• 제목/요약/키워드: Textile structures

검색결과 183건 처리시간 0.024초

Monitoring the failure mechanisms of a reinforced concrete beam strengthened by textile reinforced cement using acoustic emission and digital image correlation

  • Aggelis, Dimitrios G.;Verbruggen, Svetlana;Tsangouri, Eleni;Tysmans, Tine;Van Hemelrijck, Danny
    • Smart Structures and Systems
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    • 제17권1호
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    • pp.91-105
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    • 2016
  • One of the most commonly used techniques to strengthen steel reinforced concrete structures is the application of externally bonded patches in the form of carbon fiber reinforced polymers (CFRP) or recently, textile reinforced cements (TRC). These external patches undertake the tensile stress of bending constraining concrete cracking. Development of full-field inspection methodologies for fracture monitoring are important since the reinforcing layers are not transparent, hindering visual observation of the material condition underneath. In the present study acoustic emission (AE) and digital image correlation (DIC) are applied during four-point bending tests of large beams to follow the damage accumulation. AE helps to determine the onset of fracture as well as the different damage mechanisms through the registered shifts in AE rate, location of active sources and change in waveform parameters. The effect of wave propagation distance, which in large components and in-situ can well mask the original information as emitted by the fracture incidents is also discussed. Simultaneously, crucial information is supplied by DIC concerning the moments of stress release of the patches due to debonding, benchmarking the trends monitored by AE. From the point of view of mechanics, conclusions on the reinforcing contribution of the different repair methodologies are also drawn.

대나무-면 복합직물의 양이온화에 관한 연구 (A Study of the Cationization of Bamboo-cotton Blended Fabric)

  • 노영주;이신희
    • 한국의류산업학회지
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    • 제24권2호
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    • pp.260-266
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    • 2022
  • Cellulose fiber is a material used in various fields. It is the most used type of fiber because of its excellent hygroscopicity and dyeability. Recently, as natural fiber materials have been highlighted due to the influence of eco-friendliness and well-being, bamboo fiber has become a commonly used eco-friendly fiber. Cellulose fibers are part of the -OH hydroxyl group, which means they are more chemically reactive than synthetic fibers. In this study, the cationization properties of bamboo-cotton blended fabrics cationized using CHPTAC (3-chloro-2-hydroxypropyl trimethyl ammonium chloride) in the PDC (padding-drying-curing) method were investigated. Various characteristics according to cationization were studied through elemental analysis, FT-IR (fourier-transform infrared spectroscopy) analysis, X-ray diffraction analysis, TGA (thermogravimetric) analysis, and SEM (scanning electron microscope) analysis. The nitrogen content of the cationized bamboo-cotton blended fabric increased with an increase in the concentration of the cationizing agent CHPTAC, and it was seen to be highly bound to cellulose molecules. As a result of the FT-IR analysis, both 100% pure cotton fabrics and CHPTAC-0 and CHPTAC-150 fabrics were seen to be typical cellulose. As a result of the X-ray diffraction analysis, both 100% pure cotton fabrics and CHPTAC-0 and CHPTAC-150 fabrics showed typical cellulose I structures. As a result of the X-ray diffraction analysis, both 100% pure cotton fabrics and CHPTAC-0 and CHPTAC-150 fabrics showed typical cellulose I structures. As the cationization progressed, micropores appeared on the surface of the blended fabric.

Manufacturing and characterization of tufted preform with complex shape

  • Gnaba, Imen;Wang, Peng;Legrand, Xavier;Soulat, Damien
    • Advances in aircraft and spacecraft science
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    • 제6권2호
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    • pp.105-116
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    • 2019
  • An alternative to the multilayered preforming is to use structures reinforced through-the-thickness in order to manufacture thicker and more complex pieces. Stitching technology is developed to bind dry reinforcements together or to strengthen composites in thickness performance by inserting structural yarns. Tufting process represents the simplest one-sided sewing technology and it is specifically designed for dry preform/liquid composite molding process route. Currently, the tufting technology is getting more and more interest due to its simplest and efficient process where it involves the insertion of binder threads via a single needle through the fabric. This technique of reinforcement through-the-thickness requires only one access to the preform which makes it suitable for three-dimensional structures and complex shaped textile composites. This paper aims to improve the understanding of the mechanical performance of tufted structures. An experimental study was developed, which included tensile and bending behaviours of tufted and un-tufted preforms, in order to evaluate the effect of tufting on the mechanical performance of dry preforms. The influence of the process parameters (tufting density, loop length, tufting yarns${\ldots}$) on the mechanical performance ofthe final structure is also highlighted.

스마트 헬스케어를 위한 심장활동 신호 검출용 접촉식 직물전극의 구조가 센싱 성능에 미치는 영향 (Effect of the Configuration of Contact Type Textile Electrode on the Performance of Heart Activity Signal Acquisition for Smart Healthcare)

  • 조현승;구혜란;양진희;이강휘;김상민;이정환;곽휘권;고윤수;오윤중;박서연;김신혜;이주현
    • 감성과학
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    • 제21권4호
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    • pp.63-76
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    • 2018
  • 본 연구의 목적은 스마트 헬스케어를 위해 접촉식 직물전극의 구조가 심장활동 신호 획득에 미치는 영향을 연구하는 것이다. 본 연구에서는 심장활동 신호 측정을 위하여 전극의 크기와 구성방식을 조작한 6종의 접촉식 직물전극을 컴퓨터 자수 방식으로 구현하였고, 이를 가슴밴드에 부착하여 응용형 리드 II(modified Lead II) 방식으로 심장활동 신호를 검출하였다. 건강한 신체의 남성 4명을 대상으로 서서 정지한 자세에서 각 직물전극을 사용하여 심장활동 신호를 검출하였으며, 모든 유형의 전극에 걸쳐 4회씩 반복측정 하였다. 심장활동 신호의 수집을 위해 BIOPAC ECG100 장비를 사용하여 1 kHz로 샘플링하였으며, 검출된 원 신호를 대역통과 필터를 사용하여 필터링하였다. 직물전극의 구조에 따른 심장활동 신호 획득의 성능을 비교하기 위하여 신호의 파형과 크기를 파라미터로 하여 정성적 분석을 실시하였고, 각 전극을 통하여 획득된 심장활동 신호의 SPR(signal power ratio)을 산출함으로써 정량적 분석을 실시하였다. 산출된 SPR 값을 대상으로 하여 비모수 통계분석 방식의 차이검정과 사후검정을 실시함으로써 6개 전극의 구조에 따른 심장활동 신호 획득의 성능 차이를 구체적으로 분석하였다. 연구 결과 접촉식 직물전극의 구조에 따라 심장활동 신호의 품질에는 정성적, 정량적 측면에 걸쳐 모두 주요한 차이가 있는 것이 고찰되었다. 접촉식 직물전극의 구성 측면에 있어서는 입체전극이 평면전극에 비해 더 우수한 품질의 신호가 검출되는 것으로 나타났다. 한편 3가지 전극 크기에 따른 심장활동 신호 획득의 유의한 성능 차이는 발견되지 않았다. 이러한 결과는 심장활동 신호 획득을 위한 접촉식 직물전극 구조의 두 가지 요건 중 구성방식(평면/입체)이 웨어러블 헬스케어를 위한 심장활동 신호 획득의 성능에 주요한 영향을 미치는 것을 시사한다. 본 연구 결과를 기반으로 후속 연구에서는 직물전극이 일체형으로 통합된 의복형 플랫폼을 구현하고 성능 고도화 방안을 연구함으로써, 시공간의 제약 없이 고품질의 심장활동 모니터링이 가능한 스마트 의류 기술을 개발하고자 한다.

Characterization of Thermal Degradation of Polytrimethylene Terephthalate by MALDI-TOF Mass Spectrometry

  • Jang, Sung-Woo;Yang, Eun-Kyung;Jin, Sung-Il;Cho, Young-Dal;Choe, Eun-Kyung;Park, Chan-Ryang
    • Bulletin of the Korean Chemical Society
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    • 제33권3호
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    • pp.833-838
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    • 2012
  • The thermal degradation products of polytrimethylene terephthalate (PTT) obtained by heating the sample in the temperature range of $250-360^{\circ}C$ under non-oxidative conditions was characterized using MALDI-TOF (matrix assisted laser desorption/ionization) mass spectrometry. The structures of the degradation products were determined and the relative compositions were estimated. The MALDI-TOF mass spectra of the thermally degraded PTT sample showed three main series of oligomer products with different end groups, which were carboxyl/carboxyl, carboxyl/allyl, and allyl/allyl. In contrast to the thermal degradation of polyethylene terephthalate (PET), the oligomers containing terephthalic anhydrides were not detected, whereas the formation of oligomers containing the unsaturated allyl ester group was confirmed by mass assignment. From these results, it was concluded that the thermal degradation of PTT proceeds exclusively through the ${\beta}$-CH hydrogen transfer mechanism, which is in accordance with the proposed reaction mechanism for the thermal degradation of polybutylene terephthalate (PBT).

중공사를 이용한 침장용 소재의 구조적 특성에 따른 역학적 특성 및 태분석 (The Mechanical Properties and Hand Evaluation of Bedclothes with Hollow Spun Yarn)

  • 최현석;장현미;정문규;전연희;배지현
    • 한국염색가공학회지
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    • 제31권4호
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    • pp.298-311
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    • 2019
  • In this study, the mechanical properties and hand characteristics of the knitted and woven fabrics for bedding items are investigated in accordance with fabric structural parameters including the fiber type and proportion, the density of the fabric, and the knit/weave structure. The knit stitches and structure of the knit samples made an effect on tensile properties. The bending, shear and compression properties for the knit fabric were mainly affected by fiber contents of the samples. The tensile and bending properties of woven samples were highly correlated with the fabric density, thickness and structure, and those shear and compression properties were affected by the fiber contents and structure. Consequently, the primary hand values of the selected samples we developed were estimated to have good smoothness, fullness and softness, and soft feeling, which is well correlated to the parameters of consumer preference such as softness, warmness, and bulkiness. Also, their total hand values were increased.

현대 패션에 나타난 주름의 조형적 특성에 관한 연구 -라이프니츠와 들뢰즈를 중심으로- (A Study on the Formative Characteristics of the Pleats Expressed in Modern Fashion -Focusing on the Thought of G.W.Leifniz and G.Deleuze-)

  • 양희영;양숙희
    • 복식
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    • 제57권1호
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    • pp.130-146
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    • 2007
  • Thought of postmodernism accepted between variety and differentiation is characterized by variability and indeterminacy aimed at continuous change. For that reason, modern fashion has been grouping a lot of manners for creation of the various different form and structure. This paper studies the characteristics of the folding system, which expands efficiency of the spatial utility and shows various forms. Folding system expressed in modern fashion could be divided the pleats, which were made of the folding, and the dreaperies, which were made of bending. This selects the pleats as a enlarged concept of the folding system that contains between the former and the letter. Pleats did not mean two dimensional folding surfaces, but three dimensional spatial structures. For understanding of the folding system as a three dimensional spatial structure, this is utilized with the thought of the 'le pli' of G.W.Leifniz and G.Deleuze. The pleats expressed in modern fashion can subdivided into 4 sets; crinkle system, origami system, fractal pleats by folding system, and drapery system. And Formative characteristics of the pleats are analyzed with enlargement, fluidity, deconstruction, irregularity.

Hydrolytic Degradation of Synthetic Polytrimethylene Terephthalate and Characterization by MALDI-TOF Mass Spectrometry

  • Yang, Eun-Kyung;Jang, Sung-Woo;Cho, Young-Dal;Choe, Eun-Kyung;Park, Chan-Ryang
    • Bulletin of the Korean Chemical Society
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    • 제32권2호
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    • pp.477-482
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    • 2011
  • The structural analysis of polytrimethylene terephthalate (PTT) and characterization of the hydrolytic degradation products after acid hydrolysis were performed using MALDI-TOF mass spectrometry. Mass spectra of the PTT samples were analyzed using a self-calibration method as well as an internal calibration method with standard materials of known masses. PTT structures constituting the samples were determined from the analyses of the spectra, and their relative compositions were estimated. The MALDI-TOF mass spectra of the acid-hydrolyzed PTT sample showed three main series of oligomer products with different end groups in accordance with the hydrolysis schemes. From the spectra of both $Na^+$ and $K^+$ adducts, it was concluded that the PTT samples have higher affinity for $Na^+$ compared with $K^+$ and therefore show higher ionization efficiency with sodium ions when dithranol is used as a matrix. Two different wavelength laser beams ($\lambda$ = 337 nm and 355 nm) were tested and it was observed that the 355 nm beam was more efficient in obtaining the MALDI spectra of PTT using dithranol as a matrix under our experimental conditions.

초음파로 추출된 홍화색소의 특성 분석과 염색성 평가 (Physiochemical Properties and Dyeability of Safflower Colorants Extracted by Ultrasonic Treatment)

  • 김용숙;최종명
    • 한국의류산업학회지
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    • 제11권2호
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    • pp.337-343
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    • 2009
  • This study systematically investigated a method for extraction of safflower (Carthamus tinctorius Linnaeus) colorants by ultrasonic treatment. Compared to pigments productivity and cell wall structures of safflower after general and ultrasonic method, the ultrasonic method showed high extraction efficiency of safflower pigments due to destruction of safflower cell wall caused by high vibration energies. Microscopic analysis confirmed the hypothesis that the ultrasonic treatment of safflower caused its cell wall structure loosened and made efficient extraction of safflower pigments. And also, LC-MS/MS analysis revealed that productivities of the yellow and red safflower pigments by ultrasonic method were 21.9% and 14.6% higher, respectively, than those of pigments extracted by general method. The ultrasonic extracted yellow and red colorants could be used to dye not only natural fibers like cotton, silk and wool, but also synthetic fiber like nylon, and generally gave a better color tone than the general extracted colorants from safflower due to the affinities of red and yellow colorant on different fibers. As the yellow and red colorant were extracted by ultrasonic treatment in water, the K/S value on of 550/440nm of cotton and rayon was increased but in the case of silk and wool the change of this value was almost not detected. Finally, this technique might provide a solution to establish reproducibility and standardization for the extraction and dyeing methods on fabrics.

패션 디자인 프로세스와 스토리텔링의 관계 정립에 관한 연구 (A Study on Establishing Relationship between Fashion Design Process and Storytelling)

  • 성유정;권기영
    • 한국의류산업학회지
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    • 제11권2호
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    • pp.210-218
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    • 2009
  • The Purpose of this study is to demonstrate Storytelling as an effective device for Fashion Design by establishing relationship between Fashion Design Process and Storytelling. Through researching a social background and a concept of storytelling, found that story used interactively is a powerful tool for attention, understanding and change in both individuals and communities. Analysed the elements and the structure of storytelling and Fashion Design Process, by researching preceding researches. Therefore, we proposed a new four elements -text factor, visual factor, audio factor and virtual factor- and four steps (1)exploring stories, (2)planning a story, (3)building the story, (4)do storytelling- of storytelling and four steps-(1)gathering and analysing informations, (2)building a concept, (3)planning and developing a design, (4)do evaluation and make decision- of fashion design process. Through comparative analysis, we found a closeness between two structures, a use of common factors and also found characteristics to be considered in each stage. In the first stage, we found text, visual and audio factor as common factors. In the second stage, we suggested text and visual factor as common factors and also suggested clarity, realism and probability as characteristics. In the third stage, we found text, visual and virtual factor and also found dynamism, immersion and continuity. In the last stage, we suggested text, visual, virtual and audio factor and also suggested presence and interactivity as characteristics.