• Title/Summary/Keyword: Design consideration

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Optimum Structural Design of Space truss with consideration in Snap-through buckling (뜀-좌굴을 고려한 공간 트러스의 최적구조설계에 관한 연구)

  • Shon, Su-Deok;Lee, Seung-Jae;Choi, Jae-Hyun
    • Journal of Korean Association for Spatial Structures
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    • v.12 no.2
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    • pp.89-98
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    • 2012
  • This study investigates the optimum structural design of space truss considering global buckling, and is to obtain the minimal weight of the structure. The mathematical programming method is used for optimization of each member by member force. Besides, dynamic programming method is adapted for consideration in snap-through buckling. The mathematical modeling for optimum design of truss members consists of objective function of total weight and constrain equations of allowable tensile (or compressive) stress and slenderness. The tangential stiffness matrix is examined to find the critical point on equilibrium path, and a ratio of the buckling load to design load is reflected in iteration procedures of dynamic programming method to adjust the stiffness of space truss. The star dome is examined to verify the proposed optimum design processor. The numerical results of the model are conversed well and satisfied all constrains. This processor is a relatively simple method to carry out optimum design with consideration in global buckling, and is viable in practice with respect to structural design.

Piping Analysis for Excavation in a Embankment (굴착에 따른 인접 제방의 파이핑 해석)

  • Lee, Song;Kook, Joong-Jin;Jung, Min-Hyung
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.13 no.1 s.53
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    • pp.59-68
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    • 2009
  • One of the cause of embankment failure for piping is a routine design for piping consideration without exact understanding of that. Therefore, in this study, comparison and analysis of existing piping consideration methods had been conducted through embankment sections when sheet piles constructed on sandy ground. For the Terzaghi method and the critical hydraulic method, safety factors were changed up to double depending on the method. And for the critical velocity method, it was dramatically changed due to design parameters. Consequently, existing piping consideration method currently used is recommended not to be applied to all ground conditions uniformly but to applied with exact understanding of each consideration method characteristics depending on ground conditions.

Tendon Design for Master-slave Manipulator in Consideration of Constrained Force Reflection Control Structure (마스터-슬레이브 조작기에서 제한된 힘반영제어기 구조를 고려한 Tendon 설계)

  • Kang, Min-Sig;Yoon, Woo-Hyun
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.19 no.10
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    • pp.1043-1052
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    • 2009
  • In this work, a master-slave manipulator system which will be used for handling objects contaminated by radioactivity has been addressed. The links of manipulators are driven independently by individual motors installed on the base and the driving torque is transmitted through pre-tensioned tendons. Since the measurable variables are the positions and rates of master/slave motors, only a constrained specific bilateral control structure is available. In the consideration of the flexibility of the tendon and constrained control structure, we derived a necessity for tendon design to prevent uncontrollable vibration mode through a modal analysis. Based on a reduced rigid body model, a control design was suggested and tendons were selected. The feasibility of the proposed analysis and tendon design were verified along with some simulation results.

Water-Cooled Direct Drive Permanent Magnet Motor Design in Consideration of its Efficiency and Structural Strength

  • Lee, Ji-Young;Hong, Do-Kwan;Woo, Byung-Chul;Kim, Kyu-Seob;Hong, Jung-Pyo
    • Journal of Magnetics
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    • v.18 no.2
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    • pp.125-129
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    • 2013
  • This paper deals with a water-cooled direct drive permanent magnet (DD-PM) motor design for an injection-molding application. In order to meet the requirements for the target application and consider the practical problems of the manufacturing industry, the DD-PM motor is designed in consideration of efficiency and structural strength with many constraints. The performances of the designed motor are estimated not only by magnetic field analysis, but also by thermal and structural analysis. The design and analysis results are presented with experiment results.

Pproblems in the design of grass waterway (초생수로설계상의 유의점)

  • 서연용
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.8 no.1
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    • pp.1071-1076
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    • 1966
  • In this country grassed waterway practice has long been employed for the protection of drainage or diversion ditches in treating the sloped forest lands. However, the hydraulic characteristics of flow in the ditches have been entirely away from consideration in determining the dimensions of the ditches. This paper is intended first to bring forth some problems which should be brought ioto Consideration in designing grassed waterway including hydrologic aspect for determining the drainage requirement, erosion resistance of various grasses and other factors related to the hydraulics of ditch and second to introduce to readers a method of grassed waterway design, though modified, proposed for U. S. Soil Conservation Service practice. The method presented in the paper was primarily based upon the data originated from the experiments of U. S. Soil Conservation Service laboratories and further investigations on the factors involved are hoped to be conducted for applying the design criteria in this country. It is recommended to use the method of grassed waterway design ,presented in this paper from the view point of wide employment of grass lining on ditches which is obtainable at the lower cost and in abundance every where in this country.

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FE analyses and prediction of bursting forces in post-tensioned anchorage zone

  • Kim, Joung Rae;Kwak, Hyo-Gyoung
    • Computers and Concrete
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    • v.21 no.1
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    • pp.75-85
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    • 2018
  • To improve the design equation for the evaluation of the bursting force in the post-tensioned anchorage zone, this paper presents the analyses and design of the post-tensioned (PT) anchorage zone on the basis of three dimensional (3D) finite element (FE) analyses. The structural behavior was investigated through linear elastic finite element analyses upon consideration of the change in design parameters such as the bearing plate size, the eccentricity, and the tendon inclination. Moreover, consideration of the duct hole, which causes an increase of the bursting stress with a change in its distribution along the anchorage zone as well, is emphasized. Since that an exact prediction of the bursting force is the primary interest in design practice, additional parametric analyses are carried out to evaluate the relative contribution of all design parameters in determining the bursting force, and a comparison with the design guidelines mentioned in AASHTO-LRFD has been provided. Finally, an improved design guideline that takes into account the influence by the duct hole is suggested.

The implementation of the integrated design process in the hole-plan system

  • Ruy, Won-Sun;Ko, Dae-Eun;Yang, Young-Soon
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.4 no.4
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    • pp.353-361
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    • 2012
  • All current shipyards are using the customized CAD/CAM programs in order to improve the design quality and increase the design efficiency. Even though the data structures for ship design and construction are almost completed, the implementation related to the ship design processes are still in progress so that it has been the main causes of the bottleneck and delay during the middle of design process. In this study, we thought that the hole-plan system would be a good example which is remained to be improved. The people of outfitting division who don't have direct authority to edit the structural panels, should request the hull design division to install the holes for the outfitting equipment. For acceptance, they should calculate the hole position, determine the hole type, and find the intersected contour of panel. After consideration of the hull people, the requested holes are manually installed on the hull structure. As the above, many processes are needed such as communication and discussion between the divisions, drawings for hole-plan, and the consideration for the structural or production compatibility. However this iterative process takes a lot of working time and requires mental pressure to the related people and cross-division conflict. This paper will handle the hole-plan system in detail to automate the series of process and minimize the human efforts and time-consumption.