• 한국철도학회논문집
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• 제13권2호
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• pp.139-146
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• 2010

본 연구에서는 복잡한 3차원 유한요소모델 충돌거동과 등가인 1차원 동역학 모델링 방법을 개발하기 위하여 새로운 1-D 모델링 방법을 제안하였다. 충돌 거동을 잘 일치시키기 위해서는 충돌 시너지를 주로 흡수하는 압괴 구간의 특성을 정확하게 모델링하는 것이 중요하다. KHST 편성차량을 대상으로 3차원 유한요소 모델의 차체단면에 설정한 단면 옵션으로 충돌해석 시 차체 단면에 작용하는 충격하중과 변형을 추출하여 새로운 1차원 충돌동역학 모델의 스프링요소 특성으로 모델링하고, 국내철도차량 안전기준의 열차 대 열차 충돌사고 각본으로 수치해석을 수행하였다. 두 모델의 에너지 흡수량, 충돌 가속도, 충격하중-변형 등을 비교한 결과가 잘 일치하였다.

• Archives of Metallurgy and Materials
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• 제66권4호
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• pp.1013-1018
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• 2021

In this paper, as a purpose to apply the supersaturated solid-solutionized Al-9Mg alloy to the structural sheet parts of automotive, tensile tests were conducted under the various conditions and a constitutive equation was derived from the tensile test results. Al-9Mg alloy was produced using a special Mg master alloy containing Al₂Ca during the casting process and extruded into the sheet. In order to study the deformation behavior of Al-9Mg alloy in warm temperature forming environments, tensile tests were conducted under the temperature of 373 K-573 K and the strain rate of 0.001/s~0.1/s. In addition, by using the raw data obtained from tensile tests, a constitutive equation of the Al-9Mg alloy was derived for predicting the optimized condition of the hot stamping process. Al-9Mg alloy showed uncommon deformation behavior at the 373 K and 473 K temperature conditions. The calculated curves from the constitutive equation well-matched with the measured curves from the experiments particularly under the low temperature and high strain rate conditions.

• 한국컴퓨터그래픽스학회논문지
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• 제30권3호
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• pp.189-198
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• 2024

딥러닝 기반 모델과 물리 시뮬레이션을 결합한 연구는 의료 분야에서 중요한 발전을 이루고 있다. 이는 의료영상 데이터에서 필요한 정보를 추출하고, 물리적 법칙을 기반으로 골격 및 연조직의 변형에 대한 빠르고 정확한 예측을 가능하게 한다. 본 연구는 신경 방사 필드(NeRF), 위치 기반 동역학(PBD), 병렬 리샘플링을 융합하여 3D 볼륨데이터를 쉽게 생성하고 실시간으로 변형 및 시각화하는 시스템을 제안한다. NeRF는 2D 이미지와 카메라 좌표 정보를 사용해 고해상도 3D 볼륨 데이터를 생성하며, PBD는 물리 기반 시뮬레이션으로 획득한 데이터에 대한 실시간 변형과 상호작용을 가능하게 한다. 병렬 리샘플링은 사면체 메쉬와 GPU 병렬 처리를 통해 렌더링 효율성을 높인다. 이 시스템은 광선투사방식으로 렌더링 되어 빠른 실시간 시각화를 제공하며, 비싼 장비 없이 간단하게 3D 데이터를 생성하고 변형할 수 있어 공학, 교육, 의료 등 다양한 분야에서의 활용 가능성을 보여준다.

• 대한기계학회논문집
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• 제19권6호
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• pp.1439-1450
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• 1995

Bellows is a familiar component in piping systems as it provides a relatively simple means of absorbing thermal expansion and providing system flexibility. In routine piping flexibility analysis by finite element methods, bellows is usually considered to be straight pipe runs modified by an appropriate flexibility factor; maximum stresses are evaluated using a corresponding stress concentration factor. The aim of this study is to develop a bellows finite element, which similarly includes more complex shell type deformation patterns. This element also does not require flexibility or stress factors, but evaluates more detailed deformation and stress patterns. The proposed bellows element is a 3-D, 2-noded line element, with three degrees of freedom per node and no bending. It is formulated by including additional 'internal' degrees of freedom to account for the deformation of the bellows corrugation; specifically a quarter toroidal section of the bellows, loaded by axial force, is considered and the shell type deformation of this is include by way of an approximating trigonometric series. The stiffness of each half bellows section may be found by minimising the potential energy of the section for a chosen deformation shape function. An experiment on the flexibility is performed to verify the reliability for bellows finite element.

• 소성∙가공
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• 제28권2호
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• pp.98-104
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• 2019

The present study numerically simulates the deformation heterogeneity developed in AA1100 during multi-axial diagonal forging (MADF) using finite element analysis (FEA). Diagonal forging type consisting of diagonal forging (DF) and return-diagonal forging (R-DF) proved to be relatively beneficial compared to plane forging type which includes plane forging (PF) and return-plane forging (R-PF) for minimizing the non-uniformity of deformation developed in workpieces. Simulation of the effective strain generated in workpieces during the two types of forging was done using 3-D FEA. FEA shows the effect of friction coefficient on the deformation behavior on workpieces. The simulation of 2 types forging with different friction coefficients revealed that the magnitude of barreling effect and strain heterogeneity in workpieces increases with an increase in the friction coefficient.

• 한국측량학회지
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• 제22권2호
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• pp.179-186
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• 2004

본 연구는 산업 사진측량을 이용하여 자동차의 외형을 정밀 측정하고, 사고 등의 원인으로 변형이 발생하였을 때 변형량을 측정하는 방법에 관한 것이다. 자동차의 외형을 정밀 측정하기 위하여 점군데이터를 취득할 수 있는 프로젝션 타겟을 사용함으로써 보다 곡면에 대한 정밀한 측정이 가능하도록 하였으며, 대상물 촬영 및 좌표해석을 통하여 타겟의 3차원 좌표를 취득하였다. 취득된 점군데이터는 불규칙 삼각망으로 표면을 형성하여 3차원 모델링을 하였다. 또한, 변형 발생부위를 정밀 측정함으로써 교통사고 분석 등에 효율적이고 정밀한 데이터를 제공할 수 있을 것이다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2012년도 추계학술대회 논문집
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• pp.843-844
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• 2012

• 산업기술연구
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• 제16권
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• pp.31-38
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• 1996

This experimental study was conducted to analyze the characteristics of centrifugal pipes which were made of silica fume concrete. External load tests showed that maximum external load ranged from 1,100~5,300kgf/m with thickness ratio(t/D) of between 4.5%~10.0%. Correlation between thickness ratios and external loads was excellent with $R^2$ of 0.99. Respective correlation between measured and computed vertical deformation was good with $R^2$ of higher than 0.90. And therefore, vertical deformation and tensile stress of centrifugal concrete pipes may be theoretically computed with a good precision.

• 한국군사과학기술학회지
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• 제5권2호
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• pp.207-216
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• 2002

In this paper, the study on the behavior of the deformation of brittle material, such as concrete, ceramic, was peformed by comparison of Lagrangian technique and Smoothed Particle Hydrodynamics using commercial nonlinear hydrodynamic numerical program, Autodyn_2D. The effect of SPH technique was proved by investigating the behavior of material deformation, velocity profile and pressure profile.

• Steel and Composite Structures
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• 제22권4호
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• pp.745-752
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• 2016

An investigation has been done to study the evolution of the microstructure, mechanical and electrical properties of AlMgSi alloy destined for the transport of electric energy, in function of the deformation caused by the cold drawing process. We identified that drawing of aluminum wire causes development of a fibrous texture of type <111> and <100>. We notice also that the electrical resistivity and mechanical resistance increases with the increasing of the deformation level. Characterization methods used in this work is: The Electron Back Scattered Diffraction EBSD, X-Ray diffraction, Vickers microhardness, Tensile test, Measuring electrical resistivity, the Scanning Electron Microscope (SEM) and Energy Diffraction Spectrum (EDS).