• Title/Summary/Keyword: 하중제한

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Static Test of a Composite Wing with Damage Tolerance Design (손상 허용 설계를 적용한 복합재 날개의 정하중 시험)

  • Park, Min-Young
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.46 no.6
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    • pp.471-478
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    • 2018
  • Static tests of the composite wing structure were performed to verify damage tolerance design. Both 5 cases of DLLT and 3 cases of DULT were completed to meet requirements for static strength. After inducing BVID and open hole damages on the critical areas of the composite wing based on associated regulations, the DULT and fracture test were performed. In major wing parts, the measured strains and displacements agreed well with those of structural analysis. The initial structural fracture occurred at the area having minimum margin of safety as expected by analysis. As a result, it was confirmed that results from analytic model and strength evaluation were similar to behaviors of the composite wing structure.

Development of Resizing Techniques for Drift Designs of High-rise Buildings subjected to Lateral and Vertical Loads (횡하중과 연직하중을 받는 고층건물의 변위설계를 위한 재분배기법 개발)

  • 서지현;박효선
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.17 no.1
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    • pp.49-58
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    • 2004
  • Drift design of a high-rise building is a governing factor in the determination of structural weights and lateral resisting systems. However, high-rise buildings are composed of tens of thousands of structural member, designer can not know which members are active to lateral drift control and how much they contribute to lateral drifts. Resizing technique was proved to be a practical method for drift design of high-rise buildings. However, no resizing algorithm has been considered the effect of vertical loads in drift designs. Thus, in this paper, a resizing algorithm has been developed for drift designs of high-rise buildings subjected to both lateral and vertical loads. The drift design model has been applied to drift designs of two high-rise building examples.

A study on the GEO Satellite Tank Support Beam Form Definition at Preliminary Design (초기설계단계의 정지궤도위성 연료탱크 지지대 형상결정에 대한 연구)

  • Choi, Jung-Su;Kim, In-Gul;Kim, Sung-Hoon;Park, Jong-Seok;Kim, Chang-Ho;Yang, Gun-Ho
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.35 no.2
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    • pp.157-164
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    • 2007
  • Launch Interface Ring roles as connection department of satellite and launcher for to deliver all structure loads that occur from the satellite, and one of the most intensive load received parts. Especially COMS, the first Korean developing GEO satellite, needs Launch Interface Ring with Tank Support Beam because of dissymmetry fuel tanks. The purpose of this study is the suitable form decision of Launch Interface Ring at preliminary design of COMS. In this study, launch mass and design constraints are investigated. Moreover, optimization algorithm and simplification technique are used. At the beginning of this study, three types of launch interface ring were presented and finally model 3 was the lightest design for resistance of launch environment. Nevertheless, model 1 can be suggested for application to COMS because of the satellite gravity center control and ease of fabrication.

Point Bracing System for a Steel Frame with Double Angle Connections Under Horizontal and Vertical Loads (수평·수직하중을 동시에 받는 더블앵글로 접합된 철골조의 절점 보강시스템)

  • Yang, Jae Guen;Kim, Ho Keun;Kim, Ki Hwan
    • Journal of Korean Society of Steel Construction
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    • v.16 no.5 s.72
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    • pp.629-639
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    • 2004
  • A steel frame is one of the most commonly used structural systems due to its resistance to various types of applied loads. Many studies have been conducted to investigate the effects of several parameters, such as connection flexibility, the boundary condition of each support, and beam-to-column stiffness ratio, on the characteristic behavior of a frame. Based on the results of these studies, several design methods have been proposed. This research focused on the number of bolts on the rotational stiffness of a double-angle connection, and its effect on the story drift of a frame. To achieve these purposes, a simplified analytical model was proposed. Several experimental tests were also conducted to obtain the rotational connection stiffness of each double-angle connection.

Optimum Structural Design of Sandwich Plates Considering the Shear Buckling (전단 좌굴을 고려한 샌드위치 평판의 최적 구조 설계에 관한 연구)

  • C.D. Jang;M.S. Cho
    • Journal of the Society of Naval Architects of Korea
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    • v.33 no.3
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    • pp.56-65
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    • 1996
  • Recently, with development of mechanics of materials, as pursuing the high speed of the ships, there has been an increasing demand on the composite construction which satisfies high strength and low weight at the same time. A sandwich element is a type of composite construction, which is composed of thin, strong, stiff and relatively high density faces and a thick, light, and weaker core material. As the second moment is increased by faces separated from the neutral axis farther, a sandwich element is most effective light structural form. In this study, Rayleigh-Ritz Energy Method is adopted, which can analyze sandwich plate relatively simply and exactly. Stresses and buckling loads are analyzed exactly, when uniform lateral pressure load, inplane compression and inplane shear are acting at the sandwich plate. Including a wrinkling stress, this study can be applied to the initial design and minimum weight design of sandwich plates.

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Structural Performance of Double Rip Decks Reinforced with Inverted Triangular Truss Girders (역삼각 트러스 거더로 보강된 더블 골 데크 성능 평가)

  • Son, Hong-Jun;Kim, Young-Ho;Chung, Kyung-Soo;Kim, Dae-Jin
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.30 no.6
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    • pp.559-566
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    • 2017
  • This paper proposes a new composite deckplate system reinforced with inverted triangular truss girders(called 'D Deck'), which does not require the use of temporary supports at construction stage. The proposed system retains increased stiffness and strength while keeping the absolute floor height change to a minimum level and can be utilized as floor systems of various types beam members such as the conventional wide-flange and U-shaped composite beams. In order to evaluate the performance of the proposed system, five specimens with a span of 5.5 m were fabricated and tested under field loading conditions consisting of several intermediate steps. The load-deflection curves of each specimen were plotted and compared with the nonlinear three-dimensional finite element analysis results. The comparison showed that the effective load sharing between the truss girders and floor deck occurs and the maximum deflection under construction stage loading is well below the limit estimated by the provisions in Korea Building Code.

Numerical Computations on Hydroelastic Response of a Vertical Cylinder in Extreme Wave Loads (유탄성 응답을 고려한 수직 실린더에 작용하는 극한파의 파랑하중 수치해석)

  • Hong, Sa-Young;Kim, Byoung-Wan;Kyoung, Jo-Hyun
    • Journal of Navigation and Port Research
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    • v.31 no.1 s.117
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    • pp.21-27
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    • 2007
  • The wave load and its influence on the response of offshore structure have been well investigated through the statistical approach based on the linear theory. The linear approach has a limitation to apply the extreme condition such as extreme wave, which corresponds to extreme value of wave spectrum. The main topic of present study is to develop an efficient numerical method to predict wave load induced by extreme wave. As a numerical method, finite element method based on variational principle is adopted. The frequency-focusing method is applied to generate the extreme wave in the numerical wave tank. The wave load on the bottom mounted vertical cylinder is investigated. The hydroelastic response of the vertical cylinder is also investigated so as to compare the wave loads with the rigid body case in the extreme wave condition.

The Analysis of the Effect of .Wind Load on the Structural Stability of an Articulation type Container Crane (풍하중이 관절형 붐을 가진 컨테이너 크레인의 구조 안정성에 미치는 영향 분석)

  • Lee Jung-Myung;Lee Seong-Wook;Han Dong-Seop;Han Geun-Jo
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2005.10a
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    • pp.235-240
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    • 2005
  • Articulation type container cranes are the boom forms an inverted L shape when raise. The inner boom section is nearly vertical when raise and the outer boom section is nearly horizontal. Articulation type container cranes were developed as a lower height crane to meet aircraft clearance requirements. Because the height of an Articulation type container crane is about 70m, the crane is subjected to the effect of Wind load. Therefore, the problem on the effect of Wind load is receiving carefully study. The researches for the effect of wind load on the structural stability of a conventional container crane are conducted. In this study, we carried out the investigation for an articulation type container crane. When a wind load is applied to a container crane, we analyzed the reaction force distribution at each supporting point of a crane with respect to a wind load direction and the effect of the change of the machinery house location on the structural stability rf a crane by carrying out Finite Element Analysis.

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Evaluation of Static Structural Integrity for Composites Wing Structure by Acoustic Emission Technique (음향방출법을 응용한 복합재 날개 구조물의 정적구조 건전성 평가)

  • Jun, Joon-Tak;Lee, Young-Shin
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.37 no.8
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    • pp.780-788
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    • 2009
  • AE technique was applied to the static structural test of the composite wing structure to evaluate the structural integrity and damage. During the test, strain and displacements measurement technique were used to figure out for static structural strength. AE parameter analysis and source location technique were used to evaluate the internal damage and find out damage source location. Design limit load test, the 1st and 2nd design ultimate load tests and fracture test were performed. Main AE source was detected by an sensor attached on skin near by front lug. Especially, at the 1st design ultimate test, strain and displacements results didn't show internal damage but AE signal presented a phenomenon that the internal damage was formed. At the fracture test, AE activities were very lively, and strain and displacements results showed a tendency that the load path was changed by severe damage. The internal damage initiation load and location were accurately evaluated during the static structural test using AE technique. It is certified from this paper that AE technique is useful technique for evaluation of internal damage at static structural strength test.

Stability Analysis of Pipe Rack Module for Underground Complex Plants Construction (복합플랜트 지하 건설을 위한 파이프랙 모듈 공법 안정 해석)

  • Kim, Sewon;Lee, Sangjun;Kim, YoungSeok
    • Journal of the Korean Geosynthetics Society
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    • v.20 no.4
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    • pp.113-124
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    • 2021
  • Underground environmental infrastructure and energy production facilities, which are recognized as avoidable facilities such as landfills, are emerging as an important social issue due to urbanization and economic growth. In order to safely construct a large-scale plant facility in the underground space, it is necessary to increase the utilization of the limited space layout and minimize unnecessary columns. In this study, the plant modularization method(Pipe Rack Module) was reviewed to solve the problems of work constraints, assembly and demolition, process system interconnection, and maintenance that occur when plant facilities are underground. In addition, plant module analysis was performed by applying various load conditions (earthquake load, device load, earth pressure load, etc.) to improve spatial layout usability and secure structure stability. Based on the analysis results under various boundary condition, the implications regarding the minimum installation interval and module arrangement (draft) of basic modules required for the construction of an underground combined plant were derived.