• 제목/요약/키워드: stiffness of fabric

검색결과 178건 처리시간 0.026초

소총 사격복 착용실태 및 만족도에 관한 질적연구 (Qualitative Research on Actual Wearing Conditions and Satisfaction of Rifle Shooting Clothing)

  • 이아람;박수진;김나윤;남윤자
    • 한국의류학회지
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    • 제39권4호
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    • pp.517-528
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    • 2015
  • This study investigates actual wearing conditions and satisfaction based on qualitative research for rifle shooting clothing. The survey was conducted in two ways: in-depth interviews of 4 rifle shooting experts and subjective questionnaires for 18 active rifle shooters. They agreed on the importance of rifle shooting wear to minimize body sway and contribute to a balanced body posture. Most rifle shooters purchase made-to-measure rifle shooting clothing at a domestic store, but the clothing often needs extra adjustments due to an uncomfortable fit. Current fabric for rifle shooting clothing consists of a cotton canvas with a polyester mix; however, rifle shooters are unsatisfied with its stiffness in hot and wet conditions. Due to the specific fabric features, rifle shooting clothing should not be washed despite year-round use that represents another point of dissatisfaction. Rifle shooters always wear specially designed underclothes to improve shooting skills and comfort sensation. In conclusion, it is necessary to develop well fitted and comfort rifle shooting clothing that could improve shooters skills based upon this study.

폐석면의 활용을 위한 저온 용융처리에 대한 실험적 연구 (An experimental study on the low temperature melting treatment of waste asbestos for using)

  • 송태협;김영훈;박지선;이세현
    • 한국건설순환자원학회논문집
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    • 제5권2호
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    • pp.83-90
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    • 2010
  • As a reinforced fabric, asbestos has been utilized as a fire-resistant material as it has a superior flexural stiffness and heat resistance up to $1500^{\circ}C$. However, due to its harmfulness, its use has been prohibited recently and the even the installed asbestos materials are being repaired or supplemented if there is a concern about flying. Asbestos is mainly used for construction panels as a reinforced fabric and coating materials to ensure the fire-resistance of steel frames. Asbestos was used as fire-resistant materials for steel frames until 1991 and then prohibited as Act on Industrial Safety and Health limits the concentration of asbestos in the air. Classified as a designated waste according to Act on Waste Control, asbestos must be buried if there is no possibility of flying (panel-type materials) or cement-solidified and then buried if there is a possibility of flying (spray coating material) In general, it is required that a new waste landfill include a certain landfill facility for designated waste, but in reality there is an absolute storage of landfill facilities for designated waste as they only install facilities of the size required by the regulations. This could result in the 2nd environmental pollution as they cannot process asbestos wastes which will be generated in large volume in the future. This study explores a method that melts asbestos wastes at $700^{\circ}C$ rather than cement-solidifying the waste asbestos from construction sites, especially asbestos-containing spray coating. The study results showed that there was no change in the composition and shape even though asbestos wastes was melted at $1300^{\circ}C$, but there was a change for the specimen which was process in advance for low temperature melting and then melt at $900^{\circ}C$.

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적층 방법에 따른 복합재의 저온 영역 하에서 정적 강도 변화 (Effect of Fabrication Methods on Static Strength of Polymer Based Composites under the Low Temperature Range)

  • 엄수현;;권순철;김국진;김윤해
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2003년도 춘계학술대회
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    • pp.7-12
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    • 2003
  • When the wind turbine is used in cold regions, the mechanical properties and dimension stability of the blade will be changed. The proposal of this paper is to test the durability of the blade for wind turbine. It is necessary to select the most comfortable materials and fabrication processes for more stable wind turbine blade in cold regions. To select the most comfortable materials and processes, the static strength has to know through the tensile static tests at the severe condition as cold regions. First, the tensile static specimens made by RIM (Resin injection molding) process & vacuum bagging process with reinforcement materials and resin. Tensile static tests were carried out on three laminate lay-ups (carbon prepreg, carbon fiber dry fabric and glass fiber dry fabric) at different test temperature($24^{\circ}$, $-30^{\circ}$), determining properties such as the mechanical strength, stiffness and strain to failure. At different test temperature, in order to test the tensile strengths of these specimens used the low temperature chamber. Next, the results of this test were compared with each other. Finally, the most comfortable materials and fabrication processes can select based on these results. The results show the changes in the static behavior of three laminate lay-ups at different test temperatures. At low temperatures, the static strengths are higher than the ones at room temperature.

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한복지의 역학적 특성에 관한 연구 (제2보) 여자용 추동한복지 (A Study on the Mechanical Properties of Fabrics for Korean Folk Clothes (Part 2) On the Women's Fall & Winter Fabrics)

  • 성수광;고재운;권오경
    • 한국의류학회지
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    • 제12권2호
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    • pp.169-179
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    • 1988
  • In the part 1, relations were found between fundmental mechanical properties and primary hand values, performance of Korean women's summer fabrics. In this paper, in order to investigate the hand values and mechanical properties such as tensile, shearing, bending, compression, surface and thickness & weight of the women's fall & winter fabrics were measured by KES-F system. Sorts of 90 commercial fabrics for women's fall & winter clothes were classfied into 39 silk and 51 polyester fabrics according to meterials. The experimental results were analysed statistically to relate the hand values and the mechanical properties and concerning to formation of weared clothes and transformation behavior were investigated. Furthermore, there mechanical properties as well as their hand values were discussed in comparison with those values for kimono fabrics. The main results are summarized as follows; 1. The shape of silk fabrics in formation for weared clothes show a box-shaped silhouette. Polyester fabrics has a easy to shape-less and make a silhouette which goes along with the body. 2. Silk fabrics for Korean women's fall & winter clothes have ${\pm}1\sigma$ range of bending, shearing, surface properties and thickness as compared with kimono fabrics. 3. A wrinkle recovery and drapability of silk fabrics for Korean women's fall & winter clothes are inferior to kimono fabrics. On the other hand, the fabrics for Korean women's fall & winter clothes have conical-shaped silhouette based on higher bending rigidity. 4. Except for flexibility with soft feeling, a primary factor of mechanical properties contributes to the hand values of fabrics for Korean women's fall & winter clothes having no concern with materials were same as the women's summer fabrics. 5. As for the hand values of fabrics for Korean folk clothes, stiffness, anti-drape stiffness are larger than those of kimono fabric and stiffness, anti-drape stiffness, crispness of fabrics for Korean women's fall & winter clothes have smaller values as compared with Korean women's summer fabrics.

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비선형 강성 모델을 위한 드레이프 시뮬레이션 결과 추정 (Drape Simulation Estimation for Non-Linear Stiffness Model)

  • 심응준;주은정;최명걸
    • 한국컴퓨터그래픽스학회논문지
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    • 제29권3호
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    • pp.117-125
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    • 2023
  • 가상 시뮬레이션을 이용한 의류 디자인 개발에서는 가상과 실제의 차이가 최소화되어야 한다. 가상 의상과 실제 의상의 유사성을 높이는 데에 가장 기본이 되는 작업은 의상 제작에 사용될 옷감의 물성을 최대한 유사하게 표현할 수 있는 시뮬레이션 파라미터를 찾는 것이다. 시뮬레이션 파라미터 최적화 절차에는 전문가의 수작업으로 이루어지는 튜닝 과정이 포함되는데, 이 작업은 높은 전문성과 많은 시간이 요구된다. 특히 조정된 시뮬레이션 파라미터를 적용한 결과를 다시 확인하기 위해 시뮬레이션을 반복적으로 실행할 때 많은 시간이 소요된다. 최근 이 문제를 해결하기 위해 파라미터 튜닝에 주로 사용되는 드레이프 테스트 시뮬레이션 결과를 빠르게 추정하는 인공신경망 학습 모델이 제안되었다. 하지만 기존 연구에서는 비교적 간단한 선형 강성 모델을 사용하였으며 드레이프 시뮬레이션 전체를 추정하는 대신 일부만 추정하고 나머지는 보간하는 방식을 사용하였다. 실제 의류 디자인 개발 과정에서는 주로 비선형 강성 모델이 적용된 시뮬레이터가 사용되지만, 이에 대한 연구는 아직 부족하다. 본 논문에서는 비선형 강성 모델을 대상으로 드레이프 시뮬레이션 결과를 추정하기 위한 새로운 학습 모델을 제안한다. 본 연구에서 제안된 학습 모델은 시뮬레이션 결과인 고해상도 메시 모델 전체를 추정한다. 제시하는 방법의 성능을 검증하기 위해 세 가지 드레이프 테스트 방식을 대상으로 실험을 진행하여 추정 정확도를 평가한다.

Site response analysis using true coupled constitutive models for liquefaction triggering

  • Cristhian C. Mendoza-Bolanos;Andres Salas-Montoya;Oscar H. Moreno-Torres;Arturo I. Villegas-Andrade
    • Earthquakes and Structures
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    • 제25권1호
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    • pp.27-41
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    • 2023
  • This study focused on nonlinear effective stress site response analysis using two coupled constitutive models, that is, the DM model (Dafalias and Manzari 2004), which incorporated a simple plasticity sand model accounting for fabric change effects, and the PMDY03 model (Khosravifar et al. 2018), that is, a 3D model for earthquake-induced liquefaction triggering and postliquefaction response. A detailed parametric study was conducted to validate the effectiveness of nonlinear site response analysis and porewater pressure (PWP) generation through a true coupled formulation for assessing the initiation of liquefaction at ground level. The coupled models demonstrated accurate prediction of liquefaction triggering, which was in line with established empirical liquefaction triggering relations in published databases. Several limitations were identified in the evaluation of liquefaction using the cyclic stress method, despite its widespread implementation for calculating liquefaction triggering. Variations in shear stiffness, represented by changes in shear wave velocity (Vs1), exerted the most significant influence on site response. The study further indicated that substantial differences in response spectra between nonlinear total stress and nonlinear effective stress analyses primarily occurred when liquefaction was triggered or on the verge of being triggered, as shown by excess PWP ratios approaching unity. These differences diminished when liquefaction occurred towards the later stages of intense shaking. The soil response was predominantly influenced by the higher stiffness values present prior to liquefaction. A key contribution of this study was to validate the criteria used to assess the triggering of level-ground liquefaction using true coupled effective-stress constitutive models, while also confirming the reliability of numerical approximations including the PDMY03 and DM models. These models effectively captured the principal characteristics of liquefaction observed in field tests and laboratory experiments.

직교 이방적 사질토의 미시역학적 탄소성 모델링: II. 미시역학적 해석 (Elastic-plastic Micromechanics Modeling of Cross-anisotropic Granular Soils: II. Micromechanics Analysis)

  • 정영훈;정충기
    • 한국지반공학회논문집
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    • 제23권3호
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    • pp.89-100
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    • 2007
  • 본 논문과 함께 제출한 논문에서는 미시역학 기반의 새로운 탄소성 모델의 정식화에 대해 설명하였다. 본 논문에서는 사질토 변형의 탄성 및 탄소성 거동을 미시역학에 근거하여 자세히 분석하였다. 모델에 필요한 변수 평가를 위한 과정을 제시하였다. 등방 및 삼축 압축 시험에서 나타난 사질토의 탄성 거동을 분석한 결과, 직교 이방 탄성계수의 응력 종속성은 미시적 수직 강성에서 나타난 수직 접촉력의 거듭제곱 함수 형태가 반영되어 나타나며, 삼축 압축 응력 상태에서는 조직 이방성의 변화가 응력 종속성에 영향을 미침을 알 수 있었다. 미시역학적 해석을 통해 소성 변형이 매우 낮은 변형률 수준에서도 발현되며, 변형 중 사질토 강성의 비선형적 감소는 접촉점에서의 접선 방향 소성 변형에 의해 나타남을 밝혔다.

자동무인경전철 복합재 차체 구조물의 구조 시험 및 해석적 검증에 의한 유한요소 모델 도출 연구 (A Study on Structural Test and Derivation of Standard Finite Element Model for Composite Vehicle Structures of Automated People Mover)

  • 고희영;신광복;김대환
    • Composites Research
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    • 제22권5호
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    • pp.1-7
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    • 2009
  • WR580/NF4000 유리섬유 에폭시 면재를 갖는 알루미늄 하니컴 샌드위치 복합재가 적용된 자동무인경전철 차체 구조물은 구조 시험과 유한요소 해석에 의해 평가되었다. 구조 시험은 JIS E 7105 규정에 따라 수행되었다. 차체 구조물의 추조 안전성은 다이얼 게이지와 가속도 센서를 통해 얻어진 처짐 및 고유진동수 결과에 의해 평가되었다. 그리고 제안된 유한요소 모델은 구조 시험 결과와 비교 되었으며, 유한요소 해석은 구조 시험과 잘 일치함을 보였다. 또한, 차제 구조물의 강성을 높이기 위해 언더프레임에 보강재가 적용된 모델은 설계단계에서 제안되었다. 보강된 언더프레임 모델을 갖는 복합재 차체 구조물은 구조 강성이 약 44%가 향상되었다.

견의 효소 정련에 관한 연구 (A Study on Enzymatic Degummings of Raw Silk and Silk Fabric)

  • 이용우;송기원;정인모
    • 한국잠사곤충학회지
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    • 제28권1호
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    • pp.66-71
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    • 1986
  • 생사 및 견직물에 대한 효소정련방법을 구명하기 위한 시험 결과 1. 각종 효소정련조건이 정련효율에 비치는 영향에 있어서 정련온도 및 정련용의 산도는 Papain 7$0^{\circ}C$, pH 5-6, Trypsin 4$0^{\circ}C$ pH 8, Alkalase 50-6$0^{\circ}C$, pH 8-9에서 각각 정련효율이 가장 높았다. 2. Alkalase 처리농도가 생사의 정련효율에 미치는 영향에 있어서 처리농도가 0.6-1.0g/l 범위에서 높이면 정련시간을 단축시킬 수 있다. 3. 생사의 Alkalase정련에 있어서 정련전처리(95$^{\circ}C$, 10분 1g/l NaHCO3) 또는 정련후처리(2%, o.w.f. sodium silicate, 8$0^{\circ}C$, 20분)를 행하면 정련효율을 향상시킬 수 있었다. 4. 효소정련견사의 강력(g/d), 신도 및 라우지네스 성적은 비누 정련견사에 비하여 향상되는 경향이었다. 5. Alkalase에 의한 효소정련에 있어서 생견직물의 조련정도가 정련효율에 미치는 영향은 조련연감율이 높을수록 효소정련효율이 높았으며 205 이상에서는 하부다에 및 크\ulcorner데신 모두 완전한 정련이 가능하였다. 6. 조련연감율을 20%로 한 견포에 대하여 3종의 효소정련을 실시한 경우 Papain 및 Trypsin 정련구는 Alkalase 정련구에 비하여 정련효율이 저하되었다. 7. 효소정련견포의 강건도는 크\ulcorner데신의 경우 1.27cm로서 대조인 비누소오다 정련견포 1.53cm에 비하여 17% 저하되었고 Drape 계수는 0.297로서 비누소오다 정련견포의 0.321에 비하여 7% 감소됨으로서 유건한 촉감이 향상되었다.

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네틀 데님소재의 태의 변화에 관한 연구 (A Study on the Change of Hand of Nettle Denim)

  • 이정민
    • 패션비즈니스
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    • 제22권2호
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    • pp.107-117
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    • 2018
  • Nettle fiber, a sustainable fiber, was applied to the fabrication of denim to identify changes in textile appearance and formation. For the weaving of nettle denim, nine specimens, distinguished by three kinds of composite use of nettle fiber and three stages of fabrication processes, were used. The kinetic characteristics of the nine specimens were measured by the KES-FB system, and the images of the specimens of finished denim textiles, captured with a CCD Camera, were analyzed. In terms of the extensibility (EM) of nettle denim, all specimens showed post-processing increase, thereby suggesting an easy transformation of the textile as a source material for denim fabric. The effects of washing on the woven formation of denim were also identified. The geometric roughness (SMD), the problematic property of bast-fiber-like nettle fiber, was found to be decreased by washing. In terms of the bending rigidity (B) of the textile, the post-processing shrinking percentage of elastic nettle denim was found to decrease; all specimens that underwent bio-washing only also manifested that post-processing elasticity increased. To improve the draping of nettle denim, a mixed spinning together with washing were found to be advantageous. In terms of the shear stiffness (G), which is closely associated with the appearance of clothes, the formation of textile was improved regardless of the types of processing, including bio-washing and bleach washing.