• 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.

• Journal of Magnetics
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• 제16권4호
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• pp.386-390
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• 2011

This paper deals with the magnetic equivalent circuit modeling and permanent magnet (PM) performance evaluations of a pole changing memory motor (PCMM). We use a coupled transient finite element method (FEM) and Preisach modeling, which is presented to analyze the magnetic characteristics of the permanent magnets. The focus of this paper is on the evaluation of characteristics such as the magnetizing direction and the pole number of the machine under re- and de-magnetization conditions.

• 전기학회논문지
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• 제60권5호
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• pp.965-970
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• 2011

This paper deals with the PM performance evaluations in a pole changing memory motor (PCMM) using a coupled transient finite element method (FEM) and Preisach modeling, which is presented to analyze the magnetic characteristics of permanent magnets. The focus of this paper is the characteristics evaluation relative to magnetizing direction and the pole number of machine on re-demagnetization condition in a pole changing memory motor.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2012년도 춘계학술대회 논문집
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• pp.437-438
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• 2012

• Journal of Mechanical Science and Technology
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• 제20권10호
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• pp.1722-1729
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• 2006

Predicting the mechanical properties of the 3-D scaffold using finite element method (FEM) simulation is important to the practical application of tissue engineering. However, the porous structure of the scaffold complicates computer simulations, and calculating scaffold models at the pore level is time-consuming. In some cases, the demands of the procedure are too high for a computer to run the standard code. To address this problem, the representative volume element (RVE) theory was introduced, but studies on RVE modeling applied to the 3-D scaffold model have not been focused. In this paper, we propose an improved FEM-based RVE modeling strategy to better predict the mechanical properties of the scaffold prior to fabrication. To improve the precision of RVE modeling, we evaluated various RVE models of newly designed 3-D scaffolds using FEM simulation. The scaffolds were then constructed using microstereolithography technology, and their mechanical properties were measured for comparison.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2010년도 춘계학술대회 논문집
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• pp.9-10
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• 2010

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집C
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• pp.146-151
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• 2001

This study is an investigation for the ADS optimum design by using FEM. We write out program which express ADS perfectly and reduce the required time for correcting of model to the minimum in solution and manufacture result. We complete algorithm which can plan optimum forming of model by feedback error information in CAE. For that, we draw up ADS program which modeling rachet wheel by using visual LISP and telegraph to ANSYS, structural solution program, we can solve stress solution. Then we correct model by feedback date obtaining in solution process, repeat course following stress solution again and do modeling rachet wheel for optimum forming. That is our aim. As a result of experience, we can develope automatic design program using Visual LISP and exhibit ADS as modeling third dimension CAD for optimum design. Also, we develop optimum design algorithm using ADS and FEM. In rachet wheel, greatest equivalence stress originates in key groove comer and KS standard is proved the design for security.

• 한국지구과학회지
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• 제38권1호
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• pp.80-90
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• 2017

FEM 수치해석을 위한 사면체격자 생성을 위해서는 물체의 볼륨정보를 표현할 수 있는 Boundary Representation (B-Rep) 모델이 필요하다. 공학분야에서는 파라메트릭 솔리드 모델링(Parametric Solid Modeling) 방법을 사용하여 B-Rep 모델을 정의한다. 반면 지질모델링은 메쉬 기반의 불연속(discrete) 모델링 방법을 사용하는데 이를 지질솔리드모델(Sealed Geological Model)이라 부르며 지층, 단층, 관입암, 모델 경계면과 같은 지질학적 인터페이스들을 이용해 지질도메인을 정의한다. 공학분야의 파라메트릭 모델링과 불연속 모델링 방식의 자료구조의 차이로 인해 불연속 B-Rep 모델은 공학분야에서 사용하는 다양한 오픈소스, 상용 메쉬제작 소프트웨어와 쉽게 호환되지 않는다. 이 논문에서는 공학용 메쉬 제작 소프트웨어와의 호환성을 가지도록 지질솔리드모델을 대표적인 오픈소스인 Gmsh와 상용 FEM 해석 소프트웨어인 COMSOL로 변환하는 프로그램을 제작하였다. 지질모델링 소프트웨어를 통해 제작한 복잡한 지질구조모델을 사용자 편의성을 갖춘 다수의 상용 소프트웨어서 쉽게 활용할 수 있어 지열, 암석역학 등 다양한 지구과학 시뮬레이션 연구에 도움이 될 것으로 생각된다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2001년도 총회 및 춘계학술발표회
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• pp.77-80
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• 2001

The element-free Galerkin (EFG) method is one of meshless methods, which is an efficient method of modeling problems of fluid or solid mechanics with complex boundary shapes and large changes in boundary conditions. This paper discusses the theory of the EFG method and its applications to modeling of groundwater flow. In the EFG method, shape functions are constructed based on the moving least square (MLS) approximation, which requires only set of nodes. The EFG method can eliminate time-consuming mesh generation procedure with irregular shaped boundaries because it does not require any elements. The coupled EFG-FEM technique was introduced to treat Dirichlet boundary conditions. A computer code EFGG was developed and tested for the problems of steady-state and transient groundwater flow in homogeneous or heterogeneous aquifers. The accuracy of solutions by the EFG method was similar to that by the FEM. The EFG method has the advantages in convenient node generation and flexible boundary condition implementation.

• 한국재료학회지
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• 제18권11호
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• pp.592-596
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• 2008

Spring constants (displacement per unit applied load) of MEMS socket pins of given structures were computed by theoretical analysis and confirmed by the finite element method (FEM). In the theoretical analysis, the displacement of pins was calculated based on the 2-dimensional bending theory of the curved beam. For the 3-dimensional modeling, CATIA was used. After modeling, the raw data were transferred to ANSYS, which was employed in the 3-dimensional analysis for the calculation of the stress and strain and loaddisplacement The theoretical analysis and the FEM results were found to agree, with each showing the spring constants as 63.4 N/m within a reasonable load range. These results show that spring constants can be easily obtained through theoretical calculation without resorting to experiments and FEM analysis for simple and symmetric structures. For the some change of shape and structural stiffness, this theoretical analysis can be applied to MEMS socket pins.