• 제목/요약/키워드: residual effect

검색결과 2,295건 처리시간 0.038초

가정세탁에서 잔류오구가 백색 면직물의 황변에 미치는 영향 (Effect of Residual Soils on Yellowing of White Cotton Fabrics after Repeated Home Laundry)

  • 이일심
    • 대한가정학회지
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    • 제35권2호
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    • pp.137-145
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    • 1997
  • The effect of accumulated residual soils in wear and wash tests on yellowing of white dress shirt was studied. The test samples after repeated home laundry at 20 households for six months were measured residual soils, $\Delta$b*.As well as, correlation between residual soils and yellowing was also examined. As a result, residual soils increased with number of wear and wash cycles, a little decreased in using with enzyme detergent. The b* value of test samples with fluorescent whitening agent were distributed -12.850~0.291. Correlation coefficient between sebum soils, protein soils and $\Delta$b* was 0.98, 0.58. Ultimately, residual sebum soils have more higher correlation than residual protein soils. Hence, residual sebum soils have more effect on yellowing than residual protein soils. therefore, effective a device as improvement of laundry condition and textile development needs for decrease of sebum soils.

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Investigation on effect of neutron irradiation on welding residual stresses in core shroud of pressurized water reactor

  • Jong-Sung Kim;Young-Chan Kim;Wan Yoo
    • Nuclear Engineering and Technology
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    • 제55권1호
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    • pp.80-99
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    • 2023
  • This paper presents the results of investigating the change in welding residual stresses of the core shroud, which is one of subcomponents in reactor vessel internals, performing finite element analysis. First, the welding residual stresses of the core shroud were calculated by applying the heat conduction based lumped pass technique and finite element elastic-plastic stress analysis. Second, the temperature distribution of the core shroud during the normal operation was calculated by performing finite element temperature analysis considering gamma heating. Third, through the finite element viscoelastic-plastic stress analysis using the calculated temperature distribution and setting the calculated residual stresses as the initial stress state, the variation of the welding residual stresses was derived according to repeating the normal operation. In the viscoelastic-plastic stress analysis, the effects of neutron irradiation on mechanical properties during the cyclic normal operations were considered by using the previously developed user subroutines for the irradiation agings such as irradiation hardening/embrittlement, irradiation-induced creep, and void swelling. Finally, the effect of neutron irradiation on the welding residual stresses was analysed for each irradiation aging. As a result, it is found that as the normal operation is repeated, the welding residual stresses decrease and show insignificant magnitudes after the 10th refueling cycle. In addition, the irradiation-induced creep/void swelling has significant mitigation effect on the residual stresses whereas the irradiation hardening/embrittlement has no effect on those.

상변태에 의한 잔류응력 완화효과에 관한 실험적 연구 (An Experimental Study on The Effect of Residual Stress Relaxation due to Phase Transformation)

  • 장경호;이진형;김재환
    • 대한용접접합학회:학술대회논문집
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    • 대한용접접합학회 2003년도 추계학술발표대회 개요집
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    • pp.216-218
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    • 2003
  • Most of ferrous b.c.c weld materials may experience martensitic transformation during rapid cooling after welding. And it is well known that volume expansion due to phase transformation could influence in the case of welding of high tensile strength steels on the relaxation of welding residual stress. To apply this effect practically, it is a prerequisite to establish a numerical model which is able to estimate the effect of phase transformation on residual stress relaxation quantitatively. In this study, we investigated the effect of phase transformation on the relaxation of welding residual stress through experiment. And three-dimensional thermal elastic-plastic FEM analysis is conducted to compare the effect of phase transformation on the relaxation of welding residual stress in high strength steels(POSTEN60, POSTEN80) with analytical results which is not considering the effect of phase transformation on residual stress relaxation. According to the results, the extents of welding residual stress relaxation due to phase transformation in the case of welding of POSTEN60, POSTEN80 are 0.85 $\sigma$/$\sigma$$\sub$Y0/, 0.75$\sigma$/$\sigma$$\sub$Y0/, respectively.

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탁도(濁度) 및 알카리도(度)가 잔류(殘留)알루미늄 농도(濃度)에 미치는 영향(影響) (The Effect of Turbidity and Alkalinity on the Regidual Aluminum Concentration)

  • 최승일;이창숙
    • 상하수도학회지
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    • 제9권3호
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    • pp.88-98
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    • 1995
  • Several kinds of coagulants such as aluminum sulfate, PAC, PASS are being used to treat drinking water resulting in residual aluminum ions in the water. Recently, it has been reported that high intake of aluminum ion may cause neurological dieseases such as Alzheimer's diesease and presenile dementia. Because of the possible adverse effect, WHO and EEC recommand to regulate residual aluminum. The autorities in Korea also has plan of regulating residual alunimum from 1995. But there is not enough information about the range of residual aluminum ion concentration when the aluminum sulfate, PAC or PASS has been used as a coagulant. Therefore the study has been conducted to find out the range of residual aluminum ion concentration after using aluminum sulfate, PAC, and PASS. Furthermore the effect of turbidity and alkalinity have been investigated. The experimental results are summarized as; 1. Most of the residual aluminum ion concentrations were within $10^{-6}$ and $10^{-5}mole/l$. Three coagulants have not showed any considerable difference in the residual aluminum concentration up to 50 NTU. However PAC has showed the least residual aluminum in high turbidity water over 100 NTU. 2. The low alkalinity water having 25mg/l as $CaCO_3$ has showed less residual aluminum than the water having 50mg/l alkalinity. However, the difference was not significcant. 3. Even the lowest residual aluminum concentration was over 0.05mg/l. Therefore the process to reduce residual aluminum would be necessary in water treatment plants.

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강구조 부재의 피로균열성장에 미치는 제인자에 관한 연구( II ) -표면잔류응력이 균열닫힘에 미치는 영향- (A Study on Parameters Affected the Fatigue Crack Growth in Steel Structure Members( II ) -The Effect of Surface Residual Stress for Crack Closure-)

  • 최영재;경갑수
    • 한국강구조학회 논문집
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    • 제8권3호통권28호
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    • pp.3-11
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    • 1996
  • To investigate the effect of fatigue crack growth due to the surface residual stress, it is measured the residual stress distribution by x-ray diffraction at the crack tip each constant crack growth in the notch specimens, and quantitively assessed the effect of crack closure caused to the distribution of compressive stress at the crack tip from evaluating crack openning stress using the finite element analysis. It is concluded that the degree of the residual stress distribution at the crack tip is decreased with increasing the crack length. From the fact that it is similar to the crack openning stress ratio, it is found that the compressive residual stress distribution and size is related to the crack closure effect and surface residual stress field with propagating crack in the notch specimens depends on the stress intensity factor range at the crack tip.

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레벨링 공정 해석에 의한 교정 조건이 열연 고장도 강판의 잔류음력에 미치는 영향 연구 (Effect of the Leveling Conditions on Residual Stress Evolution of Hot Rolled High Strength Steels by Deformation Analysis of Leveling Process)

  • 박기철
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2009년도 춘계학술대회 논문집
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    • pp.326-329
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    • 2009
  • In order to analyze the effect of leveling conditions on residual stress evolution of hot rolled high strength steels, a numerical algorithm was developed. It was able to implement the effect of plastic fraction (intermesh) in leveling, line tension, work roll bending, and initial residual stress and curl distribution. The effect of work roll bending on residual stress and curl were studied by using the developed program. The validity of simulated results was verified from comparison with the experimentally measured residual stress and curl in a sheet.

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순환/재생골재의 잔류 모르타르 성분이 알칼리 실리카 반응성에 미치는 영향 평가 (The Effect of the Residual Mortar of Recycled Concrete Aggregate on Alkali Silica Reaction)

  • 김정현;김남호;양성철
    • 한국도로학회논문집
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    • 제17권4호
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    • pp.19-24
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    • 2015
  • PURPOSES : The objective of this study is to evaluate the effect of the residual mortar of recycled concrete aggregate on the expansion behavior during alkali silica reaction (ASR). METHODS: In order to evaluate the net effect of residual mortar on ASR expansion behavior, two aggregate samples with the same original virgin aggregate source but different residual mortar volumes were used. ASTM C1260 test was used to evaluate the ASR expansion behavior of these two aggregates and the original virgin aggregate. RESULTS: The greater the amount of residual mortar in recycled concrete aggregates, the less is the induced ASR expansion. Depending on the amount of residual mortar in recycled concrete aggregate, the ASR expansion of recycled concrete aggregate may be less than half of that of the original virgin aggregate. CONCLUSIONS: The residual mortar of recycled concrete aggregate may lead to the under estimation of the ASR expansion behavior of the original virgin aggregate.

Effect of Residual Stress on Femoral Arterial Stress-Strain Behavior

  • Chandran, K.B.;Mun, J.H.;Chen, J.S.;Nagaraj, A.;McPherson, D.D.
    • Journal of Mechanical Science and Technology
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    • 제15권7호
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    • pp.965-973
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    • 2001
  • It is well established that arteries are subjected to residual stress. Due to the effect of residual stress, the arteries open to a horse-shoe shape when a longitudinal cut is made on an excised arterial segment. Previously, the residual stress has been quantified by the opening angle of the horse-shoe shape. We have employed a finite element analysis of the open arterial segment to restore the same to the original cylindrical shape and computed the circumferential strain as well as the stress distribution in the wall. In this study, the stress distribution in the femoral arteries of miniswine was computed with and without the residual stress for a range of transmural pressures. Our analysis showed that the residual stress has the effect of redistribution of the circumferential stresses between the intima and the adventitia under physiological loading. The redistribution of the stress with the inclusion of residual stress may be important in the studies on effect of wall stresses on the endothelial and vascular smooth muscle cells.

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Effect of Melting Pool on the Residual Stress of Welded Structures in Finite Element Analysis

  • Lee, Jang-Hyun;Hwang, Se-Yun;Yang, Yong-Sik
    • Journal of Ship and Ocean Technology
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    • 제11권3호
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    • pp.14-23
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    • 2007
  • Welding processes cause undesirable problems, such as residual stresses and deformations due to the thermal loads imposed by local heating, melting, and cooling processes. This paper presents a computational modeling technique to simulate the Gas Metal Arc Welding (GMAW) process, emphasizing the effect of the melting bead on the residual stress distribution. Both a three-bar analogy and a three-dimensional thermo-mechanical finite element analysis are carried out in order to explain the effect. Element (de)activation, enthalpy, and adjustment of the reference temperature of thermal strain are considered with respect to the effect of the weld filler metal added to the base metal during a thermo-elastic-plastic analysis. Stress distributions obtained by the present study are compared with measured values and available data from other studies. The effect of the melting bead on the residual stress distribution is discussed and demonstrated.

자긴가공된 후육실린더의 잔류응력 해석에 관한 연구 (A Study on Residual Stress Analysis of Autofrettaged Thick-walled Cylinders)

  • 김재훈;심우성;이영신;차기업;홍석균
    • 한국정밀공학회지
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    • 제26권12호
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    • pp.110-116
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    • 2009
  • Thick-walled cylinders, such as a cannon or nuclear reactor, are autofrettaged to induce advantageous residual stresses into pressure vessels and to increase operating pressure and the fatigue lifetimes. As the autofrettage level increases, the magnitude of compressive residual stress at the bore also increases. However, the Bauschinger effect reduces the compressive residual stresses as a result of prior tensile plastic strain, and decreases the beneficial autofrettage effect. The purpose of the present paper is to predict the accurate residual stress of SNCM8 high strength steel using the Kendall model which was adopted by ASME Code. The uniaxial Bauschinger effect test was performed to decide BEF, then this constant was used in calculation. There were some differences between theoretical solution and modified solution.