• Title/Summary/Keyword: 정적/동적 하중

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The method using dynamic load and static load figures out gust factor of the membrane structure (동적하중과 정적하중을 이용한 막구조의 거스트 계수 산출 방법)

  • Wang, Ben-Gang;Jeong, Jae-Yong;You, Ki-Pyo;Kim, Young-Moon
    • Proceeding of KASS Symposium
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    • 2008.05a
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    • pp.19-24
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    • 2008
  • The thesis is for gust factor needing when calculate the wind resistance design. For the gust factor, to the membrane structural model, carry through the wind tunnel test and the static load test. Therefore, at first through the tensile test of the fabric material, designate the material of the membrane structural model. Then, to saddle, wave, arch and point four kinds of basic shape membrane structural models, carry on the wind tunnel test, determine their dynamic load and distortion on lateral direction. Finally, according to distort situation of the membrane structure in the wind tunnel test, carry on the static load experiment outside of the wind tunnel, calculate static load which corresponding with distort. According to dynamic load and the static load, figure out gust factor of these kinds of basic membrane structure.

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A Study on the Static and Dynamic Characteristics of Raised Girder Bridges (양각 거더교의 정적·동적특성에 관한 연구)

  • Ji-Yeon Lee;Sung Kim;Sung-Jin Park
    • Journal of the Society of Disaster Information
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    • v.19 no.4
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    • pp.851-858
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    • 2023
  • Purpose: A study was conducted to ensure the structural safety of a raised girder bridge with improved cross-sectional efficiency compared to the conventional PSC girder. For this purpose, the cross-sectional specifications such as girder length, height, and width were determined, the arrangement of the tendons was designed, and the practical performance of the raised girder under static and dynamic loads was verified. Method: The static performance experiment examined the serviceability limit state by measuring behavioral responses such as deflection and cracking to primary and secondary static loads. In addition, the dynamic load loading experiment measured the acceleration and displacement behavior response over time to calculate the natural frequency and damping ratio to examine the usability limit state. Result: As a result of the static performance test, the deflection value based on the maximum applied load showed stable behavior, and the crack width measured at the maximum applied load level was very small, satisfying the serviceability limit state. In addition, a natural frequency exceeding the natural frequency calculated during the design of the dynamic loading experiment was found, and a damping ratio that satisfies the current regulations was found to be secured.

Estimation of Dynamic Load Amplification Factors under Various Roughness Indices and Vehicle Classes (주행차량의 종류와 아스팔트 콘크리트 포장 평탄성에 따른 동적하중 증가계수 산정)

  • Choi, Jun-Seong;Seo, Joo-Won;Kim, Jong-Woo
    • International Journal of Highway Engineering
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    • v.14 no.2
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    • pp.29-36
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    • 2012
  • In this study, frequently passing vehicles with two, three, four, and five axles were chosen through traffic volume analysis in Kyung-In Expressway in order to analyze how the road roughness and vehicle speed affect on the dynamic loads for roads in various vehicle classes. Dynamic loads according to chosen vehicles are estimated by TruckSim program. Dynamic load amplification factor is ratio between dynamic and static loads, and it is also determined for each vehicle classes. From the result of dynamic loads estimated by the dynamic load amplification factor, it is shown that for three-axles vehicle, when IRI is 3.5 and vehicle speed is 100km/hr, asphalt pavements receive additional 36% of static loads in maximum. The analysis of the amplification factor according to each vehicle classes also indicates that the amplification factor increases as the distance between the axles becomes smaller and each axle receives more loads.

Shear Resistance of CIP Anchors under Dynamic Loading: Reinforced Anchor (선설치앵커의 동적 전단하중에 대한 저항강도: 철근보강 앵커)

  • Park, Yong Myung;Kang, Moon Ki;Roh, Jin Kyung;Ju, Ho Jung;Kang, Choong Hyun
    • Journal of Korean Society of Steel Construction
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    • v.26 no.1
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    • pp.21-30
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    • 2014
  • In this study, an experimental study was performed to evaluate the shear resistance of cast-in-place(CIP) anchors reinforced with hairpin and stirrup bars under static and dynamic loads. The reinforcement was developed using D6 bars, and the anchors were installed with 20mm diameter and 120mm edge distance. Three tests were conducted for each type of reinforced anchor under static and dynamic shear load with a pulsating frequency of 1 Hz, respectively. It was found that the strength of hairpin-reinforced anchor was affected by the concrete cover and the dynamic tests showed no capacity reduction of anchors compared with static tests. The stirrup-reinforced anchor showed little increase of resistance compared with unreinforced anchor and the resistance under dynamic loading showed nearly same strength by static loading.

Effects of Cyclic Loading Rate on response of Reinforced Concrete Structures (철근콘크리트 구조물에 대한 반복하중속도의 영향에 관한 연구)

  • Chung, Lan;Park, Hyun-Soo
    • Computational Structural Engineering
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    • v.2 no.3
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    • pp.77-84
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    • 1989
  • Small-scale models of reinforced concrete beam-column joints and anchorage-bond specimens were subjected to large cyclic displacements at two rates. To assess damage, free vibration tests were conducted. The reliability of the modeling techniques was established by comparison of the results for the slower rate with those obtained from the full-scale tests on prototype. The higher rate of loading caused a greater damage than that at the slower rate. This was evidenced by the measurements of the stiffness obtained from the free-vibration test. The relatively greater extent of damage appears to result from the different bond behavior at different rates of loading.

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Shear Resistance of CIP Anchors under Dynamic Loading: Unreinforced Anchor (선설치앵커의 동적 전단하중에 대한 저항강도: 비보강 앵커)

  • Park, Yong Myung;Kang, Moon Ki;Kim, Dong Hyun;Lee, Jong Han;Kang, Choong Hyun
    • Journal of Korean Society of Steel Construction
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    • v.26 no.1
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    • pp.11-20
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    • 2014
  • The Concrete Capacity Design(CCD) method has been used in the design of anchor since 2001 and Korean design code specify that concrete breakout capacity of CIP anchor under seismic load shall be taken as 75% of static capacity. In this study, an experimental study was performed to evaluate the concrete breakout capacity of unreinforced CIP anchors under dynamic shear force. For the purpose, three static and dynamic shear-loading tests were conducted using 20mm diameter anchors, respectively. The edge distance of 120mm was considered in the tests. In the dynamic tests, 15 cycles pulsating load with 1Hz speed was applied and the magnitude of loading step was increased until concrete breakout failure occurs. From the tests, the concrete breakout capacity under dynamic shear loading showed nearly same capacity by static loading.

말뚝기초의 내진설계

  • 이인모;오진기
    • Computational Structural Engineering
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    • v.3 no.3
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    • pp.48-52
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    • 1990
  • 최근 우리나라에서도 지진으로 인한 재해를 최소한으로 감소 또는 방지하기 위하여 일반 건축 구조물의 내진설계를 의무화 하도록 규정하고 있다. 그러나 지진하중에 대한 지반-말뚝-구조물 시스템의 내진해석과 설계는 아직도 완전하게 정립되지 못한 실정이며, 지금까지 우리나라에서 원자력발전소, 해양구조물 등과 같은 특수 구조물과 몇몇 고층건물을 제외한 대부분의 일반 건축물에 대한 말뚝의 설계도 지반의 동적특성을 제대롤 반영하지 않는 정적해석이 수행되고 있다. 그렇지만 정적하중과 지진하중의 하중특성은 근본적인 차이가 있으므로 이에 대한 설계를 추가하여야 한다. 따라서 본 고에서는 깊은 기초의 내진설계에 적용하기 위해 이제까지 연구발표된 여러가지 내진해석방법을 간략하게 소개하고 이를 비교, 검토함으로써 동적특성을 어느정도 반영하는 실용적인 설계법을 제시하고자 한다.

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Static, Dynamic and Buckling Analyses of a Power Transmission Tower under Wind Load (풍하중을 받는 송전철탑의 정적, 동적 및 좌굴해석)

  • Jung, Hyung-Jo;Shin, Dong-Seung;Moon, Byoung-Wook;Park, Ji-Hun;Lee, Sung-Kyung;Min, Kyung-Won
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.19 no.4 s.74
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    • pp.369-374
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    • 2006
  • This paper describes dynamic characteristics of a power transmission tower consisting of lots of power lines and insulators. A numerical 3D modeling for the static, dynamic and buckling analyses of the power transmission tower is presented considering the case when the power lines are cut. Eigenvalue analysis indicates that the transmission tower shows different behavior comparing to usual structures governed by several low modes. The transmission tower is governed by lots of modes. It is verified that the transmission tower is structurally safe against the static wind and buckling loads. But the structural and buckling safety is not guaranteed when all power lines are cut, which comes to collapse the transmission tower. Further study is in need to overcome such case. Wind dynamic analysis shows that fluctuating wind loads increase the response of the tower.

Sensitivity Analysis of 3-Dimensional FE Models for Jointed Concrete Pavements (줄눈 콘크리트포장 3차원 유한요소모델의 민간도 분석)

  • Yoo, Taeseok;Sim, Jongsung
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.3D
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    • pp.435-444
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    • 2006
  • This paper investigates the effect of 3-dimensional FE models to evaluation results of jointed concrete pavements which is back-calculated by AREA method. Sensitivity of 3-dimensional FE models developed to simulate the behavior of real jointed concrete pavement are analyzed after compared with 2-dimensional FE models using ILLISLAB. In comparison with 2-dimensional models, influence of concrete contraction under loading plate and base layer on surface deflections is more than that of loading configuration. Deflections at 3-dimensional model between linear and nonlinear temperature distribution under same temperature difference are similar, but noticeable differences are investigated in low elastic modulus of foundations. Dynamic deflections under loading plate are larger than static deflections in high elastic modulus of foundation, but smaller in low elastic modulus. Lower dynamic modulus of subgrade reactions are backcalculated by dynamic deflections than by static deflections. But reverse trend is investigated in the backcalculated elastic modulus of concrete which describes trends of the field backcalculation values calculated from AREA method.

New Equivalent Static Analysis Method of Dynamic Behavior during Progressive Collapse (연쇄붕괴의 동적거동을 고려한 새로운 등가정적해석 기법)

  • Kim, Chee-Kyeong;Lee, Jae-Cheol
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.20 no.3
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    • pp.239-246
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    • 2007
  • In this paper a new equivalent static analysis method of dynamic behavior during progressive collapse is presented. The proposed analysis method uses the equivalent nodal load for the element stiffness which represents the dynamic behavior influence caused by the deletion of elements during progressive collapse analysis. The proposed analysis method improves the efficiency of progressive collapse analysis haying the iterative characteristic because the inverse of the structural stiffness matrix is roused in the reanalysis. By comparing the results obtained by this analysis method with those of GSA code analysis and time history analysis, it is shown that the results obtained by this analysis method more closely approach to those of time history analysis than by GSA code analysis.