• 대한조선학회논문집
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• 제49권4호
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• pp.287-295
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• 2012

Hydrodynamic performance of a movable submerged breakwater was analyzed using energy dissipation model. Based on two-dimensional boundary element method the equation of motion including a viscous dissipation term proportional to velocity squared was solved by Newton-Raphson method. Energy dissipation coefficients as well as reflection and transmission coefficients of a submerged flat plate were calculated with various plate lengths and thickness. Both real and imaginary components of body displacement and forces were used to solve the motion of breakwater accurately. The effect of the magnitude of dissipation coefficient on the body displacement was evaluated. The results from the potential theory with no dissipation term were found to be an overestimate in resonance frequency.

• 한국자동차공학회논문집
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• 제11권6호
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• pp.190-196
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• 2003

The load sharing and teeth deflection of helical gear system are analyzed to investigate the deformation overlap. The deformation overlap, which is calculated by the results of displacement analysis, is suggested as the basis for the tooth profile modification. Helical gear systems are formulated as contact problems, and solved by elastic contact theory and FEM. The developed computer program, which offers gear teeth deflection and deformation overlap, will be of much help to the improved design of manual transmissions for automobiles.

• 한국소음진동공학회논문집
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• 제20권6호
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• pp.562-567
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• 2010

A passenger vehicle has various and complicated transmission paths of sound and vibration. In order to identify the mechanism of transfer path, estimation of excitation force and exact modeling of transfer path are required. In this paper vector synthesis technique is employed to identify the characteristics of road noise and its transmission to vehicle compartment through noise and vibration analysis. Vibration reduction efficiency of each transfer path is evaluated by comparing individual vector components obtained virtual simulation. The degree of effect is used to estimate the contribution of vibration input components to total output. And in this paper presents a new technique based on simulation studies using vector synthesis diagram and design of experiments, by which the effects of magnitude and phase change of input paths can be predicted.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 춘계학술대회논문집
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• pp.325-333
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• 2000

To predict vibrational energy density and intensity of partitioned complex system structures in medium-to-high frequency ranges, Power Flow Finite Element Method(PFFEM) programs for the plate elements are developed. The flexural, longitudinal and shear waves in plates are formulated and the joint element equations for multi-couped plates are fully developed. Also the wave transmission approach has been introduced to cover the energy transmission and reflection at the joint plate elements. Using the developed PFFEM program the energy density and intensity of the submarine and automobile shape structures are predicted with a harmonic point force at a single frequency.

• Journal of electromagnetic engineering and science
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• 제8권1호
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• pp.23-27
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• 2008

Magnetic coupling delivering wireless power in capsular endoscope(CE) is described in this paper. The characteristic of the magnetic flux linkage coil which generates the induced electromotive force(emf) under the magnetic field was analyzed. With the analyzed results, a magnetic flux linkage coil system was developed and tested. It was confirmed that the magnetic flux linkage coil system could supply more than 50 mW power at 125 kHz without changing the structure of conventional CE.

• 한국자동차공학회논문집
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• 제8권2호
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• pp.81-91
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• 2000

Dynamic models of line regulator valve(LRV) and ratio control valve (RCV) are obtained for an electronic controlled CVT. LRV and RCV are operated by variable force solenoid(VFS). Considering the CVT shift dynamics, oil pump's efficiency and saturation characteristics of VFS, simulations are performed and compared with test results. Simulation results are in good agreement with the experiments, which shows the validity of the dynamic models of LRV and RCV obtained. In addition, the effects of the orifice size in the exhaust port of RCV are investigated. Simulation results show that as the orifice size decreases, the residual pressure in the primary actuator increases which insures the large torque transmission capacity, meanwhile the duration time for the downshift increases.

• 대한치과보철학회지
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• 제35권3호
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• pp.517-534
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• 1997

It has been held that excessive mechanical forces to the osseous and soft tissues of the TMJ result in joint dysfunction. Understanding the stress pattern on TMJ is very important in TMJ research. But, it is very difficult to measure directly the biomechanical stress distribution in the TMJ when the mandible is loaded. Therefore, stress distribution in the TMJ during functional movement was studied through animal experiment or mathematical model. It was observed and compared the stress distribution occuring in the working and balancing condyle when lower right canine, lower right first molar and lower right second molar were clenched by the three dimensional finite element analysis. Also, stress distribution in the working and balancing condyles were observed and compared when $20^{\circ}$ forward and buccal bite forces were applied to the first molar. The results were as follows : 1. Stress distribution in the condyles during unilateral clenching of the first molar, second molar, canine showed no difference. In the working condyle, tensile force was concentrated on the lateral aspect of the condylar articular surface and condylar neck. And compressive force was concentrated on the anteromedial and lateral aspect of condyle. In the balancing condyle, tensile and compressive forces were concentrated on the lateral aspect of the condylar articular surface and stress transmission to the temporal bone was not observed. 2. When lateral forces were applied to the first molar, tensile forces were concentrated on the medial aspect of the condylar neck and condylar posterior surface in working and balancing condyle. Compressive force was concentrated on the anteromedial and lateral surface of the condyle and stress transmission to the temporal bone was not observed. 3. During unilateral clenching, stress in the working condyle decreased as the occlusal load moved posteriorly while the stress in the balancing condyle increased. when lateral force was applied to first molar, the incremental amount of stress was greater than vertical load. 4. During unilateral clenching, the average balancing/working condyle stress ratio was 2.52. There was a greater concentration of stress in the balancing condyle. The ratio increased as the occlusal load moved posteriorly and decreased considerably when lateral forces were applied to the first molar.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2006년도 정기 학술대회 논문집
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• pp.615-622
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• 2006

As construction technique and design are developing, the bridge tend to be longer, and also the type of bridge is verity. Steel and concrete combination improve the mechanics characteristic and economical efficient which Hybrid Structure divide Mixed Structure with Composite Structure. The connected section of the Mixed Structure should integrate steel and concrete that should show the same behavior as well, And also this connection needs big interna1 force and stiffness because it used to be a most dangerous section. This study carry out a nonlinear analysis technique with slip, check out each different type of section force's transfer mechanism on the connection. And this analysis was carried out using parameter that are front plate thickness, connection length, filled concrete strength and so on. We confirmed the profitable type of connection is front backward type. The biggest stiffness and certain stress transmission are showed at the ratio 0.075 between total length and connection length, and also most economical front plate thickness is judged when it set three times thicker than flange.

• 한국산학기술학회논문지
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• 제20권12호
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• pp.237-246
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• 2019

전기기계식 제동장치(EMB : Electro Mechanical Brake)는 자동차 및 철도차량의 차세대 제동장치로서 현재 연구가 활발히 진행되고 있다. 현재의 고속열차용 제동장치는 공압 실린더를 이용하여 제동 압부력을 발생시키나 전기기계식 제동장치 (EMB)에서는 전기 모터 및 기어와의 조합을 통하여 압부력을 발생시킨다. 본 연구에서는 고압부력 발생이 가능한 EMB 구동 메커니즘을 제안하고, 해당 메커니즘을 만드는 기구장치 중 핵심부품인 기어 및 샤프트 부품들에 대한 구조 및 진동해석을 수행하였다. 한편 모델에 대한 동적 진동해석 결과 압부력이 가해진 상태에서 외부가진이 주어졌을 때 부재의 최대 응력이 항복강도 이내임이 확인되었다. 또한, 구조해석 결과 모터샤프트의 축 직경을 최대한 크게하는 설계가 강도 상 유리함을 확인하였으며, 기어와 편심샤프트를 고정하는 볼트에서 큰 전단응력이 발생할 수 있음을 확인하였다. 한편 해석모델의 메커니즘을 재현할 수 있는 시험장치를 제작하여 가장 취약한 부위인 고정 볼트부의 변형률을 구동 토크가 가해진 상태에서 측정하였다. 변형률 측정결과는 해석결과와 오차가 10% 이내로서, 해석모델의 정확도를 검증할 수 있었다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 추계학술대회논문집
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• pp.699-702
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• 2006

Noise Path Analysis is commonly used method to analysis noise transmission characteristics of a system. To analysis transfer paths of a system, it is necessary to know operating forces at each transfer path. The method to find out operating forces is divided into two methods. The one is a direct method which measures operating forces directly and the other is an indirect method which estimates operating forces mathematically. However, the indirect method is more commonly used because of the difficulty of measurement. This paper is focused on the indirect method and air-borne noise of a vehicle. Noise Path Analysis for Air-Borne Noise is applied to a real vehicle.