• Title/Summary/Keyword: shear textures

Search Result 63, Processing Time 0.032 seconds

The effect of the spinning conditions on the structure of mesophase pitch-based carbon fibers by Taguchi method

  • Jiang, Zhao;Ouyang, Ting;Yao, Xiangdong;Fei, Youqing
    • Carbon letters
    • /
    • v.19
    • /
    • pp.89-98
    • /
    • 2016
  • Taguchi’s experimental design was employed in the melt spinning of molten mesophase pitch to produce carbon fibers. The textures of the obtained carbon fibers were radial with varied crack angles, as observed by scanning electron microscopy and polarized optical imaging. The diameter, crack angle, preferred orientation, and tensile modulus of the produced samples were examined to investigate the influence of four spinning variables. The relative importance of the variables has been emphasized for each characteristic. The results show that thicker carbon fiber can be obtained with a smaller entry angle, a higher spinning temperature, a reduced winding speed, and an increased extrusion pressure. The winding speed was found to be the most significant factor in relation to the fiber diameter. While it was observed that thicker carbon fiber generally shows improved preferred orientation, the most important variable affecting the preferred orientation was found to be the entry angle. As the entry angle decreased from 120° to 60°, the shear flow was enhanced to induce more ordered radial alignment of crystallite planes so as to obtain carbon fibers with a higher degree of preferred orientation. As a consequence, the crack angle was increased, and the tensile modulus was improved.

A Study on the Mechanical Properties of Knit Fabric Using 3D Printing -Focused on PLA, TPU Filament- (3D프린팅을 이용한 편성물의 역학적 특성 연구 -PLA, TPU 필라멘트를 중심으로-)

  • Han, Yoojung;Kim, Jongjun
    • Journal of Fashion Business
    • /
    • v.22 no.4
    • /
    • pp.93-105
    • /
    • 2018
  • Using FDM 3D printing, yarn shape and composition were modeled and 3D printed with PLA and TPU filaments currently used for apparel. Based on this, mechanical characteristics were measured to determine 3D printing yarn according to type of filaments in the 3D printed output and deformation and recovery characteristics due to differences in structure type. As a result of examining tensile and shear characteristics of PLA and TPU 3D printing compiles, TPU overall was measured with significantly lower stress than PLA. This is due to high elasticity of TPU's character, revealing that it has better flexibility than PLA. In addition, during deformation due to external forces, the more freedom between the head and foot parts of the loop, and the lower the force associated with each other, the more flexible it is. TPU revealed that it was easier to tension and recovery from tensile deformation than PLA, indicating potential for clothing materials using 3D printing. If high-molecular materials, such as PLA flexibility, it is likely to provide some flexibility through development of styles, including degree of freedom in modeling. Based on this, we provide basic data for developing 3D printing textures that can be satisfied with textile for apparel.

Plastic Strain Ratio and Texture of the ECAPed and Heat-treated Aluminum AA 1050 Sheet (ECAP 한 후 열처리한 알루미늄 AA 1050 합금 판재의 집합조직과 소성변형비 변화)

  • Akramov Saidmurod;Lee M. K.;Park B. H.;Kim I.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
    • /
    • 2005.10a
    • /
    • pp.369-372
    • /
    • 2005
  • A study on the microstructure, the texture and the formability of the samples after ECAPed and subsequent heat-treated AA 1050 aluminum alloy sheet have been carried out. The specimens after the ECAP showed a very fine grain size, a decrease of <100> // ND. The <110>// ND textures appears in the specimens after the ECAP and subsequent heat-treatment at $400^{\circ}C$ for 1 hour. One of the most important properties in sheet metals is formability. The r-value or plastic strain ratio has was as a parameter that expressed the formability of sheet metals. The change of the plastic Strain ratios after the ECAP and subsequent heat-treatment conditions were investigated and it was found that they were two times higher than those of the initial Al sheets. This could be attributed to the formation above texture components through the ECAP and subsequent heat-treatment of AA 1050 Aluminum alloy sheet.

  • PDF

Texture and Plastic deformation of the Severe Ecaped and Heatreated AA 1050 Aluminum Alloy Sheet (심한 전단변형(ECAP)과 열처리한 알루미늄 AA 1050 합금 판재의 소성변형비와 집합조직)

  • Akramov Saidmurod;Lee M. K.;Kim I.;Park B. H.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
    • /
    • 2005.05a
    • /
    • pp.148-151
    • /
    • 2005
  • A study on the microstructure and the texture of the samples after ECAP and subsequent heat treatment has been carried out. The specimens after ECAP showed a very fine grain size, a decrease of <100> // ND, and an increase of <111> // ND textures. The $\{111\}<112>,\;\{123\}<634>,\;\{110\}<001>,\;\{112\}<111>,\;\{110\}<111>,\;and\;\{013\}<231>$ texture components were increased in the specimens after the ECAP and subsequent heat-treatment at $400^{\circ}C$ for 1 hour. One of the most important properties in sheet metals is formability. The r-value or plastic strain ratio has been used as a parameter that expresses the formability of sheet metals. The change of the plastic strain ratios after the ECAP and subsequent heat-treatment conditions has been investigated and it was found that they were two times higher than those of the initial Al sheets. This could be attributed to the formation above texture components through the ECAP and subsequent heat-treatment.

  • PDF

Improvement of R-value in Al-Mg-Si-Cu Alloy Sheets by Cross Rolling (크로스 압연에 의한 Al-Mg-Si-Cu 합금 판재의 소성변형비의 향상)

  • Lee, Kwang-jin;Jeon, Jae-yeol;Woo, Kee-do
    • Korean Journal of Metals and Materials
    • /
    • v.49 no.6
    • /
    • pp.488-492
    • /
    • 2011
  • Heat-treatable Al-Mg-Si-Cu alloy sheets, which are expected to have a growing demand, were fabricated by Cross rolling to improve their formability. The mechanical properties and texture of the sheets after the final annealing process were investigated by a tensile test, EBSD and XRD analysis. The grain size of the cross-rolled sheets was remarkably decreased compared to conventional rolled sheets, and the R-value of the cross-rolled sheets was notably increased by about one and a half times that of the conventional rolled sheet. Cube{001}<100> and cubic system orientations were strongly developed in conventional rolled sheets. However, randomized textures were formed in the cross-rolled sheets without specific texture. It is thought that much shear deformation was induced during the cross rolling. The results show that the cross rolling method is effective for improving the R-value of aluminum alloys sheets and their grain refinement. As a result, it is considered that cross rolling is effective for improving formability.

Effect of Texturized Soy Protein on the Sensory Characteristics and Texture of N[eat Balls (Wanja) (조직콩 단백의 첨가가 쇠고기 완자의 기호 및 Texture에 미치는 영향)

  • 정락원;이효지
    • Korean journal of food and cookery science
    • /
    • v.1 no.1
    • /
    • pp.65-73
    • /
    • 1985
  • In this study, we tried to compare and determine wat the effects will be to the sensory characteristics and textures of a meat balls when the proportion of the textu-rized soy protein (TSP) varies from 0, 10, 20, 30, and 40%. Evaluation was conducted through sensory evaluation and objective evaluation. The results are as follows: 1. As the level of 40% TSP increased the meat ball maintained a better appearance. 2. Color, beef flavor, tenderness, juiciness and acceptability shelved the tendency to decrease as TSP proportion increased. (1) No significant change to the outside color revealed to the level of 20%. How-ever, inside color showed a significant change after the level exceeded 20%. (2) Soy flavor tended to increased and beef flavor tended to decrease as the TSP proportion increased. However up to the level of 30% one could not taste the flavor of soy. (3) Tenderness tended to decrease as the TSP proportion increased however difference was not significant. (4) Juiciness decreased as TSP proportion increased. (5) Acceptability tended to decrease as the TSP proportion increased but to a 40% addition, the level of TSP did not have much effect on the sensory characteristics as long as sufficient seasonings were added. 3. Instron measurement incidated that springiness, cohesiveness and shear force tended to dcrease as the TSP proportion increased but hardness increased and chewi-ness was the highest at 20% TSP level. 4. Color and difference meter indicated that the figure L and b tended to increase and AE decreased as the TSP proportion increased. 5. Cooking retention tended to increase as the TSP proportion increased. From thiss tudy, we can conclude that the level of up to 40% of TSP in making meat ball did not affect the preference.

  • PDF

Quality Properties of Chicken Breast Ham manufactured with Spent Broiler Breeder Hen and Spent Laying Hen (육용종계 노계와 산란노계 가슴살 햄의 품질 특성)

  • Kim, Hack-Youn;Kim, Gye-Woong
    • Korean Journal of Poultry Science
    • /
    • v.43 no.3
    • /
    • pp.191-195
    • /
    • 2016
  • This study aimed to investigate the physicochemical properties of chicken breast ham manufactured with broiler (BR), spent broiler breeder hen (SBBH), and spent laying hen (SLH). The water holding capacity and final yield of chicken breast ham manufactured with SLH was significantly lower than chicken breast ham manufactured with BR and SBBH (P<0.05). The lightness and redness of chicken breast ham manufactured with SBBH were significantly higher than those of chicken breast ham manufactured with SLH (P<0.05). The yellowness of chicken breast ham manufactured with BR and SLH was significantly higher than that of chicken breast ham manufactured with SBBH (P<0.05). The shear force of chicken breast ham manufactured with SLH was the highest. The tenderness and overall acceptability of chicken breast ham manufactured with BR and SBBH were significantly higher than those of chicken breast ham manufactured with SLH. Therefore, SBBH and SLH can lead to various textures of chicken breast hams.

Quantification of Surface Topography Using Digital Image Analysis

  • Lee, Seok-Won
    • Journal of the Korean Geotechnical Society
    • /
    • v.15 no.3
    • /
    • pp.131-149
    • /
    • 1999
  • It was found that surface roughness has a first-order effect on the interface shear strength and accordingly it should be accurately quantified if its role is to be properly understood. To quantify the surface topography, first of all, a variety of commonly used surface roughness parameters and profiling methods were reviewed in this study. Based on this review, the normalized roughness parameter. $R_n$(Uesugi and Kishida, 1986), the profile roughness parameter, $R_L$, and the surface roughness parameter, $R_n$(Dove and Frost, 1996), were selected to be appropriate candidates of roughness parameters and the digital image analysis based Optical Profile Microscopy(OPM) method(Dove and Frost, 1996) to be an appropriate profiling method for this study. Using a smooth and three textured HDPE geomembranes which encompass the range of textures and texture patterns commonly used, a series of roughness measurements on virgin and previously used geomembranes were performed. The results showed that both $R_L\; and\; R_S$ values appropriately reflect the degree of texturing for the geomembranes used in this study, however, $R_n$ value showed limited ranges of variation which may not be sufficient to permit distinction between roughness values for certain conditions. The results of this study will be extended to the investigation of the influence of surface roughness on interface strength in future study.

  • PDF

Changes of Physical Properties of Soils by Organic Material application (유기성 물질 시용에 따른 농경지 토양물리성 변화 연구)

  • Kim, Lee-Yul;Cho, Hyun-Jun;Han, Kyung-Hwa
    • Korean Journal of Soil Science and Fertilizer
    • /
    • v.37 no.5
    • /
    • pp.304-314
    • /
    • 2004
  • The objective of this study was to investigate the effect of organic materials (compost, straw, green manure, pig manure, seed production oil cake, and industrial by products including municipal sewage sludge, industrial sewage sludge, leather processing sludge, and alcohol fermentation processing sludge) on physical properties of soils in seven paddy and four upland fields with differential soil textures, sandy loam, loam, or clay loam, etc. The investigated physical parameters were bulk density (BD), air permeability (AP), macroporosity, hardness, shear resistance, frictional resistance, water stability aggregate (WSA), and Middleton's dispersion ratio. Except for coarse sandy loam field with weak structure, a decrease in BD and shear resistance, and an increase in macroporosity and AP in plots with applying organic materials compared to plots without applying organic materials appeared. In upland fields, the positive effect of organic materials on WSA, BD, and air permeability was higher than in paddy fields. The combined plot of NPK and compost had lower BD, hardness, and shear resistance, and higher macroporosity and WSA than plot with compost. Green manure had higher positive effect on physical properties of soils compared to other organic materials and the extent of positive effect had no significant correlation with soil organic matter content. Of industrial byproducts applied in coarse sandy loam soil under upland condition, municipal sewage sludge and pig manure compost had higher effect on increase of WSA than leather processing sludge and alcohol fermentation processing sludge. Unlike WSA, there were no significant differences between industrial byproduct types in other physical properties. in silty clay loam soil under the upland condition, straw had more positive effect on soil physical parameters than hairy vetch and pig manure. Therefore, different organic materials had differently active effect on physical parameters depending on types of soil and land use. Especially, it could be thought that well-decomposed organic materials have the advantage of an increase in organic matter content, while coarse organic materials of an increase in WSA.

Textural and Geochemical Characteristics and their Relation of Spinel Peridotite Xenoliths from Jeju Island (제주도 첨정석 페리도타이트 포획암의 조직 및 지화학적 특성과 그 관련성)

  • Yu, Jae-Eun;Yang, Kyoung-Hee;Kim, Jin-Seop
    • The Journal of the Petrological Society of Korea
    • /
    • v.19 no.3
    • /
    • pp.227-244
    • /
    • 2010
  • Abundant spinel lherzolite xenoliths showing distinctively different textural types such as protogranular, porphyroclastic, and mylonitic texture are trapped in the basaltic rocks from southeastern part of Jeju Island. These xenoliths show the textural spectrum from coarse-grained protogranular through porphyroclastic with bimodal grain size to fine-grained and foliated mylonitic texture. They tend to decrease in grain sizes and show more linear grain boundaries and more frequent triple junctions from protogranular through porphyroclastic to mylonitic. Spinel has different occurrence mode according the textural type. Spinel is always associated with orthopyroxene in protogranular texture, whereas it is scattered and independent of orthopyroxene in mylonitic texture. Additionally, porphyroblast from porphyroclastic and mylonitic textures has internal deformation features such as kink band, undulatory extinction and curved lamella, whereas neoblast is strain-free. These textural features indicate increasing degree of static/dynamic recrystallization from protogranular through porphyroclastic to mylonitic texture. The mg#[$=100{\times}Mg/(Mg+Fe_t)$] of olivine, orthopyroxene and clinopyroxene is relatively constant (ol: 88-91; opx: 89-92; cpx: 89-92) regardless of textural differences. The mg# of constituent minerals, NiO content (0.3~0.4 wt%) and MnO content (0.1~0.2 wt%) of olivine are similar to those of mantle xenoliths worldwide, also indicating that studied spinel lherzolite xenoliths were mantle residues having experienced 20~25% partial melting. The geochemical and textural characteristics have close relations showing that LREE and incompatible trace elements content of orthopyroxene and clinopyroxene increases from protogranular through porphyroclastic to mylonitic. These observations suggest that the studied mantle xenoliths experienced metasomatism by LREE enriched melt or fluid after partial melting, indicating a close relation between deformation and metasomatism. The metasomatism was possibly confined to narrow shear zones from where porphyroclastic and mylonitic textured xenoliths originated. These shear zones might favorably drive the percolation of LREE-enriched melts/fluids responsible for the metasomatism in the lithospheric mantle below the Jeju Island.