• Title/Summary/Keyword: 유한요소예측

Search Result 1,415, Processing Time 0.028 seconds

Behavior of Geotextile Tube by Plane Strain Analysis and 3-Dimensional Finite Element Method (평면변형해석과 3-D FEM 기법을 통한 지오텍스타일 튜브의 거동해석)

  • 신은철;오영인
    • Journal of the Korean Geotechnical Society
    • /
    • v.19 no.5
    • /
    • pp.233-241
    • /
    • 2003
  • Geotextile tube is hydraulically filled with dredged materials and has been applied to coastal protection and scour protection, dewatering method of slurry, and isolation of contaminated material. Recently, geotextile tube technology is no longer alternative construction technique but suitable desired solution. In this paper, the numerical analysis was performed to investigate the behavior of geotextile tube with various properties of geotextile sheet and hydraulic pumping conditions. Numerical analysis was executed to compare with the results from the large-scale field model tests, and also with those of plane strain analysis and 3-D FEM analysis. A geotextile tube was modeled using the commercial finite element analysis program ABAQUS and the one-quarter of tube was modeled. Behavior of geotextile tube during the hydraulic pumping procedure was analyzed by comparing the large-scale field model test and numerical analysis. The shape variation and maximum tube height between the numerical analysis results and large-scale filed test results are turned out to be in a good agreement.

Estimation of Concrete Cover Failure Time Considering the Corrosion Rate in Reinforced Concrete Structures (철근 부식속도 예측식을 이용한 철근 피복 파괴 시간 추정)

  • Jang, Bong-Seok
    • Journal of the Korea Concrete Institute
    • /
    • v.18 no.2 s.92
    • /
    • pp.233-238
    • /
    • 2006
  • In lifetime estimation, the FEM analysis method is proposed for predicting corrosion failure time of concrete structures exposed to sea-water. This study shows that the corrosion rate of rebar in artificial pore solution can be transferred to the corrosion rate of rebar in concrete using the relationship between pore volume and concrete volume by Jennings' model. And this study considered the pitting corrosion effects of reinforcement bar on corrosion failure analysis, rebar size to cover depth and nonlinear crack analysis. These analysis results have good accordance with the experimental results of Williamson's work. This methodology can be applied to lifetime prediction procedure of reinforced concrete structures and also gives more reasonable results of concrete cover failure time estimation of reinforced concrete structures exposed to sea-water.

Efficient Adaptive Finite Element Mesh Generation for Dynamics (동적 문제에 효율적인 적응적 유한요소망)

  • Yoon, Chongyul
    • Journal of the Computational Structural Engineering Institute of Korea
    • /
    • v.26 no.5
    • /
    • pp.385-392
    • /
    • 2013
  • The finite element method has become the most widely used method of structural analysis and recently, the method has often been applied to complex dynamic and nonlinear structural analyses problems. Even for these complex problems, where the responses are hard to predict, finite element analyses yield reliable results if appropriate element types and meshes are used. However, the dynamic and nonlinear behaviors of a structure often include large deformations in various portions of the structure and if the same mesh is used throughout the analysis, some elements may deform to shapes beyond the reliable limits; thus dynamically adapting finite element meshes are needed in order for the finite element analyses to be accurate. In addition, to satisfy the users requirement of quick real run time of finite element programs, the algorithms must be computationally efficient. This paper presents an adaptive finite element mesh generation scheme for dynamic analyses of structures that may adapt at each time step. Representative strain values are used for error estimates and combinations of the h-method(node movement) and the r-method(element division) are used for mesh refinements. A coefficient that depends on the shape of an element is used to limit overly distorted elements. A simple frame example shows the accuracy and computational efficiency of the scheme. The aim of the study is to outline the adaptive scheme and to demonstrate the potential use in general finite element analyses of dynamic and nonlinear structural problems commonly encountered.