• Title/Summary/Keyword: woven matrix

Search Result 70, Processing Time 0.023 seconds

Effects of Water Absorption and Surface Treatment on Mechanical Properties of Sisal Textile Reinforced Composites (사이잘 섬유 강화 복합재료의 기계적 특성에 미치는 표면처리와 흡습의 영향)

  • Kim Hyo-Jin;Seo Do-Won;Pak Han-Ju;Jeon Yang-Bae;Lim Jae-Kyoo
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.30 no.7 s.250
    • /
    • pp.779-786
    • /
    • 2006
  • Woven sisal textile reinforced composites were manufactured to evaluate fracture toughness, and tensile test. All specimens were immersed in water five times. All specimens are immersed in pure water during 9 days at room temperature, and dried in 1 day at $50^{\circ}C$. Two kinds of polymer matrices such as epoxy and vinyl-ester were used. Fractured surface were investigated to study the failure mechanism and fiber/matrix interfacial adhesion. It is shows that it can be enhanced to improve their mechanical performance to reveal the relationship between fracture toughness and water absorption fatigue according to different polymer matrices. Water uptake of the epoxy composites was found to increase with cycle times. Mechanical properties are dramatically affected by the water absorption cycles. Water-absorbed samples observed poor mechanical properties such as lower values of maximum strength and extreme elongation. The $K_{IC}$ values demonstrate a decrease in inclination with increasing cyclic times of wetting and drying fur the epoxy and vinyl-ester.

Effects of Fiber Arrangement Direction on Microstructure Characteristics of NITE-SiC Composites (NITE-SiC 복합재료의 미세구조 특성에 미치는 섬유배열방향 영향)

  • Lee, Young-Ju;Yoon, Han-Ki;Park, Joon-Soo;Kohyama, A.
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
    • /
    • 2006.11a
    • /
    • pp.158-161
    • /
    • 2006
  • SiC materials have been extensively studied for high temperature components in advanced energy conversion system and advanced gas turbine. However, the brittle characteristics of SiC such as law fracture toughness and law strain-to fracture impose a severe limitation on the practical applications of SiC materials. SiC/SiC composites can be considered as a promising candidate in various structural materials, because of their good fracture toughness. In this composite system, the direction of SiC fiber will give an effect to the mechanical properties. It is therefore important to control a properdirection of SiC fiber for the fabrication of high performance SiC/SiC composites. In this study, unidirection and two dimension woven structures of SiC/SiC composites were prepared starting from Tyranno SA fiber. SiC matrix was obtained by nano-powder infiltration and transient eutectoid (NITE) process. Effect of microstructure and density on the sintering temperature in NITE-SiC/SiC composites are described and discussed with the fiber direction of unidirection and two dimension woven structures.

  • PDF

Numerical Simulation of Mechanical Behavior of Composite Structures by Supercomputing Technology

  • Kim, Seung-Jo;Ji, Kuk-Hyun;Paik, Seung-Hoon
    • Advanced Composite Materials
    • /
    • v.17 no.4
    • /
    • pp.373-407
    • /
    • 2008
  • This paper will examine the possibilities of the virtual tests of composite structures by simulating mechanical behaviors by using supercomputing technologies, which have now become easily available and powerful but relatively inexpensive. We will describe mainly the applications of large-scale finite element analysis using the direct numerical simulation (DNS), which describes composite material properties considering individual constituent properties. DNS approach is based on the full microscopic concepts, which can provide detailed information about the local interaction between the constituents and micro-failure mechanisms by separate modeling of each constituent. Various composite materials such as metal matrix composites (MMCs), active fiber composites (AFCs), boron/epoxy cross-ply laminates and 3-D orthogonal woven composites are selected as verification examples of DNS. The effective elastic moduli and impact structural characteristics of the composites are determined using the DNS models. These DNS models can also give the global and local information about deformations and influences of high local in-plane and interlaminar stresses induced by transverse impact loading at a microscopic level inside the materials. Furthermore, the multi-scale models based on DNS concepts considering microscopic and macroscopic structures simultaneously are also developed and a numerical low-velocity impact simulation is performed using these multi-scale DNS models. Through these various applications of DNS models, it can be shown that the DNS approach can provide insights of various structural behaviors of composite structures.

Fracture Properties of Carbon Coated LPS-SiCf/SiC Composites (액상소결을 이용한 탄소코팅 SiCf/SiC복합재료의 파괴특성)

  • Kim, Sung-Won;Lee, Moon-Hee;Hwang, Seung-Kuk;Lee, Sang-Pill
    • Journal of the Korean Society of Industry Convergence
    • /
    • v.20 no.2
    • /
    • pp.149-155
    • /
    • 2017
  • Mechanical properties of carbon coated $SiC_f/SiC$ composites have been investigated, in conjunction with a detailed analysis of microstructure. Especially, the fracture behavior of $SiC_f/SiC$ composites by the induction of carbon coating layers has been examined. The matrix region of $SiC_f/SiC$ composites with ultra-fine SiC powders were consolidated by a liquid phase sintering (LPS) process, using a sintering additive of $Al_2O_3-Y_2O_3$ powder compound. In this composite, plain and satin- woven Tyranno SA fabrics were also utilized as a reinforcing material. A carbon interfacial layer was coated around satin-woven SiC fabrics. The characterization of LPS-$SiC_f/SiC$ composites was investigated by means of SEM and three point bending test.

Mechanical Properties of Carbon/Phenolic Ablative Composites (Carbon/Phenolic 내열 복합재료의 기계적 특성)

  • Kim, P.W.;Hong, S.H.;Kim, Y.C.;Yeh, B.H.;Jung, B.
    • Proceedings of the Korean Society For Composite Materials Conference
    • /
    • 1999.11a
    • /
    • pp.160-163
    • /
    • 1999
  • The mechanical properties and failure behaviour of carbon/phenolic composites were inverstigated by tension and compression. Carbon/phenolic composites were fabricated by infiltration of matrix into 8 harness satin woven fabric of PAN-based carbon fibers. The tensile and compressive tests were performed at 25℃ under air atmosphere and, at 400℃ and 700℃ under N₂ atmosphere. The tensile strengths of carbon/phenolic composites in with-laminar/0° warp direction were about 10 times higher than those in with-laminar/45° warp direction, which was analyzed due to a change of fracture mode from fiber pull-out by shear to tensile fracture of fibers. The fracture of carbon/phenolic composites in with-laminar/45° direction was analyzed due to delamination by buckling. Tensile and compressive strength of carbon/phenolic composites decreased to about 50% at 400℃, and to about 10% at 700℃ compared to that at room temperature. The main reason for the decrease of tensile or compressive strength with increasing temperature was analyzed due to a reduction of bond strength between fibers and matrix resulting from thermal degradation of phenolic resin.

  • PDF

New Solid Polymer Electrolyte for Lithium Secondary Batteries

  • Park, Jung-Ki;Lee, Yong-Min;Lee, Jun-Young;Ryou, Myeong-Hyeon
    • Proceedings of the Polymer Society of Korea Conference
    • /
    • 2006.10a
    • /
    • pp.67-68
    • /
    • 2006
  • Solid polymer electrolyte is very important in the applications to high energy density lithium batteries of high safety. In this work, solid polymer electrolytes based on PE non-woven matrix, hybrid salt, and anion receptor were successfully prepared. They could provide high ion conduction phase with maintaining mechanical strength. They also showed high electrochemical stability and lithium ion transference number. This new type of solid polymer electrolyte is expected to be a good candidate for rechargeable solid state lithium secondary batteries.

  • PDF

Radial Flow Type Bioreactor for Bioartificial Liver Assist System using PTFE Non-Woven Fabric Coated with Poly-amino Acid Urethane Copolymer

  • Miskon, Azizi;Yamaoka, Tetsuji;Uyama, Hiroshi;Kodama, Makoto
    • Proceedings of the Polymer Society of Korea Conference
    • /
    • 2006.10a
    • /
    • pp.259-259
    • /
    • 2006
  • PAU is the block copolymer consists of a small amount of a small amount of poly(${\gamma}-methyl-L-glutamate$) (PMLG) and the polyurethane. The urethane segments are hydrophobic and then strongly interact with the other hydrophobic materials such as PTFE, and the PMLG segments with the ${\alpha}-helix$ structure possess the cytocompatibility. Therefore, PAU can be easily coated onto the PTFE fiber and acts as an artificial extracellular matrix with the high cytocompatibility Results shows, the immobilization, cultured and functions of porcine hepatocytes is greatly improved.

  • PDF

Synthesis and mechanical properties of flax fabric reinforced geopolymer composites

  • Assaedi, Hasan S.;Alomayri, Thamer S.;Shaikh, Faiz U.A.;Low, It-Meng
    • Advances in materials Research
    • /
    • v.3 no.3
    • /
    • pp.151-161
    • /
    • 2014
  • Geopolymer composites reinforced with different layers of woven flax fabric are fabricated using lay- up technique. Mechanical properties, such as flexural strength, flexural modulus and fracture toughness of geopolymer composites reinforced with 2.4, 3 and 4.1 wt% flax fibres are studied. The fracture surfaces of the composites are also examined using scanning electron microscopy. The results show that all the mechanical properties of the composites are improved by increasing the flax fibre contents. It is also found that the mechanical properties of flax fabric reinforced geopolymer composites are superior to pure geopolymer matrix. Micro-structural analysis of fracture surface of the composites indicated evidence of various toughening mechanisms by flax fabrics in the composites.

A new constitutive model to predict effective elastic properties of plain weave fabric composites

  • Mazaheri, Amir H.;Taheri-behrooz, Fathollah
    • Structural Engineering and Mechanics
    • /
    • v.77 no.5
    • /
    • pp.651-659
    • /
    • 2021
  • In this study, a new constitutive model has been developed to predict the elastic behavior of plain weave textile composites, using the finite element (FE) method. The geometric conditions and basic assumptions of this model are based on the basics of a continuum theory developed for the plane curved composites. In this model, the mechanical properties of the weave region and pure matrix region is calculated separately and then imported for the FE analysis. This new constitutive model is used to implement the mechanical properties of weave region in the representative volume element (RVE). The constitutive relations are implemented as user-material subroutine code (UMAT) in ABAQUS® FE software. The results of FE analysis have been compared with experimental results and other data available in the literature. These comparisons confirmed the capability of the presented model for the prediction of effective elastic properties of plain weave fabric composites.

Effects of salt water environment on the mechanical behavior of composites (복합재료의 기계적 거동에 염수환경이 미치는 영향에 관한 연구)

  • Moon, Jin-Bum;Kim, Soo-Hyun;Kim, Chun-Gon
    • Composites Research
    • /
    • v.23 no.1
    • /
    • pp.44-50
    • /
    • 2010
  • In this paper, two different experiments, namely, salt water spray and salt water immersion, were performed to reproduce the contact of composites with the seawater for three kinds of woven fabric composite material systems which would be used for the WIG(wing in ground effect)craft. After aging 140 days in the salt water environment, material properties of carbon/epoxy and glass/epoxy composite such as tensile, compressive and shear stiffness and strength, and inter-laminar shear strength (ILSS) were measured. By comparing baseline material properties with degraded ones, the effects of the salt water environment on the composite mechanical properties were evaluated. From the experiments, it was confirmed that the difference in aging conditions had very small influence on composite properties. And it was found that tensile strength of carbon/epoxy composites showed little degradation, but much more degradation was observed in glass/epoxy composites. And large degradations on matrix dominant properties were observed. The salt water could damage the fiber-matrix interface, matrix properties and the glass fiber.