• 대한기계학회논문집A
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• 제21권11호
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• pp.1871-1884
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• 1997

This paper describes the design process of a 3-component load cell with a multiple parallel plate structure which may be used to measure transverse forces and twisting moment simultaneously. Also we have derived equations to predict the bending strains on the surface of the beams in the multiple parallel plate structure under transverse force or twisting moment. It reveals that the bending strains calculated from the derived equations are in good agreement with the results from finite element analysis and experiment. Also we have evaluated the rated output and interference error of each component, which can be efficiently used to design a 3-component load cell with a multiple parallel plate structure.

• Journal of Mechanical Science and Technology
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• 제14권1호
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• pp.57-64
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• 2000

Recent advances in the field of control theory have enabled us to design active vibration control systems for various structures. In many studies, the controller used to suppress vibration has been synthesized for the given mathematical model of structure. In these cases, the designer has not been able to utilize the degree of freedom to adjust the structural parameters of the control object. To overcome this problem, so called 'Structure/Control Simultaneous Optimization Method' is used. In this context of view, this paper is concerned with the active vibration control of bridge towers, platforms and ocean vehicles etc. Simultaneous design method is used to achieve optimal system performance. Here, a general framework for the simultaneous design problem of output feedback case is introduced based on LMI (Linear Matrix Inequality). The simulation results show that the proposed design method achieves desirable control performance.

• 한국CDE학회논문집
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• 제5권4호
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• pp.359-372
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• 2000

Current CAD systems are good enough to be used as a tool to manipulate three-dimensional shapes. This is a very important capability to be owned by a design tool because a major portion of designers'activities is spent on the shape manipulation in the design detailing process. However, the whole design process involves a lot more than the, shape manipulation. Currently, these remaining tasks, mostly logical reasoning process for the function realization together with structure decomposition in the top-down manner, are processed in the designer's brain. To support the top-down functional design process of a mechanical product, a system integrating the functional, structural and geometrical aspects of a product design in a unified environment is presented. Using this system, a designer can perform function decomposition, structure decomposition, and geometry detailing, and function verification activities in parallel and the whole design process it modeled resultantly. Once the whole design process is modeled, any redesign task can be automatically performed with the verification of the desired functions.

• 한국가스학회지
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• 제9권4호
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• pp.36-43
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• 2005

본 논문은 다구찌 설계방법을 이용하여 LNG저장탱크의 지붕 구조물에 대한 최적설계 조건을 확보하기 위해 FEM해석을 수행하였다. 다구찌 설계방법은 저장탱크 구조물의 설계인자에 가장 큰 영향을 미치는 파라메터를 고찰하고 최적화하는데 유용한 결과를 제시하였다. 다구찌 설계방법으로 수행된 FEM 해석결과에 따르면, LNG저장탱크 지붕 구조물의 최적설계에 필요한 인자로 지붕 중심부의 두께를 언급하고 있다. 안전하면서 효율적인 지붕을 건설하기 위한 철근 콘크리트 지붕의 초기 구조물 설계는 반경방향의 H빔과 원주방향의 L빔을 가능한 작은 수량으로 배열하고 두꺼운 지붕 구조물을 갖춘 LNG 외부탱크가 최적이라는 해석결과를 제시한다.

• Design & Manufacturing
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• 제16권2호
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• pp.53-59
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• 2022

Unlike other press forming processes, ISF (Incremental sheet forming) doesn't require a punch and die set. However, during the ISF processes unwanted bending deformation occurred around the target geometry. This paper is aimed to analyze the effect of the die structure, which is supported by bolts, on the geometric accuracy of the ISF processes. In this research, the ISF processes with Al5052 sheet of 0.5 mm, the tool diameter of 6 mm and the stepdown of 0.4 mm was employed. L-shaped, step-shaped, relief-shaped geometry were employed in experiments. Sectional view and the plastic strain were compared. From this research we find out that the bolt supported ISF processes increases the geometric accuracy of products very effectively.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1995년도 Proceedings of the Korea Automation Control Conference, 10th (KACC); Seoul, Korea; 23-25 Oct. 1995
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• pp.56-59
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• 1995

In this paper, we propose a new rubust design scheme of a variable structure type model reference control (VS-MRC) which can be applied to linear time-varing plants. Our idea is started from the hypothesis that the plant consists of two parts, i.e., one has time-invariant parameters and the other has time-varying parameters. We consider the former the nominal part of the plant and the latter a kind of disturbance to the nominal one. In this design scheme, the ordinary VS-MRC is adopted to the nominal part and the signum function is introduced to eliminate the influence of the disturbance.

• 비파괴검사학회지
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• 제30권3호
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• pp.257-260
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• 2010

Advancements in the imaging and computing technology have opened the path to digital holography for non-destructive investigations of technical samples, material property measurement, vibration analysis, flow visualization and stress analysis in aerospace industry which has widened the application of digital holography in the above fields. In this paper, we demonstrate the non-destructive investigation and micro-structure measurement application of digital holography to the small particles and a biological sample. This paper gives a brief description of the digital holograms recorded with this system and illustratively demonstrated.

• 한국가스학회:학술대회논문집
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• 한국가스학회 2003년도 추계학술발표회 논문집
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• pp.77-84
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• 2003

• Journal of Mechanical Science and Technology
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• 제14권3호
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• pp.306-313
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• 2000

The homogenization method and the density function method are common approaches to evaluate the equivalent material properties for design cells composed of matter and void. In this research, using a new topology optimization method based on the homogenized material with a penalty factor and the chessboard prevention strategy, we obtain the optimal layout of a structure for the natural frequency of a designated mode. The volume fraction of nodes of each finite element is chosen as the design variable and a total material usage constraint is imposed. In this paper, the subspace method is used to evaluate the eigenvalue and its corresponding eigenvector of the structure for the designated mode and the recursive quadratic programming algorithm, PLBA algorithm, is used to solve the topology optimization problem.

• Journal of Mechanical Science and Technology
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• 제18권2호
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• pp.253-261
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• 2004

A simple and effective filtering method to control the member size of an optimized structure is proposed for topology optimization. In the present approach, the original objective sensitivities are replaced with their relative values evaluated within a filtering area. By adjusting the size of the filtering area, the member size of an optimized structure or the level of its topological complexity can be controlled even within a given finite element mesh. In contrast to the checkerboard-free filter, the present filter focuses on high-frequency components of the sensitivities. Since the present filtering method does not add a penalty term to the objective function nor require additional constraints, it is not only efficient but also simple to implement. Mean compliance minimization and eigenfrequency maximization problems are considered to verify the effectiveness of the present approach.