• Title/Summary/Keyword: 유동강도

Search Result 701, Processing Time 0.026 seconds

Fluid Structure Interaction Analysis of Membrane Type LNG CCS Experiencing the Sloshing Impact by Impinging Jet Model (멤브레인형 LNG 화물창의 강도평가를 위해 적용된 분사모델을 이용한 유체구조 연성해석에 관한 연구)

  • Hwang, Se Yun;Lee, Jang Hyun
    • Journal of the Computational Structural Engineering Institute of Korea
    • /
    • v.28 no.1
    • /
    • pp.71-78
    • /
    • 2015
  • The reliable sloshing assessment methods for LNG CCS(cargo containment system) are important to satisfy the structural strength of the systems. Multiphase fluid flow of LNG and Gas Compressibility may have a large effect on excited pressures and structural response. Impinging jet model has been introduced to simulate the impact of the LNG sloshing and analyze structural response of LNG CCS as a practical FSI(fluid structure interaction) method. The practical method based on fluid structure interaction analysis is employed in order to evaluate the structural strength in actual scale for Mark III CCS. The numerical model is based on an Euler model that employs the CVFEM(control volume based finite element method). It includes the particle motion of gas to simulate not only the interphase interaction between LNG liquid and gas and the impact load on the LNG insulation box. The analysis results by proposed method are evaluated and discussed for an effectiveness of FSI analysis method.

A Study on Strength Characteristics of Dredged Soft Clay (준설 연약 점토의 전단강도 특성에 관한 연구)

  • Lee, Song;Yun, Don-Kyu;Paik, Young-Shik
    • Geotechnical Engineering
    • /
    • v.10 no.4
    • /
    • pp.153-166
    • /
    • 1994
  • In this paper, the experimental study on the behavior of the dredged clay was performed by introducing the consolidation teat method using continuous loading. Also a new testing method was examined and the strength of the dredged clay using thin plate was evaluated. The rheological characteristics of the dredged clay are described by the gingham model. The static and rheologic thin plate penetration test is proposed for the shear strength testing method. It is found that both of testing methods are reasonable and have a practicability. Especially, the strength increases for a water content which is less than two times of liquid limit in case of silty soil and clayey soil. About plasticity index, the strength increases rapidly for a value less than 10 for silt, 5 for clay which a water content is normalized by plasticity index of silty soil rather than clayey soil.

  • PDF

Flowability and Strength Properties of High Flowing Self-Compacting Concrete with Steel Fiber Reinforced (강섬유가 혼입된 고유동 자기충전 콘크리트의 유동 및 강도 특성)

  • Choi, Yun-Wang;Choi, Wook;Jung, Jea-Gwone;An, Tae-Ho
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.13 no.1 s.53
    • /
    • pp.161-168
    • /
    • 2009
  • In this study, the concrete, in which the steel fiber(SF) with different volume-surface ratios and lengths was intermixed in High flowing Self-Compacting Concrete(HSCC), was produced to compare with steel fiber reinforced concrete as a part of plan to improve the workability and the quality of steel fiber reinforced concrete. As the result of experiment, the flowing and passing characteristics of HSCC intermixed with SF was highly improved as there was no fiber ball phenomenon due to the effect of high flowability and the viscosity, and in the identical range of compressive strength, it showed the tendency that the splitting and flexural strength was increasing as the length was getting longer regardless of volume-surface ratio when compared with HSCC which was intermixed with SF. It is estimated that in case of application of HSCC intermixed with steel fiber to work sites, it would be possible to improve the workability and the quality which would be better than that of steel fiber reinforced concrete which has been used.

A case study on the lateral movement of bridge abutment foundation and repair methods (교대의 측방변위와 대책공법에 대한 사례연구)

  • Lee, Byung-Suk;Lee, Jae-Yeol
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.13 no.3
    • /
    • pp.1359-1369
    • /
    • 2012
  • In the case of using pile foundation to support bridge abutments on soft ground, the soft ground often causes serious troubles such as lateral movement of bridge abutments by lateral surcharges. In this paper, we investigated and measured the amount of strain of a bridge abutment in the south-western part of Korea. To check the stability and possibility of lateral movement of the bridge abutment, we used the four analysis methods and compared those results; lateral movement index, index for decision of lateral movement and infinite element analysis method. We performed soil and ground tests to fine the causes of the strain and lateral movement. After reviwing several types of repair methods, we suggested the anker reinforcement method along with surcharge process method as a proper repair and rehabilitation of the bridge abutment. Our investigation by through the infinite element analysis method confirmed the effectiveness of the anker reinforcement method allong with the surcharge process method.

A Study on the Behavior of Piled Abutment Subjected to Lateral Soil Movement of Soft Ground Improved by Deep Cement Mixing Method (DCM 공법으로 개량된 연약지반의 측방유동을 받는 교대 말뚝기초의 거동 분석에 관한 연구)

  • Choi, Yeonho;Kang, Gyeongho
    • The Journal of Engineering Geology
    • /
    • v.30 no.2
    • /
    • pp.131-145
    • /
    • 2020
  • The construction on these flimsy ground, activation of unsymmetrical surcharges, can often cause of the embankment road lateral flow or the destruction of the activities. In this study, the stability of the abutment pile foundation installed on soft ground and its behavior has been evaluated. The behavior of the abutment pile foundation under lateral flow was studied by verifying the behavior and reinforcement effects of the abutment pile foundation of previous studies about horizontal loads acting on the pile due to the lateral flow of the ground by performing finite element analysis. As a result of the consolidation analyses, the undrained cohesion or the strength of the soft ground, was increased by about 1.1 to 1.8 times by the increase in the strength of the soft ground according to the degree of consolidation. It is deemed reasonable to use 3.8 cm of the allowable displacement both economically and constructively, but considering the importance of the structure and the uncertainty of the ground, measurement shall be carried out during construction and thorough safety management of the lateral flow should be done.

Prediction for Liquefaction and Lateral Flow on Non-plastic Silt (비소성실트지반의 액상화 및 측방유동량 예측)

  • Yang, Taeseon;Song, Byungwoong
    • Journal of the Korean GEO-environmental Society
    • /
    • v.12 no.11
    • /
    • pp.65-70
    • /
    • 2011
  • It is well known all much information for evaluation on possibility of liquefaction and lateral flow for sand over the world. Recently, it is started to be known that liquefaction happens on non-plastic silt, too. But cyclic and post-cyclic characteristics for non-plastic silt is a few familiar to the world. Specially, it is not aware of the estimating method for lateral flow on non-plastic silt. The main purpose in this paper is to propose the evaluation for liquefaction and lateral flow on non-plastic silt. The method used in this research is that possibility for liquefaction on non-plastic silt was evaluated with cyclic direct simple shear test, and then residental strength was estimated with static shear test. Through the test results liquefaction on non-plastic silt is well not happened but strength decreases rapidly with increasing shear stress. With the proposed method it can be evaluated possibility of liquefaction and propose lateral flow.

Improving Performance of Recycled Waste Concrete (재생 폐콘크리트의 성능향상에 관한 연구)

  • 이봉학;김광우;박제선;김진영
    • Magazine of the Korea Concrete Institute
    • /
    • v.7 no.2
    • /
    • pp.136-145
    • /
    • 1995
  • A method for lmprovlng strengths of recycled concrete was studied to make use of it in nolmal concrete structures. Recycled conc~ete was prepared by replacing 50% by weight of coarse aggregate with recycled aggregate. Mix design rnet hod for crushed aggregates was used and specirriens were cured by normal moisture curing method. A plastlciser and a fly ash were added to the mix to improve performance of recycled concrete. Compressive strength, flexural strength, tensile strength, elastic modulus, stress-strain relationship, long-term compressive strength and fracture toughness were evaluated and compared with those of rlormal concretes. Recycled concrete showed, in general, lower compressive strength than normal concreks. It also showed lower elastic modulus, lower tensile and flexural strengths, and higher strain under the same stress level. However, by reducing w /c ratio down to 35% using the plasticiser. average compressive strength(${\alpha}_{28}$) of recycled concrete was reached. with slump of $16{\pm}2$cm, to $225kg/cm^2$ or hlgher, which is an acceptable strmgth level for normal structural concrete. I-Iowevei., elastic modulus and strain should be improved further for practical use of recycled concrctc: in normal structure. Fly ash addition in both concretes showed an effect of irnprovilig long term compressive strength and reducing strengths.