• Title, Summary, Keyword: infinite elements

Search Result 171, Processing Time 0.053 seconds

Cuboidal Infinite Elements for Soil-Structure-Interaction Analysis in Multi-Layered Half-Space (3차원 지반-구조물 상호작용해석을 위한 입방형 무한요소)

  • Seo, Choon-Gyo;Yun, Chung-Bang;Kim, Jae-Min
    • Journal of the Computational Structural Engineering Institute of Korea
    • /
    • v.20 no.1
    • /
    • pp.39-50
    • /
    • 2007
  • This paper presents 3D infinite elements for the elastodynamic problem with multi-layered half-space. Five different types of infinite elements are formulated by using approximate expressions of multiple wave components for the wave function in multi-layered soil media. They are horizontal, horizontal-corner, vortical, vertical-corner and vertical-horizontal-comer infinite elements. The elements can effectively be used for simulating wane radiation problems with multiple wave components. Numerical example analyses are presented for rigid disk, square footings and embedded footing on homogeneous and layered half-space. The numerical results show the effectiveness of the proposed infinite elements.

3-DIMENSIONAL DYNAMIC INFINITE ELEMENTS IN CARTESIAN COORDINATES FOR MULTI-LAYERED HALF-SPACE (3차원 수직 좌표계의 지반-구조물 상호작용해석을 위한 동적 무한요소의 개발)

  • Seo, Choon-Gyo;Yun, Chung-Bang
    • Proceedings of the Earthquake Engineering Society of Korea Conference
    • /
    • /
    • pp.628-636
    • /
    • 2006
  • This paper presents 3D infinite elements in Cartesian coordinates for the elastodynamic problem in multi-layered half-space. Five kinds of infinite elements are developed by using approximate expressions of multiple wave components for the wave function in exterior far-field soil region. They are horizontal, horizontal-corner, vertical, vertical-corner and vertical-horizontal-corner elements. The elements can be used for the multi-wave propagating problem. Numerical example analyses are presented for rigid disk, square footings and embedded footing on homogeneous and layered half-space. The numerical results obtained show the effectiveness of the proposed infinite elements.

  • PDF

THREE-DIMENSIONAL INFINITE ELEMENTS FOR WAVE FORCE EVALUATION ON OFFSHORE STRUCTURES (해양구조물의 파력산정을 위한 3-차원 무한요소)

  • Park, Woo-Sun;Yoon, Chung-Bang;Pyun, Chong-Kun
    • Proceedings of the Computational Structural Engineering Institute Conference
    • /
    • /
    • pp.8-14
    • /
    • 1991
  • The finite element technique incorporating infinite elements is applied to analyzing the general three dimensional wave-structure interaction problems within the limits of linear wave theory. The hydrodynamic farces are assumed to be inertially dominated, and viscous effects are neglected. In order to analyze the corresponding boundary value problems efficiently, two types of elements are developed. One is the infinite element for modeling the radiation condition at infinity, and the other is the fictitious bottom boundary element for the case of deep water. To validate those elements, numerical analyses are performed for several floating structures. Comparisons with the results from culler available solution methods show that the present method incorporating tile infinite and the fictitious bottom boundary elements gives good results.

  • PDF

Infinite Elements for Analysis of Diffraction and Radiation Problems in the Vertical Plane (연직 2차원 회절 및 방사문제 해석을 위한 무한요소)

  • 박우선;이달수;오영민;정원무
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.3 no.4
    • /
    • pp.235-243
    • /
    • 1991
  • This paper is concerned with developing infinite elements which are applicable to wave diffraction and radiation problems in the vertical plane. The near need region surrounding the solid body is modeled using conventional finite elements. but the far fold region is represented using the infinite elements developed in this study. The shape functions for the infinite elements are derived from the analytical eigenseries solution of the scattered waves in the far field region. The system matrices of the elements are constructed by performing the integration in the infinite direction analytically to achieve computational efficiency. Numerical analysis is carried out for two floating bodies with different cross-sectional shapes to prove the efficiency and validity of the elements. Numerical experiments are also performed to determine the suitable location of the infinite elements which directly affect accuracy and efficiency of the solution.

  • PDF

Wave Scattering Analysis of Scatterers Submerged in Water by Using a Hybrid Numerical Approach (수중 산란체의 수치적 산란해석)

  • 김재환;김세환
    • The Journal of the Acoustical Society of Korea
    • /
    • v.19 no.4
    • /
    • pp.84-92
    • /
    • 2000
  • In this paper, numerical scattering analysis for submerged scatterers is performed using finite and infinite elements. Unbounded domain is truncated into finite domain and finite elements are used in the domain. Infinite elements, So called Infinite Wave Envelope Elements (IWEE) which possess wave-like behavior, are used to take into account the infinite domain on the truncated boundary Scattering from rigid sphere is taken as an example and the effects of the order and mesh size of finite elements, size of finite element model and the order of IWEE are investigated. Quadratic finite element, refined mesh and higher order IWEE are recommended to improve the non-reflection boundary condition in the numerical scattering analysis.

  • PDF

Stochastic FE analysis of semi-infinite domain using infinite elements (무한요소를 이용한 반무한영역의 추계론적 유한요소해석)

  • 최창근;노혁천
    • Proceedings of the Computational Structural Engineering Institute Conference
    • /
    • /
    • pp.11-18
    • /
    • 1998
  • In this paper the stochastic analysis of semi-infinite domain is presented using the weighted integral method, which is expanded to include the infinite finite elements. The semi-infinite domain can be thought as to have more uncertainties than the ordinary finite domain in material constants, which shows the needs of and the importance of the stochastic finite element analysis. The Bettess's infinite element is adopted with the theoretical decomposition of the strain matrix to calculate the deviatoric stiffness of the semi-infinite domains. The calculated value of mean and the covariance of the displacement are revealed to be larger than those given by the finite domain assumptions giving the rational results which should be considered in the design of structures on semi-infinite domains.

  • PDF

Infinite Elements for Soil-Structure Interaction Anaysis (지반-구조물의 상호작용 해석을 위한 무한요소)

  • 양신추;윤정방
    • Proceedings of the Computational Structural Engineering Institute Conference
    • /
    • /
    • pp.22-27
    • /
    • 1989
  • This paper presents a study of soil-structure interaction problems using infinite elements. The infinite elements are formulated for homogeneous and layered soil media, based on approximate expressions for three components of propagating waves, namely Rayleigh, compressive and shear waves. The integration scheme which was proposed for problems with single wave component by Zienkiewicz is expanded to the multi-wave problem. Verifications are carried out on rigid circular footings which are placed on and embedded in elastic half space. Numerical analysis is performed for a containment structure of a nuclear power plant subjected seismic excitation.

  • PDF

Approximate Wave Functions of Dynamic Infinite Elements for Multi-layered Halfspaces

  • Kim, J.M.;Yun, C.B.;Yang, S.C.
    • Proceedings of the Computational Structural Engineering Institute Conference
    • /
    • /
    • pp.193-198
    • /
    • 1993
  • This paper presents a systematic procedure to obtain shape functions of the infinite elements for soil-structure interaction analysis. The function spaces are derived from the analytical solutions and appropriate assumptions based on physical interpretation. The function spaces are complete for the surface wave components, but approximate for the body wave components. Three different infinite elements are developed by using the wave functions of the derived function spaces. Numerical example analysis is presented for demonstrating the effectiveness of the present infinite elements.

  • PDF

Development of Analytical Two Dimensional Infinite Elements for Soil-Structure Interaction Analysis (지반-구조물의 상호작용 해석을 위한 해석적 2차원 무한요소)

  • 윤정방;김두기
    • Proceedings of the Computational Structural Engineering Institute Conference
    • /
    • /
    • pp.19-26
    • /
    • 1997
  • In this paper, two dimensional analytical infinite elements which can include multiple wave components to model a underlying half-space are developed. Since these elements are expressed clearly and simply using Legendre polynomials of frequencies in frequency domain, these are very economical and efficient in computing the responses of strip foundations in frequency domain and are easily transformed for SSI analysis in time domain. To prove the behavior of the proposed two dimensional analytical infinite elements, vertical, horizontal, and rocking compliances of a rigid strip foundation in layered soils are analyzed and compared with those of Tzong ' Penzie $n^{(17)}$ and with those which calculated by numerical infinite elemen $t^{(1)}$ in frequency domain, and good agreements are noticed between them. As an application for a further study, a new scheme for SSI analysis in time domain are proposed and verified by comparing the displacement responses of the soil with a underlying rock due to a rectangular impulse loading with those of a soil modeled extended FE meshes.soil modeled extended FE meshes.

  • PDF

Efficient analysis of SSI problems using infinite elements and wavelet theory

  • Bagheripour, Mohamad Hossein;Rahgozar, Reza;Malekinejad, Mohsen
    • Geomechanics and Engineering
    • /
    • v.2 no.4
    • /
    • pp.229-252
    • /
    • 2010
  • In this paper, Soil-Structure Interaction (SSI) effect is investigated using a new and integrated approach. Faster solution of time dependant differential equation of motion is achieved using numerical representation of wavelet theory while dynamic Infinite Elements (IFE) concept is utilized to effectively model the unbounded soil domain. Combination of the wavelet theory with IFE concept lead to a robust, efficient and integrated technique for the solution of complex problems. A direct method for soil-structure interaction analysis in a two dimensional medium is also presented in time domain using the frequency dependent transformation matrix. This matrix which represents the far field region is constructed by assembling stiffness matrices of the frequency dependant infinite elements. It maps the problem into the time domain where the equations of motion are to be solved. Accuracy of results obtained in this study is compared to those obtained by other SSI analysis techniques. It is shown that the solution procedure discussed in this paper is reliable, efficient and less time consuming as compared to other existing concepts and procedures.