• Selected Papers of The Society of Naval Architects of Korea
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• 제2권1호
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• pp.106-128
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• 1994

An elasto-plastic-damage constitutive model for ductile materials is proposed within the framework of a thermodynamic approach of continuum damage mechanics (CDM) in which internal irreversible thermodynamic changes of micro-structure of materials such as plastic deformation and damage evolution are considered as thermodynamic state variables. The new constitutive model can predict not only the elasto-plastic behaviors but also the sequential stiffness degradation process of ductile materials more rationally.

• 한국해양공학회지
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• 제14권2호
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• pp.70-75
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• 2000

In this paper a new constitutive model for ductile materials was proposed. This model can describe the material degradation due to the evolution of isotropic damage during elasto-platic deformation. The plastic flow rule was derived under the framework of thermodynamic approach of continuum damage mechanics(CDM) in which plastic strain hardening parameters and isotropic damage were taken as thermodynamic state variables. And the process to determine material constants for constitutive model using an experimental data was presented.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 1991년도 제2차 학술발표초록집
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• pp.63-64
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• 1991

• Korean Chemical Engineering Research
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• 제49권3호
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• pp.361-366
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• 2011

몬테칼로 시뮬레이션 방법을 사용하여 유기화합물의 열역학적 물성을 예측하는 새로운 분자 시뮬레이션 소프트웨어를 개발하였다. 분자 구조, 분자간 포텐셜 에너지 함수와 엄밀한 통계역학적 원리로부터 많은 분자들을 포함한 계의 거동에 대한 확률 분포를 구하고 거시적인 계의 열역학적 물성을 계산한다. 본 연구에서 개발된 소프트웨어 cheMC는 윈도우즈 플랫폼에 기반하여 사용자 접근성이 좋고, 가시화 도구 및 차트 생성 기능 등 직관적인 인터페이스로 시뮬레이션 관리가 쉽다. 분자 시뮬레이션은 기존의 상태 방정식을 사용한 열역학 물성 연구를 보완하고, 향후 그 역할이 점점 더 커질 것으로 기대된다.

• Structural Engineering and Mechanics
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• 제76권1호
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• pp.115-127
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• 2020

This study presents an analytical approach to investigate the thermodynamic behavior of functionally graded beam resting on elastic foundations. The formulation is based on a refined deformation theory taking into consideration the stretching effect and the type of elastic foundation. The displacement field used in the present refined theory contains undetermined integral forms and involves only three unknowns to derive. The mechanical characteristics of the beam are assumed to be varied across the thickness according to a simple exponential law distribution. The beam is supposed simply supported and therefore the Navier solution is used to derive analytical solution. Verification examples demonstrate that the developed theory is very accurate in describing the response of FG beams subjected to thermodynamic loading. Numerical results are carried out to show the effects of the thermodynamic loading on the response of FG beams resting on elastic foundation.

• 한국재료학회지
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• 제20권1호
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• pp.42-46
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• 2010

Phosphorus exhibits considerable segregation in steelmaking slag. In order to recover phosphorus from slag to $K_3PO_4$ via molten iron, a carbothermic reaction using microwave heating was suggested recently. The carbothermic reduction of phosphorus from slag to molten iron using microwave heating was carried out at 2073K. However, at this temperature the thermodynamic properties of both slag and molten iron cannot be determined experimentally. Therefore, the computational approach of the so-called CALPHAD method is very useful to understand the transfer of phosphorus from slag to metal and to enhance this reaction. In the present investigation, a theoretical study of the reduction behavior of phosphorus in slag was carried out at much lower temperatures using the recently developed thermodynamic database in the FactSage program. The calculated results showed reasonable accordance with the experimental data; namely, the thermodynamic database could be applied successfully to higher temperature reactions. The current study found that higher temperature and high $SiO_2$ concentration are favorable for the recovery of phosphorus from slag.

• 방사성폐기물학회지
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• 제21권3호
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• pp.397-410
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• 2023

This study examined the efficacy of various chlorinating agents in partitioning light water reactor spent fuel, with the aim of optimizing the chlorination process. Through thermodynamic equilibrium calculations, we assessed the outcomes of employing MgCl₂, NH₄Cl, and Cl₂ as chlorinating agents. A comparison was drawn between using a single agent and a sequential approach involving all three agents (MgCl₂, NH₄Cl, and Cl₂). Following heat treatment, the utilization of MgCl₂ as the sole chlorinating agent resulted in a moderate separation. Specifically, this method yielded a solid separation with 96.9% mass retention, 31.7% radioactivity, and 44.2% decay heat, relative to the initial spent fuel. In contrast, the sequential application of the chlorinating agents following heat treatment led to a final solid separation characterized by 93.1% mass retention, 5.1% radioactivity, and 15.4% decay heat, relative to the original spent fuel. The findings underscore the potential effectiveness of a sequential chlorination strategy for partitioning spent fuel. This approach holds promise as a standalone technique or as a complementary process alongside other partitioning processes such as pyroprocessing. Overall, our findings contribute to the advancement of spent fuel management strategies.

• 한국응용과학기술학회지
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• 제28권4호
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• pp.449-454
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• 2011

This surfactant can be used as a cosmetics and chemical dispersants. The variation of critical micelle concentration(CMC) with temperature for N-eicosyl pyridinium bromide over the range $40^{\circ}C$ to $60^{\circ}C$ has been measured by drop methods. Thermodynamic quantities for micellization of N-eicosyl pyridinium bromide in water have been calculated by polynominal equation.

• 대한조선학회논문집
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• 제29권4호
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• pp.179-192
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• 1992

연속해 손상역학 분야의 열역학적 정식화 과정에 따라 연성재료의 탄소성-손상 구성방정식을 유도하였다. 이때, 재료 내부의 비가역적인 열역학적 상태변화를 표현하는 소성변형, 손상진전 등의 물리적현상을 내부상태변수로 간주하였다. 이 새로운 구성방정식 모형을 실제 문제에 적용함으로써 연성재료의 탄소성 거동 뿐만 아니라 재료의 자체가 손상을 입어 약화되는 과정 까지도 합리적으로 예측 가능함을 확인할 수 있었다.

• Bulletin of the Korean Chemical Society
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• 제18권5호
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• pp.501-509
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• 1997

In recent papers[Bull. Kor. Chem. Soc. 1996, 17, 735; ibid 1997, 18, 478] we reported results of molecular dynamics (MD) simulations for the thermodynamic, structural, and dynamic properties of liquid normal alkanes, from n-butane to n-heptadecane, using three different models. Two of the three classes of models are collapsed atomic models while the third class is an atomistically detailed model. In the present paper we present results of MD simulations for the corresponding properties of liquid branched-chain alkanes using the same models. The thermodynamic property reflects that the intermolecular interactions become weaker as the shape of the molecule tends to approach that of a sphere and the surface area decreases with branching. Not like observed in the straight-chain alkanes, the structural properties of model Ⅲ from the site-site radial distribution function, the distribution functions of the average end-to-end distance and the root-mean-squared radii of gyration are not much different from those of models Ⅰ and Ⅱ. The branching effect on the self diffusion of liquid alkanes is well predicted from our MD simulation results but not on the viscosity and thermal conductivity.