• Title/Summary/Keyword: 전단 중심

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Transverse Shear Behavior of Thin-Walled Composite Beams with Closed Cross-Sections (폐쇄형 단면을 갖는 박벽 복합재료 보의 전단변형 거동 해석)

  • Park, Il-Ju;Jung, Sung-Nam
    • Composites Research
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    • v.19 no.5
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    • pp.1-6
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    • 2006
  • In this study, a closed-form analysis has been developed for the transverse shear behavior of thin-walled composite beams with closed cross-sections. The shear flow distributions and cross-section stiffness coefficients are derived analytically by using a mixed beam approach. The theory has been applied to single-celled composite box-beams with elastic couplings. The location of the shear center and the effect of transverse shear deformation on the static behavior of composite beams are investigated in the framework of the analysis. The present results are validated against those of a two-dimensional finite element analysis and a good correlation has been obtained for box-beam cases considered in this study.

Development of a Shear Yielding Steel Damper for Concentrically Braced Frames (중심가새골조의 내진성능향상을 위한 전단항복댐퍼의 개발)

  • Ghamar, Ali;Jeong, Seong-Hoon
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.34 no.6
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    • pp.437-443
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    • 2021
  • In this study, the use of a steel yielding damper is considered as an appropriate method to enhance the behavior of CBFs and a steel damper which is economical and straightforward to construct and replace after a severe earthquake is developed. The proposed damper was investigated experimentally and numerically. In addition, a parametric study was performed to evaluate the effect of the three types of damper mechanisms (shear, shear-flexural, and flexural) on the behavior of the proposed damper. The experimental results, as well as the numerical results, indicate that the shear damper exhibits better performance than the other dampers in terms of strength and stiffness.

A Study on the share surface size deformation of Fine Blanking Process (파인블랭킹 공정에서 전단면의 크기 변형에 관한 연구)

  • Lee, Chun-Kyu;Kim, Young-Choon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.8
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    • pp.3650-3655
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    • 2013
  • A state purpose to produce fine blanking die gets to be the maximum size of share surface the study considered that change a size of share area. the clearance affecting most greatly size of share surface fixing as 1% of material thickness and while change share speed, A distance change from share line to V-ring center, A change of V-ring angle. it designed. Each test specimen taken from the share surface size analysis of the V-ring distance of 2mm, the outer $45^{\circ}$ / inner$30^{\circ}$ if the, Shear speed was found that the area of the entire cross section is largest the 6.4m/min.

Evaluation of Shear Capacity of Wide Beams Reinforced with GFRP and Steel Plates with Openings by Various Supporting Areas (지지부 조건에 따른 유공형 판으로 전단보강된 넓은 보의 전단성능 평가)

  • Kim, Heecheul;Ko, Myung Joon;Kim, Min Sook;Lee, Young Hak
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.29 no.3
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    • pp.269-275
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    • 2016
  • In this paper, shear performance of concrete wide beams was evaluated through shear failure tests. The specimens were designed to have two continuous spans with a column at the center of the wide beam. Also the specimens were reinforced with plates with openings as shear reinforcements. For the test, total eight specimens, including five specimens were reinforced with steel plates and the other three specimens were reinforced with GFRP plates were manufactured. And the shear strengths obtained from the tests were compared with ones from the equation provided by ACI 318. Support width of wide beam, support section of wide beam and shear reinforcement material were considered as variables. The results showed that the support width was proportional to the increase of shear strength. Also, regardless of material type of shear reinforcement, the shear reinforcing effect was similar when the amount of shear reinforcement was the same.

Shear Behavior Prediction of Reinforced Concrete Columns Using Transformation Angle Truss Model (변환각 트러스 모델에 의한 철근콘크리트 기둥의 전단거동 예측)

  • Kim Sang-Woo;Chai Hyee-Dae;Lee Jung-Yoon;Lee Bum-Sik
    • Journal of the Korea Concrete Institute
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    • v.17 no.3 s.87
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    • pp.435-444
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    • 2005
  • This paper predicted the shear behavior of reinforced concrete columns using Transformation Angle Truss Model (TATM) considered the effects of bending moment and axial force. Nine columns with various shear span- to-depth ratios and axial force ratios were tested to verify the theoretical results obtained from TATM. Fine linear displacement transducers (LVDT) were attached to a side of the column near the shear critical region to measure the curvature, the longitudinal and transverse axial deformations, and the shear deformation of the column. The test was terminated when the value of the applied load dropped to about $85\%$ of the maximum-recorded load in the post-peak descending branch. All the columns were failed in shear before yielding of the flexural steel. The shear strength and the stiffness of the columns increased, as the axial force increased and the shear span-to-depth ratio decreased. Shear stress-shear strain and shear stress-strain of shear reinforcement curves obtained from TATM were agreed well with the test results in comparison to other truss models (MCFT, RA-STM, and FA-STM).

Bending-Torsional Vibration Characteristics of Large Structures Influenced by Coupling Effects (연성효과에 의한 대형 구조물의 굽힘-비틀림 진동특성)

  • 송창용;손충열;송재영
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 1995.10a
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    • pp.208-216
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    • 1995
  • 대형선박, 항공기, 초고층 건축물 등은 얇은 박판 형태의 보로 이상화하여 구조 및 진동해석을 수행할 수 있다. 이러한 형태로 이상화한 구조물은 비틀림 강도면에서 매우 취약함을 보이고, 굽힘-비틀림 진동은 단면형상에 따라 연성도가 심화된다. 상하 굽힘 진동은 탄성거동 영역에서 도심과 전단중심이 일치하는 대칭 진동(Symmetric vibration) 현상을 보인다. 그러나, 수평 굽힘 진동은 도심과 전단중심의 차이가 커질수록 즉, 연성도가 높아질수록 비틀림 진동과 복합되어 복잡한 비대칭 진동(Antisymmetric vibration) 현상을 나타낸다. 본 논문에서는 연성효과에 의한 수평 굽힘 진동과 비틀림 진동 현상에 대한 연구를 수행하였고, 진동계산을 위해서 전달행렬법(Transfer Matrix Method)을 사용하였다. 수치계산은 첫번째로, 도심과 전단중심의 차이가 매우 작아 연성도를 무시할 수 있을 정도의 구조물에 대해서 일반적인 수평 굽힘 진동 현상과 비틀림 진동 현상을 연구하였다. 두번째로, 연성도가 매우 심할 경우에 굽힘-비틀림 연성 진동 현상을 Timoshenko 보의 이론과 Vlasov 보의이로네 따라 각각 계산을 수행하였다. 마지막으로, 첫번째와 두번째 구조를 결합한 경우에 대해서 굽힘-비틀림 연성 진동 현상을 연구하였다. 이 경우에 두 구조물의 결합부에서 비틀림 강성과 Warping 강성의 심한 변화로 인한 불연속 경계면이 발생하게 되고 이때의 진동해석을 위해서 보 이론에 기초를 두고 상당히 높은 정확도를 제공하는 Haslum[2] 등과 Pedersen[3]이 제시한 이론을 이용하였다.

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Ductility Capacity of Shear-Dominated Steel Plate Walls (전단지배 강판벽의 연성능력)

  • Park, Hong Gun;Choi, In Rak;Jeon , Sang Woo;Kim, Won Ki
    • Journal of Korean Society of Steel Construction
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    • v.18 no.4
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    • pp.457-468
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    • 2006
  • An experimental study was performed to investigate the maximum energy dissipation and the ductility capacity of shear-dominated steel plate walls with thin web plates. Three specimens of three-story plate walls with thin web plates were tested. The parameters for the test specimens were the aspect ratio of the web plate and the shear strength of the column. A concentrically braced frame and a moment-resisting frme were a also tested for comparison. The steel plate walls exhibited much better ductility and energy dissipation capacity than the concentrically braced frame and the moment-resisting frame. The results showed that unlike other structural systems, the sh as well as strength, and can therefore be used as an effective earthquake-resisting system. A method of predicting the energy dissipation capacity of a steel plate wall was proposed.

Stress Behavior of Substrate by Thin Film Pattern (박막 패턴에 의한 기판의 응력 거동)

  • Nam, Myung Woo;Hong, Soon Kwan
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.1
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    • pp.8-13
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    • 2020
  • Stress is the main cause of warpage failure of very thin substrates with thickness of several hundred ㎛, such as IC packages. Stress usually results from differences in crystal structures and corresponding thermal expansion coefficients when depositing different substances on a substrate. In this study, the behaviors of stress occurring in substrates were numerically analyzed by the thin-film pattern of the rectangles stacked on the substrates. First, the substrate displacement was obtained and the substrate strain and stress were obtained using it. When the tensile force is concentrated at the edge of the thin film pattern, normal and shear stresses are generated around the edge of the thin film pattern. Normal stress occurs near the edges of the thin film pattern and the vertexes. Shear stress also occurs around the edge of the thin film pattern, but unlike normal stress, it does not appear near the vertexes. It was also confirmed that the magnitude and direction of shear stress are changed around the edge. When edge forces of thin-film pattern are equal, the normal stress was about 10 times larger than the shear stress. This indicates that normal stress is the biggest cause of warpage failure.

Nonlinear Analysis of Shear Behavior on Pile-Sand Interface Using Ring Shear Tests (링전단시험을 이용한 말뚝 기초-사질지반 간 인터페이스 거동 분석)

  • Jeong, Sang-Seom;Jung, Hyung-Suh;Whittle, Andrew;Kim, Do-Hyun
    • Journal of the Korean Geotechnical Society
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    • v.37 no.5
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    • pp.5-17
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    • 2021
  • In this study, the shear behavior between pile-sandy soil interface was quantified based on series of rigorous ring shear test results. Ring shearing test was carried out to observe the shear behavior prior to failure and behavior at residual state between most commonly used pile materials - steel and concrete - and Jumunjin sand. The test was set to clarify the shear behavior under various confinement conditions and soil densities. The test results were converted in to representative friction angles for various test materials. Additional numerical analysis was executed to validate the accuracy of the test results. Based on the test results and the numerical validation, it was found that due to the dilative and contractive nature of sand, its interface behavior can be categorized in to two different types : soils with higher densities tend to show peak shear stress and moves on to residual state, while on the other hand, soils with lower densities tend to show bilinear load-transfer curves along the interface. However, the relative density and the confining stress was found to affect the friction angle only in the small train range, and converges as it progresses to large deformation. This study established a large deformation analysis method which can successfully simulate and predict the large deformation behavior such as ring shear tests. Moreover, the friction angle derived from the ring shear test result and verified by numerical analysis can be applied to numerical analysis and actual design of various pile foundations.