• Wind and Structures
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• v.10 no.5
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• pp.421-435
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• 2007

A two-dimensional flutter analysis method (2d-3DOF method) was developed to simultaneously investigate the relationship between oscillation parameters and aerodynamic derivatives of three degrees of freedom, and to clarify the coupling effects of different degrees of freedom in flutter instability. With this method, the flutter mechanism of two typical bridge deck sections, box girder section and two-isolated-girder section, were numerically investigated, and both differences and common ground in these two typical flutter phenomena are summarized. Then the flutter stabilization effect and its mechanism for long-span bridges with box girders by using central-slotting were studied by experimental investigation of aerodynamic stability and theoretical analysis of stabilizing mechanism. Possible explanation of new findings in the evaluation trend of critical wind speed through central vent width is finally presented.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.11
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• pp.89-97
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• 1999

A new parallel gripper mechanism is proposed in this work. This device has a parallelogrammic platform which can be flexibly folded. Therefore, this mechanism not only can be used to grasp an object having irregular shape or large volume, but also can be used as a micro-positioning device after grasping. Based on the position and kinematic analysis for this mechanism, this mechanism has been developed and the motion performance has been tested to corroborate the effectiveness of this mechanism.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.2
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• pp.116-122
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• 2022

This study proposed a method of testing the stability when selecting gears to reduce the weight of a 3-DOF wrist mechanism for a pick-and-place 3-DOF parallel robot with an increased workspace by using an additional straight axis at its top. We performed SolidWorks^® modeling- and ANSYS^®-based structural analysis of a pinion gear, which is most vulnerable to the force from a 3-DOF wrist mechanism, to lighten the robot weight for performing various tasks. When the initial analysis results considerably differed from the theoretical values calculated in advance, we checked and identified the errors in the contact conditions or input values. Ultimately, it is believed that the methodology presented in this paper will help in mitigating errors during analysis and determine the accurate values for a lightweight 3-DOF wrist mechanism for a parallel robot with an expanded workspace.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.729-733
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• 2003

Hybrid RMU is a kind of power circuit breaker and protects electric devices from over-current. In this paper we built a dynamic model of RMU driving mechanism using ADAMS and performed a optimal design of several design parameters. Finally we developed a prototype of RMU driving mechanism through results of analysis and confirmed it to satisfy design requisitions.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.04a
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• pp.813-818
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• 1996

This paper presents a method for tolerance design using the Taguchi Method(TM) and general purpose mechanism analysis program. Also the tolerance design method is with respect to performance improvement of a mechanism. To use the orthogonal array, mathematical model of a mechanism is established and experiments are carried out by the general purpose mechanism analysis program. The contact model is used to consider a clearance effect. This method is applied to the tolerance design of the VTR Deck mechanism. This method can be used in tolerance design of general mechanisms.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.6
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• pp.7-13
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• 1999

The unbalanced heavy-loaded elevation-driving system is composed of link-mechanism, hydraulic cylinder and compensator for the static unbalanced moment of the load. Control and compensation of elevation-driving system is very difficult because these mechanisms imply highly nonlinear properties due to hydraulic fluid characteristics and mechanical rotation of link-mechanism. In this study, through the analysis of the link-mechanism, the optimal design of the link-mechanism is suggested. Also to estimate the control performance of the unbalanced, heavy-loaded servo-controlled system, modeling and simulation of nonlinear system are carried out. To prove the validity of performance estimation program, simulation results are compared with the experimental results. Both results are similar, therefore this program will be helpful to study the improvement of the system control performance.

• International Journal of Ocean Engineering and Technology Speciallssue:Selected Papers
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• v.6 no.1
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• pp.38-43
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• 2003

This paper presents the results of a post-tensioning test and analysis of a pyramidal unit structure that is basic element for space structures. The behavior characteristics was analyzed and compared with the numerical analysis and the mechanism in test model was confirmed with geometrical analysis. The results of this paper show that the behaviors of space structures can be predicted in multi-directional Mero joint system. And the authors suggest the possibility of erection and shaping formation with comparatively small post-tensioning, and space structure with the mechanism should consider the nonlinear behavior due to large deformation.

• 제어로봇시스템학회:학술대회논문집
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• 1987.10b
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• pp.264-268
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• 1987

This paper is concerned on kinematic analysis and simulation of an automatic feeding mechanism subjected by the motion of a curvilinear inverse can. The curvilinear cam is rotated by positioning a translating roller and the automatic feeding mechanism is moved to the sliding position by the motion of a campin fixed on the curvilinear cam. The curvilinear cam consists of two arcs of circles and two straight lines. The modular approach is used for the kinematic analysis of the feeding mechanism. As the first part of the paper for the motion simulation of the cam-feeding system, this paper discusses the algorithm to simulate the motion of the cam-feeding mechanism. The second part of the paper presents the state-of-art for the graphics-oriented CAD technique,

• Proceeding of KASS Symposium
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• 2006.05a
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• pp.142-152
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• 2006

The purpose of this study is to explore an inquisitive and innovative approach to structure and form, Calatrava's morphogenetic mechanism and to trace the ideas behind his working methods and his theoretical preoccupations. The bridges and buildings of S. Calatrava possess a breathtaking rhythm and of them some are designed to expand and contract like living organisms. The analogy Calatrava has used as a creative tool to mutate human bodies into arcing roof forms and bridge suspensions is introduced to illustrate the morphogenetic process. At the same time, the analysis used developing how to design frame structures foldable with brilliant mathematical solution is also investigated. Consequently, the potentialities of Calatrava's morphogenetic mechanism to invent new systems are generated by methodological hypothesis; analysis and analogy.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.11a
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• pp.501-502
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• 2008