• 한국정밀공학회지
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• 제19권12호
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• pp.158-162
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• 2002

In this paper, the usefulness of a three-dimensional forging simulation technique is verified through its application to process design in rotor pole forging. A simulator, AFDEX3D developed based on the rigid-plastic finite element method and hexahedral elements, is employed. The simulated results of an application example found in a precision forging company are compared with the actually forged ones in detail. It has been verified that the simulation results are in good agreement with the actual phenomena.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1996년도 자동차부품 제작기술의 진보
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• pp.111-131
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• 1996

In order to analyze stamping processes and to select optimum material properties of sheet steels for customer lines, 3-dimensional finite element analysis software were used. Commercial explicit finite element code, PAM-STAMP, was able to simulate 3-dimensional press formed parts with good accuracy and gave some useful results by orthogonal array experiments. Deformation of draw-bead were predicted by ABAQUS accurately, so that material selection for those parts by simulation were possible.

• Korean Chemical Engineering Research
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• 제55권5호
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• pp.698-703
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• 2017

Bubble flow characteristics in fluidized beds were analyzed by CPFD simulation. A fluidized bed, which had the size of $0.3m-ID{\times}2.4m-high$, was modeled by commercial CPFD $Barracuda^{(R)}$. Properties of bed material were $d_p=150{\mu}m$, ${\rho}_p=2,330kg/m^3$, and $U_{mf}=0.02m/s$. Gas was uniformly distributed and the range of superficial gas velocity was 0.07 to 0.16 m/s. Two other geometries were modeled. The first was a three-dimensional model, and the other was a two-dimensional model of $0.01m{\times}0.3m{\times}2.4m$. Bubble size and rising velocity were simulated by axial and radial position according to superficial gas velocity. In the case of three-dimensional model, simulated bubble rising velocity was different from correlations, because there was zigzag motion in bubble flow, and bubble detection was duplicated. To exclude zigzag motion of bubble flow, bubble rising velocity was simulated in the two-dimensional model and compared to the result from three-dimensional model.

• 한국측량학회지
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• 제25권2호
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• pp.99-105
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• 2007

본 연구는 항공사진을 이용 3차원 도로설계 시뮬레이션을 적용하는데 그 목적이 있다. 기존의 수치지도를 이용한 도로설계 방법대신 수치지도에서 정확히 나타나지 않는 지형과 지물을 수치항공사진을 이용하여 3차원 도로설계에 적용하였다. 먼저 항공사진을 이용해서 정사사진을 만들고 DEM을 추출하여 수치표고모델을 생성하였다. 그리고 실제 평면 설계에 쓰이는 좌표값을 3차원설계에 적용함으로서, 도로 노선 및 경관분석에 많은 도움이 될 것으로 보인다. 또한 Virtual GIS를 이용하므로 도시계획, 식물, 토양, 수로 또는 도로형태, 홍수계획 등 많은 인자들이 평가에 사용되며 이러한 노선설계기준에 따라서 3차원 시뮬레이션을 적용하여 그 효과를 검토하고자 한다. 본 논문에서는 구조물 3차원 설계에 관한 기초적인 연구를 시행하였으며, 3차원설계를 통해 의사결정시 효율적인 판단을 할 수 있었다. 향후, 환경 친화적 시공 및 설계에 대한 연구가 이루어져야 될 것으로 판단된다.

• 전자공학회논문지D
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• 제34D권8호
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• pp.41-51
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• 1997

The device simulator (BANDIS) which can analyze efficiently the electrical characteristics of the semiconductor devices under the three dimensional stationary conditions on the IBM PC was developed. Poisson, electon and hole continuity equations are discretized y te galerkin method using a tetrahedron as af finite element. The frontal solver which has exquisite data structures and advanced input/output functions is dused for the matrix solver which needs the highest cost in the three dimensional device simulation. The discretization method of the continuity equations used in BANDIS are compared with that of the scharfetter-gummel method used in the commercial three-dimensional device. To verify an accuracy and the efficiency of the discretization method, the simulation results of the PN junction diode and the BJT from BANDIS are compared with those of the commercial three-dimensiional device simulator such as DAVINCI. The maximum relative error within 2% and the average number of iterations needed for the convergence is decreased by more than 20%. The total simulation time of the BJT with 25542 nodes is decreased to about 60% compared with that of DAVINCI.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회B
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• pp.2401-2405
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• 2008

In the present study, a three-dimensional least square/level set based two-phase flow code was developed for the simulation of three-dimensional sloshing problems using finite element discretization. The present method can be utilized for the analysis of a free surface flow problem in a complex geometry due to the feature of FEM. Since the finite element method is employed for the spatial discretization of governing equations, an unstructured mesh can be naturally adopted for the level set simulation of a free surface flow without an additional load for the code development except that solution methods of the hyperbolic type redistancing and advection equations of the level set function should be devised in order to give a bounded solution on the unstructured mesh. From the numerical experiments of the present study, it is shown that the proposed method is both robust and accurate for the simulation of three-dimensional sloshing problems.

• 터널과지하공간
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• 제19권3호
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• pp.167-173
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• 2009

지하비축기지는 터널의 규모와 건설공정의 복잡성, 지질 및 지반공학적인 문제들로 인해 가장 난해한 지하공간건설 프로젝트로 알려져 있다. 최근 복잡한 지하구조를 3차원으로 가시화하고, 건설 자원과 지반조건 그리고 공정계획을 고려한 4차원 시뮬레이션을 활용하여 건설공정을 최적화하는 기술이 지하비축기지 건설 프로젝트에 적용되었다. 이 사례연구는 지하구조의 3차원 모델링을 통해 작업자가 복잡한 지하 현황을 쉽게 이해하고, 정확한 3차원 공간상에서 지질자료를 분석하고 검토할 수 있도록 도와줄 수 있음을 보여주고 있다. 또한 건설공정과 실제 공기를 고려한 4차원 시뮬레이션을 활용하여 자재와 버력의 반출입에서 나타날 수 있는 bottle neck의 위치와 시점을 판단하거나 일일 공사비의 변동을 검토하고, 작업조와 투입장비의 수, 터널 시공방향 및 굴착 착수 시점, 버력 및 자재의 운반경로를 검토함으로써 공정의 최적화를 달성할 수 있었다.

• 한국가스학회지
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• 제4권2호
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• pp.15-19
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• 2000

본 연구에서는 기존의 연구 개발된 다양한 확산모델의 비교 및 분석을 통하여 국내 석유화학시설에 적용하는 것이 적합하다고 판단되는 미국 EPA의 Industrial Source Complex(ISC)모델을 3차원 모사 대상으로 선정하여, 3차원 모사논리를 적용한 모사시스템을 개발하였다. 따라서 개발된 모사 시스템을 국내 화학산업시설에 적용할 경우, 정확한 사고피해 범위 예측과 더불어 화학산업시설의 비상조치계획 수립, 점화원 관리 등의 사고예방 및 사고피해의 최소화 측면에서도 많은 부분 기여할 수 있을 것이다.

• 대한족부족관절학회지
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• 제27권3호
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• pp.112-116
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• 2023

A 74-year-old female patient, who underwent surgery for a left distal tibiofibular fracture 40 years earlier, visited the hospital with an ankle varus deformity due to malunion. The patient complained of discomfort while walking due to the ankle and hindfoot varus deformity but did not complain of ankle pain. Therefore, correction using supramalleolar osteotomy was planned, and through virtual surgical simulation, it was predicted that a correction angle of 24° and an osteotomy gap open of 12 mm would be necessary. An osteotomy guide and an osteotomy gap block were made using three-dimensional (3D) printing to perform the osteotomy and correct the deformity according to the predicted goal. One year after surgery, it was observed that the ankle varus was corrected according to the surgical simulation, and the patient was able to walk comfortably. Thus, for correction of deformity, virtual surgical simulation and a 3D-printed osteotomy guide can be used to predict the target value for correction. This is useful for increasing the accuracy of correction of the deformity.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.1448-1451
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• 2004

This study is concerned about the design and development of three dimensional bending machine. The purpose of this study is design and development of three-dimensional bending machine by analysis of bending process and structural analysis simulation. The analysis is carried out by FEM simulation using DEFORM and CATIA V5 software. Based on this study, the three dimensional bending machine was developed. In order to evaluate a performance and reliability of the developed three dimensional bending machine, we used laser interferometer and three axial measuring system.