• Title, Summary, Keyword: slope-deflection method

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Transverse Strength of Oli Tanker Using S.D.M (Slope-Deflection Method에 의한 유조선의 횡강도 해석)

  • S.J.,Yim;S.J.,Kang
    • Bulletin of the Society of Naval Architects of Korea
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    • v.22 no.4
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    • pp.17-27
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    • 1985
  • In this paper, an approximate calculation method on the transverse strength of oil tankers by use of slop-deflection method os described which considers the effect of shear deflection and varing section in elements and the result of calculation in models and actual ships, is presented. The object of this paper is focused on the development of program which can be used widely regardless strut numbers in transverse frame rings. To examine the reliability of the above method, the results in this paper are compared with the results which are obtained by use of SAP4(Structure Analysis Program) based on finite element method. The application of the Slope-Deflection Method on the transverse strength of oil tankers has the advantage that this method takes less than the other methods in calculation.

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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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Expansion Spool Design of an Offshore Pipeline by the Slope Deflection Method

  • Choi, Han-Suk;Do, Chang-Ho;Na, Young-Jang
    • Journal of Ocean Engineering and Technology
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    • v.24 no.5
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    • pp.1-7
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    • 2010
  • Offshore, sub-sea pipelines that transport oil and gas experience thermal expansion induced by the temperature of the transported medium during operation. The expansion of the pipeline can induce overload and cause damage to offshore platforms or sub-sea structures that are connected to the pipelines. To mitigate and prevent these incidents, expansion spools are installed between offshore, sub-sea pipelines and risers on the platform. This paper presents the results of the study and development of a simplified design method for expansion spools, using the slope deflection method for the purpose of preliminary design or front-end engineering and design (FEED).

Slope variation effect on large deflection of compliant beam using analytical approach

  • Khavaji, A.;Ganji, D.D.;Roshan, N.;Moheimani, R.;Hatami, M.;Hasanpour, A.
    • Structural Engineering and Mechanics
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    • v.44 no.3
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    • pp.405-416
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    • 2012
  • In this study the investigation of large deflections subject in compliant mechanisms is presented using homotopy perturbation method (HPM). The main purpose is to propose a convenient method of solution for the large deflection problem in compliant mechanisms in order to overcome the difficulty and complexity of conventional methods, as well as for the purpose of mathematical modeling and optimization. For simplicity, a cantilever beam of linear elastic material under horizontal, vertical and bending moment end point load is considered. The results show that the applied method is very accurate and capable for cantilever beams and can be used for a large category of practical problems for the aim of optimization. Also the consequence of effective parameters on the large deflection is analyzed and presented.

On the Calculation of 3-Dimensional Strength of Oil Tanker by Slope -Deflection Method (기울기-처짐법에 의한 유조선의 입체 강도 해석)

  • S.J.,Yim;J.H.,Kim
    • Bulletin of the Society of Naval Architects of Korea
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    • v.23 no.3
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    • pp.27-38
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    • 1986
  • In the recent years, the finite element method has been a leading method in calculating the strength of ship hull structural members. But such a calculation has many difficulties in constructing data, reducing CPU-time and connecting it with optimal design. This paper describes more efficient method for three dimensional strength calculation of the hull structure of oil tanker by using the slope-deflection method, and the computer program based on this method is developed. The results of the calculation by using this method are compared with those by using the SAP4 program based on the finite element method. Some advantages are obtained from the application of the slop-deflection method described in this paper in the calculation of the hull structure oil tanker.

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Minimum Weight Design of Transverse Frames of Oil Tankers by Generalized Slope Deflection Method (일반화 경사처짐법에 의한 유조선 횡강도 부재의 최소 중량 설계)

  • Chang-Doo Jang;Seung-Soo Na
    • Journal of the Society of Naval Architects of Korea
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    • v.33 no.3
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    • pp.103-111
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    • 1996
  • A generalized slope deflection method has already been developed by the authors from the existing one, and applied to the 3-dimensional structural analysis of tankers idealized as frame models to verify the effectiveness of the method from the analysis viewpoint. In this study, a minimum hull weight design program of tankers is developed to verify the effectiveness of the method from the design viewpoint by the combination of generalized slope deflection method and optimization method considering discrete design variables. By this program, it is possible to determine the scantling of each member of actual tankers that give minimum weight under given constraints. Also, a considerable weight saving has been found compared with existing ship.

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Effect of higher order terms of Maclaurin expansion in nonlinear analysis of the Bernoulli beam by single finite element

  • Zahrai, Seyed Mehdi;Mortezagholi, Mohamad Hosein;Mirsalehi, Maryam
    • Structural Engineering and Mechanics
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    • v.58 no.6
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    • pp.949-966
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    • 2016
  • The second order analysis taking place due to non-linear behavior of the structures under the mechanical and geometric factors through implementing exact and approximate methods is an indispensible issue in the analysis of such structures. Among the exact methods is the slope-deflection method that due to its simplicity and efficiency of its relationships has always been in consideration. By solving the differential equations of the modified slope-deflection method in which the effect of axial compressive force is considered, the stiffness matrix including trigonometric entries would be obtained. The complexity of computations with trigonometric functions causes replacement with their Maclaurin expansion. In most cases only the first two terms of this expansion are used but to obtain more accurate results, more elements are needed. In this paper, the effect of utilizing higher order terms of Maclaurin expansion on reducing the number of required elements and attaining more rapid convergence with less error is investigated for the Bernoulli beam with various boundary conditions. The results indicate that when using only one element along the beam length, utilizing higher order terms in Maclaurin expansion would reduce the relative error in determining the critical buckling load and kinematic parameters in the second order analysis.

Finite Elements Analysis Application to the Structural Design of the Frame Type Furniture (골조형(骨造型) 가구구조설계(家具構造設計)에의 유한요소해석 응용)

  • Chung, Woo-Yang;Eckelman, Carl A.
    • Journal of the Korean Wood Science and Technology
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    • v.23 no.3
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    • pp.8-15
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    • 1995
  • This analytical study was carried out to make quality and productivity up in designing the frame-type furniture with semi-rigid joint by understanding the mechanical and structural behavior of the joint and by evaluating the validity of application of the time-saving Finite Element Method to its structural analysis. Slope deflection equation for rigid joint was modified to describe the moment-rotation behavior of semi-rigid joint and the joint stiffness factor(Z) could be calculated to lessen the experimental expense. It was proved that Finite Element Analysis with imaginary elements having equivalent MOE to the semi-rigid joint could be the alternative method for the structural analysis of the frame-type furniture, comparing the internal rotation of the 2-dimensional beam-to-column model with two-pin(wooden dowel) from the finite element method with other available theoretical and experimental rotation value.

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Numerical method to determine the elastic curve of simply supported beams of variable cross-section

  • Biro, Istvan;Cveticanin, Livija;Szuchy, Peter
    • Structural Engineering and Mechanics
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    • v.68 no.6
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    • pp.713-720
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    • 2018
  • In this paper a new numerical method to determine the elastic curve of the simply supported beams of variable cross-section is demonstrated. In general case it needs to solve linear or small nonlinear second order differential equations with prescribed boundary conditions. For numerical solution the initial values of the slope and the deflection of the end cross-section of the beam is necessary. For obtaining the initial values a lively procedure is developed: it is a special application of the shooting method because boundary value problems can be transformed into initial value problems. As a result of these transformations the initial values of the differential equations are obtained with high accuracy. Procedure is applied for calculating of elastic curve of a simply supported beam of variable cross-section. Results of these numerical procedures, analytical solution of the linearized version and finite element method are compared. It is proved that the suggested procedure yields technically accurate results.

Deformation Behavior and Slope Stability Effect of Anchored Retention Walls Installed in Cut Slope (절개사면에 설치된 앵커지지 합벽의 변형거동 및 사면안정효과)

  • Hong Won-Pyo;Han Jung-Geun
    • Journal of the Korean Geotechnical Society
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    • v.20 no.9
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    • pp.57-64
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    • 2004
  • In order to establish the design method of anchored retention walls in cut slope, the behavior of anchored retention walls and backside ground needs to be investigated and checked in detail. In this study, the behavior of anchored retention walls was investigated by instrumentation installed in cut slope for an apartment construction site stabilized by a row of piles and anchored retention walls. When the anchor was installed at each excavating stages, the horizontal deflection of retention wall decreased, while the horizontal deformation of backside ground increased. The deflection of anchored retention wall decreased as the anchor was prestressed. The prestressed anchor farce has a great effect on the deflection of retention walls, while it has little effect on the deformation of its backside ground. The maximum horizontal deflection of anchored retention walls was developed between $1\%\;and\;4\%$ of excavation depth, which are $2\~8$ times larger than max. horizontal deflection of anchored retention walls including rock layers with backside horizontal ground. Meanwhile, SLOPILE (ver. 3.0) program analyzes the slope stability effects for anchored retention walls. As a result of analysis on slope stability analysis, the lateral earth pressure applied at anchored retention piles could be used as the mean values of empirical lateral pressures using anchored retention wall with horizontal ground at its backside.