• Title/Summary/Keyword: 집중 하중

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Performance Evaluation of Softwood Plywood as Structural and Concrete-Form Panels (침엽수 합판의 구조용 및 콘크리트 거푸집용으로서의 성능 평가)

  • Lee, Jun-Jae;Kim, Gwang-Chul;Lee, Guk-Sik
    • Journal of the Korean Wood Science and Technology
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    • v.28 no.3
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    • pp.14-24
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    • 2000
  • In present research, the plywoods made of radiata pine or Japanese larch, the potential softwood species in mass supply, were discussed to examine their feasibility as the structural and concrete form panels through the basic properties test. First, plywood qualities and its nail performance were tested. The performance test for concrete form or structural panel by concentrated and uniformly distributed load were conducted to investigate the possibility as structural material for light frame and concrete constructions. Test results of basic quality such as specific gravity, cupping, bowing, and twisting appeared to satisfy the criteria for structural use. Also, nail performance test results, for roof and wall sheathing panels, nail lateral resistance, nail withdrawal resistance, and nail push head resistance proved to meet the required standard for structural use. The test results on performance as structural panel by concentrated and uniformly distributed load and as concrete form panel showed that these two species could be used for structural sheathing, subfloor, and concrete form panels.

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Study on Analysis of Skew Grillage Girder Bridges by Transfer Matrix Method (전달행렬법에 의한 경사 격자교의 해석에 관한 연구)

  • Kim, Yong-Hee;Lee, Yoon-Young;Kim, Kwang-Ho
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.9 no.1
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    • pp.159-170
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    • 2005
  • The grid structure is parallel main girders intersected with crossgirder. It distribute the loads to adjoining main girder through the crossgirder when a girder is subjected to a load. grillage girder bridge has high load-carrying capacity, it can save materials and become more economical type of bridge. In this paper, the grillage girder bridge analysis program developed by using the transfer matrix method deals with following problems: the comparision with Leonhardt, Szabo, FEM yang and jung in the analysis of grillage girder bridges, quality of straight and curved bridges with skew angle, forces of straight and curved bridges according to skew angle and bending stiffness/torsional stiffness ratio.

The Behavior of Rammed Aggregate Piers (RAP) in Soft Ground (I) (연악지반의 쇄석다짐말뚝에 대한 거동 분석 (I))

  • Bae, Kyung-Tae;Lee, Chong-Kyu
    • Journal of the Korean Geotechnical Society
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    • v.23 no.4
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    • pp.169-183
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    • 2007
  • Numerical analysis was performed to investigate the behavior of rammed aggregate piers (RAP) in soft ground with various interface conditions, area replacement ratio, aspect ratio and surcharge loads of pile and soil. And field modulus load test was carried out to predict the input parameters. Field prototype (unit cell) tests are in progress to compare the result of numerical analysis. Also a modified load transfer equation of RAP on soft foundation was proposed. According to the results, the behavior of RAP depended on such as interface conditions, settlement characteristics (free strain) and stress concentration ratio. On the other hand, maximun stress concentration ratio increased as area replacement ratio and aspect ratio increased, and it was remarkably affected by surcharge loads.

Effect of the Combination of Point Loads on the Design Flexural Capacity for Fiber Reinforced Concrete Floor Slab (집중하중 조합에 의한 섬유 보강 콘크리트 바닥슬래브의 설계 휨 내력)

  • Lee, Jong-Han;Cho, Baik-Soon;Kim, Jung-Sik;Cho, Bum-Gu;Ki, Han-Sik
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.4 no.1
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    • pp.47-54
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    • 2016
  • In this study, the flexural capacity of fiber reinforced concrete floor slabs were evaluated using main design loads, racking and moving loads. Based on design standards and guidelines, the magnitude and loaded area of each load were determined, and its relationship was assessed. For the application of a single load, flexural capacity should be evaluated in the edge of a floor slab. In addition, the slab with thickness and concrete strength, greater than 180mm and 35MPa, respectively, sufficiently satisfied flexural capacity with a minimum of equivalent flexural strength ratio. The combination of racking loads required the largest equivalent flexural strength ratio to satisfy the flexural capacity of the floor slab. The combination of racking and moving loads showed equivalent flexural strength ratio smaller than the case of combination of racking loads, but larger than the application of single racking or moving loads. The results of this study indicated that the flexure of fiber reinforced concrete floor slabs should be designed using the combination of design loads.

Random Vibration and Harmonic Response Analyses of Upper Guide Structure Assembly to Flow Induced Loads (유체유발하중을 받는 상부안내구조물의 랜덤진동 및 조화응답해석)

  • 지용관;이영신
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.15 no.1
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    • pp.59-68
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    • 2002
  • The cylindrical Upper Guide Structure assembly of the reactor intervals wish the Core Support Barrel and the Inner Barrel Assembly is subjected to flow induced loads horizontally which include random pressure fluctuation due to turbulent flow and pump pulsation pressures. The purpose of this papers is to perform random vibration and harmonic response analyses fort flow induced loads. The dynamic response characteristics due to random turbulence and pump pulsation loads were evaluated using the lumped mass beam model. Especially the model considered the annulus effects due to water gaps existing between cylindrical structures such as the Upper Guide Structure Barrel, the Core Support Barrel, and the Inner Barrel Assembly. The effect of the Inner Barrel Assembly inside the Upper Guide Structure assembly was studied. The peak dynamic responses lot each loading condition due to the addition of IBA were affected by the natural frequencies of the structures. Therefore the peak dynamic responses of the structures should be conservatively obtained from evaluation of dynamic analysis for various loading conditions.

Quantitative Damage Model of Steel Members under Severe Seismic Loading (강한 지진하중하에서 강부재의 정량적인 손상 모델)

  • Park, Yeon Soo;Park, Sun Joon
    • Journal of Korean Society of Steel Construction
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    • v.10 no.3 s.36
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    • pp.339-353
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    • 1998
  • In this paper, the previous damage models for structures and their components under seismic repeated loading were reviewed systematically. A failure criterion for steel members under severe cyclic excitations as in strong earthquakes was described. A new approach to seismic damage assessment for steel members was proposed. This method was based on a series of the experimental and numerical investigations for steel members under very low cyclic loading. In this study, very low cyclic loading means repetitive loading, 5 to 20 loading cycles, within the large plastic range. The proposed damage assessment method was focused on the local strain history at the cross-section of the most severe concentration of deformation.

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Antiplane Problem of Interfacial Cracks Bonded with Transversely Isotropic Piezoelectric Media (횡등방 압전재료의 면외 계면균열문제)

  • Choi, Sung-Ryul
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.36 no.6
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    • pp.665-672
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    • 2012
  • Interfacial cracks bonded with dissimilar transversely isotropic piezoelectric media that are subjected to combined anti-plane mechanical and in-plane electrical loading are analyzed. The problem is formulated using complex function theory, from which the Hilbert problem is derived. By solving the Hilbert problem, the general form solution is obtained. Using this solution, closed-form solutions for one or two finite cracks as well as a semi-infinite crack are obtained, for the problem in which one concentrated mechanical and electrical load is imposed on the crack surface. This solution could be used as a Green's function to generate solutions to other problems with the same geometry but different loading conditions.

Post-buckling of Non-uniform Cantilever Column Subjected to a Combined Load (결합하중을 받는 임의단면 기둥의 좌굴후 해석)

  • Shin, Young-Jae;Chiba, Masakatsu
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.12 no.5
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    • pp.323-329
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    • 2002
  • This paper presents the application of the technique of differential transformation to the post-buckling problem of non-uniform cantilever column subjected to a combined load. Numerical calculations are carried out and compared with previously published results to validate the results of the present method. The results obtained by this method agree very well with those reported in the previous works. The results obtained by the present method are presented for both various non-uniform columns and loads.

The Investigation of the Effects on Bent-up Bars within Beam-Column Joint Core with High-Strength Concrete (고강도 콘크리트 보-기둥접합부의 역학적 거동에 대한 연구 -구부림 철근을 중심으로-)

  • 이광수;오정근;신성우;최문식
    • Magazine of the Korea Concrete Institute
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    • v.3 no.2
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    • pp.123-132
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    • 1991
  • The purpose of this study was to Investigate the effects of bent - up bar Within beam - column 1lint core with High - Strength Concrete up to 800kg/$cm^2$. To achieve these objectives, 5 specimens were designed and tested under monotoric loading and reversed cyclic loadings. The primary variables were the number of bent-up bars, compressive strength of concrete and loading patterns. The results showed that the load capacity of specimen subjected to monotonic loading had more large than that of specirnn subjected to reversed cyclic loadings and the bent - up bar within joint core could prevented the crack at the joint face from propagating into the pint core but the failure was concentrated at the face of beam - column pint. Thus the study on flexural strength ratio should be accomplished before using bent - up bars within the joint core.

A Study on Stress Concentration Factor at Fillet Welded Joint (필렛용접이음부의 응력집중계수에 관한 연구)

  • S.W. Kang;W.I. Ha;J.S. Shin;J.S. Jae
    • Journal of the Society of Naval Architects of Korea
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    • v.33 no.3
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    • pp.1-7
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    • 1996
  • The stress concentration factor gives the significant effect the fatigue strength of welded joints. The model used herein is the type of the load carrying fillet welded cruciform joint with full or partial penetration. In order to obtain the stress concentration factor at the weld toe of fillet joint, the reasonable element size of the toe part is investigated and the stress analysis for the series models by FEM under tensile load is performed. On the basis of the calculation results, the estimated formulae for the stress concentration factor(Kt) at weld toe part of the fillet welded joint, which the effect of toe radius, flank angle and other parameters are taken into account, is derived.

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