tunnelling need to consider not only the stability of tunnel itself but also the ground movement regarding adjacent structures. This paper present 3-D behavior of adjacent structures due to tunnelling induced ground movements by means of field measuring data and nonlinear FEM tunnel analysis. The results of the analytical methods from Mohr-Coulomb model are compared with the site measurement data obtained during the twin tunnel construction. It was found that the location and stiffness of the structure influence greatly the shape and pattern of settlement trough. The settlement trough for Greenfield condition was different from the trough for existing adjacent structures. Therefore the load and stiffness of adjacent structures should be taken into account for the stability analysis of the structures.

• 한국분무공학회지
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• 제24권2호
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• pp.58-65
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• 2019

A 3D FEM (Finite Element Method) based Helmholtz solver has been commonly used to characterize fundamental acoustic behavior and investigate dynamic instability features in many combustion systems. In this approach, a geometrical simplification of the target system has been generally made in order to reduce computational time and cost because a real combustor and fuel nozzle have a very complicated flow passage. The feasibility of these simplifications is quantitatively investigated in a small aero gas turbine nozzle in term of acoustic characteristics. It is found that the simplification in a nozzle geometry during the 3D FEM analysis process has no great influence on the acoustic modeling results, while the calculation complexity can be improved for a similar modeling accuracy.

• Geomechanics and Engineering
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• 제28권3호
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• pp.225-237
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• 2022

Settlement evaluation is important for shallow tunnels in big cities to estimate the settlement that occurs due to the excavation of twin tunnels. The majority of earlier research on analytical solutions, on the other hand, concentrated on calculating the settlement for a single tunnel. This research introduces a procedure to evaluate the settlement induced by the excavation of twin tunnels (two parallel tunnels). In this study, a series of numerical analysis were performed to validate the analytical solution results. Two geological conditions were considered to derive the settlement depending on each case. The analytical and numerical methods were compared, which involved considering many sections and conducting a parametric study; the results have good agreement. Moreover, a comparison of the 3D flat model and 2D (FEM) with the analytical solution shows that in the fill soil, the maximum settlement values were obtained by the analytical solution. In contrast, the values obtained by the analytical solution in the rock is more conservative than those in the fill. Finally, this method was shown to be appropriate for twin tunnels dug side by side by utilizing finite element analysis 3D and 2D (PLAXIS 3D and PLAXIS 2D) to verify the analytical equations. Eventually, it will be possible to use this approach to predict settlement troughs over twin tunnels.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제4B권1호
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• pp.6-11
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• 2004

The single phase switched reluctance motor (SRM) has many merits; simple structure and driving circuits, easy operation and speed control, and etc. This paper presents the torque characteristics of disk type single phase SRM by changing the salient pole lengths and pole arcs. The prototype single phase SRM has a three dimensional magnetic flux pattern because of its structure. That is, the radial and axial magnetic flux contributes to torque generation. Thus, 3D analysis is required for computation of its magnetic field. In this paper, 3D FEM is used for analyzing the magnetic flux distribution and magnetic co-energy.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제55권11호
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• pp.564-571
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• 2006

In this paper, the estimation of Z-axis thrust ripple and vibration of BLDC motor with asymmetrical permanent magnet overhang is performed by 3-D Finite Element Method (3-D FEM) and vibration experimentation. The ripple of Z-axis thrust is due to armature reaction field in BLDC motor driven to squire wave. That is generating to Z-axis vibration. The analysis results of Z-axis thrust and the vibration by Z-axis thrust ripple is validated by comparison with experimental result.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제51권11호
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• pp.612-615
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• 2002

The main advantages of Disk type Single-Phase Switched Reluctance Motor (DSPSRM) is the simple construction, rugged structure, low manufacturing cost and simple driving circuit. It is especially possible to make the short axial length of DSPSRM. Therefore, it is suitable to setup this motor in a narrow space. This paper presents the shape design to maximize the average torque of DSPSRM that is achieved by 3D Finite Element Method (3D FEM) considering the nonlinear of magnetic material. The characteristics of two different rotor shapes are compared. The design parameters, such as the rotor and stator pole arc, are selected to the parametric study. The effect of pole arc ratios on the torque performance is investigated. From these results, the optimal pole arc to produce the maximum torque is determined.

• 전기학회논문지
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• 제57권12호
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• pp.2194-2198
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• 2008

In this paper, the construction of secondary reaction plate is analyzed by 3-D Finite Element Method(3-D FEM) to consider the influence of its variation on the transverse edge effect of LIM. The effective 3-D analysis model for considering the transverse edge effect caused by the finite widths of the primary and the secondary is proposed. The simple method measuring the transverse edge effect by using the patterns of currents induced in the secondary reaction plate is also proposed. With this effective analysis method, various models of secondary reaction plate with overhang and cap has been analyzed to consider the relationship between the construction of secondary reaction plate and the transverse edge effect of LIM.