• 대한기계학회논문집
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• 제19권7호
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• pp.1665-1674
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• 1995

An optimum design has been performed to maximize specific energy (SED) of composite flywheel rotor for energy storage system. The flywheel rotor is assumed to be an axisymmetric thick laminated shell with a plane strain state for structural analysis. For the structural analysis the centrifugal force is considered and the stiffness matrix equation was derived for each ring considering the interferences between the rings. The global stiffness matrix was derived by integrating the local stiffness matrix satisfying the conditions of force and displacement compatibilities. Displacements are then calculated from the global stiffness matrix and the stresses in each ring are also calculated. 3-D intra-laminar quadratic Tsai-Wu criterion is then used for the strength analysis. An optimum procedure is also developed to find the optimal interferences and lay up angle to maximize SED using the sensitivity analysis.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 추계학술대회논문집
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• pp.898-901
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• 2003

In order to get the drive reliability and low Power-consumption characteristics, most of small form factor HDD has und the load/unload mechanism instead of CSS type. Compared with CSS mechanism, the load/unload system has little opportunity of head/media contact during the disk spin-up and down. However, the load/unload mechanism needs the precise integration technology with slider, suspension, ramp and load/unload velocity, and all of these component s should be designed simultaneously, not an individually. In this paper, we focus the design of the suspension stiffness using the specified ABS design. We use the CML software to calculate the load/unload dynamic and use the RSM(Response surface method) to get the optimal condition of the suspension stiffness.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.985-988
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• 2002

The Spindle-]fearing System is very important unit for geometrical accuracy in machine tools. To improve effectively the weak point of spindle system, it is necessary that the contribution ratio of spindle core parts to static and dynamic stiffness is clarified. In this paper, static contribution ratio of core parts is calculated by overlapping static deformation of basic spindle design with one flexible parts. The dynamic contribution ratio for natural frequency and dynamic deformation at spindle end is obtained by calculating correlation between original and basic spindle deformation, by curve fitting with regressive method. It is proved the validity of estimation result is correct.

• 소음진동
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• 제10권5호
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• pp.811-818
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• 2000

This paper deals with the design of a car seat for enhancing dynamic ride quality using a Biomechanical Model that was developed from the measured whole-body vibration characteristic. For evaluation of seat ride quality, the z-axis acceleration of floor as an input of biomechanical model was measured on a driving passenger car at highway and national road. Form the floor signal and the estimated biomechanical model, overall ride value evaluated by parameter study of seat stiffness and damping. The result shows that overall ride value decreases as the seat damping increases and the sear stiffness decreases. A lot of polyurethane foams were manufactured and tried to evaluate dynamic ride quality of a seat. It is found that stiffness and damping of a seat show a linear relationship, which means the stiffness and damping are not independent each other, So the optimal seat parameters within practically achievable space are determined.

• 한국자동차공학회논문집
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• 제24권5호
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• pp.612-617
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• 2016

A motorcycle frame is a structure that endures the load and retains durability under various driving environments. A motorcycle has been developed with a diverse utility range, and its design has always been expanded to the newly created concept based on advanced engineering technologies. In this study, a compact motorcycle frame is considered to perform parametric studies that can enhance the stiffness of a frame with computational simulation. Finite element analysis is used to compare the deformation and stiffness of a base model and four case-models with three design-change-parameters. The parametric studies are analyzed to provide available methods that can be expected in the industrial fields of engineering design for a motorcycle frame.

• 한국소음진동공학회논문집
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• 제23권11호
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• pp.996-1002
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• 2013

Conditions of stiffness for a steel spring torsional vibration damper are difficult and ambiguous. Nevertheless correct estimation of stiffness is essential and important in the damper design for the damper to activate properly in the field. In this paper, to build up the estimation method of steel spring torsional vibration damper a miniaturized model was developed for modelling between a spring and inner star of the damper. The method obtained from the results through the experiment and analysis of it was applied to the prototype torsional damper.

• 한국정밀공학회지
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• 제18권12호
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• pp.145-151
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• 2001

The dimensional accuracy of the cold forged part is depended on the elastic characteristics of the die. To increase the stiffness of the prestressed die, the first stress ring of the tungsten carbide alloy (WC) is considered. For the design, Lame's equation is used. Diameter ratios and interferences have been determinated by maximum inner pressure without yielding of materials. The design of the prestressed die has been compared with the conventional one. For the comparison, the FE-analysis using ANSYS has been performed. The results indicate that the prestressed die with the high stiffness can be obtained by the using the high stiffness material as the first stress ring.

• 한국강구조학회 논문집
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• 제21권2호
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• pp.105-113
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• 2009

가새골조 성능을 개선하기 위해 연결부 (거싯 플레이트) 강도, 강성, 연성이 골조 디자인에 직접적으로 고려되어야 한다. 연결부의 강도는 지진력에 저항하도록 디자인 되어야하고 필요한 골조시스템의 연성을 확보하는데 기여해야한다. 그리고 연결부의 강성은 구조요소와 연결부의 동적 반응과 변위 요구에 영향을 준다. 이 논문에서 지난 실험 결과를 이용하여 거싯 플레이트 연결부에 대한 현 디자인 모델을 검토하고 평가한다. 현 디자인 모델은 연결부 디자인 가이드라인을 주기엔 적절하지 못하고 실제 거싯 플레이트의 응력과 변위 상태는 비선형이고 굉장히 복잡하다. 구조 디자이너들은 시스템과 연결부의 성능을 대략적으로 예측하기 위해 보와 기둥을 포함한 단순한 모델을 원한다. 이를 위해 단순화한 디자인 모델이 개발되고 평가된다. 이 모델은 비교적 정확하고 신뢰성 있는 연결부 강성 평가를 제공한다.

• 한국지진공학회논문집
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• 제13권2호
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• pp.59-68
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• 2009

안전하고 경제적인 내진설계를 위해서는 설계 초기단계부터 모멘트재분배와 부재소성변형을 고려하는 것이 바람직하다. 본 연구에서는 할선강성해석을 사용하여 각 부재의 재분배된 모멘트와 소성변형을 직접적으로 고려할 수 있는 내진설계방법을 개발하였다. 모멘트재분배에 의하여 발생된 비대칭 부재강성을 나타내기 위하여, 비강접 단부접합부를 갖는 보-기둥요소(NREC요소)를 사용하여 구조물을 모델링하였다. NREC요소에 사용되는 할선강성은 건물 및 부재의 요구연성도에 기반하여 결정하였다. 할선강성 구조모델에 대한 선형해석을 수행하여 내진설계를 위한 부재력과 소성변형을 구하였다. 본 연구에서는 할선강성해석을 모멘트골조와 이중골조의 내진설계에 적용하였고, 설계결과를 정밀한 비선형해석 결과와 비교하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.1274-1277
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• 2004

The objective of this research work is to investigate into characteristics of bending stiffness and failure for the ISB ultra-lightweight panel with internally structured material. The expanded metal with a pyramid shape and woven metal are employed as an internally structured material. In order to investigate the characteristics, the specific stiffness and failure map are estimated using the results of three-points bending test. From the results of the experiment, the influence of design parameters of ISB panel on the specific stiffness and failure mode has been found. In addition, it has been shown that ISB panel with expanded metal is prefer to that with woven metal from the view point of optimal design for ISB panel.