• Title/Summary/Keyword: consolidation process

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Measurement Method of Residual Stresses in Thick Composite Cylinders (두꺼운 복합재 원통의 잔류응력 측정방법)

  • Kim, Jong-Woon;Park, Dong-Chang;Lee, Dai-Gil
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2005.04a
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    • pp.245-248
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    • 2005
  • During manufacturing thick composite cylinders, large thermal residual stresses are developed and induce catastrophic interlaminar failures. Since the residual stresses are dependent on many process parameters, such as temperature distribution during cure, cure shrinkage, winding tension, and migration of fibers, calculation of the residual stresses is very difficult. Therefore a radial-cut method have been used to measure the residual stresses in the composite cylinders. But the conventional radial-cut method needs to know numerous material properties which are not only troublesome to obtain but also vary with change of fiber arrangement during consolidation. In this paper, a new radial-cut method with cut-cylinder-bending test was proposed and the measured residual stresses were compared with calculated thermal residual stresses. It was found that the new radial-cut method which does not need to know any of material properties gave better estimation of residual stresses regardless of radial variation of material properties. Additionally, interlaminar tensile strength could be obtained by the cut-cylinder-bending test.

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The Study on the Behavior of Closed-Faced Shield Tunneling by Two Dimensional Elasto-Plastic Analysis (2차원 탄소성해석에 의한 밀폐형 실드터널의 거동에 관한 연구)

  • 진치섭;이홍주;한상중
    • Computational Structural Engineering
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    • v.9 no.4
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    • pp.199-207
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    • 1996
  • In the past decade soft clay shield tunneling technology have been improved to permit continuous support to the face of a tunnel. These advanced shield can be operated such that an initial heaving is created, this helps to decrease the inward soil movement into the tail void. In this paper, the measurement of slurry shield and EPB shield were used and two dimensional elasto-plastic programs EPSHILD developed for shield tunnel analysis were approved. The excavation steps corresponding with construction stages were settled and heaving load, load factors were considered. This study is based on the instantaneous settlement which is occured in the process of shield construction but not the secondary settlement by consolidation.

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Ecological and Cultural Village Renewal in Germany (독일의 생태.문화적 마을재정비(Dorferneuerung)에 관한 고찰)

  • 이상문
    • Journal of Korean Society of Rural Planning
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    • v.2 no.1
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    • pp.57-68
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    • 1996
  • Village Renewal(Dorferneuerung) Policy Program in Germany, directly originated from Rural Beutification Movement between mid 18C and mid 19C, has several characteristics as follows. First, we can find out the planned approach in land use and settlement reorganization of Pillage Renewal Program. There are three ways to designate the planning area of the village rearrangement project in countryside. One is to designate the detailed B-plan district by urban plan for the village over some size defined legally. Another is to have a living space of settlement be contained in land allotment project area. In this case, residential areas of several villages related to agricultural land consolidation should be simultaneously designated as the project area. The last is only for the built environment focused on the living space. Second, the emphasis in German village encouragement program can be made on the integral approach through which sets of policy programs of the land allotment, the living environment improvement, the physical landscape management and the cultural resources conservation are intensively implemented together. Third, the bottom-up and community participation approach can be greatly stressed on the planning and implementation process, Community participation, subsidy application to local government by residents themselves, community consensus on architectural style and outdoor spatial form, etc. have been recognized as an effective strategy to accomplish the task of village activity promotion.

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A Study on the Property of Dredging Soils Stratified by Two dimensional Segregating Sedimentation (2차원 분리퇴적에 의한 준설토의 성상에 관한 연구)

  • Kim, Hyeong-Joo;Shim, Min-Bo;Jeon, Hye-Sun;Lee, Min-Sun;Paek, Pil-Soon;Choe, Dae-Il
    • Proceedings of the Korean Geotechical Society Conference
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    • 2006.10a
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    • pp.481-489
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    • 2006
  • Two dimensional diffusion model test was conducted to investigate the sedimentation properties and consolidation process of reclaimed ground using dredging coarse soil which is composed of passing amount 20 percentage and 45 percentage of #200 sieve size respectively. The passing amount of #200 sieve size affected on sedimentation properties. The coarse soil which is passing amount of 20 percent showed that the sedimentation structure was layered type and passing amount of 45 percentage was wall-partition type according diffusion distance. Furthermore, the water content of surface and section, and distribution of fine soil were changed according to diffusion distance. and the change amount of pore water pressure and strength property when soil is diffused, segregated and accumulated can be applied efficiently in design of dredging and reclamation.

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Relationship Between Farm Land Structure and Machine Operation in Korea

  • Singh, Gajendra;Ahn, Duck-Hyun
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • 1993.10a
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    • pp.129-138
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    • 1993
  • The shortage of agricultural labour due to industrial growth has greatly induced the mechanization in Korean agriculture. However small and scattered land holdings have been the main constraints in the process of mechanization. This paper describes the interrelationships of farm land structure, machinery selection and machinery operation areas. The sandy silt loam irrigated paddy land having single crop a year was selected as a target areas for this study. Machine operation cost is greatly influenced by operation period, plot geometry and operation area. On the improved geometry plots, optimal machine size increases slowly with increase in operation area. Operable area increases due to increased effective machine capacity on better geometry plot. The difference between the effects of operation period and plot geometry is that in the former case, the cost reduction is caused by delay in increase of machine size, whereas in the latter case timeliness cost is reduced by increase ffective capacity. The effect of farmland consolidation is greater on small plots than that on big plots. Increasing wage rates have induced the adoption of more labor saving machinery. Bigger labor saving machines require enlargement of operation area and larger plots through improvement in farm land structure. Machine cost on poor plot geometry increases more rapidly than that on the good plot geometry and as operation area increases machine cost reduces significantly. It is concluded that the development of agricultural mechanization ion Korea will depend on the improvement in farm land structure and enlargement of operation area.

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Prediction of the load-displacement response of ground anchors via the load-transfer method

  • Chalmovsky, Juraj;Mica, Lumir
    • Geomechanics and Engineering
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    • v.20 no.4
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    • pp.359-370
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    • 2020
  • Prestressed ground anchors are important structural elements in geotechnical engineering. Despite their widespread usage, the design process is often significantly simplified. One of the major drawbacks of commonly used design methods is the assumption that skin friction is mobilized uniformly along an anchor's fixed length, one consequence of which is that a progressive failure phenomenon is neglected. The following paper introduces an alternative design approach - a computer algorithm employing the load-transfer method. The method is modified for the analysis of anchors and combined with a procedure for the derivation of load-transfer functions based on commonly available laboratory tests. The load-transfer function is divided into a pre-failure (hardening) and a post-failure (softening) segment. In this way, an aspect of non-linear stress-strain soil behavior is incorporated into the algorithm. The influence of post-grouting in terms of radial stress update, diameter enlargement, and grout consolidation is included. The axial stiffness of the anchor body is not held constant. Instead, it gradually decreases as a direct consequence of tensile cracks spreading in the grout material. An analysis of the program's operation is performed via a series of parametric studies in which the influence of governing parameters is investigated. Finally, two case studies concerning three investigation anchor load tests are presented.

Fabrication of FeCuNi alloy by mechanical alloying followed by consolidation using high-pressure torsion

  • Asghari-Rad, Peyman;Kim, Yongju;Nguyen, Nhung Thi-Cam;Kim, Hyoung Seop
    • Journal of Powder Materials
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    • v.27 no.1
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    • pp.1-7
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    • 2020
  • In this research, a new medium-entropy alloy with an equiatomic composition of FeCuNi was designed using a phase diagram (CALPHAD) technique. The FeCuNi MEA was produced from pure iron, copper, and nickel powders through mechanical alloying. The alloy powders were consolidated via a high-pressure torsion process to obtain a rigid bulk specimen. Subsequently, annealing treatment at different conditions was conducted on the four turn HPT-processed specimen. The microstructural analysis indicates that an ultrafine-grained microstructure is achieved after post-HPT annealing, and microstructural evolutions at various stages of processing were consistent with the thermodynamic calculations. The results indicate that the post-HPT-annealed microstructure consists of a dual-phase structure with two FCC phases: one rich in Cu and the other rich in Fe and Ni. The kernel average misorientation value decreases with the increase in the annealing time and temperature, indicating the recovery of HPT-induced dislocations.

Review of the KCAB International Arbitration Rules, Recently Revised, in Comparison with the Revised ICC Arbitration Rules (대한상사중재원 국제중재규칙의 개정 동향 - ICC 중재규칙의 개정과 비교하여 -)

  • Park, Won-Hyung
    • Journal of Arbitration Studies
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    • v.22 no.2
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    • pp.159-176
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    • 2012
  • The Korean Commercial Arbitration Board (KCAB) recently revised its International Arbitration Rules in a way that reflects its efforts to advance its procedures, leading directly to improved competitiveness as an arbitration institute. Apart from certain limitations, the KCAB's international arbitration rule revision introduced several new arbitration mechanisms, including fast-track arbitration and an empowered administrative office. The International Chamber of Commerce (ICC) released a revised set of arbitration rules (ICC Arbitration Rules), which have been said to be probably the most consulted-on arbitration rules ever. Even though the changes codify existing ICC court practice and add to the 1998 rules only provisions felt necessary in light of input from the users of arbitration, some of the changes will have huge implications for future aspects of arbitration mechanisms, especially those of KCAB. Although it remains to be seen what impact the ICC Arbitration Rules will have in practice, the new rules have been well received by the arbitration community and represent a modern set of provisions consistent with the current needs of the users of international arbitration. That is why, here in the Korean arbitration environment, further research is needed on the possibilities of introducing several elements of the revised ICC Arbitration Rules to improve the speed and cost efficiency of international arbitration.

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Settlement of Embankment and Foundation for Concrete Track of Gyungbu High Speed Railroad (경부고속철도 콘크리트궤도 토공 및 원지반 침하 (I))

  • Yang, Shin-Chu;Moon, Jae-Suk;Lee, Hyun-Jung;Kang, Dae-Woong;Kim, Dae-Sang
    • Journal of the Korean Society for Railway
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    • v.9 no.6 s.37
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    • pp.644-651
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    • 2006
  • An application of concrete track is being actively processed for the construction of Korean railroad. The concrete track has an advantage to decrease the maintenance ire, but is very difficult system to maintain after earthwork settlement occurred. Therefore, the management and control of embankment and foundation settlement is very important for the successful concrete track construction. We expect that the main part of the settlement of the concrete track is the one of embankment and foundation supporting it. Settlements vulnerable to the concrete track among the causes of lots of settlements are primary consolidation and secondary compression settlement of foundation, creep settlement of embankment, settlement caused by train load, and unequal settlement resulting from the difference of embankment material and construction process. This paper investigated the settlement causes to make badly effects on the concrete track and also evaluated the settlement with field tests and numerical analysis.

Conservation of Embroidered Textiles and Textile Works (자수 및 직물 공예품의 보존처리)

  • Ryu, Hyo-Seon
    • Journal of the Korean Society of Costume
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    • v.58 no.5
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    • pp.198-210
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    • 2008
  • The purpose of this study is to establish the conservation methods of embroidered textiles and textile works. The conservation of remained textiles is consisting of examination, cleaning, support and consolidation, restoration, and storage and display process. It aims to prevent the damage on textile remains for long time display and storage and to prolong their aesthetics and functionality. The embroidered textiles and textiles works, which are remained by handed down or excavated or included in the Buddhist are embossed with colorful threads on the fabrics: the stitches include embroideries on clothing, bed clothes, wrapping clothes, utensil pouches, panels and Buddhist goods; textile works include hats, ornaments, shoes, attachments of clothes etc. These are composed of mainly fabrics, precious metals, leathers and precious stones, etc., and are fabricated by several techniques such as braiding, twining, sewing as well as weaving. Metal threads were also used to add a decorative effect on these goods. In order to conserve and preserve the remained goods, a special care must be taken on the metal threads, which are the most fragile material among the constituents. Hence, characteristics of metal threads and its cleaning methods, general conservation techniques of a rank badge, which is brocaded and partly attached to Cheogori and Samo(men's hat) from the excavated old tombs are introduced here.