• Title/Summary/Keyword: Relative Deformation

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Three-Dimensional Sheet Modeling Using Relative Coordinate (상대 좌표를 이용한 종이류 모델링 기법)

  • Cho Heui Je;Bae Dae Sung
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.29 no.2 s.233
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    • pp.247-252
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    • 2005
  • This research presents a three-dimensional modeling technique for a flexible sheet. A relative coordinate formulation is used to represent the kinematics of the sheet. The three-dimensional flexible sheet is modeled by multi-rigid bodies interconnected by out-of-plane joints and plate force elements. A parent node is designated as a master body and is connected to the ground by a floating joint to cover the rigid motion of the flexible sheet in space. Since the in-plane deformation of a sheet such as a paper and a film is relatively small, compared to out-of-plane deformation, only the out-of-plane deformation is accounted for in this research. The recursive formulation has been adopted to solve the equations of motion efficiently. An example is presented to show the validity of the proposed method.

Simulation and Experimental Methods for Media Transport System: Part I, Three-Dimensional Sheet Modeling Using Relative Coordinate

  • Cho, Heui-Je;Bae, Dea-Sung;Choi, Jin-Hwan;Lee, Soon-Geul;Rhim, Sung-Soo
    • Journal of Mechanical Science and Technology
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    • v.19 no.spc1
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    • pp.305-311
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    • 2005
  • This research presents a three-dimensional modeling technique for a flexible sheet. A relative coordinate formulation is used to represent the kinematics of the sheet. The three-dimensional flexible sheet is modeled by multi-rigid bodies interconnected by out-of-plane joints and plate force elements. A parent node is designated as a master body and is connected to the ground by a floating joint to cover the rigid motion of the flexible sheet in space. Since the in-plane deformation of a sheet such as a paper and a film is relatively small, compared to out-of-plane deformation, only the out-of-plane deformation is accounted for in this research. The recursive formulation has been adopted to solve the equations of motion efficiently. An example is presented to show the validity of the proposed method.

Simulation and Experimental Methods for Three-Dimensional Sheet Media Transport System Using Relative Coordinate (상대좌표를 이용한 3차원 미디어 이송장치에 대한 실험방법과 Simulation에 대한 연구)

  • Dae, Dae-Sung;Cho, Heui-Je
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2005.11a
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    • pp.573-576
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    • 2005
  • This research presents a three-dimensional modeling technique for a flexible sheet. A relative coordinate formulation is used to represent the kinematics of the sheet. The three-dimensional flexible sheet is modeled by multi-rigid bodies interconnected by out-of-plane joints and plate force elements. A parent node is designated as a master body and is connected to the ground by a floating joint to cover the rigid motion of the flexible sheet in space. Since the in-plane deformation of a sheet such as a paper and a film is relatively small, compared to out-of-plane deformation, only the out-of-plane deformation is accounted for in this research. The recursive formulation has been adopted to solve the equations of motion efficiently. An example is presented to show the validity of the proposed method.

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Seismic Behavior of Steel Moment Connections with Different Structural Characteristics (철골 모멘트 연결부의 구조특성에 따른 지진 거동 연구)

  • Joh, Chang-Bin
    • Journal of the Korean Society of Safety
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    • v.17 no.2
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    • pp.76-84
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    • 2002
  • The seismic behaviors of steel moment connections with different structural characteristics are investigated. The rupture index, which represents the fracture potential, is adopted to study the effect of concrete slab and the relative strength between the coin the beam, and Panel zone on the ductility of connections. The results show that the presence of slab increases the beam strength, imposes constraint near the beam top flange, and consequently, induces concentrated deformation near the beam access hall, which reduces the ductility of the connection. The total deformation capacity of the connection depends not only on the beam but also on the column and panel zone. Therefore, the detrimental slab effects and the relative strength should be considered in the seismic design of the connection.

LIMIT RELATIVE CATEGORY THEORY APPLIED TO THE CRITICAL POINT THEORY

  • Jung, Tack-Sun;Choi, Q-Heung
    • Bulletin of the Korean Mathematical Society
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    • v.46 no.2
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    • pp.311-319
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    • 2009
  • Let H be a Hilbert space which is the direct sum of five closed subspaces $X_0,\;X_1,\;X_2,\;X_3$ and $X_4$ with $X_1,\;X_2,\;X_3$ of finite dimension. Let J be a $C^{1,1}$ functional defined on H with J(0) = 0. We show the existence of at least four nontrivial critical points when the sublevels of J (the torus with three holes and sphere) link and the functional J satisfies sup-inf variational inequality on the linking subspaces, and the functional J satisfies $(P.S.)^*_c$ condition and $f|X_0{\otimes}X_4$ has no critical point with level c. For the proof of main theorem we use the nonsmooth version of the classical deformation lemma and the limit relative category theory.

Geotechnical parameter estimation in underwater tunnel using relative convergence measurement (하저터널에서 상대내공변위 계측을 통한 지반정수 예측)

  • Kim, Do-Hoon;Jang, Jea-Hyuck;Lee, In-Mo
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.03a
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    • pp.792-802
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    • 2008
  • If a tunnel is constructed below the groundwater level, the groundwater flow will occur inducing the seepage force toward the tunnel and will result in the increase of tunnel convergence. The longitudinal deformation during tunnel excavation will also be increased due to seepage pressure. A back-analysis methodology in underwater tunnel was proposed in this study based on the relative longitudinal deformation measured in-situ. Geotechnical parameters can be estimated utilizing the proposed method where the prior estimate as well as the measured convergence can be reasonably combined by adopting the Extend Bayesian Method.

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CRITICAL POINTS RESULT FOR THE C1,1 FUNCTIONAL AND THE RELATIVE CATEGORY THEORY

  • Jung, Tacksun;Choi, Q-Heung
    • Journal of the Chungcheong Mathematical Society
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    • v.21 no.4
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    • pp.437-445
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    • 2008
  • We show the existence of at least four nontrivial critical points of the $C^{1,1}$ functional f on the Hilbert space $H=X_0{\oplus}X_1{\oplus}X_2{\oplus}X_3{\oplus}X_4$, $X_i$, i = 0, 1, 2, 3 are finite dimensional, with f(0) = 0 when two sublevel subsets, torus with three holes and sphere, of f link, the functional f satisfies sup-inf variatinal linking inequality on the linking subspaces, the functional f satisfies $(P.S.)_c$ condition, and $f{\mid}_{X_0{\oplus}X_4}$ has no critical point with level c. We use the deformation lemma, the relative category theory and the critical point theory for the proof of main result.

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Experimental research on seismic behavior of steel reinforced high-strength concrete short columns

  • Zhu, Weiqing;Jia, Jinqing;Zhang, Junguang
    • Steel and Composite Structures
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    • v.25 no.5
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    • pp.603-615
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    • 2017
  • This experimental research presents the seismic performance of steel reinforced high-strength concrete (SRHC) short columns. Eleven SRHC column specimens were tested under simulated earthquake loading conditions, including six short column specimens and five normal column specimens. The parameters studied included the axial load level, stirrup details and shear span ratio. The failure modes, critical region length, energy dissipation capacity and deformation capacity, stiffness and strength degradation and shear displacement of SRHC short columns were analyzed in detail. The effects of the parameters on seismic performance were discussed. The test results showed that SRHC short columns exhibited shear-flexure failure characteristics. The critical region length of SRHC short columns could be taken as the whole column height, regardless of axial load level. In comparison to SRHC normal columns, SRHC short columns had weaker energy dissipation capacity and deformation capacity, and experienced faster stiffness degradation and strength degradation. The decrease in energy dissipation and deformation capacity due to the decreasing shear span ratio was more serious when the axial load level was higher. However, SRHC short columns confined by multiple stirrups might possess good seismic behavior with enough deformation capacity (ultimate drift ratio ${\geq}2.5%$), even though a relative large axial load ratio (= 0.38) and relative small structural steel ratio (= 3.58%) were used, and were suitable to be used in tall buildings in earthquake regions.

Study on Evaluating Displacement Tolerance of Sky-bridge in Tall Buildings (고층 스카이브리지의 변위 허용치 산정에 대한 연구)

  • Kim, Yun Gon
    • Journal of the Architectural Institute of Korea Structure & Construction
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    • v.36 no.4
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    • pp.135-142
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    • 2020
  • The new method for evaluating the displacement tolerance of sky-bridges with pin-roller type supports was proposed considering both return period of phase difference between connected buildings and geometrical characteristics of skybridge. Because displacement tolerance is relative value, which is most affected by the phase difference of the connected buildings, the dynamic response of these building with time history analysis should be evaluated. However, the initial phase could not be specified, so the result of displacement tolerance would be varied with respect to initial value. Thus, the tolerance can be reasonably evaluated SRSS calculation with design displacements based on statistical approach and of each building. In addition, the geometrical characteristics of sky-bridge should be considered because the transverse displacement of sky-bridge span causes the shear deformation of the bridge and longitudinal displacement tolerance cannot release the shear deformation. Therefore, the some pin-end support in sky-bridge should have longitudinal displacement tolerance to accommodate the shear deformation. By resolving this shear deformation, it is possible not only to accommodate transverse displacement, but also to avoid the complicated joint details such as both pot bearing and guided supports with shear key.

Effect of Adhesives and Finger Pitches on Bending Creep Performances of Finger-Jointed Woods

  • Park, Han-Min;Oh, Seong-Won;Byeon, Hee-Seop
    • Journal of the Korean Wood Science and Technology
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    • v.33 no.5 s.133
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    • pp.57-65
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    • 2005
  • Following our previous reports for finger-jointed woods with various finger profiles studied for the efficient use of small diameter logs and woods containing various defects, twelve types of finger-jointed woods glued with three kinds of adhesives and with two sizes of finger pitches were made with sitka spruce and red pine. The effects of the adhesives and finger pitches on bending creep performances of finger-jointed woods were investigated. The shape of creep curves differed among the used adhesives and finger pitches of finger-jointed woods for both tested species. Their creep curves showed a linear behavior beyond about one hour, and the N values fitted to power law increased with increasing finger pitches. The initial deformation increased with increasing finger pitches, regardless of the tested species and kinds of adhesives, whereas the effect of finger pitches on the creep deformation was not clear. For finger-jointed woods glued with polyvinyl acetate (PVAc) resin, creep failure occurred in 106 hours after the load was applied. And the difference of the creep compliance between finger-jointed woods glued with resorcinol-phenol formaldehyde (RPF) resin and aqueous vinyl urethane (AVU) resin was small. The ratios for creep performances of finger-jointed woods glued with RPF resin and AVU resin versus solid wood were higher in creep deformation than initial deformation for both species, and the difference between both adhesives was not found. The relative creep decreased with increasing finger pitches, and the marked differences was not found between RPF resin and AVU resin.