• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2008년도 학술발표회 논문집
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• pp.1818-1822
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• 2008

여수로와 같은 3차원 수리구조물을 설계하고 수리현상을 조사하거나, 형상 및 안정성을 파악하기 위해서는 일반적으로 수리모형실험을 통하여 실제 현상을 모의하는 경우가 많다. 그러나 수리모형실험을 하기 위해서는 많은 시간과 비용 및 공간이 필요하며 실제 수리구조물을 축소시켜 측정하는 것은 대단히 어렵고 표면장력 등이 실험결과에도 상당한 영향을 미칠 수 있으며 다양한 경우의 실험은 현실적으로 불가능하다. 따라서, 수치해석을 통하여 적정한 초기결과를 도출할 필요성이 있으며, 이를 통하여 수리모형실험의 대상을 결정하고 결과를 비교한다면 경제적이고 합리적인 수리구조물의 설계와 평가가 가능하다. 본 연구에서는 최적의 여수로를 설계하기 위하여 월류형 여수로를 대상으로 수치해석을 수행하였고, 수리모형실험에 대한 실험적인 접근을 통하여 수리적 조건을 향상시킬 수 있는 보다 나은 설계안을 제시하였다. 이러한 수리모형실험 계측결과를 통하여 개선된 수리구조물 설계안을 제안하였고, 개선된 설계안에 대한 개선효과를 조사하였다.

• 유공압시스템학회논문집
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• 제4권4호
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• pp.21-27
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• 2007

A hydraulic breaker for construction machinery generally used for the destroying and disassembling of buildings, crashing road pavement, breaking rocks at quarry and so on. So the measurement of the impact energy of a hydraulic breaker is very important thing to prove its capability to manufacturers and customers. Therefore the prediction of impact energy in design process is very helpful to the most of breaker manufacturers. In this study, we carried on modeling and simulation of a hydraulic breaker to predict impact energy via commercial CAE software. The modeling and simulation of a hydraulic breaker was achieved with two parts. One is a hydraulic circuit analysis part via AMESim and the other is impact strain analysis part via ANSYS.

• International Journal of Safety
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• 제10권2호
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• pp.1-5
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• 2011

The structural integrity assessment of APR1400 (Advanced Power Reactor 1400) reactor vessel internals has been being performed referring the US Nuclear Regulatory Commission regulatory guide 1.20 comprehensive vibration assessment program prior to commercial operation. The program is composed of a hydraulic and structural analysis, a vibration measurement, and an inspection. This paper describes the hydraulic and structural analysis on the reactor vessel internals due to hydraulic loads caused by the turbulence of reactor coolant. Three-dimensional models were built for the hydraulic and structural analysis and then hydraulic loads and structural responses were predicted for five analysis cases with CFX and ANSYS respectively. The structural responses show that the APR1400 reactor vessel internals have sufficient structural integrity in comparison with the acceptance criteria.

• 한국도로학회논문집
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• 제15권3호
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• pp.45-52
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• 2013

PURPOSES : This study is to construct the regression models of drainage asphalt concrete specimens and to provide the appropriate coefficients of hydraulic conductivity prediction models. METHODS: In terms of easy calculation of the hydraulic conductivity from porosity of asphalt concrete pavement, the estimation model of hydraulic conductivity was proposed using regression analysis. 10 specimens of drainage asphalt concrete pavement were made for measurement of the hydraulic conductivity. Hydraulic conductivity model proposed in this study was calculated by empirical model based on porosity and the grain size. In this study, it shows the compared results from permeability measured test and empirical equation, and the suitability of proposed model, using regression analysis. RESULTS: As the result of the regression analysis, the hydraulic conductivity calculated from the proposal model was similar to that resulted from permeability measured test. Also result of RMSE (Root Mean Square Error) analysis, a proposed regression model is resulted in more accurate model. CONCLUSIONS: The proposed model can be used in case of estimating the hydraulic conductivity at drainage asphalt concrete pavements in fields.

• 한국농공학회논문집
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• 제55권4호
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• pp.1-11
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• 2013

Unsaturated hydraulic conductivity function is one of key parameters to solve the flow phenomena in problems of landslide. Prediction models for hydraulic conductivity function related to soil-water retention curve equations in many geotechnical applications have been still used instead of direct measurement of the hydraulic conductivity function since prediction models from soil-water retention curve equations are attractive for their fast and easy use and low cost. However, many researchers found that prediction models for the hydraulic conductivity function can not predict the hydraulic conductivity exactly in comparison with experimental outputs. This research introduced an inverse analysis to evaluate the hydraulic conductivity function corresponding to experimental output from the flow pump system. Optimisation process was carried out to obtain the hydraulic conductivity function. This research showed that the inverse analysis with flow pump system was suitable to assess the hydraulic conductivity in unsaturated soil, and the prediction models for the hydraulic conductivity were led to the significant discrepancy from actual experimental outputs.

• 소음진동
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• 제9권1호
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• pp.42-48
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• 1999

In this paper, a computer simulation method for dynamic analysis of the hydraulic engine mount system is proposed. The hydraulic engine mount system controls the damping characteristics using the viscosity of fluid flow The complex stiffness of the main rubber of the hydraulic engine mount system is computed by finite element analysis for the viscoelastic materials and hydro-static elements. A numerical analysis method is presented to solve nonlinear equations of the hydraulic engine mount system. which is composed of an engine mass, fluid in inertia track and a vertical inertia force of reciprocating mass in the engine. Also. dynamic properties of the hydraulic engine mount system are analyzed in the frequency domain. Effects of the hydraulic engine mount system running over the rough road are investigated using a vehicle dynamic model. These results are compared with those of the rubber mount system.

• The Journal of the Acoustical Society of Korea
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• 제21권1E호
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• pp.42-48
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• 2002

In this paper, a computer simulation method is presented far the dynamic analysis of a hydraulic engine mount system. The hydraulic engine mount system controls the damping characteristics using the viscosity of fluid flow. The complex stiffnesses of the main rubber for the hydraulic engine mount system are computed using a finite element analysis. The equations of motion considering the parameters of the hydraulic engine mount system are derived. To investigate the effects of the hydraulic engine mount system, the computer simulation running over a typical rough road is carried out using a vehicle dynamic model. These results are compared with those of the conventional rubber mount system.

• 한국정밀공학회지
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• 제17권4호
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• pp.189-196
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• 2000

In this study, the hydraulic breaker system was analyzed and the analysis tool using GUI was developed. The analysis on the system with the accumulator was included. from the parametric analysis, the effects of each factor were revealed. Through the simulation with varying parameters, the method to improve the performance of the hydraulic breaker system was presented. The analysis tool will help a man without special knowledge about programming analyzse the hydraulic breaker system. The result of this study will help improve the hydraulic breaker system in sight of "Blow energy" and "Blows per minute".ws per minute".uot;.

• 한국신뢰성학회지:신뢰성응용연구
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• 제9권3호
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• pp.177-193
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• 2009

Hydraulic breakers, the attachment devices of the excavators, refer to a machine that converts back and forth motions of pistons into energies to break objects down finely. As the use of hydraulic breakers has been steadily increasing world-wide, consumers have become more interested in not just the quality of hydraulic breakers but their reliability. This study show functions and usages of several main parts on hydraulic breakers. In addition, based on the effect of action of hydraulic breakers, FMEA was performed to figure out the major causes and manifestations of malfunctioning. As above mentioned, we analyzed reliability of hydraulic breakers by models, and the data that had been used for the analyses were obtained from malfunctioning data in the field.

• 한국기계기술학회지
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• 제20권6호
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• pp.929-935
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• 2018

This paper develops a flow control block for a hydraulic system of a tunnel boring machine. The flow control block is a necessary component to ensure stability in the operation of the hydraulic system. In order to know the pressure distribution of the flow control block, the flow analysis was performed using the ANSYS-CFX. It was confirmed that the pressure and flow rate were normally supplied to the hydraulic system even if one of the four ports of the flow control block was not operated. In order to evaluate the structural stability of the flow control block, structural analysis was performed using the ANSYS WORKBENCH. As a result, the safety factor of the flow control block is 1.54 and the structural stability is secured.