• Title/Summary/Keyword: Stress variation

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Elasto-plastic Joint Finite Element Analysis of Root-pile Using the Direct Shear Test Model (직접전단시험모델에 의한 뿌리말뚝의 탄소성조인트 유한요소해석)

  • Han, Jung-Geun
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.5 no.4
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    • pp.19-30
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    • 2002
  • The stability of slope using root-pile like to the reinforcements is affected by the interaction behavior mechanism of soil-reinforcements. Through the studying on the interaction in joint of its, therefore, the control roles can be find out in installed slope. In study, the stress level ratio based on the insert angle of installed reinforcements in soil used to numerical analysis, which was results from the duty direct shear test in Lab. The maximum shear strain variation on the reinforcements was observed at insert angle, which was approximately similar to the calculated angle based on the equation proposed by the Jewell. The elasto-plastic joint model on the contact area of soil-reinforcements was presumed, the reinforced soil assumed non-linear elastic model and the reinforcements supposed elastic model, respectively. The finite element analysis of assumed models was performed. The shear strain variation of non-reinforced state obtained by the FEM analysis including elasto-plastic joint elements were shown the rationality of general limit equilibrium analysis for the slope failure mode on driving zone and resistance zone, which based on the stress level step according to failure ratio. Through the variation of shear strain for the variation of inserting angle of reinforcements, the different mechanism on the bending and the shear resistance of reinforcements was shown fair possibility.

Stress Patterns of Compound Nouns in English (영어 복합명사의 강세형)

  • Lee Yeong-Kil
    • MALSORI
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    • no.42
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    • pp.25-36
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    • 2001
  • Stress assignment has been much discussed in the literature on English compound nouns. The general view of the stress pattern of English compound nouns is that a main stress falls on the first element and a secondary stress on the second element; however, a stress pattern is often employed that provides counterevidence to the traditional pedagogical approach. A new idea is suggested by Ladd(1984) that 'compound stress represents the deaccenting of the head of the compound.' Recent studies show that initial stressing does not indicate compounds and syntactic phrases are not always characterized by final stressing. In his pilot test Pennanen comments on the frequent variation of stress patterns on individual items, on the basis of which Bauer confirms Pennanen's results with different informants. This paper is an attempt to justify Bauer's analysis with the same data as Bauer's and different subjects. It turns out that the competences of native-speaker informants do not rovide clear-cut answers. Some factors should be taken into account in assigning appropirate stress to compound nouns.

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Thermal stress analysis around a cavity on a bimetal

  • Baytak, Tugba;Bulut, Osman
    • Structural Engineering and Mechanics
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    • v.69 no.1
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    • pp.69-75
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    • 2019
  • The plates made of two materials joined to each other having the different coefficient of thermal expansions are frequently encountered in the industrial applications. The stress analysis of these members under the effect of high-temperature variation has great importance in design. In this study, the stress analysis of the experimental model developed for the problem considered here was performed by the method of photothermoelasticity. The thermal strains were formed by the mechanical way and these were fixed by the strain freezing method. For the stress measurements, the method of slicing is applied which provides three-dimensional stress analysis. The analytical solution in the literature was compared with the related stress distribution obtained from the model. Moreover, the axisymmetric finite element model developed for the problem was solved by ABAQUS and the results obtained here compared with those of the experimental model and the analytical solution. As a result of this study, this experimental method and numerical model can be used for these type of thermal stress problems which have not been comprehensively analyzed yet.

A Study on Structural Analysis of Globe Valve for LNG Carrier (LNG선박용 글로브 밸브 구조해석에 관한 연구)

  • Kim, Dong-Kyoon;Kim, Jeong-Hwan
    • Journal of Advanced Marine Engineering and Technology
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    • v.31 no.8
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    • pp.1013-1019
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    • 2007
  • This paper is about structural analysis of globe valve for controlling cryogenic LNG's flow or stop in normal temperature. The used valve is demanded safety resistance for inner pressure and temperature variation caused by using it in cryogenic, high pressure surrounding. This study evaluates for safety resistance for inner pressure and temperature variation by heat transfer analysis in cryogenic surrounding, heat stress analysis in temperature variation and deformation analysis in high pressure.

Characteristic Variation of Underwater Acoustic Transducer with Electric Decoupler (절연층을 고려한 수중음향 트랜스듀서의 특성변화 고찰)

  • Seo, Hee-Sun;Kim, Jung-Suk;lee, Jeong-Min
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2005.11a
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    • pp.244-246
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    • 2005
  • The Tonpiltz transducer is one of the essential elements in sonar application. The characteristics of transducer depend on the piezoelectric ceramics and mechanical elements such as head mass, tail mass, pre-stress rod and so on. One of the important characteristics is stable electric resistance for high power transmitting operation. This paper presents characteristics variation of the underwater acoustic transducer with material variation of electric decoupler.

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Analysis on Specific Cutting Resistance Variation by Tool Angles Based on a Concept of Representative Stres (겉보기 응력 개념에 기반한 공구각에 따른 비절삭저항 변화 분석)

  • Jeon, Eun-Chae;Choi, Hwan-Jin;Lee, Kyu-Min;Lee, Yun-Hee;Je, Tae-Jin;Kim, Jeong-Hwan;Choi, Doo-Sun
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.13 no.2
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    • pp.64-72
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    • 2014
  • In the past, prism patterns have been linear triangular shapeswith a $90^{\circ}$ angle; however, new micro prism patterns having acute angles or obtuse angles have recently been the subject of demandin the display, lighting and photovoltaic industries. Micro-cutting experiments for micro-prism patterns having $60^{\circ}$, $90^{\circ}$, and $120^{\circ}$ angles on an electroplated Ni mold were performed and it was found in this study that the specific cutting resistance increased with a decrease in the tool angles (prism pattern angles). The cause of this variation had been thought to be the increase of the ploughing force due to tip rounding and the friction force due to the edge effect. However, the depth of the cut was large enough that it was possible to neglect these effects. Therefore, this study introduced the concept of representative stress of indentation. The measured stress was varied according to the indentation depth eventhoughthetestedspecimenswereidentical ; the varied stress was termed the representative stress. According to indentation theory, the strain that the Ni mold experienced increased with a decrease in the tool angle. Based on the stress-strain relationship, higher strain means higher stress and higher specific cutting resistance. Therefore, the specific cutting resistance was higher at smaller tool angles that had higher strain and stress.

Stress Conversion Factor on Penetration Depth of Knoop Indentation for Assessment of Nano Residual Stress (나노 잔류응력 측정을 위한 비등방 압입자의 깊이별 응력환산계수 분석)

  • Kim, Won Jun;Kim, Yeong Jin;Kim, Young-Cheon
    • Journal of the Microelectronics and Packaging Society
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    • v.26 no.4
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    • pp.95-100
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    • 2019
  • Nanoindentation has been widely used for evaluating mechanical properties of nano-devices, from MEMS to packaging modules. Residual stress is also estimated from indentation tests, especially the Knoop indenter which is used for the determination of residual stress directionality. According to previous researches, the ratio of the two stress conversion factors of Knoop indentation is a constant at approximately 0.34. However, the ratio is supported by insufficient quantitative analyses, and only a few experimental results with indentation depth variation. Hence, a barrier for in-field application exists. In this research, the ratio of two conversion factors with variation in indentation depth using finite elements method has been attempted at. The magnitudes of each conversion factors were computed at uniaxial stress state from the modelled theoretical Knoop indenter and specimen. A model to estimate two stress conversion factor of the long and short axis of Knoop indenter at various indentation depths is proposed and analyzed.

The variation of poisson's ratio for The Cretaceous Sandstones and Shale in the Euiseoung Subbasin. (백악기 사암과 세일에 대한 포아송비의 변화)

  • 정태종
    • The Journal of Engineering Geology
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    • v.6 no.2
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    • pp.103-110
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    • 1996
  • This study shows the variation of poisson's ratio according to stress for the Cretaceous sandstones and shale in the Euiseoung Subbasin. To make a mechanical experiment, samples prepared with 3.0 cm in diameter and 6.2 cm in length were used in testing stress and strain. Generally poisson's ratio has been considered as one of properties, but contrary to steel, the test result makes sure that poisson's ratio has functional relation to stress. I had used four methods to calculate poisson's ratio, Poisson's ratio shows considerable different results according to the calculating, method but it has similar tendency in an elastic limit. Poisson' s ratio increases rapidly and is distinguished clearly in internal fracture region according to the calculating method. Poisson's ratio of sandstone and shale is different from one another in low and high stress regimes,but it is linearly proportional to the stress in an elastic regimes, that is, ${\nu}_t={\;}{\nu}_0+P_{\sigma}({\nu}_0$:first stage Poisson's ratio, ${\nu}_t$:poisson's ratio, P: poisson's coefficient, $\sigma$:stress). Poisson's ratios of two kinds of rock samples show continuous variation from 0.1 to 0.21 in an elastic regime. The variation of poisson's ratio is much wider in an internal fracture regine. It varies from 0.22 to 0.45 in sandstone, which is out of elastic regime.

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