• Title/Summary/Keyword: three-dimensional nonlinear analysis

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Three dimensional seismic and static stability of rock slopes

  • Yang, X.L.;Pan, Q.J.
    • Geomechanics and Engineering
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    • v.8 no.1
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    • pp.97-111
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    • 2015
  • The kinematical approach of limit analysis is used to estimate the three dimensional stability analysis of rock slopes with nonlinear Hoek-Brown criterion under earthquake forces. The generalized tangential technique is introduced, which makes limit analysis apply to rock slope problem possible. This technique formulates the three dimensional stability problem as a classical nonlinear programming problem. A nonlinear programming algorithm is coded to search for the least upper bound solution. To prove the validity of the present approach, static stability factors are compared with the previous solutions, using a linear failure criterion. Three dimensional seismic and static stability factors are calculated for rock slopes. Numerical results of indicate that the factors increase with the ratio of slope width and height, and are presented for practical use in rock engineering.

Interface Design of Virtual Modeling Dataand Nonlinear Analysis Program (Virtual Modeling Data와 비선형 해석 프로그램의 Interface 설계)

  • Park, Jae-Guen;Lee, Heon-Min;Jo, Sung-Hoon;Lee, Kwang-Myong;Shin, Hyun-Mock
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2008.04a
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    • pp.100-103
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    • 2008
  • Recently Development of construction system that subjective operators share and control information efficiently based on the three-dimensional space and design information throughout life cycle of construction project is progressing dynamically. In case of civil structures which are infrastructure, Demand for structure of complex system which has multi-functions such as super and smart bridges and express rails is increasing and system development which computerizes and integrates process of structure design is in need. For that, research about link way between three dimensional modeling data and structure analysis programs should be preceded. In this research, therefore, research about interface design between three dimensional virtual modeling data to automate efficient civil-structure-design and nonlinear finite element analysis program which is made up of reinforced concrete material model that express material's character clearly.

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Fibered Element for the Three-Dimensional Nonlinear Analysis of Prestressed Concrete Frames (PSC 뼈대의 3차원 비선형 해석을 위한 화이버 모델 요소)

  • 이재석;최규천
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2003.10a
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    • pp.195-201
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    • 2003
  • A fibered element for the material and geometric nonlinear analysis of three-dimensional reinforced and prestressed concrete frame is presented. The fibered frame element is idealized as an assemblage of concrete and reinforcing steel fibers in order to account for varied material properties within the cross section of the frame element through elastic, cracking and ultimated stages of materials. Prestressing tendon is modeled as an assemblage of multilinear prestressing steel segments each of which spans a frame element. The contribution of each prestressing steel is added directly to the fibered frame element. Numerical results from the ultimate analysis of three-dimensional PSC box girder are compared with those obtained from other investigator. The validity and the capability of the present nonlinear analysis model is well demonstrated.

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Three-Dimensional Seismic Analysis for Spent Fuel Storage Rack

  • Lee, Gyu-Mahn;Kim, Kang-Soo;Park, Keun-Bae;Park, Jong-Kyun
    • Nuclear Engineering and Technology
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    • v.30 no.2
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    • pp.91-98
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    • 1998
  • Time history analysis is usually performed to characterize the nonlinear seismic behavior of a spent fuel storage rack(SFSR). In the past, the seismic analyses of the SFSR were performed with two-dimensional planar models, which could not account for torsional response and simultaneous multi-directional seismic input In this study, three-dimensional seismic analysis methodology is developed for the single SFSR using the ANSYS code. The 3D- Model can be used to determine the nonlinear behavior of the rack, i.e., sliding, uplifting, and impact evaluation between the fuel assembly and rack, and rack and the pool wall, This paper also reviews the 3-D modeling of the SFSR and the adequacy of the ANSYS for the seismic analysis. AS a result of the adquacy study, the method of ANSYS transient analysis with acceleration time history is suitable for the seismic analysis of highly nonlinear structure such as an SFSR but it isn't appropriate to use displacement time history of seismic input.

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An Analysis of three-dimensional collision probability according to approaching objects to the KOMPSAT series (아리랑 위성들의 경향에 따른 및 3차원 충돌확률 분석)

  • Seong, Jae-Dong;Kim, Hae-Dong;Lim, Seong-Min
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.41 no.2
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    • pp.156-163
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    • 2013
  • Collision probability is the most common method to measure the risk of space debris, it is widely used that two dimensional linear collision probability using the closest approach distance. This paper represents the characteristics of object that approach KOMPSAT 2, 3, 5 that have operated or will be operated by Korea. And more precise method than two dimensional linear collision probability, we analyzed the properties of three dimensional nonlinear collision probability using STK/Nonlinear Collision Probability Tool. Through this, efficiency of three dimensional nonlinear collision probability for KOMPSAT series satellites was investigated. The result represents that three dimensional nonlinear collision probability showed the precise outcome at a relative velocity of less than 350m/s. Also, KOMPSAT series satellites appeared to few low relative velocity approaches and showed low efficiency for the three dimensional nonlinear collision probability.

Three-dimensional limit analysis of seismic stability of tunnel faces with quasi-static method

  • Zhang, B.;Wang, X.;Zhang, J.S.;Meng, F.
    • Geomechanics and Engineering
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    • v.13 no.2
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    • pp.301-318
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    • 2017
  • Based on the existing research results, a three-dimensional failure mechanism of tunnel face was constructed. The dynamic seismic effect was taken into account on the basis of quasi-static method, and the nonlinear Mohr-Coulomb failure criterion was introduced into the limit analysis by using the tangent technique. The collapse pressure along with the failure scope of tunnel face was obtained through nonlinear limit analysis. Results show that nonlinear coefficient and initial cohesion have a significant impact on the collapse pressure and failure zone. However, horizontal seismic coefficient and vertical seismic proportional coefficient merely affect the collapse pressure and the location of failure surface. And their influences on the volume and height of failure mechanism are not obvious. By virtue of reliability theory, the influences of horizontal and vertical seismic forces on supporting pressure were discussed. Meanwhile, safety factors and supporting pressures with respect to 3 different safety levels are also obtained, which may provide references to seismic design of tunnels.

Numerical analysis of a three-dimensional turbulent wall-jet flow (3차원 난류 벽면제트 유동의 수치해석)

  • Ryu, S.Y.;Choi, D.H.;Kim, S.J.
    • Proceedings of the KSME Conference
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    • 2000.04b
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    • pp.479-484
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    • 2000
  • A Navier-stokes based finite volume method has been developed to analyze an incompressible, steady state, turbulent wall-jet flow. The standard k-e model, the RNG ${\kappa}-{\varepsilon}$ model and their nonlinear counterparts are adopted as a closure relationship. Comparison with the experimental data shows that a linear ${\kappa}-{\varepsilon}$ model performs satisfatorily for two-dimensional wall-jet flows. However, as the flow becomes three dimensional, the linear model fails to predict the spanwise jet growth accurately and the nonlinear model needs to be adopted to capture three-dimensional flow characteristics.

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A Three-Dimensional Material Nonlinear Analysis of Reinforced Concrete (철근콘크리트의 3차원 재료비선형해석)

  • 박성수;성재표
    • Magazine of the Korea Concrete Institute
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    • v.8 no.2
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    • pp.119-127
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    • 1996
  • Objection of this study is to present the three-dimensional material nonlinear analysis of reinforced concrete. A concrete is idealized with three-dimensional 16-node solid element including triaxial nonlinear stress-strain behavior, cracking, crushing and strain softening: a steel with three-dimensional 3 node truss element including elastic-plastic behavior with strain hardening. The cracked shear retention factor is introduced to estimate the effective shear modulus con sidering aggregate interlock after c:racking and a modified newton method is used to obtain a nu merical solution. Numerical results in a gauss point is displayed graphically. Numerical examples of Krahl's reinforced concrete beam and Hedgreds shell are selected to compare with the experimental and numerical results.

Nonlinear Inelastic Optimal Design Using Genetic Algorithm (유전자 알고리즘을 이용한 비선형 비탄성 최적설계)

  • 마상수;김승억
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2003.10a
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    • pp.145-152
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    • 2003
  • An optimal design method in cooperated with nonlinear inelastic analysis method is presented. The proposed nonlinear inelastic method overcomes the difficulties due to incompatibility between the elastic global analysis and the limit state member design in the conventional LRFD method. The genetic algorithm uses a procedure based on Darwinian notions of survival of the fittest, where selection, crossover, and mutation operators are used among sections in the database to look for high performance ones. They satisfy the constraint functions and give the lightest weight to the structure. The objective function is set to the total weight of the steel structure and the constraint functions are load-carrying capacities, serviceability, and ductility requirement. Case studies of a three-dimensional frame and a three-dimensional steel arch bridge are presented.

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Enhanced finite element modeling for geometric non-linear analysis of cable-supported structures

  • Song, Myung-Kwan;Kim, Sun-Hoon;Choi, Chang-Koon
    • Structural Engineering and Mechanics
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    • v.22 no.5
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    • pp.575-597
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    • 2006
  • Enhanced three-dimensional finite elements for geometrically nonlinear analysis of cable-supported structures are presented. The cable element, derived by using the concept of an equivalent modulus of elasticity and assuming the deflection curve of a cable as catenary function, is proposed to model the cables. The stability functions for a frame member are modified to obtain a numerically stable solution. Various numerical examples are solved to illustrate the versatility and efficiency of the proposed finite element model. It is shown that the finite elements proposed in this study can be very useful for geometrically nonlinear analysis as well as free vibration analysis of three-dimensional cable-supported structures.