• Title/Summary/Keyword: Case depth

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Determining the Depth of Normal-Strength Concrete with Early-Frost Damage Through Dry Test (초기동해 피해를 입은 보통강도 콘크리트의 건조시험에 의한 깊이판정)

  • Kim, Tae-Woo;Beak, Cheol;Lee, Jae-Jin;Kim, Dong-Gyu;Han, Min-Cheol;Han, Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2017.11a
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    • pp.65-66
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    • 2017
  • Early-frost damages easily take place in smaller and thinner walls and slabs. In case of slabs, it is difficult to visually determine the depth of early-frost damage. As such, the current study aims to determine the depth of early-frost damage caused to concrete structures due to bad curing in the winter. As a result, the study found that the depth of early-frost damages increased from the top as the atmospheric temperature on the concrete surface decreased. The changes in the color allowed the observer to easily identify the depth of early-frost damage with the naked eye. In particular, the color difference between potentially damaged parts and undamaged parts were the greatest around thirty minutes of drying after wetting.

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Surface Hardening Characteristics of SK5 Steel by Pulsed YAG LASER (YAG 레이저에 의한 SK5 표면경화 특성)

  • 강형식;문종현;전태옥;박홍식
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1995.10a
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    • pp.921-924
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    • 1995
  • Case hardening behavior of carbon tool steel(SK5) was investigated after pulsed YAG laser irradiation. In the case od beam passes,martensite formed in the melt zone and in former pearlite regions of the austenitization zone exhibits vary high Vickers hardness values. The molten depth and width decrease as the beam power density increase. The influence of depth and width of color painted specimen was also investigated. The molten zone of the black painted specimen was the largest. The were loss of the black painted specimen was smaller than any other painted or raw material.

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Characteristic of Vertical Stress in Sandy Soil according to Loading Types (재하방법에 따른 사질토 지반의 연직응력 특성)

  • Nam, Hyo-Seok;Lee, Sang-Ho;Kwon, Moo-Nam
    • Journal of The Korean Society of Agricultural Engineers
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    • v.51 no.6
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    • pp.83-90
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    • 2009
  • This study was carried out to evaluate the vertical stress properties in sandy soil according to changes of loading type in soil bin compacted three layers. The following conclusions and comparisons have been made based on careful analysis from theoretical and experimental methods. : When sandy soil subjected to cycle-loading, compression of foundation and diffusion of vertical stress increment(${\Delta}{\sigma}_2$) were influenced by magnitude of loading plate. When sandy soil subjected to reloading after removing of pre-loading, the distribution of ${\Delta}{\sigma}_2$ depth at one time of loading plate width was different from its distribution at more deep point cause of load hysteresis, so in case of design of structure, the effect of ${\Delta}{\sigma}_2$ as depth must be considered. The increment of vertical stress will be different as loading condition and foundation depth, the loading condition must be considered in case of structure design.

Finite Element Analysis and Experimental Investigation of Non-isothermal Foming Processes for Aluminum-Alloy Sheet Metals(Part 1. Experiment) (알루미늄 합금박판 비등온 성형공정의 유한요소해석 및 실험적 연구 (제1부. 실험))

  • 류호연;김영은;김종호;구본영;금영탁
    • Transactions of Materials Processing
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    • v.8 no.2
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    • pp.152-159
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    • 1999
  • This study is to investigate the effects of warm deep drawing with aluminum sheets of A1050-H16 and A5020-H32 for improving deep drawability. Experiments for producing circular cups and square cups were carried out for various working conditions, such as forming temperature and blank shapes. The limit drawing ratio(LDR) of 2.63 in warm deep drawing of circular cups in case of A5020-H32 sheet, whereas LDR of 2.25 in case of A1050-H16, could be obtained and the former was 1.4 times higher than the value at room temperature. The maximum relative drawing depth for square cups of A5020-H32 material was also about 1.92 times deeper than the depth drawn at room temperature. The effects of blank shape and forming temperature on drawability as well as thickness distribution of drawn cups were examined and discussed.

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The Problem of using N-value to assume the displacement depth (실무에서의 N척 적용 및 문제점 (연약한 해성점토층의 경우))

  • 이충호
    • Proceedings of the Korean Geotechical Society Conference
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    • 2001.10a
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    • pp.293-298
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    • 2001
  • N-value is usually used to assume the displacement depth of embankment on the soft marine clay. But N-value of the soft marine clay tend to underestimate unlike overestimating of general cases. In general case, if the length of rod is more long then N-value is more large because it is under the influence of energy loss of hammer blow. So it is reasonable to correct N-value down. But in the case of soft marine clay, N-value must not be correct down. Especially to assume the displacement depth of embankment on the soft marine clay, it must be used laboratory test results or CPT, Vane Test than N-value. In this study, it is compared with two field cases that design displacement method of embankment.

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The Effects of Tin in Bottom Surface to Ion Exchange of Float Glasses (Float 판유리에 있어서 바닥면의 Tin성분이 이온교환에 미치는 영향)

  • 이동인;이용근;이희수
    • Journal of the Korean Ceramic Society
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    • v.27 no.6
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    • pp.763-768
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    • 1990
  • The gradient and depth of tin at the side of glasses by float process were measured. The effects of tin to ion exchanged of glasses in the molten salt of KNO3 and AgNO3 were presented by means of Ag+ ion penetration depth, diffusion coefficient variation, spectral transmittance and color coordinates. The diffusion coefficient of Ag+ ion of tin side was higher than air side, and the activation energy of tin side was 0.2-0.6Kcal/mole lower than air side. Therefore Ag+ ion penetration depth of tin side is 2-10$\mu\textrm{m}$ deeper, hence it can be seen that tin promote Ag+ ion diffusion. The same treatment of ion exchange, reddish-brown oflong wavelength in case of tin present, yellowish-amber of short wavelength in case of tin absence were revealed.

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Effects of Background Depth Information on the Judgment of Two-dimensional Shapes (배경 깊이정보가 이차원 자극의 형태 판단에 미치는 영향)

  • Kim, Young-Geun;Shin, Hyun-Jung
    • Korean Journal of Cognitive Science
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    • v.17 no.4
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    • pp.287-301
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    • 2006
  • Two experiments were performed to investigate effects of background depth information on the judgment of two-dimensional shapes, using the Posner et al.'s(1969) physical match task. In both experiments, the focus was on whether the background depth information affects the decisions of physical shape sameness of two letters or figures presented successively. In Experiment 1, artificially constructed rues of linear perspective and texture gradient were used, whereas cues contained in a real road situation were used in Experiment 2. The results of both experiments showed that the depth cues affect the perception of two-dimensional shapes. That is, when two stimuli of the same physical shape were likely to be perceived differently due to the given depth cues, response accuracies('yet' in this case) decreased and reaction tines of physical match increased. And when two stimuli of the different physical shape were likely to be perceived the same due to the given depth cues, response accuracies('no' in this case) decreased and reaction times of physical match increased likewise. These results wert discussed in terms of some conceptual methodological problems of the previous studies on the shape constancy and the directions of future research.

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A Relative Study on the Displacement of Earth Retaining Wall by 2 and 3 Dimensional Analysis (2차원 및 3차원 해석에 의한 토류벽의 변위에 관한 비교 연구)

  • Kim, Jong-Hwan;Park, Choon-Sik
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.09b
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    • pp.181-185
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    • 2010
  • Until now, design of Earth Retaining is practiced by 2 dimensional analysis for convenience of analysis and time saving. However, the construction field is 3 dimension, in this study, practised the 3 dimensional analysis which can reflect the field condition more exactly the scope of earth retaining wall, and researched about the effective and economical way of design, compared and reviewed with the results, by practising both the 2 and 3 dimensional analysis. existing 2 dimension. the depth of excavation, depth of embedded and soil condition. As result, under the whole conditions, more displacement came to appear to the value as result of 3 dimensional analysis more than the result of 2nd dimensional analysis. Accordingly, the displacement by the 2 dimension analysis is underestimated. Moreover, results of 2 and 3 dimensional analysis, there is no difference at displacement, when the depth of embedded is 0.5H and 1.0H, but Displacement of 1.5H is smaller than 0.5H, 1.0H. That is, the bigger the depth of embedded becomes, the displacement of Earth Retaining Wall appeared smaller. The displacement of earth retaining wall according to depth of excavation appeared bigger, when the depth of excavation is increased. In the meantime, when the soil condition is different, in the 2 dimensional analysis, the displacement appeared biggest, in case of the clay layer, but in the 3 dimensional analysis, in the beginning of excavating, the displacement of earth retaining wall appeared bigger in case of clay layer, but as excavating is in progress, the displacement of both compound soil layer and sand layer appeared big.

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Linear Temperature Dependence of Magnetic Penetration Depth Length at Low T in an Isotropic Superconductor

  • Nam, Sang-Boo
    • Progress in Superconductivity
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    • v.2 no.1
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    • pp.11-14
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    • 2000
  • The notion of the finite pairing interaction energy range Td is shown to result in a linear temperature dependence of the London magnetic penetration depth length, ${\Delta}{\lambda}{/\lambda}(0)=(T/Td)2/\pi)ln2$ at low T in the case of the s-wave pairing state, accounting for data of high Tc superconductor by Hardy et al.

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Applicability Evaluation on the Analytical Formulas of the Scour Depth Estimation in the Bight River (교량세굴심 산정을 위한 만곡부하천에서의 산정식 적용성 평가)

  • Park, Soo-Jin;Park, Jae-Wan
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.10
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    • pp.4845-4852
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    • 2012
  • This research calculated the scour depth of bridge according to inflow and outflow changes of stream's flood discharge and curves by applying scour depth formula for piers and abutments, and by comparing and examining them, evaluated the applicability of scour depth formulas. Overall, if the angles of flood discharge and inflow and outflow increase, the deviation rate of scour depth in bight increased. Especially the deviation rate was 58% at the inflow and outflow angle of $105^{\circ}$ that the bridge plan for this geography need careful examination. Next, as a result of calculating the deviation rate of scour depth at the bight by scour depth formulas, in case of pier, Andru formula showed 58% deviation rate, Laursen formula showed 26% deviation rate, and CSU. formula showed 17% deviation rate. In the case of abutment, Froehlich formula shows 44% deviation rate that when applying above scour depth formulas, scour depth calculation considering repairable characteristics of bight is necessary. Finally, about inflow and outflow angles of $45^{\circ}{\sim}135^{\circ}$ that showed big deviation rate of scour depth, this research performed regression analysis of deviation rates of scour depth due to flood discharge to suggest the regression formula.