• Title/Summary/Keyword: Design Load Cases

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Buckling lengths of unbraced multi-storey frame columns

  • Ozmen, Gunay;Girgin, Konuralp
    • Structural Engineering and Mechanics
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    • v.19 no.1
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    • pp.55-71
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    • 2005
  • In several design codes and specifications, simplified formulae and diagrams are given for determining the buckling lengths of frame columns. It is shown that these formulae may yield rather erroneous results in certain cases. This is due to the fact that, the code formulae utilise only local stiffness distributions. In this paper, a simplified procedure for determining approximate values for the buckling loads of multi-storey frames is developed. The procedure utilises lateral load analysis of frames and yields errors in the order of 10%, which may be considered suitable for design purposes. The proposed procedure is applied to several numerical examples and it is shown that all the errors are in the acceptable range and on the safe side.

Development of Design Oriented Finite Element Program for DAD Integration (구조설계의 CAD화를 위한 설계지향 유한요소 프로그림의 개발에 관한 연구)

  • 이성우
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1989.10a
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    • pp.1-6
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    • 1989
  • To intergrate finite elements Into CAD enviroment, design oriented structure of the finite element program is desirable. For this purpose a program called CFEP has been developed. Generation of geometry data is independently treated in the program to ease the modification of property or loading data. By conveniently handling the large number of load cases with various load combinations, and by comprehensively reporting the results through inclusive output for the multiple analyses, the program greatly facilitates the design process. Interfacing with interactive graphic post-processor, the results of analyses and final designed values are obtained in a compact and comprehensive manner. The paper also describes necessary tasks for developing such program on the economical microcomputer. Sample output of printed and graphical form well illustrates the procedure.

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A Parametric Study on the Behavior of Integral Abutment rSC Beam Bridge (일체식교대 PSC빔 교량의 거동에 관한 매개변수 해석)

  • 홍정희;정재호;유성근;박종면;윤순종
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2002.10a
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    • pp.412-419
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    • 2002
  • This paper presents a parametric study on the behavior of integral abutment PSC beam bridge. An integral abutment bridge is a simple span or multiple span continuous deck type bridge having the deck integral with the abutment wall. The rational structural model and design load combinations accounting for each construction stage are proposed. It can be used for defining the effect of earth pressure and temperature change in the design process including for determining maximum flexural responses. The bending moment at each response location due to the design load combination is investigated according to the change of flexural rigidity of piles and abutment height. The flexural responses of proposed model are computed for the cases of applying the Rankine passive earth pressure and the earth pressure based on the soil-structure interaction respectively, and the results are discussed.

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Slider-Bearing Design with Micro-Machined Wavy-Cavity: Parametric Characterization of Thermohydrodynamic-Operation-Scheme

  • Ozalp B. Turker;Ozalp A. Alper
    • Journal of Mechanical Science and Technology
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    • v.20 no.10
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    • pp.1590-1606
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    • 2006
  • Slider bearings are widely applied in mechanical systems, where the design needs cover increased load capacity, lowered friction and power consumption and creative designs. This work is governed to perform a parametric characterization, by generating a novel structure on the upper slider surface, which can formally be expressed in micro-machined wavy-form, where the individual and combined influences of various structural design parameters and boundary conditions, on the performance records, are also evaluated. Computations put forward that the contribution of the wave amplitude on power loss values is highly dependent on the level of inlet pressure; higher amplitudes are determined to increase power loss in the lowest inlet pressure case of 1.01, whereas the contrary outcome is determined in the higher inlet pressure cases of 3.01 & 5.01. Designing the slider bearing system, based on optimal load capacity, produced the optimum wave number ranges as 10-45, 7-11 and 5-8 for the pad inclinations of $5^{\circ},\;4^{\circ}$ and $3^{\circ}$ respectively.

A Study on the Load Bearing Characteristics Depending on Pile Construction Methods and Pile Load Test Methods Based on Case Analyses (사례분석에 기초한 말뚝시공법 및 재하시험방법에 따른 하중지지특성에 관한 연구)

  • Hong, Seok-Woo;Choi, Yong-Kyu
    • Journal of the Korean Geotechnical Society
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    • v.28 no.4
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    • pp.5-21
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    • 2012
  • In our country, in the case of traditional design of pile foundations, only a design depending on end bearing has been performed. However, through the load transfer measurement data that have been carried out for in-situ piles, it was known that skin frictional force was mobilized greatly. In this study, through the analysis of the load transfer test cases of driven steel pipe piles and large-diameter drilled shafts, load bearing aspects of pile foundation depending on pile construction methods and pile load test methods were established. The average sharing ratios of skin frictional force were independent of pile types, pile load test methods, relative pile lengths, pile diameters and soil types. Because the average sharing ratios were over 50%, the case pile foundations mostly behaved as a friction pile and the extremely partial case pile foundation behaved as a combined load bearing pile.

Seismic Design and Analysis of Seismically Isolated KALIMER Reactor Structures (면진된 KALIMER 원자로 구조물의 내진설계 및 지진해석)

  • 이형연
    • Journal of the Earthquake Engineering Society of Korea
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    • v.3 no.1
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    • pp.75-92
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    • 1999
  • In this paper, the seismic analysis model for seismically isolated KALIMER reactor structures is developed and the modal analysis and the seismic time history analysis are carried out for seismic isolation and non-isolation cases. To check the seismic stress limit according to the ASME Code, the equivalent seismic stress analyses are preformed using the 3-D finite element model. From the seismic stress analysis, the seismic margins are calculated for structural members. The limit of seismic load is defined to show that the maximum input acceleration ensures the structural safety for seismic load. In comparison of seismic responses between seismic isolation and non-isolation cases, the seismic isolation design gives significantly reduced acceleration responses and relative displacements between structures. The seismic margin of KALIMER reactor structure is high enough to produce the limit seismic load 0.8g.

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Strength assessment method of ice-class propeller under the design ice load condition

  • Ye, L.Y.;Guo, C.Y.;Wang, C.;Wang, C.H.;Chang, X.
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.11 no.1
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    • pp.542-552
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    • 2019
  • The strength assessment is the most important part at the design of ice-class propeller. Based on ice rules for ice-class propeller in IACS URI3 and FEM, the strength assessment method of ice-class propeller is established in this paper. To avoid the multifarious meshing process of propeller blade, an automatic meshing method has been developed by dividing the propeller geometry into a number of 8-node hexahedron elements along radial, chordwise and thickness directions, then the loaded areas in five cases can easily be calculated and identified. The static FEM is applied to calculate the stress and deformation of propeller blade. The fair agreements between the results of the present method and ANSYS/Workbench demonstrate its robust and the feasibility, and also the method is able to produce smooth gradient field. The blade stress and deformation distributions for five load cases are studied, and then the strength of the whole blade is checked.

Elastic Critical Load and Effective Length Factors of Continuous Compression Member by Beam Analogy Method

  • Lee, Soo-Gon;Kim, Soon-Chul
    • Architectural research
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    • v.2 no.1
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    • pp.47-54
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    • 2000
  • The critical load of a continuous compression member was determined by the beam-analogy method. The proposed method utilizes the stress-analysis results of the analogous continuous beam, where imaginary concentrated lateral load changing its direction is applied at each midspan. The proposed method gives a lower bound error of critical load and can predict the span that buckles first. The effective length factors for braced frame columns can be easily determined by the present method, but result in the upper bound errors in all cases, which can lead to a conservative structural design.

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Load Carrying Capacity of Back-to-Back Reinforced Soil Walls (Back-to-Back 보강토 옹벽의 하중지지 특성)

  • Yoo, Chung-Sik;Kim, Sun-Bin
    • Journal of the Korean Geotechnical Society
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    • v.24 no.12
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    • pp.41-52
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    • 2008
  • This paper concerns the load carrying capacity of back-to-back reinforced soil wall for use in roadway and railway construction. Two test conditions, designed with due consideration of the FHW A design guideline, were first developed and a number of cases having different reinforcement lengths were tested under a surchage loading until failure. The results indicated that for cases in which two sides of reinforcements do not overlap, the wall behavior was similar to those of single wall. For cases in which the reinforcements overlap each other, on the other hand, the load carrying capacity of the wall significantly decreased when reinforced with reinforcement layers having lengths less than 50% of the wall height.

Estimation Method of the Design Wind Load of Soundproof Wall Using GIS (GIS를 이용한 방음벽의 설계풍하중 산정방법)

  • Lee, Dong-Ho;Choi, Se-Hyu
    • Spatial Information Research
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    • v.23 no.5
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    • pp.75-85
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    • 2015
  • Recently deformed or destroyed of soundproof wall by local winds and typhoon has increased. This research proposed the estimation method of the design wind load of soundproof wall using spatial information analysis based on 1:5,000 digital map and performed comparative analysis with actual application cases. According to the result of quantitative evaluation using GIS, the surface roughness in the downtown area packed with buildings was III and the surface roughness in the suburban district with a relatively small number of buildings was II and the surface roughness in the district packed with open areas and typical farmhouses was I. This shows that the wind load of the soundproof walls reflecting the actual surface conditions was estimated. If the quantitative GIS analysis presented in this study is applied to wind-resistant design of soundproof walls, it is supposed that this will be helpful in more rational wind-resistant design by remedying the existing problem in which the wind load varies depending on designer's subjectivity.