• Title/Summary/Keyword: finite-deflections

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Review of Transverse Steel Design in Continuously Reinforced Concrete Pavement through Finite Element Analysis (유한요소해석을 이용한 연속철근콘크리트 포장의 횡방향 철근 설계 검토)

  • Choi, Pangil;Ha, Soojun;Chon, Beom Jun;Kil, Yong Su;Won, Moon-Cheol
    • International Journal of Highway Engineering
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    • v.16 no.2
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    • pp.25-34
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    • 2014
  • PURPOSES : This paper numerically evaluates the contribution of transverse steel to the structural behavior of continuously reinforced concrete pavements to understand the role of transverse steel. METHODS : Two-lane continuously reinforced concrete pavements with and without transverse steel were analyzed through finite element analysis with the aid of commercial finite element analysis program DIANA; the difference in their structural behavior such as deflection, joint opening, and stress distribution was then evaluated. Twenty-node brick elements and three-node beam elements were used to model concrete and steel, respectively. Sub-layers were modeled with horizontal and vertical tensionless spring elements. The interactions between steel and surrounding concrete were considered by connecting their nodes with three orthogonal spring elements. Both wheel loading and environmental loading in addition to self-weight were considered. RESULTS : The use of transverse steel in continuously reinforced concrete pavements does not have significant effects on the structural behavior. The surface deflections change very little with the use of transverse steel. The joint opening decreases when transverse steel is used but the reduction is quite small. The transverse concrete stress, rather, increases when transverse steel is used due to the restraint exerted by the steel but the increase is quite small as well. CONCLUSIONS : The main role of transverse steel in continuously reinforced concrete pavements is supporting longitudinal steel and/or controlling unexpected longitudinal cracks rather than enhancing the structural capacity.

A study of the analysis of shaft alignment considering hull deflections for 50,000 DWT oil/chemical tankers (5만 DWT 석유화학제품운반선의 선체변형을 고려한 추진축계 정렬해석 연구)

  • Lee, Jae-Ung
    • Journal of Advanced Marine Engineering and Technology
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    • v.40 no.3
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    • pp.191-197
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    • 2016
  • The shaft system of a vessel becomes stiffer because of larger engine power, whereas the hull structure becomes more flexible because of scantling optimization conducted by using high-tensile thick steel plates. The draught-dependent deformation of the hull affects each bearing offset and reaction force comprising the subsequent shaft system. This is the reason that more sophisticated shaft alignments are required. In this study, an FE analysis performed under the expected operating conditions of two (2) vessels, as maximum draught change and to analyze the shaft alignment using the relative bearing offset change, which was derived from an FE analysis of the 50,000 DWT oil/chemical tanker, which has become an eco-friendly vessel in recent years. Based on this, the influence of the hull deflection on the bearing offset was reviewed against results for shaft alignment conditions.

Effects of Flexural Rigidity of Center Tower in Four-Span Suspension Bridges (4경간 현수교에서의 중앙주탑 휨강성의 영향)

  • Gwon, Sun-Gil;Yoo, Hoon;Choi, Dong-Ho
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.34 no.1
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    • pp.49-60
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    • 2014
  • For simple and accurate analysis for behaviors of multi-span suspension bridges which are expected to be frequently constructed as strait-crossing bridges, the deflection theory as the peculiar theory of a suspension bridge can be applied. This paper performs a structural analysis for four-span suspension bridges using the deflection theory. Simply-supported beams with tension are used for girders and the deflections of the beams due to the vertical loads and moments at supports are calculated. The calculation is performed iteratively until the deflections satisfy the compatibility equations of cables. The results of the deflection theory analysis considering tower rigidity are compared with those of the finite element analysis for verification. Importance of the tower rigidity for four-span suspension bridges is confirmed using various compatibility equations of the cable due to variation of the constraint conditions between main cable and top of towers. In addition, the simple parametric analysis for variation of the center tower rigidity is performed.

The behaviour of structures under fire - numerical model with experimental verification

  • Toric, Neno;Harapin, Alen;Boko, Ivica
    • Steel and Composite Structures
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    • v.15 no.3
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    • pp.247-266
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    • 2013
  • This paper presents a comparison of results obtained by a newly developed numerical model for predicting the behaviour of structures under fire with experimental study carried out on heated and simply supported steel beam elements. A newly developed numerical model consists of three submodels: 3D beam model designed for calculating the inner forces in the structure, 2D model designed for calculation of stress and strain distribution over the cross section, including the section stiffness, and 3D transient nonlinear heat transfer model that is capable of calculating the temperature distribution along the structure, and the distribution over the cross section as well. Predictions of the calculated temperatures and vertical deflections obtained by the numerical model are compared with the results of the inhouse experiment in which steel beam element under load was heated for 90 minutes.

A Study on the Copper Bus-bar Drawing Dies using APDL/UIDL (APDL/UIDL을 이용한 동부스바 인발금형에 관한 연구)

  • Kwon H.H.;Lee J.R.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2001.11a
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    • pp.45-53
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    • 2001
  • Copper bus-bar is made by drawing process and used in many part of industry. When design drawing die for copper bus-bar, design factor is focused on the deformation of die-land by drawing force and shrink fit. In this paper, to determine shrink fit value is analyzed by automatic shrink fit analysis program, APDL/UIDL language in a commercial FEM package, ANSYS, has been developed that enables optimal design of the dies taking into account the elastic deflections generated in shrink fitting the die inserts and that caused by the stresses generated in the process and by using DEFORM software for drawing process analysis. This data can be processed as load input data for a finite element die-stress analysis. Process simulation and stress analysis are thus combined during the drawing die design. The stress analysis of the dies is used to determine optimized dimension of die-land.

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Bending Behaviors of CAS and CUS Thick-walled Composite Channel Beam (대칭 및 반 대칭으로 적층된 복합재료 채널 빔의 굽힘 거동)

  • Park, Mi-Jung;Chun, Heoung-Jae;Byun, Jun-Hyung
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2005.04a
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    • pp.167-171
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    • 2005
  • The thick open section composite beams are used extensively as load carrying members and stiffeners of structural elements. However, most of studies on thick composite beams are limited only to closed section beams. In this study, an open cross-section thick-walled composite beam model which includes coupled stiffness, transverse shear, and warping effects is suggested and the deflections associated with the thick-walled composite beams and thin-walled composite beams are obtained and compared with the finite element analysis results. The correlation between thin and thick walled composite beam was achieved for two different layup configurations which are the circumferentially asymmetric stiffness (CAS) and circumferentially uniform stiffness (CUS) beams.

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Bending and Torsional Behaviors of Thick Composite Channel Beam (두꺼운 복합재료 채널빔의 굽힘 및 비틀림 거동)

  • Park, Mi-Jung;Choi, Yong-Jin;Chun, Heung-Jae;Byun, Joon-Hyung
    • Proceedings of the KSME Conference
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    • 2004.11a
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    • pp.480-485
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    • 2004
  • The applications of composite materials have increased over the past few decades in a variety of structures that require high ratio of stiffness and strength to weight ratios. Recently the thick open section composite beams are used extensively as load carrying members and stiffeners of structural elements. However, most of studies on thick composite beams are limited only to closed section beams. In this study, an open cross-section thick-walled composite beam model which includes coupled stiffness, transverse shear, and warping effects is suggested and the deflections associated with the thick-walled composite beams and thin-walled composite beams are obtained and compared with the finite element analysis results.

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Die Design of Drawing for the Copper Bus-bar (동부스바 인발 금형설계)

  • 권혁홍;이정로
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.11 no.4
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    • pp.82-88
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    • 2002
  • Copper bus-bar is made by drawing process and used in many part of industry. Ohen design drawing die for copper bus-bar, design factor is focused on the deformation of die-land by drawing force and shrink fit. In this paper it is analyzed to determine shrink fit value by shrink fit analysis program which is used with APDL/UIDL language in a commercial FEM package, ANSYS. The shrink fit analysis has been developed that enables optimal desist of the dies taking into account the elastic deflections. Elastic deflection is generated in shrink fitting the die inserts and that caused by the stresses generated using DEFORM software for drawing process analysis. This data can be processed as load input data fir a finite element die-stress analysis. Process simulation and stress analysis are thus combined during the drawing die design. The stress analysis of the dies is used to determine optimized dimension of die-land.

Large Deflection Analysis of Plates By Using Small Local Deflections And Rotational Unit Vectors (미소 변형 및 회전 단위 벡터를 이용한 판의 대변형 해석)

  • 이기수
    • Journal of the Korean Society for Precision Engineering
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    • v.17 no.2
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    • pp.201-210
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    • 2000
  • The large deflection of plate is analyzed by co-rotational formulations using small local displacements and rotating unit vectors on the nodal points. The rotational degrees of the freedom are represent ed by the unit vectors1 In the nodal points, and the equilibrium equations are formulated by using small deflection theories of the plates by assuming that the directions of the unit vectors of the nodal points are known apriori. The translational degrees of freedom are independently solved from the rotational degrees of freedom in the equilibrium equations, and the correct directions of the unit vectors are computed by the iterative scheme by imposing the moment equilibrium constraint. The equilibrium equations and the associated solution procedure are explained, and the verification problems are solved.

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Analysis of Box Girder Bridge for Finte Element Method (유한요소법(有限要素法)에 의한 상자항교(箱子桁橋)의 해석(解析))

  • Jang, In Ho;Choi, We Ho
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.9 no.2
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    • pp.11-22
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    • 1989
  • The finite element utilizing isoparametric plate element is applied for the elastic analysis of straight box girder bridges. A continuous box girder is analyzed as an example to verify the validity and accuracy of this method. It is indicated that the deflections and longitudinal stresses obtained by this method agree well with those from the orther methods. This theory may, therefore, be directly used as an efficient tool to analyze and design box girder bridges subjected to arbitrary loading and boundary conditions.

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