• Title/Summary/Keyword: 선하중

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50m급 비행선 구조하중 해석

  • Kang, Wang-Gu;Kim, Dong-Min;Lee, Jin-Woo;Yeom, Chan-Hong
    • Aerospace Engineering and Technology
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    • v.1 no.2
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    • pp.11-18
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    • 2002
  • The structural load analysis of 50m class airship was performed. The airship maneuver condition for analysis was defined. Aerodynamic, inertia and buoyance models were built. Control surface motion to make defined maneuver condition were calculated. Load factors, load, shear and bending moment envelops were developed for full airship and tailwing. Gondola design loads were developed.

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A Study on the Axle Load Limits of Asphalt Concrete Pavements (아스팔트 콘크리트 포장구조체의 제한교통하중에 관한 연구)

  • Kim, Soo Il;Choi, Jun Sung
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.12 no.2
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    • pp.67-76
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    • 1992
  • A procedure to determine the axle load limits of asphalt concrete pavements are proposed in this study. Axle load limits are determined by calculating maximum tensile strains at the bottom of the asphalt stabilized base layer and maximum vertical strains at the top of the subgrade. In order to investigate the efficiency of axle configuration, calculated influence line of wheel load on domestic expressway pavement system is used. Limiting strains are selected through the analysis of conventional failure criteria. From the analysis of axle load limits about axle composition(single-axle, tandem-axle, tridem-axle), it is found that the axle load limits of tandem-axle and tridem-axle can be calculated by muitipling the axle load limits of single-axle by axle numbers and that axle load limits are closely related to the thickness of each layer of pavement structure. It is also found that the axle load limits by tensile strains are more critical than those by vertical strains on asphalt concrete pavement models of YOUNG-DONG, KYONG-IN and KYONG-BU expressways.

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Development of a Static Prosthesis-Alignment Device Using a Force Plate and a Laser Light (힘측정판과 레이저 광을 이용한 정적 의족정렬장치의 개발)

  • 이기원;김기완;김영호
    • Journal of Biomedical Engineering Research
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    • v.21 no.4
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    • pp.385-390
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    • 2000
  • The alignment of the prosthetics is very important in an amputee's gait. In the present study. a static prosthesis-alignment device was developed. It consisted of a force plate with four load cells, a laser beam controlled by a step motor, and a control part programmed by PCBASIC. Using the static prosthesis-alignment device, we measured the distance between the load line and various joints of 24 normal volunteers in three standing postures. such as neutral, forward leaning, and backward leaning. Only neutral postures were evaluated on four trans-tibial amputees. The load line for the normal person's neutral position located anterior to the ankle, the knee, and the greater trochanter, but posterior to the shoulder joint. Forward and backward leaning of the normal person resulted in a significant anterior and posterior movements of the load line, respectively. The load line for the amputated side of the trans-tibial amputee also located anterior to the ankle, the extremity prostheses, providing a good relative locations of the load line with respect to various joints.

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Transient Effects of Wind-wave Hybrid Platform in Mooring Line Broken Condition (부유식 파력-해상풍력 복합발전 구조물의 계류선 손상 시 과도 응답 해석)

  • Bae, Yoon Hyeok;Lee, Hyebin
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.19 no.2
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    • pp.129-136
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    • 2016
  • Floating offshore structures keep its position by a mooring system against various kind of environmental loadings. For this reason, a reliable design of the mooring system is a key factor for initial design stage of a floating structure. However, there exists possibility of mooring failure, even the system is designed with enough safety margin, due to the unexpected extreme environmental conditions or long-term fatigue loadings. The breaking of one of the mooring lines may change the tension level of the other mooring lines, which can potentially result in a progressive failure of the entire structure. In this study, time domain numerical simulation of 10MW class wind-wave hybrid platform was carried out with partially broken mooring line. Overall platform responses and variations of the mooring line tension were numerically evaluated.

Experimental Study on the Performance of Korean PS Anchorage System in terms of Load Transfer Test (한국형 PS정착구의 하중전달성능에 관한 연구)

  • Kim, Jin-Kook;Lee, Pil-Goo;Jang, Seok-Youn
    • Proceedings of the Korea Concrete Institute Conference
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    • 2009.05a
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    • pp.37-38
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    • 2009
  • In this paper, the load transfer test of Korean PS anchorage system was conducted for 1860MPa PS strand and 2200MPa PS strand. The test is in compliance with ETAG013. All the anchorage system tested satisfied the allowance criteria of the test for 1860MPa PS strand but only one of the anchorage systems for 2200MPa PS strand. In order to generally use 2200MPa PS strand to prestressed concrete structures, new anchorage systems shall be developed.

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Development of Moving Force Identification Algorithm Using Moment Influence Lines at Multiple-Axes and Density Estimation Function (다축모멘트 영향선과 밀도추정함수를 사용한 이동하중식별 알고리듬의 개발)

  • Jeong, Ji-Weon;Shin, Soobong
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.10 no.6
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    • pp.87-94
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    • 2006
  • Estimating moving vehicle loads is important in modeling design loads for bridge design and construction. The paper proposes a moving force identification algorithm using moment influence lines measured at multi-axes. Density estimation function was applied to estimate more than two wheel loads when estimated load values fluctuated severely. The algorithm has been examined through simulation studies on a simple-span plate-girder bridge. Influences of measurement noise and error in velocity on the identification results were investigated in the simulation study. Also, laboratory experiments were carried out to examine the algorithm. The load identification capability was dependent on the type and speed of moving loads, but the developed algorithm could identify loads within 10% error in maximum.

The Earth Pressure on the Effect of Surcharge Load at the Narrowly Backfilled Soil (좁은 공간 되메움 지반에서의 상재하 영향에 의한 토압)

  • 문창열;이종규
    • Geotechnical Engineering
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    • v.13 no.6
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    • pp.165-180
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    • 1997
  • The structure such as underground external walls of buildings, conduit and box culvert supports the surcharge loads (point, strip and line loads) . The vertical and horizontal stresses in a soil mass depend on the backfill width and wall friction, etc. The investigations described in this paper is designed to identify the magnitude and the distributions of the lateral and vertical pressure which is occurred by the narrowly backfilled soil in an open cut by the surcharge loads. For these purposes, model tests were performed for various width of backfill in a model test box by considering the wall friction using carbon rods. The results of test were compared with the theories of Weissenbach and VS Army Code and also with the results of the numerical analysis using finite difference method which introduces Mohr-Coulomb failure hypothesis.

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An Experimental Study on the Flexural Behavior of Pre-loaded RC Beams Strengthened with CFRP-Rod (선하중(先荷重)을 받은 RC보의 CFRP-Rod 휨보강 효과에 대한 실험적 연구)

  • Ye, Sang-Min;Chun, Woo-Chul;Kang, Joo-Won;Park, Sung-Moo
    • Journal of Korean Association for Spatial Structures
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    • v.7 no.1 s.23
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    • pp.79-85
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    • 2007
  • Steel plate bonding method with epoxy is common applied to repair and strengthen RC structures, but Steel is apt to corrode quickly, hard to manufacture and heavy. To overcome these defects, it is carried out research on strengthening RC structures with FRP(Fibre Reinforced Polyrner/Plastic) FRP is generally used in the shape of Plate or Sheet, but it has weak point such as premature failure, difficult work. To cope with these problem, NSMR(Near Surface Mounted Reinforcement) which uses CFRP in the shape of Rod is proposed and carried out active research on strengthening effect of variables such as quantity, anchorage length and space of CFRP-Rod. Strengthening with CFRP-Rod is carried out under loading to some degree in fact, and so the amount of pre-loading is selected as variable in this research. The amount of pre-loading is chosen in proportion to nominal strength of non-strengthened specimen with CFRP-Rod.

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Early loading on a maxillary posterior single implant with deepened threads: a case report (깊은 나사선을 갖는 임플란트를 이용한 상악 구치부 조기 하중: 증례보고)

  • Han, Chang-Hoon;Kim, Hyun-Seung;Park, Sang-Won;Yun, Kwi-Dug;Joo, Han-Sung;Lim, Hyun-Pil
    • Journal of Dental Rehabilitation and Applied Science
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    • v.30 no.3
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    • pp.253-258
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    • 2014
  • This case report shows an early loading at the maxillary posterior area with the wide diameter implant which has a deepened threads after removal of failed implant. Implant Stability Quotient (ISQ) value has represented favorable result for one year. This clinical report describes the potential of early loading on a maxillary posterior single implant with deepened threads.

교량 하중 모형화

  • 황의승;홍영균
    • Computational Structural Engineering
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    • v.5 no.1
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    • pp.4-10
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    • 1992
  • 이 글에서는 교량하중모델의 개발에 대하여 기술하였다. 사하중, 적재하중 및 충격하중에 대한 확률론적 모형이 제시되었다. 적재하중의 경우 트럭 Data Base를 기초로 하여 일차선 교량 또는 단경간(지간 약 40m까지)에서는 한대의 트럭이, 2차선 교량의 경우는 완전상관된 두대의 평행트럭에 의해 결정되어진다. 대부분의 경우 현재의 AASHTO의 보분배계수는 안전측이 된다.(특히 보간격이 긴 경우) 충격하중계수는 노면 요척 및 교량과 트럭의 동적특성을 고려한 모의해석을 통하여 구해지는데 두대의 차량을 고려한 경우가 한대의 트럭을 고려할 경우보다 더 낮은 것으로 나타났다.

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