• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 춘계학술대회논문집
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• pp.648-655
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• 2005

The resilient mounts of a diesel engine installed onboard a ship should be designed for both static and dynamic loads. If possible, the resonance frequencies of the six rigid body modes of the installation and the flexible modes of the engine support structure should not lie within the engine operation range. In this paper a design criterion is proposed to evaluate an isolation system which involves the summation of dynamic forces transmitted through the resilient mounts and elastic potential energy index stored in the mounts. A case study is also presented in which a diesel engine generator, which had an elastic foundation and was mounted in a 5500 TEU container vessel, was studied both theoretically and experimentally. The theoretical analysis of the test model was performed by using a single mass 6 degree of freedom system. Actual measurements of mechanical vibration of the Engine and its foundation onboard were carried out, which showed the importance of including the flexibility of the engine support structure in the mode

• 구강회복응용과학지
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• 제18권2호
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• pp.119-126
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• 2002

The purpose of this study was to restorate a patient who has a few remaining teeth with #15,23,24 supported Konus telescope denture in Maxillar and #44,43,33,34 supported Dolder bar retained overdenture in Mandible. Konus telescope and bar retained overdenture was taken better results in retention, support, stability compair with regular Removable partial denture. In Removable partial denture, the change of remaining teeth and edentulous ridge is natural. But Konus telescope and bar retained overdenture is a little effected in this change, so it is possiblble in long-term use. In cosider of patient's medical history and the possibility of additional tooth loss, Konus telescope denture can be easily repaired. Compaired with Konus telescope and bar retained overdenture showed high stability and easy cleansing because of rigid support, cross - arch splinting, and simple design. In delivery, patient had a difficulty with removal of denture and plaque control, but showed better condition, good oral hygienic care. Patient satisfied with denture functionally and esthetically. This study showed Konus telescope and bar retained overdenture was effective for treatment of patient remaing a few teeth in function, esthetic and psycologic satisfaction.

• 한국기계가공학회지
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• 제16권4호
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• pp.38-45
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• 2017

A finite element analysis-based approach which investigates the causes of the breakdown in the outer ring of the choke at hot rod rolling mill is presented. Two-dimensional drawings of the whole vertical-type mill stand are transformed into three-dimensional CAD models. Non-linear elasto-plastic deformation analysis of material at the roll gap is performed for computing roll force and torque of the work roll. Then, the reaction forces of the bearing rings together with a set of roller bearings that support the work roll are obtained by means of rigid body motion analysis. Finally, stress behaviors in the bearing rings together with a set of roller bearings that support the work roll are investigated by linear elastic analysis. Results reveal that stress at the contact area between the outer ring and roller bearing is extraordinary high when an internal gap between an external surface of the outer ring and the internal surface of the chock due to wear of the inside of the chock occurs.

• 한국소음진동공학회논문집
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• 제16권4호
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• pp.329-338
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• 2006

The resilient mounts of a diesel engine installed onboard a ship should be designed for both static and dynamic loads. If possible, the resonance frequencies of the six rigid body modes of the installation and the flexible modes of the engine support structure should not lie within the engine operation range. In this paper a design criterion is proposed to evaluate an isolation system which involves the summation of dynamic forces transmitted through the resilient mounts and elastic potential energy index stored in the mounts. A case study is also presented in which a diesel engine generator, which had an elastic foundation and was mounted in a 5500 TEU container vessel, was studied both theoretically and experimentally. The theoretical analysis of the test model was performed by using a single mass 6 degree of freedom system. Actual measurements of mechanical vibration of the engine and its foundation onboard were carried out, which showed the importance of including the flexibility of the engine support structure in the mode.

• 국제초고층학회논문집
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• 제7권4호
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• pp.313-325
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• 2018

Concrete-filled steel tubular (CFST) members are commonly used as composite columns in modern construction. However, the current guidelines for members' fire design (EN1994-1-2) have been proved to be unsafe in case the relative slenderness is higher than 0.5. In addition, the simplified design methods of Eurocode 4 are limited to circular and square CFST columns, while in practice columns with rectangular and elliptical hollow sections are being increasingly used because of their architectural aesthetics. In the last years a large experimental research has been carried out at Coimbra University on the topic. They have been tested concrete filled circular, square, rectangular and elliptical hollow columns with restrained thermal elongation. Some parameters such as the slenderness, the type of cross-section geometry as well as the axial and rotational restraint of the surrounding structure to the column have been tested in order to evaluate their influence on the fire resistance of such columns. In this paper it is evaluated the influence of the boundary conditions (pin-ended and semi-rigid end-support conditions) on the behavior of the columns in case of fire. In these tests it could not be seen a marked effect of the tested boundary conditions but it is believed that the increasing of rotational stiffness increases the fire resistance of the columns.

• Current Optics and Photonics
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• 제6권3호
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• pp.236-243
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• 2022

Monocrystalline silicon has excellent properties, but it is difficult to design and manufacture silicon-based mirrors that can meet engineering applications because of its hard and brittle properties. This paper used monocrystalline silicon as the main mirror material in an imaging system to carry out a feasibility study. The lightweight design of the mirror is completed by the method of center support and edge cutting. The support structure of the mirror was designed to meet the conditions of wide temperature applications. Isight software was used to optimize the feasibility sample, and the optimized results are that the root mean square error of the mirror surface is 3.6 nm, the rigid body displacement of the mirror is 2.1 ㎛, and the angular displacement is 2.5" under the conditions of a temperature of ∆20 ℃ and a gravity load of 1 g. The optimized result show that the silicon-based mirror developed in this paper can meet the requirements of engineering applications. This research on silicon-based mirrors can provide guidance for the application of other silicon-based mirrors.

• Structural Engineering and Mechanics
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• 제2권4호
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• pp.369-381
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• 1994

This paper is concerned with the elastic buckling of cylindrical shells with internal rigid ring supports. The internal supports impose a zero lateral deflection constraint on the buckling modes at their locations. An automated Rayleigh-Ritz method is presented for solving this buckling problem. The method can handle any combination of end conditions and any number of internal supports. Moreover, it is simple to code and can yield very accurate solutions. New buckling results for cylindrical shells with a single internal ring support, and under lateral pressure and hydrostatic pressure, are given in the form of design charts. These results should be valuable to engineering designers.

• Earthquakes and Structures
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• 제15권1호
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• pp.97-111
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• 2018

Buildings featuring a transfer structure can be commonly found in metropolitan cities situated in regions of lower seismicity. A transfer structure can be in the form of a rigid plate or an array of deep girders positioned at the podium level of the building to support the tower structure of the building. The anomalous increase in the shear force demand on the tower walls above the podium is a major cause for concern. Design guidance on how to quantify these adverse effects is not available. In this paper a simplified method for quantifying the increase in the shear force demand on the tower walls is presented. In view of the very limited ductile nature of this type of construction the analysis presented herein is based on linear elastic behaviour.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2001년도 추계학술대회(한국공작기계학회)
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• pp.111-116
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• 2001

In this paper, a simple 2 D.O.F. planar motion model is proposed in order to analyze the snake motion of a machining center cross head assembly, that is travelling on linear guide rails. In the proposed mathematical model, the friction between head and guide ways is neglected, and also the support structures including guide rails, rear- and side-panels of the machining center are assumed to be rigid. The equations of motion of the proposed model are derived and successfully solved to determine vibration responses of the head assembly due to some applied traction forces.

• Structural Engineering and Mechanics
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• 제76권2호
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• pp.239-250
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• 2020

This paper deals with free vibration of plates with steps and internal line supports by using a modified matched interface and boundary (MMIB) method. Different kinds of interfaces caused by steps, rigid and elastic line supports and their combinations are taken into account. Detailed MMIB procedures for dealing with these different interfaces are presented. Various examples are chosen to illustrate the accuracy and convergence of MMIB method. Numerical results show that the proposed MMIB is a highly accurate and convergent approach for solving the title issue. This study will extend the application range of MMIB method.