• 한국잠사학회:학술대회논문집
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• 한국잠사학회 2003년도 International Symposium of Silkworm/Insect Biotechnology and Annual Meeting of Korea Society of Sericultural Science
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• pp.57-57
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• 2003

Kayagum strings are usually made of raw silk. It is in need of good vibration and durability during playing the Kayagum. This study was carried out to increase durability of the strings by treatment of water soluble acrylic adhesive. (omitted)

• 한국생산제조학회지
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• 제19권3호
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• pp.376-380
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• 2010

The capability of automotive suspension system depends on steering safety of knuckle and lower control arm. In this study, light weight is applied with lower arm by the material of aluminium alloy. Distributed stress, fatigue life and proper vibration are analyzed with multiple loads happened by automobile. The durability of lower arm can be verified by the result of structural analysis.

• 한국소음진동공학회논문집
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• 제24권6호
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• pp.452-461
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• 2014

Two stroke low speed diesel engines that have many advantages such as high thermal efficiency and durability have been widely used for marine engine. However, it is also true that many problems have occurred due to the high explosion pressure and severe operating environment. Especially problems of shaft damage etc. intensively occurred due to the phenomenon of crankshaft exceeding the allowable stress, including the shaft vibration of the engine model in the early stage. In this study, the crankshaft fracture phenomenon of early engine model was evaluated and analyzed by using up-to-date torsional vibration calculation program and measurement instrument. And this was numerically shown.

• 한국생산제조학회지
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• 제21권4호
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• pp.525-531
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• 2012

This study aims at the structural analysis of vibration and fatigue according to the configuration of engine mount. Maximum equivalent stress or deformation is shown at bracket or case respectively. As harmonic vibration analysis, the maximum displacement amplitude is happened at 4,000Hz. Among the cases of nonuniform fatigue loads, 'SAE bracket history' with the severest change of load becomes most unstable but 'Sample history' or 'Saw tooth' becomes most stable. In case of 'Sample history' or 'Saw tooth' with the average stress of 4,200MPa or 0MPa and the amplitude stress of -3,000MPa or 7MPa, the possibility of maximum damage becomes 70%. This stress state can be shown with 7 times more than the damage possibility of 'SAE bracket history' or 'SAE transmission'. The structural result of this study can be effectively utilized with the design on engine mount by investigating prevention and durability against its damage.

• 대한기계학회논문집A
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• 제34권10호
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• pp.1339-1344
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• 2010

모달중첩법은 구조물의 진동특성을 고려하여 내구수명을 평가할 수 있는 내구해석 기법이다. 본 논문에서는 모달중첩법과 유사하면서도 다물체 동역학 해석시 모달좌표를 직접 계산하여 전체적인 해석시간을 줄일 수 있는 모달응력 회복법을 이용한 내구해석 기법의 타당성에 대하여 검토하였다. 이를 위해 자동차 부품 중 대표적으로 동특성을 고려해야 하는 토션빔 액슬에 대하여 모달응력 회복법을 이용한 내구해석 및 시험을 실시하였다. 해석결과는 시험결과와 취약위치, 내구수명 등이 양호한 일치 결과를 나타내었다. 따라서 모달응력 회복법을 이용한 내구해석 기법은 다양한 구조물의 동특성을 반영한 내구수명 평가에 적용될 수 있을 것이다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.880-885
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• 2007

Diesel engines have been widely used in ships and power plants because of its higher thermal efficiency, mobility and durability compared to other prime movers. Though these merits, diesel engine including main components are sometimes vibrated due to higher combustion pressure in cylinders. Especially torsional, axial and structural vibrations in propulsion shafting may be severely manifested by the malfunction of torsional and axial dampers and misfiring and unbalanced load in cylinder. The structural vibration of main body and turbocharger core hole are also occurred by the loosen top bracing and excess wear-out or failure of turbocharger's bearings. The marine diesel engine should be safely designed from these vibrations. This paper introduces experimental methods to develop the prototype of integrated vibration monitoring system for marine diesel engine.

• 한국소음진동공학회논문집
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• 제22권4호
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• pp.372-376
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• 2012

The most common type of the piezoelectric energy harvester is the cantilevered beam since it is attached to the host structure and tuned to the frequency of the base excitation easily. However, the excessive strain at the fixed end of cantilevered beam causes some problems such as fatigue and durability. The use of higher vibration modes of the cantilevered beam may reduce the concentration of the strain at the fixed end since the strains of higher modes are distributed along the span. The results show that the use of high vibration mode is not efficient for power generation, but it reduces the excessive strain lever at typical region to prevent the failure by fatigue.

• 한국생산제조학회지
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• 제6권2호
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• pp.67-75
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• 1997

The noise . vibration characteristics of Hypoid gears which were made from three seperate materials(SCM, TSCM, SNCM) under the identical process were investigated for the sake of durability improvement of differential gear compatible with low level noise gear set. For this study, we developed a rig experimental equipment which can perform close noise.vibration experiment of differential gear. Consequently, we could analyze the noise.vibration characteristics of final reduction gear by materials, and also we observed changes in both metallic structure and hardness according to the materials of pinion gear. In addition to this, the correlation between the vibration of the differential gear and the interior noise of the passenger vehicles was proved by analyzing the results of rig vibration experiment and field noise test.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 춘계학술대회논문집
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• pp.416-422
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• 2007

Prime movers in most large merchant ships adapt two stroke low speed diesel engine which has higher efficiency, mobility and durability. However, severe torsional vibration in these diesel engines may be induced by higher fluctuation of combustion pressures. Consequently, it may lead sometimes to propulsion shafting failure due to the accumulated fatigue stresses. Shaft fatigue strength analysis had been done traditionally in time domain but this method is complicated and difficult in analysing bi-modal vibration system such as the case of cylinder misfiring condition. In this paper authors introduce an assessment method of fatigue strength estimation for propulsion shafting system with two stroke low speed diesel engine in the frequency domain.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 춘계학술대회 논문집
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• pp.110-118
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• 2014

In the past two stroke low speed diesel engine were widely used for marine propulsion. these engine have many merit for example, higher thermal efficiency and durability. however, shaft vibration problem was continuously rise up due to large power of two stroke low speed diesel engine. specially, the initial stage engine revolution counter & stress has acculated. For that reason, sometimes occurred crankshaft crack accident. In this study, regarding the initial stage engine, trying to analyze what is cause the crack phenomenon using by latest torsional vibration calculation program & measurement equipment.