• Title/Summary/Keyword: 등가탄성해석방법

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A Simplified Analysis Method of GFRP Composites Deck (GFRP 복합소재 바닥판의 간편해석법)

  • Son, Byung Jik;Ji, Hyo Seon
    • Journal of Korean Society of Steel Construction
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    • v.25 no.4
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    • pp.359-368
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    • 2013
  • This paper presents a simplified analysis method using the elastic equivalent modelling not using the global finite element modelling of deck for the basic design GFRP composites deck with cellular tubes or sandwich structural type. In order to verify the validation of the simplified method ANSYS software package is used and compared the results analyzed on the global finite element modelling and the elastic equivalent modelling. And the laboratory testing by 4-point bending is conducted to compare the results based on the simplified analysis method proposed in this paper. The comparison of the results based on the analysis and the testing are discussed. It is found that the presented simplified analysis is applicable to the use in the basic design GFRP composite deck.

Improved Modal Pushover Analysis of Multi-span Continuous Bridge Structures (다경간 연속 교량 구조물의 지진응답 평가를 위한 개선된 모드별 비탄성 정적 해석법에 관한 연구)

  • Kwak, Hyo-Gyoung;Hong, Seong Jin;Kim, Young Sang
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.3A
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    • pp.497-512
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    • 2006
  • In this paper, a simple but effective analysis procedure to estimate seismic capacities of multi-span continuous bridge structures is proposed on the basis of modal pushover analysis considering all the dynamic modes of structure. Unlike previous studies, the proposed method eliminates the coupling effects induced from the direct application of modal decomposition by introducing an identical stiffness ratio and an approximate elastic deformed shape. Moreover, in addition to these two introductions, the use of an appropriate distributed load {P} makes it possible to predict the dynamic responses for all kinds of bridge structures through a simpler analysis procedure. Finally, in order to establish the validity and applicability of the proposed method, correlation studies between rigorous nonlinear time history analysis and the proposed method are conducted for multi-span continuous bridges.

Evaluation of Inelastic Displacement Response for Multi-Span Bridge Structures Subjected to Earthquakes (지진하중에 대한 다경간 교량의 비탄성 변위응답 평가)

  • Song, Jong-Keol;Nam, Wang-Hyun;Chung, Yeong-Hwa
    • Journal of Industrial Technology
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    • v.24 no.A
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    • pp.195-204
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    • 2004
  • To evaluate inelastic seismic responses of multi-span bridge structures, the capacity spectrum method(CSM) incorporating the equivalent single-degree-of freedom(ESDOF) method is presented. Application of the CSM incorporating the ESDOF method is illustrated by example analysis for symmetric and asymmetric bridge structures. To investigate an accuracy of the CSM, the maximum displacements estimated by the CSM are compared to those by inelastic time history analysis for several artificial earthquakes. The results show that the CSM provided conservative estimates of the maximum displacements for the symmetric and asymmetric bridge structures, and the trend of conservative estimates of the asymmetric bridge structures was significantly larger than that of the symmetric bridge structure.

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Buckling Analysis of Laminated Composite Trapezoidal Corrugated Plates (적층 복합재료 사다리꼴 주름판의 좌굴해석)

  • Park, Kyung-Jo;Kim, Young-Wann
    • Composites Research
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    • v.32 no.4
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    • pp.185-190
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    • 2019
  • This work investigates the elastic buckling characteristics of laminated composite trapezoidal corrugated plates with simply supported edges using the analytical method. In the analysis, three types of in-plane loading conditions: uniaxial, biaxial and shear loads are considered. Because it is very difficult to determine the mechanical behavior of 3-dimensional corrugated structures analytically, the equivalent homogenization model is adapted to investigate the overall mechanical behavior of corrugated plates. The corrugated element is homogenized as an orthotropic material. The previous formulae for bending rigidities of corrugated plate are adapted in this paper. The comparisons of the proposed analytical results with those of FEA based on the shell element are made to verify the proposed analytical method. In the comparison study both the critical buckling loads and the buckling mode shapes are presented. Some numerical results are presented to check the effect of the geometric properties.

An Effective Approach of Equivalent Elastic Method for Three-Dimensional Finite Element Analysis of Ceramic Honeycomb Substrates (세라믹 하니컴 담체의 3차원 유한요소해석을 위한 등가탄성방법의 효과적인 접근)

  • Baek, Seok-Heum;Cho, Seok-Swoo
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.35 no.3
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    • pp.223-233
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    • 2011
  • A ceramic monolithic catalyst is a honeycomb structure that consists of two layers. The honeycomb structure is regarded as a continuum in structure and heat-flow analysis. The equivalent mechanical properties of the honeycomb structure were determined by performing finite element analysis (FEA) for a test specimen. Bending strength experiments and FEA of the test specimen used in ASTM C1674-08 standard test were performed individually. The bonding coefficient between the cordierite ceramic layer and the washcoat layer was almost zero. The FEA test specimen was modeled on the basis of the bonding coefficient. The elastic modulus, Poisson's ratio, and the thermal properties of the ceramic monolithic substrate were determined by performing the FEA of the test specimen.

An Analytical Investigation on the Flexural Behavior of FRP Reinforced Concrete Slab by Orthotropic Plate Theory (직교이방성 판이론에 의한 FRP 보강 콘크리트 슬래브의 휨해석)

  • 손경욱;정재호;정상균;윤순종;이승식
    • Composites Research
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    • v.17 no.2
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    • pp.9-14
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    • 2004
  • In this study, analytical investigations on the flexural behavior of FRP reinforced concrete slab were discussed. In the derivation of analytic solution, the FRP reinforced concrete slab was modeled as a structural orthotropic plate. To determine the flexural rigidities of an orthotropic plate model, the elastic equivalence method was employed. In the finite element analysis, the approximate method to determine the rigidity matrix of orthotropic plate element was also suggested using the elastic equivalence method. The results obtained by the analytical solution and the finite element analysis were compared with that of experiment.

Equivalent Linear Stiffness Matrix of Pile Foundation for the Seismic Response Analysis of Bridges (교량의 지진응답해석을 위한 말뚝기초의 등가 선형 강도행렬)

  • 박형기;조양희
    • Journal of the Earthquake Engineering Society of Korea
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    • v.5 no.3
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    • pp.1-8
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    • 2001
  • Seismic design forces for bridge components may be determined by modifying elastic member forces of design earthquakes using appropriate response modification factors according to the national design code of bridges Modeling technique of pile foundation system is one of the important parameters which greatly affects the results in the process of the elastic seismic analysis of a bridge system with pile foundation. In this paper, a approximate and simplified modeling technique of a pile foundation system for the practical purposes is presented. The modeling technique is based on the stiffnesses of pile foundation during earthquake. The horizontal stiffnesses are determined from the resistance-deflection curves derived from the results of dynamic field tests using cyclic loads and the vertical stiffness includes the effects of the end bearing capacities and side friction of piles as well as the pile compliances under the expected vertical load level. The applicability of the proposed technique has been validated through the some example bridge analyses.

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Seismic Retrofit of Asymmetric.Elasto-Plastic Structure Using Viscous Dampers (점성감쇠기를 이용한 비대칭.비탄성구조물의 내진보강)

  • 김진구;방성혁
    • Journal of the Earthquake Engineering Society of Korea
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    • v.6 no.3
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    • pp.87-93
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    • 2002
  • A procedure for figuring out proper amount of additional viscous damping required to keep the inelastic deformation of a plan-wise asymmetric structure within a given target performance point was developed. To this end the behavior of an asymmetric nonlinear structure after yielding is investigated. Then a formula for the required amount of equivalent damping was derived based on the ductility demand of the structure. The procedure was applied to a five-story asymmetric structure subjected to an earthquake load. According to the comparison with the results from the dynamic time-history analysis, the structure with viscous dampers installed in accordance with the proposed procedure showed satisfactory seismic performance in both the stiff and the flexible edges.

Prediction of Member Plastic Rotation Demands for Earthquake Design of Moment Frames (모멘트골조의 내진설계를 위한 부재 소성변형 요구량 예측)

  • Eom, Tae-Sung;Park, Hong-Gun
    • Journal of the Earthquake Engineering Society of Korea
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    • v.13 no.5
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    • pp.51-60
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    • 2009
  • To secure the structural safety of structures and members against earthquakes, the plastic deformation capacity demand of members should be accurately predicted. In the present study, a method for the evaluation of the plastic deformations of members for moment frames was developed. To facilitate the practical use of the proposed method in equivalent seismic design, the plastic deformations of members were evaluated based on the results of elastic analysis, without using nonlinear analysis. The plastic deformation demands of members were formulated as functions of story drift demand, redistributed moment and member stiffness. Story drift demand and moment redistribution were directly determined from elastic analysis. The proposed method was applied to an 8 story-2 bay moment frame, and the predicted plastic deformations were verified using nonlinear analysis. The results showed that the proposed method could be used to accurately predict the member plastic rotations with simple calculations. The proposed method can be applied both to the earthquake design of new structures and to the performance evaluation of existing structures.

Seismic Performance Evaluation of Multi-Span Bridges considering Effect of Lateral Load Distributions and Equivalent SDOF methods (횡하중 분포와 등가단자유도 방법의 영향을 고려한 다경간 교량의 내진성능 평가)

  • Song, Jong-Keol;Nam, Wang-Hyun;Chung, Yeong-Hwa
    • Journal of Industrial Technology
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    • v.26 no.A
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    • pp.163-171
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    • 2006
  • To evaluate inelastic seismic responses of multi-span-bridge, the equivalent single-degree-of-freedom (ESDOF) methods and the lateral load distributions are applied to the capacity spectrum method(CSM). From the pushover analysis results using the four ESDOF methods and the six types lateral load distributions, the ESDOF method more than lateral load distribution is found to have an important influence upon the pushover analysis. The effects of the higher mode on the bridge seismic behaviors are also increased as the number of pier increase. Therefore, it can be concluded that lateral load distributions and ESDOF methods for reflection of higher mode effects should be considered in the seismic analysis of the bridge structural.

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