• Title/Summary/Keyword: 내부 요소

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Computational Numerical Analysis and Experimental Validation of the Response of Reinforced Concrete Structures under Internal Explosion (내부폭발 시 철근콘크리트 구조물 거동에 대한 전산수치해석과 실험적 검증)

  • Ji, Hun;Moon, Sei-Hoon;Chong, Jin-Wung;Sung, Seung-Hun;You, Yang-Sun
    • Journal of the Korea Society for Simulation
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    • v.27 no.1
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    • pp.101-109
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    • 2018
  • Field experiments as well as numerical analyses with finite element analysis codes are two valuable and complemental ways to understand the structural response under explosive blast load. However, there seems to be only limited information available about finite element analysis and experimental validation on the response of structural components under internal explosions. For complementary use of the two ways, the numerical analyses should be validated with field experiments by comparing their results. In this paper, a small-scaled reinforced concrete building with a room is employed for experimental investigations. An amount of TNT is detonated at the center of the room. Pressure at three different sites in the room, displacement of centers of two walls, and damage patterns of four walls are measured and compared to results from numerical analyses. The experimental results are much similar to the numerical analyses results. The finite element analysis code ANSYS AUTODYN is employed to numerically analyze both pressure distribution inside the room and response of walls subjected to blast pressure. The feasibility and validity of the numerical analysis on the reponses of structural components under internal explosions are discussed in terms of structural damage assessment, and evaluated as the same damage in the analysis and the experiments.

Finite Element Analysis of Inverted Umbrella-type Hyperbolic Paraboloid Shell (역우산형 쌍곡포물선 쉘의 유한요소해석)

  • Kwon, Hung-Joo;Yu, Eun-Jong;Rha, Chang-Soon
    • Journal of Korean Association for Spatial Structures
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    • v.11 no.1
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    • pp.87-95
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    • 2011
  • This study presents the comparisons between the analysis results based on membrane theory and finite element analysis for the inverted umbrella-type hyperbolic paraboloid shell structure. The effects of the roof angle on the roof deflections, member forces of edge beams and ribs, and shell stress are also investigated with various roof angles. Results show that the membrane theory overestimates the member forces of edge beams and ribs. On the contrary, the shell stresses are underestimated in the membrane theory when compared to the results from the finite element analysis. The deflections of roof slabs by finite element analysis show drastic increasement as the roof angle decreases.

Composite Surface Modeling of Three-Dimensional Structures -Theory and Algorithms- (3차원(次元) 구조물(構造物)의 복합곡면(複合曲面)모델링-이론(理論) 및 알고리즘)

  • Koh, Hyun Moo;Park, Young Ha
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.10 no.4
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    • pp.43-52
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    • 1990
  • Theoretical foundation and algorithms are presented of a new surface modeling and pre-processing system for the three-dimensional structures. The modeling method is based on the boundary representation scheme and composed of two hierarchical model structures: curve-network and surface models. The concept of modeling curve as a union of links is introduced to facilitate surface modeling via various transfinite mapping techniques or Coons Patches. Efficiency and novel aspects of the present method are discussed. Finite element mesh genceration and application procedures will be reported in a later paper.

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Development of $5^{th}$ percentile female finite Element Model for Crashworthiness Simulation - Part II Detail Modeling of Internal Components (충돌 안전도 해석을 위한 $5^{th}$ percentile 성인 여성 유한요소 모델 개발 - Part II 신체 부위 별 상세 모델 개발)

  • 나상진;최형연;이진희
    • Journal of Biomedical Engineering Research
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    • v.25 no.4
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    • pp.283-288
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    • 2004
  • The finite element modeling of small female occupant for crash simulation is presented in this paper subsequently to the part I of articulated rigid body model. The limbs and internal components are additionally modeled by joining them to the articulated rigid body model for predicting the crash injuries such as bone fractures and joint dislocations. The behavioral characteristics of each limbs and internal components were validated against available cadaveric test results. Accordingly, the human model proposed in this paper could be utilized for the investigation of impact injury mechanism and further complement the lacking biofidelity of current crash dummy.

A Numerical Study on the Static Strength of Tubular X-Joints With an Internal Ring Stiffener (환보강 X형 관이음부의 정적강도에 관한 수치적 연구)

  • Ryu Yeon-Sun;Cho Hyun-Man
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.18 no.3
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    • pp.265-275
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    • 2005
  • The objective of this paper is to numerically assess the behavior of tubular X-joints with an internal ing stiffener, and to evaluate the reinforcement effect of a ring stiffener, and to establish the strength formulae. Nonlinear finite element analysis is used to compute the static strength of axially loaded tubular joints. Numerical and experimental results are in good agreement for tubular X-joints. The chord lengths of simple and ring-stiffened X-joints are suggested to reduce chord end effect. And, internal ring stiffener is found to be efficient In improving static strength of tubular X-joints. Maximum strength ratios are calculated as $1.5\sim3.5$. Regression analyses are performed considering practical size of ring stiffener and strength estimation formulae for tubular X-joints with an internal ring stiffener are proposed.

Octree-Based Adaptive Tetrahedral Meshing (옥트리 기반의 적응적 사면체 요소망구성)

  • Kim, Chul-Won;Park, Suk-Hoon;Choi, Min-Gyu
    • Journal of the Korea Computer Graphics Society
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    • v.17 no.2
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    • pp.45-53
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    • 2011
  • This paper proposes a volume meshing method that fills the inside of an object with tetrahedra, of which dihedral angles are good. The suggested method is fast, stable and easy to implement It can also utilize an octree structure to space-efficiently fill an object with graded tetrahedra by reducing the total number of tetrahedra. To obtain a high-quality mesh with good dihedral angles, we restrict the octree such that any pair of neighboring cells only differs by one level. To efficiently construct a restricted-octree and generate a volume mesh from the octree, we utilize a signed distance field of an object on its bounded workspace. The suggested method can be employed in FEM-based simulation of large elasto-plastic deformation and tetrahedral-mesh-based simulation of fluid flow.

p-Adaptive Analysis by Three Dimensional Hierarchical Hexahedral Solid Element (3차원 계층적 육면체 고체요소에 의한 p-적응적 해석)

  • Woo, Kwang-Sung;Jo, Jun-Hyung;Shin, Young-Sik
    • Journal of Korean Association for Spatial Structures
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    • v.8 no.4
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    • pp.81-90
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    • 2008
  • This paper presents a finite element formulation for the three-dimensional hierarchical solid element using Integrals of Legendre polynomials. The proposed hexahedral solid element is composed of four different modes including vertex, edge, face, and internal mode, respectively. The eigenvalue and patch test have been carried out to confirm the zero-energy mode and constant strain condition. In addition to these, a posteriori error estimation has been studied for the p-adaptive finite element analysis that is based on a smoothing technique to compute a post-processed solution from the finite element solution. The uniform p-refinement and non-uniform p-refinement are compared in terms of convergence rate as the number of degree of freedom is increased. The simple cantilever beam is tested to show the performance of the proposed solid element.

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Movie Factors Affecting Satisfaction of 3D Stereoscopic Movie Audiences (3D입체영화관객의 만족에 영향을 미치는 영화적 요인)

  • Yun, Jae-Sun;Lim, Chan
    • The Journal of the Korea Contents Association
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    • v.11 no.9
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    • pp.106-117
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    • 2011
  • The purpose of this study is to examine factors that affect 3D stereoscopic movie audiences' satisfaction in Korea, and to provide strategic solutions to improve audiences' satisfaction. According to study about movie audiences' satisfaction, factors that affect movie audiences' satisfaction are separated to movie internal factors, movie environmental factors and movie audience factors. And leverage of movie internal factors is bigger than either. But 3D stereoscopic movie is different from ordinary movie in shooting, screening, seeing and recognizing method. So it is expected that movie environmental factors and audience factors' influence is bigger than internal factors. So this study carried out a survey targeting 3D stereoscopic audiences. Main result of this study are shown as follows. First, the method to reduce visual fatigue is necessary for satisfaction. Second, it is required that improvement method of seat arrangement to provide high quality 3D stereoscopic contents. Third, level of 3D stereoscopic movies' price need to adjust to valid level.