• 한국정밀공학회지
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• 제6권2호
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• pp.77-87
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• 1989

This study is carried out to estimate the influence of cutting speed on the dynamic stability of a drilling machine. The theoretical stabilityu chart is constructed by using the measurd dynamic characteristics of the drilling machine. The critical cutting width and speed predicted from the stability chart show excellent agreements with those measured. Therefore it is confirmed that the analysis technique used in this study is useful for the prediction of the dynamic instability and improvement of the dynamic characteristics of drilling machines.

• 한국공작기계학회논문집
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• 제13권1호
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• pp.88-93
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• 2004

In general, a fundamental structural design consideration for an automobile is the overall dynamic behavior in bending and torsion. Dynamic behavior of the automobile are mainly influenced by the structural stiffness of B.I.W.(body-in-white) and the physical property of trim components. In this paper, the modeling techniques for various trim components of middle-sized bus are presented, and the dynamic effects of the trim components on the vibration characteristics of the bus are investigated. The $1^{st}$ torsional frequency is decreased by attaching windshield and backlite to the B.I.W., but the $1^{st}$ vertical bending frequency and the $1^{st}$ lateral bending frequency are increased. The natural frequencies of the bus are decreased by attaching doors and windows. And also, the natural frequencies of the bus are large decreased by attaching seats, instrument panel etc. The study shows that the dynamic characteristics of the bus can be effectively predicted in the initial design stage.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1993년도 봄 학술발표회논문집
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• pp.37-44
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• 1993

There are a lot of linear dynamic analysis methods for complex structures. Each method has advantages and shortcomings. Method of dynamic analysis for complex structure is selected considering characteristics of dynamic loading, computer facility available number of degree of freedem and accuracy of results. It is a main point of view to get economical results rather then accurate ones for analysis of general complex structures, Mode superposition method and direct integration method are generally used. However, the characteristics of load is not considered in mode superpositon method, the personal computer cannot be used in direct integration methods. To over-come these shortcomings, the component mode method incorporating Ritz algorithm updated is proposed to solve economically dynamic behavior of the structures. The purpose of study is a formulation of algorithm, and computer programing suitable for dynamic analysis of the complex structure in personal computer environment.

• 한국산학기술학회논문지
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• 제8권1호
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• pp.10-17
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• 2007

자동차 미끄럼방지 장치의 최적 제어를 위해서는 유압 모듈레이터 특히, 솔레노이드 밸브에 대한 정확한 동특성 해석이 필요하다. 그러나, 현재까지 진행된 대부분의 연구들은 솔레노이드 밸브 자체만을 고려하였기 때문에 실제 자동차 미끄럼방지 장치에 제한적으로 적용되었다. 본 연구에서는 유압 모듈레이터에 작용하는 압력을 고려한 솔레노이드 밸브의 동특성 해석을 위하여 실험과 이론 해석을 실시하였다. 작동 압력이 솔레노이드 밸브의 동특성에 끼치는 영향을 정량적으로 해석하였고 설계인자를 변화시키면서 성능향상 방안을 제안하였다. 따라서, 본 연구에서 수행한 솔레노이드 밸브 동특성 해석결과는 자동차 미끄럼방지 장치의 최적 제어 기준으로 활용할 수 있을 것이다.

• Tribology and Lubricants
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• 제16권4호
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• pp.274-281
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• 2000

In this paper, linearized dynamic characteristics of parallel line pivoted pad thrust bearing (here-inafter refer to PLP thrust bearing) was analyzed by perturbation method with inlet pressure. Inlet pressure and excitation frequency influence dynamic characteristics of PLP thrust bearing at all operating conditions, such as angular pivot position, mass of pad. Therefore, the characteristics have to be analyzed with inlet pressure, excitation frequency, mass of pad and thickness of pad. Otherwise, the analysis may be over or under estimate.

• 한국소음진동공학회논문집
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• 제15권12호
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• pp.1332-1339
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• 2005

The vibration of Powertrain are one of the import design characteristics of a vehicle. Powertrain is mostly mounted to the front subframe and powertrain mounting has an important role in determining the vehicle vibration characteristics. In this paper, the accuracy of the vibration analysis for the front subframe is discussed. The dynamic characteristic of subframe are measured from vehicle test and the finite element model updating are performed that natural frequency, mass and MAC of the experimental and theoretical modal analysis are compared. The subframe mounting stiffness are obtained the iteration method based on the vibration of subframe from vehicle test. Finally, the result of dynamic analysis which is operated dynamic load is compared with experimental one of vehicle test.

• 한국소음진동공학회논문집
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• 제13권3호
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• pp.164-171
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• 2003

Dynamic analysis using impulse responses is formulated to estimate effect of slider rail shape on dynamic responses in near-field optical recording drive. Impulse responses are obtained on numerical nonlinear model including rigid motion of a slider and fluid motion of an air bearing under the slider. Dynamic characteristics of slider motion are evaluated by utilizing the decay ratio of impulse responses and modal frequencies from frequency response functions. The dynamic characteristics of the designed NFR slider are checked by comparing those of a HDD slider(Nutcracker). Also, sensitivities of slider Position conditions and rotation speed on the dynamic characteristics are investigated.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 추계학술대회논문집 II
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• pp.586-591
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• 2001

Dynamic analysis using impulse responses is formulated to estimate effect of slider rail shape on dynamic responses. Impulse responses are obtained on numerical nonlinear model including rigid motion of slider and fluid motion of air bearing under the slider. Dynamic characteristics of slider motion are evaluated by utilizing the decay ratio of impulse responses and modal frequencies from frequency response functions. The dynamic characteristics of the developed NFR(Near Field Recording) slider are checked by comparing those of HDD sider(Nutcracker). Also, sensitivities of slider position conditions and rotation speed on the dynamic characteristics are investigated. The researches show that the utilized method is a good indicator of designing the better slider.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문집
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• pp.68-73
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• 2002

It is necessary first to understand dynamic characteristics of bus full BIW assembly for fatigue endurance analysis. FE model has been used usually for analyzing the dynamic behavior of structures. A lot of experience and effort, however, is necessary to make the credible FE model. Experimental modal analysis of structures has been performed to verify the credibility of initial FE model and to update the model. In this work, experimental modal analysis was performed to understand dynamic characteristics of bus full BIW assembly in free-free boundary condition and the result was used to verify the initial FE model. In addition, some practical techniques, which were used in this experiment, were mentioned.

• 한국공간구조학회논문집
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• 제18권3호
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• pp.45-55
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• 2018

The arched stone bridge has been continuously deteriorated and damaged by the weathering and corrosion over time, and also natural disaster such as earthquake has added the damage. However, masonry stone bridge has the behavior characteristics as discontinuum structure and is very vulnerable to lateral load such as earthquake. So, it is necessary to analyze the dynamic behavior characteristics according to various design variables of arched stone bridge under seismic loads. To this end, the arched stone bridge can be classified according to arch types, and then the discrete element method is applied for the structural modelling and analysis. In addition, seismic loads according to return periods are generated and the dynamic analysis considering the discontinuity characteristics is carried out. Finally, the dynamic behavior characteristics are evaluated through the structural safety estimation for slip condition.