• Title/Summary/Keyword: bending rigidity

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Effect of Wet and Dry Thermal Setting Conditions of Stretch Fabric to Fabric Mechanical Property and Garment Formability (습·건열 열고정 조건이 스트레치 직물의 역학특성과 의류형성성능에 미치는 영향)

  • Kim, Hyun-Ah;Kim, Seung-Jin
    • Fashion & Textile Research Journal
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    • v.20 no.1
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    • pp.83-92
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    • 2018
  • This paper investigated garment formability and fabric mechanical properties of one-way and two-way stretch fabrics according to the thermal treatment methods. One-way and two-way stretch fabrics were woven using 75d and 150d PET/spandex covering yarns and then these were wet thermal treated with four kinds of finishing machines. The fabric mechanical properties of these stretch fabrics specimens were measured and compared with the regular PET fabrics. The stretch ratio of one-way stretch fabric was ranged 12 to 26 percentage, 15 to 45 percentage for 2-way stretch fabrics and 4 to 10 percentage for regular fabrics. Garment formability of stretch fabric was superior than that of regular fabrics, in addition, 2-way stretch fabric was better than one-way. The garment formability of the stretch fabrics treated with CPB and Lava wet thermal machines showed the highest values, and the stretch ratio of these 2-way stretch fabrics was also the highest, which was ranged 20 to 45 percentage. This phenomenon was assumed to be due to high extensibility and bending rigidity with low shear modulus of the 2-way stretch fabric treated with CPB and Lava wet thermal machines. It was shown that the garment formability of stretch fabrics treated without dry thermal treatment was higher than that of dry thermal treated fabrics. It revealed that high stretch fabric was available under the condition of low process tension in the wet and dry thermal treatments of the finishing process, which makes high garment formability.

Strength Assessment of 8m-class High-Speed Planing Leisure Boat (8m급 고속 활주선형 레저보트의 구조강도 평가)

  • Ko, Dae-Eun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.10
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    • pp.418-423
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    • 2018
  • Recently, research and development of high-value leisure vessels has been carried out in Korea to revitalize the marine leisure industry and tap into the global maritime leisure market. FRP composite materials, which have excellent physical properties and are available for the manufacture of light hulls, are used widely. One of the most important design technologies is to secure structural safety of leisure vessels made from FRP composite materials. In this study, the structural strength was assessed for the design of an 8-meter high-speed planing leisure boat made from FRP composite materials. The design loads to verify the structural safety were calculated according to the rules for the classification of high speed light craft (KR, 2015), and structural analysis was conducted using a finite element model composed of an isotropic shell element, which has equivalent bending rigidity with the FRP sandwich panel. The analysis results were compared with the results of the strength test for fabricated specimens, and all internal structural components are sufficiently satisfied with the structural strength.

Analysis of Fracture Risk due to Alterations of Bone Quality by Metastatic Bone Tumor (전이성 골암으로 인한 골질 변화와 이로 인한 골절 위험성 분석)

  • Lim, Dohyung
    • Journal of Biomedical Engineering Research
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    • v.33 no.4
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    • pp.213-222
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    • 2012
  • While much has been learned about the mechanisms of metastatic spread of cancer to bone, there has been little headway in establishing guidelines for monitoring the alteration in bone quality and estimating fracture risk. The aims of this study are, therefore, 1) to evaluate bone quality induced by metastatic bone tumor by analyzing the characteristics on bone microarchitecture and degree of bone mineralization and 2) analyze fracture risk increased secondary to the bone quality changes by metastatic bone tumor through calculating mechanical rigidities based on in-vivo micro CT images. For this study, eighteen female SD rats (12 weeks old, approximate 250 g) were randomly allocated in Sham and Tumor groups. W256 (Walker carcinosarcoma 256 malignant breast cancer cell) was inoculated in the right femur (intraosseous injection) in Tumor group, while 0.9% NaCl (saline solution) was injected in Sham group. The right hind limbs of all rats were scanned by in-vivo micro-CT to acquire structural parameters and degree of bone mineralization at 0 week, 4 weeks, 8 weeks, and 12 weeks after surgery. At the same time, urine was collected by metabolic cages for a biochemical marker test in order to evaluate bone resorption. Then, bone metastasis had been directly identified by positron emission tomography. Finally, axial, bending and torsional rigidities had been calculated based on in-vivo micro CT images for predict fracture risk. The results of this study showed that metastatic bone tumor might induce significant decrease in bone quality and increase of fracture risk. This study may be helpful to monitoring a degree of bone metastasis and predicting fracture risk due to metastatic bone tumor. In addition, this noninvasive diagnostic methodology may be utilized for evaluating other bone metabolic diseases such as osteoporosis.

A Study on the Development of Persimmon Juice Dyed Print-fabrics following the Printing Method and a Comparative Study of the Products' Properties (감즙염색포의 날염방법에 따른 문양직물의 개발과 그 특성에 관한 연구)

  • Park, Soon-Ja
    • The Korean Journal of Community Living Science
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    • v.23 no.3
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    • pp.317-328
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    • 2012
  • In this study, printing was introduced to the common dip-dyeing method of persimmon juice dyeing so as to develop two different colored persimmon juice dyed fabrics with printings of 'jorangmal' patterns (a national monument) instead of producing a plain textile. Following are the results of a comparative study between the persimmon dyed fabric and undyed fabric, both with printings, in terms of its properties, and hand values. Cotton and rayon were chosen as samples and were compared separately. Firstly, the samples showed differences in terms of clarity and visual sensation depending on the presence of persimmon dye, even if the same pattern and color was used. Secondly, the air permeability of two samples improved after persimmon dyeing even though their thickness increased, and their moisture regain increased as well in all humidity conditions. Thirdly, protectiveness against UV increased in dyed samples, and sweat, sunlight, and compound colorfastness improved in printed dye-fabrics compared to plain dyed ones. Therefore, printing proved to be effective in preventing discoloration. Fourthly, tensile linearity and resilience, bending rigidity, compressive linearity and resilience, and shearing stiffness increased more in the dyed samples compared to undyed ones. However, shearing recovery decreased in both dyed fabrics. Fifthly, the result of its hand value showed that Koshi value increased in all samples than undyed ones, whereas Fukurami, Numeri, and Softosa values decreased. Incorporating printing in persimmon dyeing process could expect creative outcomes not only in today's diverse fashion but in areas of arts or crafts as well.

Relationship Between Frictional Sounds and Mechanical Properties of Vapor Permeable Water Repellent Fabrics for Active Wear (스포츠웨어용 투습발수직물의 마찰음과 역학적 성질 간의 상관성)

  • Yang, Yoon-Jung;Park, Mi-Ran;Cho, Gil-Soo
    • Fashion & Textile Research Journal
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    • v.10 no.4
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    • pp.566-571
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    • 2008
  • Frictional sounds of 8 vapor permeable water repellent fabrics by sound generator were recorded and analyzed through FFT fast Fourier transform analysis. The frictional Sounds were quantified by calculating level pressure of total sound(LPT), the level range(${\Delta}L$) and the frequency difference(${\Delta}f$). Mechanical properties were measured by KES-FB. LPT values of specimens finished wet coating were higher than those of other kinds of finishing. ${\Delta}L$ values of specimens laminated were highest. Absolute values of ${\Delta}f$ were high in the cire finished and laminated specimens. Values for bending rigidity, shear stiffness and energy required for the compression of coated specimens increased compared with the cire finished and laminated specimens. Laminated specimens had high values of frictional coefficient and low values of surface roughness. Relationship between frictional sounds and mechanical properties analysed by use of correlation coefficients and stepwise regression. LPT showed significant correlation with elongation, tensile energy, geometrical roughness, weight and thickness. ${\Delta}L$ was highly correlated with tensile linearity, frictional coefficient, and ${\Delta}f$ with tensile linearity, weight and thickness. LPT were revealed to be explained by elongation and weight. ${\Delta}L$were predicted by tensile linearity, and ${\Delta}f$ by tensile linearity and thickness.

Enhancement of Oil Delivery by A Mixture of Coacervate Systems (복합 코아세르베이트의 오일 전달 효율 증대)

  • Song, Sang-Hun;Son, Seong Kil
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.44 no.3
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    • pp.285-293
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    • 2018
  • A structure of coacervate affects the adsorption of oil and polymer as a conditioning ingredient. This study aims to elucidate a structural characterization of the coacervate of which is a mixture of alkyl cellulose and guar gum. It is well known that the guar gum supports stiffness to the hair when it is adsorbed on the hair. However, addition of guar gum in the formulation composed of alkyl cellulose tremendously increased flexibility in hair. The stable complex system is induced by an electrostatic force between a head group of anionic surfactant and an quarternary ammonium at the alkyl cellulose, and the affinity of alkyl chain to the oil inside the micelle of surfactant by hydrophobic interactions. Taken together, amount of the coacervate increased oil-delivery upon hair in shampooing and these caused a low bending rigidity and calming on the hair swatch.

Seismic response of 3D steel buildings with hybrid connections: PRC and FRC

  • Reyes-Salazar, Alfredo;Cervantes-Lugo, Jesus Alberto;Barraza, Arturo Lopez;Bojorquez, Eden;Bojorquez, Juan
    • Steel and Composite Structures
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    • v.22 no.1
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    • pp.113-139
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    • 2016
  • The nonlinear seismic responses of steel buildings with perimeter moment resisting frames (PMRF) and interior gravity frames (IGF) are estimated, modeling the interior connections first as perfectly pinned (PPC), and then as partially restrained (PRC). Two 3D steel building models, twenty strong motions and three levels of the PRC rigidity, which are represented by the Richard Model and the Beam Line Theory, are considered. The RUAUMOKO Computer Program is used for the required time history nonlinear dynamic analysis. The responses can be significantly reduced when interior connections are considered as PRC, confirming what observed in experimental investigations. The reduction significantly varies with the strong motion, story, model, structural deformation, response parameter, and location of the structural element. The reduction is larger for global than for local response parameters; average reductions larger than 30% are observed for shears and displacements while they are about 20% for bending moments. The reduction is much larger for medium- than for low-rise buildings indicating a considerable influence of the structural complexity. It can be concluded that, the effect of the dissipated energy at PRC should not be neglected. Even for connections with relative small stiffness, which are usually idealized as PPC, the reduction can be significant. Thus, PRC can be used at IGF of steel buildings with PMRF to get more economical construction, to reduce the seismic response and to make steel building more seismic load tolerant. Much more research is needed to consider other aspects of the problem to reach more general conclusions.

A Study on the High Functional Finishing of Polyester Flat Fabrics Treated with Chitosan (키토산 처리한 폴리에스테르 편평사 직물의 고기능화 가공에 관한 연구)

  • 이석영;박성우;김삼수
    • Textile Coloration and Finishing
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    • v.16 no.3
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    • pp.22-30
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    • 2004
  • The polyester fabrics were treated with the chitosan with various solubility in optimized treatment condition. The treatment method was discussed to be a high functional finishing for the polyester fabric to obtain the high moisture absorption and anti-microorganism property by evaluating the effect of the chitosan purification method on the yield and anti-microorganism property of the chitosan. On the other hand, soluble polyurethane was added to the chitosan treatment solution and/or plasma pretreatment was done. The addition of soluble polyurethane give a high add-on ratio as well as a linen like effect of treated polyester fabric. The results were as follows: 1. In the treatment of polyester fabric by the chitosan solution, a soluble PU resin and low temperature plasma treatment were done to obtain high binding force between the fabrics and the chitosan. The add-on rate and the moisture absorption ratio of the fabrics treated with the chitosan-PU after treated with the plasma slightly increased more than those of the fabrics treated with the chitosan only. 2. Anti-static property of the fabrics treated with the chitosan decreased rapidly with increasing of the chitosan concentration. The washing fastness of the fabrics treated with the chitosan-PU after treated with the plasma was better than those of the fabrics treated with chitosan only. The wrinkle resistance of the treated fabrics decreased constantly with the concentration of the chitosan. The bending rigidity of the treated fabrics increased greatly. On the treatment of polyester fabric under optimum condition, the microorganism reduction rate kept above 90% after 10times launderings. 3. As the polyester fabrics which has flat yam was used as a weft yams were treated with the chitosan-PU as give a functional finishing effects such as durability, moisture absorption, anti-static and anti- microorganism property. Treated polyester fabric showed a good functional finishing effect and a linen like property.

A Study on the Three-dimensional Expression of Fashionable Textiles based on Analyses of 3D Scanning and Textile Properties -Focus on the Work of Iris van Herpen- (패션소재의 입체적 표현에 대한 3D Scanning 및 소재특성 분석 연구 -Iris van Herpen의 작품을 중심으로-)

  • Lee, ReA;Kim, Jongjun
    • Journal of Fashion Business
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    • v.20 no.2
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    • pp.124-133
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    • 2016
  • Currently the fashion industry is developing to create a novel culture due to the very sensitive and knowledge-oriented advancement of the IT industry. With fast turnover of information, consumers have come to have a more diverse desire for purchasing. Cubical expression techniques, which empathizes formativeness, can be a creative expression method adjusting into the trend of this era. Along with functional aspects of consumers, even in a textile manufacturing sector, new materials are required to meet sensitive and emotional aspects. Consumers' desire for new and creative designs and the development and adoption of new materials are essential to meet their emotions. The IT industry and fashion industry are forced to combine and a 3D apparel CAD system has been developed, enabling virtual clothing to be represented within a computer virtual space. All processes such as design, pattern creation, sewing and simulation are possible in 3D level. Digital clothing can shorten the production process time and is very effective in that it can reduce clothing waste generated during the sample production. This paper reviewed the works of Dutch designer, Iris van Herpen, who has developed formative designs. She tries to build, construct, and sculpt employing diversified materials other than soft textile materials, as shown in her series of fashion shows. The materials include films, 3D printed polymers, stiff and sheer organza, and artificial leather textiles. A few characteristics of her works have been selected in order to prepare patterns exhibiting the traits. The paper further focused on the physical features of the textile materials used to express similar techniques and its various forms were reviewed.

Free vibration analysis of large sag catenary with application to catenary jumper

  • Klaycham, Karun;Nguantud, Panisara;Athisakul, Chainarong;Chucheepsakul, Somchai
    • Ocean Systems Engineering
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    • v.10 no.1
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    • pp.67-86
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    • 2020
  • The main goal of this study is to investigate the free vibration analysis of a large sag catenary with application to the jumper in hybrid riser system. The equation of motion is derived by using the variational method based on the virtual work principle. The finite element method is applied to evaluate the numerical solutions. The large sag catenary is utilized as an initial configuration for vibration analysis. The nonlinearity due to the large sag curvature of static configuration is taken into account in the element stiffness matrix. The natural frequencies of large sag catenary and their corresponding mode shapes are determined by solving the eigenvalue problem. The numerical examples of a large sag catenary jumpers are presented. The influences of bending rigidity and large sag shape on the free vibration behaviors of the catenary jumper are provided. The results indicate that the increase in sag reduces the jumper natural frequencies. The corresponding mode shapes of the jumper with large sag catenary shape are comprised of normal and tangential displacements. The large sag curvature including in the element stiffness matrix increases the natural frequency especially for a case of very large sag shape. Mostly, the mode shapes of jumper are dominated by the normal displacement, however, the tangential displacement significantly occurs around the lowest point of sag. The increase in degree of inclination of the catenary tends to increase the natural frequencies.