• Title/Summary/Keyword: Horizontal Stress

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Sidesway가 생기는 강구조의 Moment분배법 완전해법

  • Kim, Taek-Sin
    • Korean Architects
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    • no.11 s.82
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    • pp.26-35
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    • 1975
  • The present Structuralists have usually calculated the end Moment of Rigid-frame members by using the Moment Distribution Method, presented by Hardy Cross in 1930, on the Basis of Elastic Law. But this method is considered to be an unfinished solution in case of the moment condition, which the Non-Equilibrium distributed loads or the Horizontal Force acted upon it result in deflection. Hence, after finishing the calculation of stress by means of the Moment Distribution Method, the stress condition due to Horizontal Forces had to be corrected approximatly. However we can directly get the solution of Rigid-frame having sidesway not by above method but by the Moment Distribution computation. Consequently this method is regarded as a Perfect Moment Distribution Method. Here 1 present.

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Design of the monoleaflet polymer valve to minimize stress and displacement (응력 및 변위를 최소화하기 위한 단엽식 고분자 판막의 설계)

  • Han, G.J.;Kim, S.H.
    • Proceedings of the KOSOMBE Conference
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    • v.1993 no.11
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    • pp.99-103
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    • 1993
  • A monoleaflet polymer artificial heart valve which showed the remarkable improvement in pressure drop compared with other types of artificial valve was designed to decrease the deflection in vertical direction and the displacement or the valve tip in horizontal direction. Stress distribution change was studied as the location of the supporting members or the valve frame changed. And it was found that using the valve tip horizontal displacement the minimum valve thickness could be obtained in order to prevent the gap between the valve tip and the frame wall.

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Thermoelastic Finite Element Analysis of Multiple horizontal Subsurface Cracks Due to Sliding Surface Traction (마찰열을 고려한 미끄럼 접촉시 내부 복수 수평균열 전파해석)

  • 이진영;김석삼
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2000.11a
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    • pp.50-58
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    • 2000
  • A linear elastic fracture mechanics analysis of multiful subsurface cracks propagation in a half-space subjected to moving thermomechanical surface traction was peformed using the finite element method. The effect of frictional heat at the sliding surface on the crack growth behavior is analyzed in terms of the thermal load and peclet number. The crack propagation direction is predicted in light of the magnitudes of the maximum shear and tensile stress intensity factor ranges. When moving thermomechanical surface traction exists, subsurface horizontal cracks are propagation in-plane crack growth rate at the beginning but they are propagation out-of-plane crack growth rate by the frictional heat which is occurrence by the repeated sliding contact.

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Stability Analysis of Vertical Pipeline Subjected to Underground Excavation (지하공간 굴착에 따른 수직파이프 구조물의 안정성해석)

  • 김종우
    • Tunnel and Underground Space
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    • v.10 no.4
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    • pp.533-543
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    • 2000
  • Deformation behavior and stability of vertical pipeline subjected to underground excavation have been studied by means of numerical analysis. Vortical ground displacements cause the pipe to be compressed, while horizontal ones cause it to be bent. In that region the vertical pipeline meets with the induced compressive stress and bending stress. In addition horizontal rock stress subjected to underground excavation may press the tube in its radial direction and it finally produces the tangential stress of pipe. In this study active gas well system is considered as an example of vertical pipelines. Factor analysis has been conducted which has great influence on the pipeline behavior. Three case studies are investigated which have the different pillar widths and gas well locations in pillar. For example, where overburden depth is 237.5 m and thickness of coal seam is 2.5 m, chain pillar of 45.8 m width in the 3-entry longwall system is proved to maintain safely the outer casing of gas welt which is made of API-55 steel, 10$\frac{3}{4}$ in. diameter and 0.4 in. thickness. Finally an active gas well which was broken by longwall mining is analyzed, where the induced shear stress turn out to exceed the allowable stress of steel.

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Effect of Particle Crushing on the Results on DMT in Sand (입자 파쇄가 사질토의 DMT 결과에 미치는 영향)

  • Lee, Moon-Joo;Choi, Young-Min;Kim, Min-Tae;Bae, Kyung-Doo;Lee, Woo-Jin
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.03a
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    • pp.740-746
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    • 2010
  • Most important characteristics of calcareous sand are the particle angularity and hollow structure. These characteristics lead to the different behavior of calcareous sand compared to siliceous sand. This study performs a series of dilatometer test using calibration chamber, in order to analyze the effect of particle characteristic of calcareous sand on DMT indices. From experimental test, it is observed that the horizontal stress index($K_D$) and dilatometer modulus($E_D$) of calcareous Jeju sand is underestimated compared to siliceous sand. This is because the particle crushing during penetration induces the less contraction of the dilatometer membrane. A slightly smaller influence of particle crushing is reflected in $E_D$ rather than $K_D$, because $P_1$ pressure reflects the deformation characteristics of un-crushed particle relatively well. It is also observed that $K_D$ of Jeju sand is differently influenced by the vertical effective stress compared with that of siliceous sand.

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Effects of Residual Stress with Welding Condition in the Steel Structure of H-beam (H 빔 구조물의 T-Joint에서 용접조건에 따른 용접잔류응력의 영향)

  • 석한길
    • Journal of Welding and Joining
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    • v.21 no.5
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    • pp.568-574
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    • 2003
  • In the welding for the steel structure of H-beam with mild steel and 490N/$\textrm{mm}^2$ high tensile steel, we applied the fillet weld mostly and 6-8mm weld length(AISC-spec.). And a new developed metal-cored-wire is used in automatic welding as well as semi-automatic welding. In this study we have attempted to raise the welding productivity and to stabilize the quality on horizontal positions of fillet welding with the following items: - We improved the weld productivity using metal based cored wire with a high deposition rate in the steel structure of H-beam. - We tested the weldability and evaluated the quality of the weldmetal by horizontal fillet $CO_2$ welding. The process is carried out in combination with a special purpose metal-based FCW with excellent resistance to porosity and high welding speed. - We studied the micro structure of the weldmetal by the various welding conditions. - We studied the effect of welding residual stress by the welding conditions in T-joint. Therefore, it can be assured that more productive and superior quality of the weldmetal can be taken from this study results.

A STUDY ON INITIAL CHANGES DURING CANINE RETRACTION BY THE FINITE ELEMENT METHOD (견치 원심이동시의 초기변화에 관한 유한요소법적 연구)

  • Kim, Young-Won;Sohn, Byung-Hwa
    • The korean journal of orthodontics
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    • v.18 no.1 s.25
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    • pp.25-53
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    • 1988
  • Retraction of canines represents a fundamental stage in a considerable number of orthodontic treatment. Correct position of the canine after retraction is most important for function, stability, and esthetics. The purpose of this study was to investigate the stress in the periodontal tissue at the initial phase during canine retraction using various types of sectional retraction springs, by finite element method. Three dimensional model of tooth, periodontal ligament, bone and eight springs were simulated and tested. The following results were obtained. 1. In sectional retraction springs, increasing number of helix and the closed loop in preference to the open loop provided an decrease in horizontal force. Without angulating the arms of spring, the T-loop revealed the highest Moment-to-force ratio. 2. The Moment-to-force ratio raised by angulating mesial and distal arms of spring, but very large horizontal force was applied to canine. 3. When optimal force and optimal moment was applied to canine, the stress induced was homogeneous and the difference of stress value from cervix to the apex was little.

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Effects of the earth fissure on the seismic response characteristics of a nearby metro station

  • Jiang Chang;Yahong Deng;Huandong Mu
    • Earthquakes and Structures
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    • v.24 no.1
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    • pp.53-64
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    • 2023
  • Earth fissures with several kilometers will inevitably approach or cross the metro line, significantly threatening the safety of the underground structure in the earth fissure site. However, the influence of the earth fissure site's amplification effect on the metro station's dynamic response is still unclear. A representative earth fissure in Xi'an was taken as an example to establish a numerical model of a metro station in the earth fissure site. The dynamic response characteristics of the metro stations at different distances from the earth fissure under various seismic waves were calculated. The results show that the existence of the earth fissure significantly amplifies the dynamic response of the nearby underground structures. The responses of the axial force, shear force, bending moment, normal stress, horizontal displacement, inter-story drift, and relative slip of the metro station were all amplified within a specific influence range. The amplification effect increases with the seismic wave intensity. The amplification effect caused by the earth fissure has relatively weak impacts on the axial shear, shear force, bending movement, normal stress, and horizontal movement; slightly larger impacts on the inter-story drift and acceleration; and a significant impact on the relative slip. The influence ranges of the axial force and normal stress are approximately 20 m. The influence ranges of the acceleration and inter-story drift can reach 30 m. Therefore, the seismic fortification level of the underground structure in the earth fissure site needs to be improved.

Capacity of Horizontally Loaded Suction Anchor Installed in Silty Sand (세립 사질토 지반에 설치된 석션 앵커의 수평 지지력)

  • Kim, Surin;Choo, Yun Wook;Kim, Dong-Soo;Sung, Hong Gun
    • Journal of Ocean Engineering and Technology
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    • v.27 no.1
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    • pp.59-66
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    • 2013
  • A suction anchor is one of the most popular anchors for deepsea floating systems. An anchor used for catenary mooring is predominantly under a horizontal load. In this study, the behavior of a suction anchor installed in cohesionless soil was investigated when the anchor was mainly subjected to a horizontal load induced by a catenary line. In order to study the behavior of the suction anchor, 3D FEM analysis models were developed and analyzed. Depending on the location of the load (padeye), the ultimate horizontal load was monitored. The distributions of the reaction forces around the anchor induced by the seabed were analyzed using the circumferential stress to understand the behavior of the suction anchor under a horizontal load.