• Title, Summary, Keyword: residual effect

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

  • 이일심
    • Journal of the Korean Home Economics Association
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    • v.35 no.2
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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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The effect of initial stress induced during the steel manufacturing process on the welding residual stress in multi-pass butt welding

  • Park, Jeong-ung;An, Gyubaek;Woo, Wanchuck
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.10 no.2
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    • pp.129-140
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    • 2018
  • A residual stress generated in the steel structure is broadly categorized into initial residual stress during manufacturing steel material, welding residual stress caused by welding, and heat treatment residual stress by heat treatment. Initial residual stresses induced during the manufacturing process is combined with welding residual stress or heat treatment residual stress, and remained as a final residual stress. Because such final residual stress affects the safety and strength of the structure, it is of utmost importance to measure or predict the magnitude of residual stress, and to apply this point on the design of the structure. In this study, the initial residual stress of steel structures having thicknesses of 25 mm and 70 mm during manufacturing was measured in order to investigate initial residual stress (hereinafter, referred to as initial stress). In addition, thermal elastic plastic FEM analysis was performed with this initial condition, and the effect of initial stress on the welding residual stress was investigated. Further, the reliability of the FE analysis result, considering the initial stress and welding residual stress for the steel structures having two thicknesses, was validated by comparing it with the measured results. In the vicinity of the weld joint, the initial stress is released and finally controlled by the weld residual stress. On the other hand, the farther away from the weld joint, the greater the influence of the initial stress. The range in which the initial stress affects the weld residual stress was not changed by the initial stress. However, in the region where the initial stress occurs in the compressive stress, the magnitude of the weld residual compressive stress varies with the compression or tension of the initial stress. The effect of initial stress on the maximum compression residual stress was far larger when initial stress was considered in case of a thickness of 25 mm with a value of 180 MPa, while in case of thickness at 70 mm, it was 200 MPa. The increase in compressive residual stress is almost the same as the initial stress. However, if initial stress was tensile, there was no significant change in the maximum compression residual stress.

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

  • 장경호;이진형;김재환
    • Proceedings of the KWS Conference
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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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The Effect of Turbidity and Alkalinity on the Regidual Aluminum Concentration (탁도(濁度) 및 알카리도(度)가 잔류(殘留)알루미늄 농도(濃度)에 미치는 영향(影響))

  • Choi, Suingil;Lee, Changsook
    • Journal of Korean Society of Water and Wastewater
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    • v.9 no.3
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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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A Study on Parameters Affected the Fatigue Crack Growth in Steel Structure Members( II ) -The Effect of Surface Residual Stress for Crack Closure- (강구조 부재의 피로균열성장에 미치는 제인자에 관한 연구( II ) -표면잔류응력이 균열닫힘에 미치는 영향-)

  • Choi, Young Jae;Kyung, Kab Soo
    • Journal of Korean Society of Steel Construction
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    • v.8 no.3
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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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Effect of the Leveling Conditions on Residual Stress Evolution of Hot Rolled High Strength Steels by Deformation Analysis of Leveling Process (레벨링 공정 해석에 의한 교정 조건이 열연 고장도 강판의 잔류음력에 미치는 영향 연구)

  • Park, K.C.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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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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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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    • v.15 no.7
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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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    • v.11 no.3
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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.

FEM Analysis of Plasticity-induced Error on Measurement of Welding Residual Stress by the Contour Method

  • Shin, Shang-Hyon
    • Journal of Mechanical Science and Technology
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    • v.19 no.10
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    • pp.1885-1890
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    • 2005
  • The contour method relies on deformations that occur when a residually stressed component is cut along a plane. The method is based on the elastic superposition principle. When plasticity is involved in the relaxation process, stress error in the resulting measurement of residual stress would be caused. During the cutting the specimen is constrained at a location along the cut so that deformations are restrained as much as possible during cutting. With proper selection of the constraining location the plasticity effect can also be minimized. Typical patterns of longitudinal welding residual stress state were taken to assess the plasticity effect along with constraining locations.

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

  • Kim, Jae-Hoon;Shim, Woo-Sung;Lee, Young-Shin;Cha, Ki-Up;Hong, Suck-Kyun
    • Journal of the Korean Society for Precision Engineering
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    • v.26 no.12
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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.