• 제목/요약/키워드: Predicted residual

검색결과 388건 처리시간 0.021초

Prediction of Residual Tension of Securing Rope by Oscillation Test

  • Kim, Young-Du;Saito, Katsuhiko
    • 한국항해항만학회지
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    • 제32권7호
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    • pp.537-542
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    • 2008
  • A lot of cargo accidents occurred due to insufficient securing in the case of marine transportation. If the residual tension of securing rope can be predicted, it will be very useful in the handling of cargo securing work of operators. It was confirmed in the previous study that the fluctuation tension cf securing rope by oscillation could be predicted. In this paper, in order to the prediction of residual tension of securing rope, the experiments were carried out to measure the residual tension of securing rope under the oscillation and cyclic loadings. The residual tensions of two tests were in good agreement with each other. It can be predicted through the cyclic loading test in the estimated fluctuation tension without oscillation test by ship motion simulator.

상수관망내 잔류염소농도 분포 예측 (Prediction of Chlorine Residual in Water Distribution System)

  • 주대성;박노석;박희경;오정우
    • 상하수도학회지
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    • 제12권3호
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    • pp.118-124
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    • 1998
  • To use chlorine residual as an surrogate parameter of the water quality change during the transportation in the water distribution system(WDS), the correct prediction model of chlorine residual must be established in advance. This paper shows the procedure and the result of applying the water quality model to the field WDS. To begin with, hydraulic model was calibrated and verified using fluoride as an tracer. And chlorine residual was predicted through simulation of water quality model. This predicted value was compared with the observed value. With adjusting the bulk decay coefficient(kb) and the wall decay coefficient(kw) according to the pipewall environment, the predicted chlorine residual can represent the observed value relatively well.

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자유체적이론을 고려한 플라스틱의 급냉시 잔류응력의 분포 (The Distribution of Residual Stresses in Quenched Plastic Parts including Fee Volume Theory)

  • 김종선
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2000년도 춘계학술대회논문집
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    • pp.106-111
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    • 2000
  • The residual stresses in molded plastic parts can be divided into the flow induced residual stresses produced in flowing stages and the thermally induced residual stresses produced in cooling state. Reducing residual stresses in the final parts is one of the goals in recent study. The present study focused on comparing the predicted values for thermal residual stresses in freely and constrained quenched plastic plates with and without free volume theory. As a result the final residual stresses showed the opposite pattern in thickness direction. furthermore by applying free volume theory the predicted residual stress at the center showed about 50% of the values without free volume theory for constrained quenched case.

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피로강도 및 수명에 미치는 Shot Peening에 의한 잔류응력의 영향 (Influence of residual stress due to shot peening on fatigue strength and life)

  • 이종규;김정규
    • 대한기계학회논문집A
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    • 제21권9호
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    • pp.1498-1506
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    • 1997
  • Procedures are presented for influence of shot peening on fatigue strength, fatigue life and effects of shot peening are discussed from experiments were taken between shot peened and unpeened SPS5, SM45C specimens. After the residual stress on shot peened specimens was measured by X-ray diffractometer, rotating bending fatigue tests were carried out. In addition, the compressive residual stress profile was obtained by the superposition method of three stresses which is based on Al-Obaid's equation. Predicted fatigue life considering residual stress profile which was obtained by the Al-Obaid's equation and another predicted fatigue life considering residual stress profile which was measured in test were compared. For the purpose of predicting fatigue life, Morrow's equation considering the residual stress and mean stress was used.

SS330 용접재에서 재분포 압축잔류응력 및 균열닫힘의 영향을 고려한 피로거동에 관한 연구 (A Study on Fatigue Behavior considering Effects of Redistributing Compressive Residual Stress and Crack Closure in SS330 Weldment)

  • 이용복
    • 한국생산제조학회지
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    • 제6권2호
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    • pp.26-33
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    • 1997
  • In this study effect of residual stress and its redistribution in weldment on the fatigue crack propagation was investigated. Fatigue tests were conducted by the center notched specimens machined with welded plate. The residual stress and its redistribution after the crack growth were measured by the magnetizing stress indicator and hole-drilling method. Fatigue crack propagation was estimated by the specimens having residual stress redistributed after the cracks growth and having the effects of crack closure. Crack growth rates were predicted and compared with experimental results. It had been found that the predicted crack propagation rates have a good agreement with experimental results when the redistribution of residual stress was considered.

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SS330 용접재에서 재분포 압축 잔류응력 및 균열닫힘의 영향을 고려한 피로거동에 관한 연구 (A Study on Fatigue Behavior Considering Effects of Redistributing Compressive Residual Stress and Crack Closure in SS330 Weldment)

  • 이용복
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 1996년도 춘계학술대회 논문집
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    • pp.165-169
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    • 1996
  • In this study residual stress in weldment was considered about the effect on the fatigue propagation and about the effect of redistribution of residual stress. Then, fatigue tests were conducted by the center notched specimens machined with welded plate. The residual stress and its redistribution after the crack growth were measured by the magnetizing stress indicator and hole-drilling method. Fatigue crack propagation was estimated by the specimens having residual stress redistributed after the cracks growth and having the effects of crack closure. Crack growth rates were predicted and compared with experimental results. It had been found that the predicted crack propagation rates have a good agreement with experimental results when the redistribution of residual stress was considerd.

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Residual stresses and viscoelastic deformation of an injection molded automotive part

  • Kim, Sung-Ho;Kim, Chae-Hwan;Oh, Hwa-Jin;Choi, Chi-Hoon;Kim, Byoung-Yoon;Youn, Jae-Ryoun
    • Korea-Australia Rheology Journal
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    • 제19권4호
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    • pp.183-190
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    • 2007
  • Injection molding is one of the most common operations in polymer processing. Good quality products are usually obtained and major post-processing treatment is not required. However, residual stresses which exist in plastic parts affect the final shape and mechanical properties after ejection. Residual stresses are caused by polymer melt flow, pressure distribution, non-uniform temperature field, and density distribution. Residual stresses are predicted in this study by numerical methods using commercially available softwares, $Hypermesh^{TM},\;Moldflow^{TM}\;and\;ABAQUS^{TM}$. Cavity filling, packing, and cooling stages are simulated to predict residual stress field right after ejection by assuming an isotropic elastic solid. Thermo-viscoelastic stress analysis is carried out to predict deformation and residual stress distribution after annealing of the part. Residual stresses are measured by the hole drilling method because the automotive part selected in this study has a complex shape. Residual stress distribution predicted by the thermal stress analysis is compared with the measurement results obtained by the hole drilling method. The molded specimen has residual stress distribution in tension, compression, and tension from the surface to the center of the part. Viscoelastic deformation of the part is predicted during annealing and the deformed geometry is compared with that measured by a three dimensional scanner. The viscoelastic stress analysis with a thermal cycle will enable us to predict long term behavior of the injection molded polymeric parts.

재료 물성 모델러와 Abaqus를 활용한 핫 프레스 포밍 후의 보론 강판내 잔류음력의 예측 (Prediction of Residual Stresses in the Boron Steel Sheet after Hot Press Forming using Material Properties Modeler and Abaqus)

  • 지민욱;서영성;김영석
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2008년도 춘계학술대회 논문집
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    • pp.493-496
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    • 2008
  • The residual stress generated in the boron steel blank formed via hot press forming process was predicted by JMatPro, a material property modeler, and Abaqus. The numerical predictions were compared by the experimental measurements obtained by the instrumented indentation. Both the predicted and measured principal stresses monitored at the outer surface of central bending position were qualitatively in good agreement. It was concluded that the residual stresses generated from hot forming process is not negligible as it has been generally assumed, although the spring back deformation is quite small. This should be specially considered from the part design stage since the tensile nature of the residual stress exhibited on the surface may lead to the stress corrosion cracking.

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SS330 용접재에서 재분포 잔류응력 및 균열닫힘영향을 고려한 파로거동에 관한 연구 (A Study on Fatigue Behavior Considering Effects of Redistributing Tensile Residual Stress and Crack Closure in SS330 Weldment)

  • 이용복;정진성;조남익
    • 대한기계학회논문집A
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    • 제20권7호
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    • pp.2234-2245
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    • 1996
  • In this study residual stress in weldment was considered about the effect on the fatigue propagation and about the effect of redistribution of residual stress. Then, fatigue tests were conducted by the center notched specimens machined with welded plate. The residual stress and its redistribution after the crack growth were measured by the magnetizing stress indicator and hole-drilling method. Fatigue crack propagation was estimated by the specimens having residual stress redistributed after the cracks growth and having the effects of crack closure. Crack growth rates were predicted and compared with experimental results. It had been found that the predicted crack propagation rates have a good agreement with experimental results when the redistribution of residual stress was considerd.

회귀(回歸)에서 결합영향력(結合影響力)를 위(爲)한 예측잔차(豫測殘差)제곱합(合)의 특성(特性)에 대(對)한 연구(硏究) (Characterization of Predicted Residual Sum of Squares for Detecting Joint Influence in Regression)

  • 오광식
    • Journal of the Korean Data and Information Science Society
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    • 제3권1호
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    • pp.1-16
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    • 1992
  • In regression diagnostics, a number of joint influence measures based on various statistical tools have been discussed. We consider an alternate representation in terms of the predicted residual and g-leverage determined by the remaining points. By this approach, we choose the predicted residual sum of squares for the keypoints as joint influence measure and propose a new expression of it so that we can extend the single case form to the multiple case one. Furthermore we suggest a seach method for joint influence after investigating some properties of the new expression.

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