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Sample records for high modulus woven

  1. Residual stress in high modulus carbon fibers

    Science.gov (United States)

    Chen, K. J.; Diefendorf, R. J.

    1982-01-01

    The modulus and residual strain in carbon fibers are measured by successively electrochemically milling away the fiber surface. Electrochemical etching is found to remove the carbon fiber surface very uniformly, in contrast to air and wet oxidation. The precision of fiber diameter measurements is improved by using a laser diffraction technique instead of optical methods. More precise diameter measurements reveal that past correlations of diameter and fiber modulus are largely measurement artifact. The moduli of most carbon fibers decrease after the outer layers of the fibers are removed. Owing to experimental difficulties, the moduli and strengths of the fibers at their centers are not determined, and moduli are estimated on the basis of microstructure. The calculated residual stresses are found to be insensitive to these moduli estimates as well as the exact form of regression equation used to describe the moduli and residual strain distributions. Axial compressive residual stresses are found to be very high for some higher modulus carbon fibers. It is pointed out that the compressive stress makes the fibers insensitive to surface flaws when loaded in tension but it may initiate failure by buckling when loaded in compression.

  2. High Strain Rate Compressive Tests on Woven Graphite Epoxy Composites

    Science.gov (United States)

    Allazadeh, Mohammad Reza; Wosu, Sylvanus N.

    2011-08-01

    The behavior of composite materials may be different when they are subjected to high strain rate load. Penetrating split Hopkinson pressure bar (P-SHPB) is a method to impose high strain rate on specimen in the laboratory experiments. This research work studied the response of the thin circular shape specimens, made out of woven graphite epoxy composites, to high strain rate impact load. The stress-strain relationships and behavior of the specimens were investigated during the compressive dynamic tests for strain rates as high as 3200 s-1. One dimensional analysis was deployed for analytical calculations since the experiments fulfilled the ratio of diameter to length of bars condition in impact load experiments. The mechanics of dynamic failure was studied and the results showed the factors which govern the failure mode in high strain deformation via absorbed energy by the specimen. In this paper, the relation of particle velocity with perforation depth was discussed for woven graphite epoxy specimens.

  3. Ultra-high Modulus Nano-Fluoroelastomers

    Science.gov (United States)

    Pan, David H.

    2004-03-01

    The cross-linking densities, glass transition temperatures, and physical properties of fluoroelastomers filled with a nanometer-size particle have been determined as a function of filler concentration and co-solvent using both dry and wet filler incorporation methodologies. Addition of alcohol to the casting solvent such as methyl isobutyl ketone results in about a factor of 1.5-3 increase in elastic modulus for elastomer of the same filler concentration. It is discovered that a properly prepared nano-fluoroelastomer can exhibit as much as a two-order-of-magnitude increase in elastic modulus as the filler concentration increases from zero to 35 parts per hundred of rubber (phr) by weight while the glass transition temperature does not change substantially with filler concentration. The effect of cross-linking density on the elastic modulus for these materials will be discussed in this paper.

  4. Experimental Evaluation of Tensile Strength and Young’s Modulus of Woven Jute fiber and Polyurethane Composite

    Directory of Open Access Journals (Sweden)

    Shrikant Shinde*

    2015-08-01

    Full Text Available Natural fiber reinforced composites (NFRCs are increasingly used in a variety of commercial applications, but there has been little theoretical, micromechanical modeling of structure/property relationships in these materials. These can’t be met by conventional metal alloys. The scope of possible uses of natural fibers is enormous.Plenty of research work is done on natural fiber composites. But, woven jute fiber and bio based polyurethane resin matrix is not used extensively for research studies. Mostly mathematical model is used to investigate and predict the properties and fiber loads effect on mechanical properties. The combination of jute fiber with PU produced the material that is competitive to synthetic composites. Literature review shows that composite made of combination of these constituents is not studied mechanically in order to evaluate its properties. The present paper focus is on the experimental analysis and testing of untreated woven jute fiber and PUR composite. The tensile properties of natural fiber reinforced composites (NFRCs are modeled experimental method.

  5. Cold Resistant Properties of High Modulus Polyurethane

    Institute of Scientific and Technical Information of China (English)

    LI Minghua; XIA Ru; ZHANG Yuchuan; HUANG Zhifang; YAO Heping; HUANG Wanli; WANG Yifeng; HUI Jianqiang; WU Chunyu

    2009-01-01

    Six kinds of polyurethane(PU)elastomers were prepared based on different poly-esters,polyethers and chain extenders.The structure,mechanical properties and cold resistant proper-ties of PU were systematically investigated by FTIR,XRD,DMTA,universal testing machine and flex ductility machine.The results show that T_g of soft segment is the main factor of the cold resistant properties of polyurethane elastomer.Compared with the same relative molecular mass of the polyester and the polyether,the polyether flexibility is better,the glass transition temperature(T_g)is lower and the cold resistant properties is remarkable,for example the cold resistant properties of PU based on poly(tetramethylene glycol),1,4-BG and MDI achieves the fifth level.The physics performances of polyurethane elastomers,such as breakdown strength,Young's modulus and the cold resistant prop-erties,are all superior.

  6. Non-toxic invert analog glass compositions of high modulus

    Science.gov (United States)

    Bacon, J. F. (Inventor)

    1974-01-01

    Glass compositions having a Young's modulus of at least 15 million psi are described. They and a specific modulus of at least 110 million inches consist essentially of, in mols, 15 to 40% SiO2, 6 to 15% Li2O, 24 to 45% of at least two bivalent oxides selected from the group consisting of Ca, NzO, MgO and CuO; 13 to 39% of at least two trivalent oxides selected from the group consisting of Al2O3, Fe2O3, B2O3, La2O3, and Y2O3 and up to 15% of one or more tetravelent oxides selected from the group consisting of ZrO2, TiO2 and CeO2. The high modulus, low density glass compositions contain no toxic elements. The composition, glass density, Young's modulus, and specific modulus for 28 representative glasses are presented. The fiber modulus of five glasses are given.

  7. High elastic modulus nanopowder reinforced resin composites for dental applications

    Science.gov (United States)

    Wang, Yijun

    2007-12-01

    Dental restorations account for more than $3 billion dollars a year on the market. Among them, all-ceramic dental crowns draw more and more attention and their popularity has risen because of their superior aesthetics and biocompatibility. However, their relatively high failure rate and labor-intensive fabrication procedure still limit their application. In this thesis, a new family of high elastic modulus nanopowder reinforced resin composites and their mechanical properties are studied. Materials with higher elastic modulus, such as alumina and diamond, are used to replace the routine filler material, silica, in dental resin composites to achieve the desired properties. This class of composites is developed to serve (1) as a high stiffness support to all-ceramic crowns and (2) as a means of joining independently fabricated crown core and veneer layers. Most of the work focuses on nano-sized Al2O3 (average particle size 47 nm) reinforcement in a polymeric matrix with 50:50 Bisphenol A glycidyl methacrylate (Bis-GMA): triethylene glycol dimethacrylate (TEGDMA) monomers. Surfactants, silanizing agents and primers are examined to obtain higher filler levels and enhance the bonding between filler and matrix. Silane agents work best. The elastic modulus of a 57.5 vol% alumina/resin composite is 31.5 GPa compared to current commercial resin composites with elastic modulus alumina, diamond/resin composites are studied. An elastic modulus of about 45 GPa is obtained for a 57 vol% diamond/resin composite. Our results indicate that with a generally monodispersed nano-sized high modulus filler, relatively high elastic modulus resin-based composite cements are possible. Time-dependent behavior of our resin composites is also investigated. This is valuable for understanding the behavior of our material and possible fatigue testing in the future. Our results indicate that with effective coupling agents and higher filler loading, viscous flow can be greatly decreased due to the

  8. Research on Properties of Woven Fabrics Treated by High Pressure Water Jet

    Institute of Scientific and Technical Information of China (English)

    黄故

    2001-01-01

    The paper introduces a new technique for the treatment of the woven fabrics. Sprayed by high pressure water jet, the appearance, handle and stiffness of the fabric are improved. Other properties of the high pressure water treated fabrics like drape coefficient, air permeability, tenacity are also presented.

  9. Mechanical Components from Highly Recoverable, Low Apparent Modulus Materials

    Science.gov (United States)

    Padula, Santo, II (Inventor); Noebe, Ronald D. (Inventor); Stanford, Malcolm K. (Inventor); DellaCorte, Christopher (Inventor)

    2015-01-01

    A material for use as a mechanical component is formed of a superelastic intermetallic material having a low apparent modulus and a high hardness. The superelastic intermetallic material is conditioned to be dimensionally stable, devoid of any shape memory effect and have a stable superelastic response without irrecoverable deformation while exhibiting strains of at least 3%. The method of conditioning the superelastic intermetallic material is described. Another embodiment relates to lightweight materials known as ordered intermetallics that perform well in sliding wear applications using conventional liquid lubricants and are therefore suitable for resilient, high performance mechanical components such as gears and bearings.

  10. The impact resistance of Kevlar woven fabrics impregnated with highly concentrated multiphase suspensions

    Institute of Scientific and Technical Information of China (English)

    Liu Jun; Xiong Dangsheng

    2016-01-01

    The stab and puncture resistance of Kevlar woven fabrics impregnated with different kinds of highly concentrated multiphase suspensions was studied with self-made dual-catheter drop-hammer tester. The results showed that the shear thickening of multiphase particles was possibly based on hydrocluster and particle jamming mechanism; the introduction of alumina silicate fibre can remarkably improve the composite spike resistance, and multiphase particles co-strengthening can provide best protection effect; otherwise, the stab resistance increases weakly.

  11. High modulus invert analog glass compositions containing beryllia

    Science.gov (United States)

    Bacon, J. F. (Inventor)

    1974-01-01

    Glass compositions having a Young's modulus of at least 15 million psi and a specific modulus of at least 110 million inches consisting essentially of, in mols, 10-45% SiO2, 2-15% Li2O, 3-34% BeO, 12-36% of at least one bivalent oxide selected from the group consisting of CaO, ZnO, MgO and CuO, 10-39% of at least one trivalent oxide selected from the group consisting of Al2O3, B2O3, La2O3, Y2O3 and the mixed rare earth oxides, the total number of said bivalent and trivalent oxides being at least three, and up to 10% of a tetravalent oxide selected from the group consisting of ZrO2, TiO2 and CeO2.

  12. Effects of SBS Configuration on Performance of High Modulus Bitumen Based on Dynamic Mechanical Analysis

    OpenAIRE

    Ming Liang; Yong Hu; Xiangjun Kong; Weiyu Fan; Xue Xin; Hui Luo

    2016-01-01

    High modulus bitumens modified by polystyrene-block-polybutadiene-block-polystyrene (SBS) with different molecular structure were investigated on dynamic shear rheometer and fluorescence microscopy to evaluate viscoelastic properties and morphology of binders. The results shows that storage modulus (G’) is obviously less than loss modulus (G”), which means viscous behaviour of bitumen is dominant, and anti-rutting factor (G* ⁄ sin δ) is markedly enhanced by star SBS than by linear SBS. The mo...

  13. Ultra-high modulus organic fiber hybrid composites

    Science.gov (United States)

    Champion, A. R.

    1981-01-01

    An experimental organic fiber, designated Fiber D, was characterized, and its performance as a reinforcement for composites was investigated. The fiber has a modulus of 172 GPa, tensile strength of 3.14 GPa, and density of 1.46 gm/cu cm. Unidirectional Fiber D/epoxy laminates containing 60 percent fiber by volume were evaluated in flexure, shear, and compression, at room temperature and 121 C in both the as fabricated condition and after humidity aging for 14 days at 95 percent RH and 82 C. A modulus of 94.1 GPa, flexure strength of 700 MPa, shear strength of 54 MPa, and compressive strength of 232 MPa were observed at room temperature. The as-fabricated composites at elevated temperature and humidity aged material at room temperature had properties 1 to 20 percent below these values. Combined humidity aging plus evaluated temperature testing resulted in even lower mechanical properties. Hybrid composite laminates of Fiber D with Fiber FP alumina or Thornel 300 graphite fiber were also evaluated and significant increases in modulus, flexure, and compressive strengths were observed.

  14. Laboratory Performance Evaluation of High Modulus Asphalt Concrete Modified with Different Additives

    Directory of Open Access Journals (Sweden)

    Peng Li

    2017-01-01

    Full Text Available The objective of this study is to evaluate comprehensive performance of high modulus asphalt concrete (HMAC and propose common values for establishing evaluation system. Three gradations with different modifiers were conducted to study the high and low temperature performance, shearing behavior, and water stability. The laboratory tests for HMAC included static and dynamic modulus tests, rutting test, uniaxial penetration test, bending test, and immersion Marshall test. Dynamic modulus test results showed that modifier can improve the static modulus and the improvements were remarkable at higher temperature. Moreover, modulus of HMAC-20 was better than those of HMAC-16 and HMAC-25. The results of performance test indicated that HMAC has good performance to resist high temperature rutting, and the resistances of the HMAC-20 and HMAC-25 against rutting were better than that of HMAC-16. Then, the common values of dynamic stability were recommended. Furthermore, common values of HMAC performance were established based on pavement performance tests.

  15. High-power biofuel cell textiles from woven biscrolled carbon nanotube yarns.

    Science.gov (United States)

    Kwon, Cheong Hoon; Lee, Sung-Ho; Choi, Young-Bong; Lee, Jae Ah; Kim, Shi Hyeong; Kim, Hyug-Han; Spinks, Geoffrey M; Wallace, Gordon G; Lima, Márcio D; Kozlov, Mikhail E; Baughman, Ray H; Kim, Seon Jeong

    2014-06-02

    Biofuel cells that generate electricity from glucose in blood are promising for powering implantable biomedical devices. Immobilizing interconnected enzyme and redox mediator in a highly conducting, porous electrode maximizes their interaction with the electrolyte and minimizes diffusion distances for fuel and oxidant, thereby enhancing power density. Here we report that our separator-free carbon nanotube yarn biofuel cells provide an open-circuit voltage of 0.70 V, and a maximum areal power density of 2.18 mW cm(-2) that is three times higher than for previous carbon nanotube yarn biofuel cells. Biofuel cell operation in human serum provides high areal power output, as well as markedly increased lifetime (83% remained after 24 h), compared with previous unprotected biofuel cells. Our biscrolled yarn biofuel cells are woven into textiles having the mechanical robustness needed for implantation for glucose energy harvesting.

  16. Comparing non-woven, filmateci and woven gauze swabs.

    Science.gov (United States)

    Thomas, S; Loveless, P; Hay, N P; Toyick, N

    1993-01-02

    The physical characteristics and performance of seven non-woven swabs intended for topical use were compared with those of filmated swabs and woven cotton gauze in a series of laboratory tests. The results of this study suggest that the non-woven swabs have significant advantages over the other type examined. Based upon current pricing structures they represent a highly cost-effective alternative to the more traditional products for routine wound management procedures. As the various non-wovens have very different handling characteristics, it should be possible to select a swab to suit most requirements from the range of products available.

  17. High temperature nanoindentation hardness and Young's modulus measurement in a neutron-irradiated fuel cladding material

    Science.gov (United States)

    Kese, K.; Olsson, P. A. T.; Alvarez Holston, A.-M.; Broitman, E.

    2017-04-01

    Nanoindentation, in combination with scanning probe microscopy, has been used to measure the hardness and Young's modulus in the hydride and matrix of a high burn-up neutron-irradiated Zircaloy-2 cladding material in the temperature range 25-300 °C. The matrix hardness was found to decrease only slightly with increasing temperature while the hydride hardness was essentially constant within the temperature range. Young's modulus decreased with increasing temperature for both the hydride and the matrix of the high burn-up fuel cladding material. The hydride Young's modulus and hardness were higher than those of the matrix in the temperature range.

  18. Performance evaluation of high modulus asphalt concrete mixes

    Science.gov (United States)

    Haritonovs, V.; Tihonovs, J.; Zaumanis, M.

    2016-04-01

    Dolomite is one of the most available sedimentary rocks in the territory of Latvia. Dolomite quarries contain about 1000 million tons of this material. However, according to Latvian Road Specifications, this dolomite cannot be used for average and high intensity roads because of its low quality (mainly, LA index). Therefore, mostly imported magmatic rocks (granite, diabase, gabbro, basalt) or imported dolomite are used which makes asphalt expensive. However, practical experience shows that even with these high quality materials roads exhibit rutting, fatigue and thermal cracks. The aim of the research is to develop a high performance asphalt concrete for base and binder courses using only locally available aggregates. In order to achieve resistance against deformations at a high ambient temperature, a hard grade binder was used. Workability, fatigue and thermal cracking resistance, as well as sufficient water resistance is achieved by low porosity (3-5%) and higher binder content compared to traditional asphalt mixtures. The design of the asphalt includes a combination of empirical and performance based tests, which in laboratory circumstances allow simulating traffic and environmental loads. High performance AC 16 base asphalt concrete was created using local dolomite aggregate with polymer modified (PMB 10/40-65) and hard grade (B20/30) bitumen. The mixtures were specified based on fundamental properties in accordance to EN 13108-1 standard.

  19. High Modulus, High Conductivity Nanostructured Polymer Electrolyte Membranes via Polymerization-Induced Phase Separation

    Science.gov (United States)

    McIntosh, Lucas; Schulze, Morgan; Hillmyer, Marc; Lodge, Timothy

    2014-03-01

    Solvent-free, solid-state polymer electrolyte membranes (PEMs) will play a vital role in next-generation electrochemical devices such as Li-metal batteries and high- T fuel cells. The primary challenge is that these applications require PEMs with substantial mechanical robustness, as well as high ionic conductivity. The key to optimizing orthogonal macroscopic properties is to use a heterogeneous composite with well-defined nanoscopic morphology--specifically, long-range co-continuity of high modulus and ion transport domains, which has proven difficult to achieve in commonly-studied diblock copolymer-based electrolytes. We report a simple synthetic strategy to generate PEMs via polymerization-induced phase separation, where the delicate balance between controlled addition of styrene onto a poly(ethylene oxide) macro-chain transfer agent and simultaneous chemical crosslinking by divinylbenzene results in a disordered structure with domain size of order 10 nm. Crucially, both domains exhibit long-range continuity, which results in PEMs that are glassy solids (modulus ~ 1 GPa) owing to the isotropic network of stiff, crosslinked polystyrene, and are highly conductive (> 1 mS/cm at 70 °C) because ions migrate in channels of low Tg poly(ethylene oxide).

  20. In-situ measurement of elastic modulus for ceramic top-coat at high temperature

    Institute of Scientific and Technical Information of China (English)

    齐红宇; 周立柱; 马海全; 杨晓光; 李旭

    2008-01-01

    The ceramic thermal barrier coatings (TBCs) play an increasingly important in advanced gas turbine engines because of their ability to further increase the engine operating temperature and reduce the cooling, thus help achieve future engine low emission, high efficiency and improve the reliability goals. Currently, there are two different processes such as the plasma spraying (PS) and the electron beam-physical vapor deposition (EB-PVD) techniques. The PS coating was selected to test the elastic modulus. Using the nanoindentation and resonant frequency method, the mechanical properties of ceramic top-coat were measured in-situ. According to the theory of the resonant frequency and composite beam, the testing system was set up including the hardware and software. The results show that the accurate characterization of the elastic properties of TBCs is important for stress-strain analysis and failure prediction. The TBCs systems are multi-layer material system. It is difficult to measure the elastic modulus of top-coat by tensile method. The testing data is scatter by nanoindentation method because of the microstructure of the ceramic top-coat. The elastic modulus of the top-coat between 20?1 150 ℃ is obtained. The elastic modulus is from 2 to 70 GPa at room temperature. The elastic modulus changes from 62.5 GPa to 18.6 GPa when the temperature increases from 20 ℃ to 1 150 ℃.

  1. Effects of SBS Configuration on Performance of High Modulus Bitumen Based on Dynamic Mechanical Analysis

    Directory of Open Access Journals (Sweden)

    Ming Liang

    2016-07-01

    Full Text Available High modulus bitumens modified by polystyrene-block-polybutadiene-block-polystyrene (SBS with different molecular structure were investigated on dynamic shear rheometer and fluorescence microscopy to evaluate viscoelastic properties and morphology of binders. The results shows that storage modulus (G’ is obviously less than loss modulus (G”, which means viscous behaviour of bitumen is dominant, and anti-rutting factor (G* ⁄ sin δ is markedly enhanced by star SBS than by linear SBS. The morphology indicated that star SBS improved the softening point more obviously, tending to form a cross-linked network in bitumen. As for linear SBS, it is dispersed in bitumen in the form of globules and enhances the ductility of binder.

  2. Full deflection profile calculation and Young’s modulus optimisation for engineered high performance materials

    Science.gov (United States)

    Farsi, A.; Pullen, A. D.; Latham, J. P.; Bowen, J.; Carlsson, M.; Stitt, E. H.; Marigo, M.

    2017-04-01

    New engineered materials have critical applications in different fields in medicine, engineering and technology but their enhanced mechanical performances are significantly affected by the microstructural design and the sintering process used in their manufacture. This work introduces (i) a methodology for the calculation of the full deflection profile from video recordings of bending tests, (ii) an optimisation algorithm for the characterisation of Young’s modulus, (iii) a quantification of the effects of optical distortions and (iv) a comparison with other standard tests. The results presented in this paper show the capabilities of this procedure to evaluate the Young’s modulus of highly stiff materials with greater accuracy than previously possible with bending tests, by employing all the available information from the video recording of the tests. This methodology extends to this class of materials the possibility to evaluate both the elastic modulus and the tensile strength with a single mechanical test, without the need for other experimental tools.

  3. High modulus asphalt (EME) technology transfer to South Africa and Australia: shared experiences

    CSIR Research Space (South Africa)

    Denneman, E

    2015-08-01

    Full Text Available The paper describes experiences with the implementation of French enrobés à module élevé (EME) (high modulus asphalt) technology in South Africa and Australia. Tentative performance specifications for EME mixes were set in the two countries based...

  4. Isothermal fatigue behavior and damage modeling of a high temperature woven PMC[Polymer Matrix Composite

    Energy Technology Data Exchange (ETDEWEB)

    Gyekenyesi, A.L.

    2000-01-01

    This study focuses on the fully reversed fatigue behavior exhibited by a carbon fiber/polyimide resin woven laminate at room and elevated temperatures. Nondestructive video edge view microscopy and destructive sectioning techniques were used to study the microscopic damage mechanisms that evolved. The elastic stiffness was monitored and recorded throughout the fatigue life of the coupon. In addition, residual compressive strength tests were conducted on fatigue coupons with various degrees of damage as quantified by stiffness reduction. Experimental results indicated that the monotonic tensile properties were only minimally influenced by temperature, while the monotonic compressive and fully reversed fatigue properties displayed greater reductions due to the elevated temperature. The stiffness degradation as a function of cycles, consisted of three stages; a short-lived high degradation period, a constant degradation rate segment covering the majority of the life, and a final stage demonstrating an increasing rate of degradation up to failure. Concerning the residual compressive strength tests at room and elevated temperatures, the elevated temperature coupons appeared much more sensitive to damage. At elevated temperatures, coupons experienced a much larger loss in compressive strength when compared to room temperature coupons with equivalent damage. The fatigue damage accumulation law proposed for the model incorporates a scalar representation for damage, but admits a multiaxial, anisotropic evolutionary law. The model predicts the current damage (as quantified by residual stiffness) and remnant life of a composite that has undergone a known load at temperature. The damage/life model is dependent on the applied multiaxial stress state as well as temperature. Comparisons between the model and data showed good predictive capabilities concerning stiffness degradation and cycles to failure.

  5. Effect of hydroxyapatite concentration on high-modulus composite for biodegradable bone-fixation devices.

    Science.gov (United States)

    Heimbach, Bryant; Grassie, Kevin; Shaw, Montgomery T; Olson, James R; Wei, Mei

    2016-06-14

    There are over 3 million bone fractures in the United States annually; over 30% of which require internal mechanical fixation devices to aid in the healing process. The current standard material used is a metal plate that is implanted onto the bone. However, metal fixation devices have many disadvantages, namely stress shielding and metal ion leaching. This study aims to fix these problems of metal implants by making a completely biodegradable material that will have a high modulus and exhibit great toughness. To accomplish this, long-fiber poly-l-lactic acid (PLLA) was utilized in combination with a matrix composed of polycaprolactone (PCL) and hydroxyapatite (HA) nano-rods. Through single fibril tensile tests, it was found that the PLLA fibers have a Young's modulus of 8.09 GPa. Synthesized HA nanorods have dimensions in the nanometer range with an aspect ratio over 6. By dip coating PLLA fibers in a suspension of PCL and HA and hot pressing the resulting coated fibers, dense fiber-reinforced samples were made having a flexural modulus up to 9.2 GPa and a flexural strength up to 187 MPa. The flexural modulus of cortical bone ranges from 7 to 25 GPa, so the modulus of the composite material falls into the range of bone. The typical flextural strength of bone is 130 MPa, and the samples here greatly exceed that with a strength of 187 MPa. After mechanical testing to failure the samples retained their shape, showing toughness with no catastrophic failure, indicating the possibility for use as a fixation material. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2016.

  6. Some important aspects in testing high-modulus fiber composite tubes designed for multiaxial loading.

    Science.gov (United States)

    Sullivan, T. L.; Chamis, C. C.

    1972-01-01

    Tubular specimens were potted in metal grips to determine the feasibility of this gripping method in applying multiaxial loads. Strain gage rosettes were used to assess grip transitional strains, through thickness strain variation and strain variations along the tube length and circumference. The investigation was limited to loading 0, 45, plus or minus 45, and 90 deg graphite/epoxy and glass/epoxy tubes in axial tension. Results include modifications made to the grips to reduce transitional strains, illustrations of the tube failure modes, and some material properties. The gripping concept shows promise as a satisfactory technique for applying multiaxial loads to high-strength, high-modulus fiber composite tubes.

  7. Transient Thermal Tensile Behaviour of Novel Pitch-Based Ultra-High Modulus CFRP Tendons

    Directory of Open Access Journals (Sweden)

    Giovanni Pietro Terrasi

    2016-12-01

    Full Text Available A novel ultra-high modulus carbon fibre reinforced polymer (CFRP prestressing tendon made from coal tar pitch-based carbon fibres was characterized in terms of high temperature tensile strength (up to 570 °C with a series of transient thermal and steady state temperature tensile tests. Digital image correlation was used to capture the high temperature strain development during thermal and mechanical loading. Complementary thermogravimetric (TGA and dynamic mechanical thermal (DMTA experiments were performed on the tendons to elucidate their high temperature thermal and mechanical behaviour. The novel CFRP tendons investigated in the present study showed an ambient temperature design tensile strength of 1400 MPa. Their failure temperature at a sustained prestress level of 50% of the design tensile strength was 409 °C, which is higher than the failure temperature of most fibre reinforced polymer rebars used in civil engineering applications at similar utilisation levels. This high-temperature tensile strength shows that there is potential to use the novel high modulus CFRP tendons in CFRP pretensioned concrete elements for building applications that fulfill the fire resistance criteria typically applied within the construction industry.

  8. The thermal conductivity of high modulus Zylon fibers between 400 mK and 4 K

    Science.gov (United States)

    Wikus, Patrick; Figueroa-Feliciano, Enectalí; Hertel, Scott A.; Leman, Steven W.; McCarthy, Kevin A.; Rutherford, John M.

    2008-11-01

    Zylon is a synthetic polyurethane polymer fiber featuring very high mechanical strength. Measurements of the thermal conductivity λZ(T) of high modulus Zylon fibers at temperatures between 400 mK and 4 K were performed to assess if they can be successfully employed in the design of high performance suspension systems for cold stages of adiabatic demagnetization refrigerators. The linear mass density of the yarn used in these measurements amounts to 3270 dtex, which is also a measure for the yarn's cross section. The experimental data for the thermal conductivity was fitted to a function of the form λZ=(1010±30)·TpWmmdtexK. This result was normalized to the breaking strength of the fibers and compared with Kevlar. It shows that Kevlar outperforms Zylon in the investigated temperature range. At 1.5 K, the thermal conductivity integral of Zylon yarn is twice as high as the thermal conductivity integral of Kevlar yarn with the same breaking strength. A linear mass density of 1 tex is equivalent to a yarn mass of 1 g/km. High modulus Zylon has a density of 1.56 g/cm 3.

  9. Evaluation of elastic modulus and hardness of highly inhomogeneous materials by nanoindentation

    Science.gov (United States)

    Epshtein, Svetlana A.; Borodich, Feodor M.; Bull, Steve J.

    2015-04-01

    The experimental and numerical techniques for evaluation of mechanical properties of highly inhomogeneous materials are discussed. The techniques are applied to coal as an example of such a material. Characterization of coals is a very difficult task because they are composed of a number of distinct organic entities called macerals and some amount of inorganic substances along with internal pores and cracks. It is argued that to avoid the influence of the pores and cracks, the samples of the materials have to be prepared as very thin and very smooth sections, and the depth-sensing nanoindentation (DSNI) techniques has to be employed rather than the conventional microindentation. It is shown that the use of the modern nanoindentation techniques integrated with transmitted light microscopy is very effective for evaluation of elastic modulus and hardness of coal macerals. However, because the thin sections are glued to the substrate and the glue thickness is approximately equal to the thickness of the section, the conventional DSNI techniques show the effective properties of the section/substrate system rather than the properties of the material. As the first approximation, it is proposed to describe the sample/substrate system using the classic exponential weight function for the dependence of the equivalent elastic contact modulus on the depth of indentation. This simple approach allows us to extract the contact modulus of the material constitutes from the data measured on a region occupied by a specific component of the material. The proposed approach is demonstrated on application to the experimental data obtained by Berkovich nanoindentation with varying maximum depth of indentation.

  10. Impact of compression on gas transport in non-woven gas diffusion layers of high temperature polymer electrolyte fuel cells

    Science.gov (United States)

    Froning, Dieter; Yu, Junliang; Gaiselmann, Gerd; Reimer, Uwe; Manke, Ingo; Schmidt, Volker; Lehnert, Werner

    2016-06-01

    Gas transport in non-woven gas diffusion layers of a high-temperature polymer electrolyte fuel cell was calculated with the Lattice Boltzmann method. The underlying micro structure was taken from two sources. A real micro structure was analyzed in the synchrotron under the impact of a compression mask mimicking the channel/rib structure of a flow field. Furthermore a stochastic geometry model based on synchrotron X-ray tomography studies was applied. The effect of compression is included in the stochastic model. Gas transport in these micro structures was simulated and the impact of compression was analyzed. Fiber bundles overlaying the micro structure were identified which affect the homogeneity of the gas flow. There are significant deviations between the impact of compression on effective material properties for this type of gas diffusion layers and the Kozeny-Carman equation.

  11. High elastic modulus polymer electrolytes suitable for preventing thermal runaway in lithium batteries

    Science.gov (United States)

    Mullin, Scott; Panday, Ashoutosh; Balsara, Nitash Pervez; Singh, Mohit; Eitouni, Hany Basam; Gomez, Enrique Daniel

    2014-04-22

    A polymer that combines high ionic conductivity with the structural properties required for Li electrode stability is useful as a solid phase electrolyte for high energy density, high cycle life batteries that do not suffer from failures due to side reactions and dendrite growth on the Li electrodes, and other potential applications. The polymer electrolyte includes a linear block copolymer having a conductive linear polymer block with a molecular weight of at least 5000 Daltons, a structural linear polymer block with an elastic modulus in excess of 1.times.10.sup.7 Pa and an ionic conductivity of at least 1.times.10.sup.-5 Scm.sup.-1. The electrolyte is made under dry conditions to achieve the noted characteristics. In another aspect, the electrolyte exhibits a conductivity drop when the temperature of electrolyte increases over a threshold temperature, thereby providing a shutoff mechanism for preventing thermal runaway in lithium battery cells.

  12. Background data for modulus mapping high-performance polyethylene fiber morphologies.

    Science.gov (United States)

    Strawhecker, Kenneth E; Sandoz-Rosado, Emil J; Stockdale, Taylor A; Laird, Eric D

    2017-02-01

    The data included here provides a basis for understanding "Interior morphology of high-performance polyethylene fibers revealed by modulus mapping" (K.E. Strawhecker, E.J. Sandoz-Rosado, T.A. Stockdale, E.D. Laird, 2016) [1], in specific: the multi-frequency (AMFM) atomic force microscopy technique and its application to ultra-high-molecular-weight Polyethylene (UHMWPE) fibers. Furthermore, the data suggests why the Hertzian contact mechanics model can be used within the framework of AMFM theory, simple harmonic oscillator theory, and contact mechanics. The framework is first laid out followed by data showing cantilever dynamics, force-distance spectra in AC mode, and force-distance in contact mode using Polystyrene reference and UHMWPE. Finally topography and frequency shift (stiffness) maps are presented to show the cases where elastic versus plastic deformation may have occurred.

  13. A High-Speed Dual Modulus Prescaler Using 0.25μm CMOS Technology

    Institute of Scientific and Technical Information of China (English)

    杨文荣; 曹家麟; 冉峰; 王健

    2004-01-01

    A high-speed dual-modulus divide-by-32/33 prescaler has been developed using 0.25μm CMOS technology. The source-coupled logic (SCL) structure is used to reduce the switching noise and to ameliorate the power-speed tradeoff. The proposed prescaler can operate at high frequency with a low-power consumption. Based on the 2.5 V, 0.25μm CMOS model, simulation results indicate that the maximum input frequency of the prescaler is up to 3.2 GHz. Running at 2.5 V, the circuit consumes only 4.6 mA at an input frequency 2.5 GHz.

  14. Background data for modulus mapping high-performance polyethylene fiber morphologies

    Directory of Open Access Journals (Sweden)

    Kenneth E. Strawhecker

    2017-02-01

    Full Text Available The data included here provides a basis for understanding “Interior morphology of high-performance polyethylene fibers revealed by modulus mapping” (K.E. Strawhecker, E.J. Sandoz-Rosado, T.A. Stockdale, E.D. Laird, 2016 [1], in specific: the multi-frequency (AMFM atomic force microscopy technique and its application to ultra-high-molecular-weight Polyethylene (UHMWPE fibers. Furthermore, the data suggests why the Hertzian contact mechanics model can be used within the framework of AMFM theory, simple harmonic oscillator theory, and contact mechanics. The framework is first laid out followed by data showing cantilever dynamics, force-distance spectra in AC mode, and force-distance in contact mode using Polystyrene reference and UHMWPE. Finally topography and frequency shift (stiffness maps are presented to show the cases where elastic versus plastic deformation may have occurred.

  15. Design and fabrication of a metastable β-type titanium alloy with ultralow elastic modulus and high strength

    Science.gov (United States)

    Guo, Shun; Meng, Qingkun; Zhao, Xinqing; Wei, Qiuming; Xu, Huibin

    2015-10-01

    Titanium and its alloys have become the most attractive implant materials due to their high corrosion resistance, excellent biocompatibility and relatively low elastic modulus. However, the current Ti materials used for implant applications exhibit much higher Young’s modulus (50 ~ 120 GPa) than human bone (~30 GPa). This large mismatch in the elastic modulus between implant and human bone can lead to so-called “stress shielding effect” and eventual implant failure. Therefore, the development of β-type Ti alloys with modulus comparable to that of human bone has become an ever more pressing subject in the area of advanced biomedical materials. In this study, an attempt was made to produce a bone-compatible metastable β-type Ti alloy. By alloying and thermo-mechanical treatment, a metastable β-type Ti-33Nb-4Sn (wt. %) alloy with ultralow Young’s modulus (36 GPa, versus ~30 GPa for human bone) and high ultimate strength (853 MPa) was fabricated. We believe that this method can be applied to developing advanced metastable β-type titanium alloys for implant applications. Also, this approach can shed light on design and development of novel β-type titanium alloys with large elastic limit due to their high strength and low elastic modulus.

  16. Analysis of Apparent Elasticity Constants of Woven Fabrics

    Institute of Scientific and Technical Information of China (English)

    董侠; 张建春; 张燕

    2001-01-01

    The woven fabric can be defined as orthogonal elastomer if the extension force that puts on the fabric is very small. Based on the precondition, the apparent elasticity constants of a woven fabric were analyzed theoretically in the paper. The bias angle (which is between weft yarns and extension direction ) affects apparent elasticity modulus and elasticity coefficient of the fabric in the extension direction. And the experiment describes fluxes of elasticity constants going with the bias angle of the fabric.

  17. Force measurements on natural membrane nanovesicles reveal a composition-independent, high Young's modulus

    Science.gov (United States)

    Calò, Annalisa; Reguera, David; Oncins, Gerard; Persuy, Marie-Annick; Sanz, Guenhaël; Lobasso, Simona; Corcelli, Angela; Pajot-Augy, Edith; Gomila, Gabriel

    2014-01-01

    Mechanical properties of nano-sized vesicles made up of natural membranes are crucial to the development of stable, biocompatible nanocontainers with enhanced functional, recognition and sensing capabilities. Here we measure and compare the mechanical properties of plasma and inner membrane nanovesicles ~80 nm in diameter obtained from disrupted yeast Saccharomyces cerevisiae cells. We provide evidence of a highly deformable behaviour for these vesicles, able to support repeated wall-to-wall compressions without irreversible deformations, accompanied by a noticeably high Young's modulus (~300 MPa) compared to that obtained for reconstituted artificial liposomes of similar size and approaching that of some virus particles. Surprisingly enough, the results are approximately similar for plasma and inner membrane nanovesicles, in spite of their different lipid compositions, especially on what concerns the ergosterol content. These results point towards an important structural role of membrane proteins in the mechanical response of natural membrane vesicles and open the perspective to their potential use as robust nanocontainers for bioapplications.Mechanical properties of nano-sized vesicles made up of natural membranes are crucial to the development of stable, biocompatible nanocontainers with enhanced functional, recognition and sensing capabilities. Here we measure and compare the mechanical properties of plasma and inner membrane nanovesicles ~80 nm in diameter obtained from disrupted yeast Saccharomyces cerevisiae cells. We provide evidence of a highly deformable behaviour for these vesicles, able to support repeated wall-to-wall compressions without irreversible deformations, accompanied by a noticeably high Young's modulus (~300 MPa) compared to that obtained for reconstituted artificial liposomes of similar size and approaching that of some virus particles. Surprisingly enough, the results are approximately similar for plasma and inner membrane nanovesicles, in

  18. Proton conducting, high modulus polymer electrolyte membranes by polymerization-induced microphase separation

    Science.gov (United States)

    Chopade, Sujay; Hillmyer, Marc; Lodge, Timothy

    Robust solid-state polymer electrolyte membranes (PEMs) are vital for designing next-generation lithium-ion batteries and high-temperature fuel cells. However, the performance of diblock polymer electrolytes is generally limited by poor mechanical stability and network defects in the conducting pathways. We present the in-situ preparation of robust cross-linked PEMs via polymerization-induced microphase separation, and incorporation of protic ionic liquid (IL) into one of the microphase separated domains. The facile design strategy involves a delicate balance between the controlled growth of polystyrene from a poly(ethylene oxide) macro-chain transfer agent (PEO-CTA) and simultaneous chemical cross-linking by divinylbenzene in the presence of IL. Small angle X-ray scattering and transmission electron microscopy confirmed the formation of a disordered structure with bicontinuous morphology and a characteristic domain size of order 20 nm. The long-range continuity of the PEO/protic IL conducting nanochannels and cross-linked polystyrene domains imparts high thermal and mechanical stability to the PEMs, with elastic modulus approaching 10 MPa and a high ionic conductivity of 15 mS/cm at 180 °C.

  19. Highly Stretchable, Ultrasensitive, and Wearable Strain Sensors Based on Facilely Prepared Reduced Graphene Oxide Woven Fabrics in an Ethanol Flame.

    Science.gov (United States)

    Yin, Biao; Wen, Yanwei; Hong, Tao; Xie, Zhongshuai; Yuan, Guoliang; Ji, Qingmin; Jia, Hongbing

    2017-09-11

    The recent booming development of wearable electronics urgently calls for high-performance flexible strain sensors. To date, it is still a challenge to manufacture flexible strain sensors with superb sensitivity and a large workable strain range simultaneously. Herein, a facile, quick, cost-effective, and scalable strategy is adopted to fabricate novel strain sensors based on reduced graphene oxide woven fabrics (GWF). By pyrolyzing commercial cotton bandages coated with graphene oxide (GO) sheets in an ethanol flame, the reduction of GO and the pyrolysis of the cotton bandage template can be synchronously completed in tens of seconds. Due to the unique hierarchical structure of the GWF, the strain sensor based on GWF exhibits large stretchability (57% strain) with high sensitivity, inconspicuous drift, and durability. The GWF strain sensor is successfully used to monitor full-range (both subtle and vigorous) human activities or physical vibrational signals of the local environment. The present work offers an effective strategy to rapidly prepare low-cost flexible strain sensors with potential applications in the fields of wearable electronics, artificial intelligence devices, and so forth.

  20. Highly porous, low elastic modulus 316L stainless steel scaffold prepared by selective laser melting.

    Science.gov (United States)

    Čapek, Jaroslav; Machová, Markéta; Fousová, Michaela; Kubásek, Jiří; Vojtěch, Dalibor; Fojt, Jaroslav; Jablonská, Eva; Lipov, Jan; Ruml, Tomáš

    2016-12-01

    Recently, porous metallic materials have been extensively studied as candidates for use in the fabrication of scaffolds and augmentations to repair trabecular bone defects, e.g. in surroundings of joint replacements. Fabricating these complex structures by using common approaches (e.g., casting and machining) is very challenging. Therefore, rapid prototyping techniques, such as selective laser melting (SLM), have been investigated for these applications. In this study, we characterized a highly porous (87 vol.%) 316L stainless steel scaffold prepared by SLM. 316L steel was chosen because it presents a biomaterial still widely used for fabrication of joint replacements and, from the practical point of view, use of the same material for fabrication of an augmentation and a joint replacement is beneficial for corrosion prevention. The results are compared to the reported properties of two representative nonporous 316L stainless steels prepared either by SLM or casting and subsequent hot forging. The microstructural and mechanical properties and the surface chemical composition and interaction with the cells were investigated. The studied material exhibited mechanical properties that were similar to those of trabecular bone (compressive modulus of elasticity ~0.15GPa, compressive yield strength ~3MPa) and cytocompatibility after one day that was similar to that of wrought 316L stainless steel, which is a commonly used biomaterial. Based on the obtained results, SLM is a suitable method for the fabrication of porous 316L stainless steel scaffolds with highly porous structures.

  1. Origin of high strength, low modulus superelasticity in nanowire-shape memory alloy composites

    Science.gov (United States)

    Zhang, Xudong; Zong, Hongxiang; Cui, Lishan; Fan, Xueling; Ding, Xiangdong; Sun, Jun

    2017-04-01

    An open question is the underlying mechanisms for a recent discovered nanocomposite, which composed of shape memory alloy (SMA) matrix with embedded metallic nanowires (NWs), demonstrating novel mechanical properties, such as large quasi-linear elastic strain, low Young’s modulus and high yield strength. We use finite element simulations to investigate the interplay between the superelasticity of SMA matrix and the elastic-plastic deformation of embedded NWs. Our results show that stress transfer plays a dominated role in determining the quasi-linear behavior of the nanocomposite. The corresponding microstructure evolution indicate that the transfer is due to the coupling between plastic deformation within the NWs and martensitic transformation in the matrix, i.e., the martensitic transformation of the SMA matrix promotes local plastic deformation nearby, and the high plastic strain region of NWs retains considerable martensite in the surrounding SMA matrix, thus facilitating continues martensitic transformation in subsequent loading. Based on these findings, we propose a general criterion for achieving quasi-linear elasticity.

  2. High elastic modulus nanoparticles: a novel tool for subfailure connective tissue matrix damage.

    Science.gov (United States)

    Empson, Yvonne M; Ekwueme, Emmanuel C; Hong, Jung K; Paynter, Danielle M; Kwansa, Albert L; Brown, Chalmers; Pekkanen, Allison M; Roman, Maren; Rylander, Nichole M; Brolinson, Gunnar P; Freeman, Joseph W

    2014-09-01

    Subfailure matrix injuries such as sprains and strains account for a considerable portion of ligament and tendon pathologies. In addition to the lack of a robust biological healing response, these types of injuries are often characterized by seriously diminished matrix biomechanics. Recent work has shown nanosized particles, such as nanocarbons and nanocellulose, to be effective in modulating cell and biological matrix responses for biomedical applications. In this article, we investigate the feasibility and effect of using high stiffness nanostructures of varying size and shape as nanofillers to mechanically reinforce damaged soft tissue matrices. To this end, nanoparticles (NPs) were characterized using atomic force microscopy and dynamic light scattering techniques. Next, we used a uniaxial tensile injury model to test connective tissue (porcine skin and tendon) biomechanical response to NP injections. After injection into damaged skin and tendon specimens, the NPs, more notably nanocarbons in skin, led to an increase in elastic moduli and yield strength. Furthermore, rat primary patella tendon fibroblast cell activity evaluated using the metabolic water soluble tetrazolium salt assay showed no cytotoxicity of the NPs studied, instead after 21 days nanocellulose-treated tenocytes exhibited significantly higher cell activity when compared with nontreated control tenocytes. Dispersion of nanocarbons injected by solution into tendon tissue was investigated through histologic studies, revealing effective dispersion and infiltration in the treated region. Such results suggest that these high modulus NPs could be used as a tool for damaged connective tissue repair.

  3. Bulk modulus and high-pressure crystal structures of tetrakis(trimethylsilyl)methane C

    Science.gov (United States)

    Dinnebier; Carlson; van Smaalen S

    2000-04-01

    The pressure dependence of the crystal structure of cubic tetrakis(trimethylsilyl)methane C[Si(CH3)3]4 (TC) (P 10 GPa) a transformation is observed into a c.c.p. structure that is different from the face-centred-cubic structure at ambient conditions. A non-linear compression behaviour is observed, which could be described by a Vinet relation in the range 0.28-4.8 GPa. The extrapolated bulk modulus of the high-pressure phase III was determined to be K0 = 7.1 (8) GPa. The crystal structures in phase III are refined against X-ray powder data measured at several pressures between 0.49 and 4.8 GPa, and the molecules are found to be fully ordered. This is interpreted to result from steric interactions between neighbouring molecules, as shown by analysing the pressure dependence of intramolecular angles, torsion angles and intermolecular distances. Except for their cell dimensions, phases I, II and III are found to be isostructural to the corresponding phases at low temperatures.

  4. A high-damping magnetorheological elastomer with bi-directional magnetic-control modulus for potential application in seismology

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Miao, E-mail: yumiao@cqu.edu.cn; Qi, Song; Fu, Jie; Zhu, Mi [Key Lab for Optoelectronic Technology and Systems, Ministry of Education, College of Optoelectronic Engineering, Chongqing University, Chongqing 400044 (China)

    2015-09-14

    A high-damping magnetorheological elastomer (MRE) with bi-directional magnetic-control modulus is developed. This MRE was synthesized by filling NdFeB particles into polyurethane (PU)/ epoxy (EP) interpenetrating network (IPN) structure. The anisotropic samples were prepared in a permanent magnetic field and magnetized in an electromagnetic field of 1 T. Dynamic mechanical responses of the MRE to applied magnetic fields are investigated through magneto-rheometer, and morphology of MREs is observed via scanning electron microscope (SEM). Test result indicates that when the test field orientation is parallel to that of the sample's magnetization, the shear modulus of sample increases. On the other hand, when the orientation is opposite to that of the sample's magnetization, shear modulus decreases. In addition, this PU/EP IPN matrix based MRE has a high-damping property, with high loss factor and can be controlled by applying magnetic field. It is expected that the high damping property and the ability of bi-directional magnetic-control modulus of this MRE offer promising advantages in seismologic application.

  5. Long-term pavement performance monitoring and the revision of performance criteria for high modulus asphalt in South Africa

    CSIR Research Space (South Africa)

    Komba, Julius

    2016-09-01

    Full Text Available Enrobé à Module Élevé (EME) technology, a High Modulus Asphalt (HiMA), was originally developed in France. The technology is primarily suitable for construction of heavily trafficked routes, airports and container terminals. The key performance...

  6. Woven-Yarn Thermoelectric Textiles.

    Science.gov (United States)

    Lee, Jae Ah; Aliev, Ali E; Bykova, Julia S; de Andrade, Mônica Jung; Kim, Daeyoung; Sim, Hyeon Jun; Lepró, Xavier; Zakhidov, Anvar A; Lee, Jeong-Bong; Spinks, Geoffrey M; Roth, Siegmar; Kim, Seon Jeong; Baughman, Ray H

    2016-07-01

    The fabrication and characterization of highly flexible textiles are reported. These textiles can harvest thermal energy from temperature gradients in the desirable through-thickness direction. The tiger yarns containing n- and p-type segments are woven to provide textiles containing n-p junctions. A high power output of up to 8.6 W m(-2) is obtained for a temperature difference of 200 °C.

  7. Young modulus variation of a brickwork masonry element submitted to high temperatures

    Directory of Open Access Journals (Sweden)

    Maciá, M. E.

    2013-03-01

    Full Text Available In order to understand the thermal behavior of the masonry elements submitted to high temperatures we need to know the variation of their thermal properties with regard to the temperature. Submitted to high temperatures clay brick masonry presents thermomechanical effects (as the variation of Young's modulus, the thermal expansion of the unit and the mortar, spalling, losses of resistance … as well as variation of the properties of the material as result of its degradation. In this article the variation of the module of elasticity of the unit and the mortar is described with regard to high temperatures according to the state of the knowledge. In this article is also exposed the results obtained from the experimental program carried out on elements of clay brick masonry submitted to high temperatures in order to observe the variation of Young's module related to temperature.

    La definición del comportamiento térmico de los elementos de fábrica sometidos a la acción del fuego requiere del conocimiento de la variación de sus propiedades termomecánicas con respecto a la temperatura. Ante las altas temperaturas la fábrica cerámica presenta efectos termomecánicos, como la variación del módulo de Young entre otros, así como la variación de las propiedades del material debidas a la degradación del mismo. En este artículo se describe la variación del módulo de elasticidad de la pieza y el mortero con respecto a altas temperaturas según el estado del conocimiento y se exponen los resultados obtenidos del programa experimental llevado a cabo sobre elementos de fábrica sometidos a altas temperaturas con el fin de observar la variación del módulo de Young con respecto a la temperatura.

  8. Adsorption of proteins from plasma at polyester non-wovens.

    Science.gov (United States)

    Klomp, A J; Engbers, G H; Mol, J; Terlingen, J G; Feijen, J

    1999-07-01

    Polyester non-wovens in filters for the removal of leukocytes from platelet concentrates (PCs) must be platelet compatible. In PC filtration, the adsorption of proteins at the plasma-non-woven interface can be of great importance with respect to the yield of platelets. Unmodified and radio frequency glow discharge (RFGD) treated poly(ethylene terephthalate) non-woven (NW-PET) and two commercial surface-modified non-wovens were contacted with human plasma. Protein desorption by sodium dodecyl sulphate (SDS) was evaluated by X-ray photoelectron spectroscopy (XPS). The desorbed proteins were characterized by gel electrophoresis and immunoblotting. Compared to the commercial surface-modified non-wovens, unmodified and RFGD-treated NW-PETs adsorbed a relatively high amount of protein. Significantly more protein was removed from the hydrophobic NW-PET by SDS than from the hydrophilic RFGD-treated non-wovens. RFGD treatment of NW-PET reduces the reversibility of protein adsorption. Less albumin and fibrinogen were removed from the RFGD-treated non-wovens than from NW-PET. In addition, a large amount of histidine-rich glycoprotein was removed from RFGD-treated non-wovens, but not from NW-PET. The different behaviour of RFGFD-treated non-wovens towards protein adsorption is probably caused by differences in the chemical reactivity of the non-woven surfaces.

  9. Experimental study on non-woven filamentous fibre micro-filter with high filtration speed.

    Science.gov (United States)

    Niu, Siping; Park, Kisoo; Guerra, Heidi B; Kim, Youngchul

    2015-01-01

    A laboratory study was undertaken to pursue the filter performance of a micro-filter module employing highly porous fibre media under a high filtration rate (≥1,500 m/day), faster than that of any conventional filter process. The effects of filtration rate, head loss, raw water turbidity, and filter aid chemicals on filter performance were analysed. In spite of the extremely high filtration rate, the filter achieved an attractive efficiency, reducing the raw water turbidity by over 80%. As with other filter systems, the filter aid used ((polyaluminium chloride (PAC)) greatly affected the performance of this particular fibre filter. Long-term repetitive runs were additionally carried out to confirm the reproducibility of the filter performance. Also, a comparison was carried out with other high-rate filter systems which are either being tested for use in experimental studies, or are already commercially available. This study reveals that the filter performance under a high filtration speed is still attractive especially as PAC is used. Due to the high porosity of the fibre, the filter had small head loss even though the filtration rate was high. These results ascertain that it is possible to operate the filters with high filtration rate achieving reliable treatment performance.

  10. Woven hybrid composites: Tensile and flexural properties of oil palm-woven jute fibres based epoxy composites

    Energy Technology Data Exchange (ETDEWEB)

    Jawaid, M. [School of Industrial Technology, Universiti Sains Malaysia, 11800 Penang (Malaysia); Abdul Khalil, H.P.S., E-mail: akhalilhps@gmail.com [School of Industrial Technology, Universiti Sains Malaysia, 11800 Penang (Malaysia); Abu Bakar, A. [School of Materials and Mineral Resources Engineering, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia)

    2011-06-15

    Highlights: {yields} Woven hybrid composites show good tensile and flexural properties. {yields} Hybridization with 20% woven jute gives rise to sufficient modulus to composites. {yields} Layering pattern affect mechanical properties of hybrid composites. {yields} Statistical analysis shows that there is significant difference between composites. - Abstract: In this research, tensile and flexural performance of tri layer oil palm empty fruit bunches (EFB)/woven jute (Jw) fibre reinforced epoxy hybrid composites subjected to layering pattern has been experimentally investigated. Sandwich composites were fabricated by hand lay-up technique in a mould and cured with 105 deg. C temperatures for 1 h by using hot press. Pure EFB and woven jute composites were also fabricate for comparison purpose. Results showed that tensile and flexural properties of pure EFB composite can be improved by hybridization with woven jute fibre as extreme woven jute fibre mat. It was found that tensile and flexural properties of hybrid composite is higher than that of EFB composite but less than woven jute composite. Statistical analysis of composites done by ANOVA-one way, it showed significant differences between the results obtained. The fracture surface morphology of the tensile samples of the hybrid composites was performed by using scanning electron microscopy.

  11. High modulus rare earth and beryllium containing silicate glass compositions. [for glass reinforcing fibers

    Science.gov (United States)

    Bacon, J. F. (Inventor)

    1976-01-01

    Glass compositions having a Young's modulus of at least 16 million psi and a specific modulus of at least 110 million inches consisting essentially of approximately, by weight, 20 to 43% SiO2, 8 to 21% Al2O3, 4 to 10% BeO, 27 to 58% of at least one oxide selected from a first group consisting of Y2O3, La2O3, Nd2O3, Ce2O3, Ce2O3, and the mixed rare earth oxides, and 3 to 12% of at least one oxide selected from a second group consisting of MgO, ZrO2, ZnO and CaO are described. The molar ratio of BeO to the total content of the first group oxides is from 1.0 to 3.0.

  12. An improved fully integrated, high-speed, dual-modulus divider

    Science.gov (United States)

    Zheng, Sun; Yong, Xu; Guangyan, Ma; Hui, Shi; Fei, Zhao; Ying, Lin

    2014-11-01

    A fully integrated 2n/2n+1 dual-modulus divider in GHz frequency range is presented. The improved structure can make all separated logic gates embed into correlative D flip—flops completely. In this way, the complex logic functions can be performed with a minimum number of devices and with maximum speed, so that lower power consumption and faster speed are obtained. In addition, the low-voltage bandgap reference needed by the frequency divider is specifically designed to provide a 1.0 V output. According to the design demand, the circuit is fabricated in 0.18 μm standard CMOS process, and the measured results show that its operating frequency range is 1.1-2.5 GHz. The dual-modulus divider dissipates 1.1 mA from a 1.8 V power supply. The temperature coefficient of the reference voltage circuit is 8.3 ppm/°C when the temperature varies from -40 to +125 °C. By comparison, the dual-modulus divide designed in this paper can possess better performance and flexibility.

  13. An improved fully integrated, high-speed, dual-modulus divider

    Institute of Scientific and Technical Information of China (English)

    Sun Zheng; Xu Yong; Ma Guangyan; Shi Hui; Zhao Fei; Lin Ying

    2014-01-01

    A fully integrated 2n/2n+l dual-modulus divider in GHz frequency range is presented.The improved structure can make all separated logic gates embed into correlative D flip-flops completely.In this way,the complex logic functions can be performed with a minimum number of devices and with maximum speed,so that lower power consumption and faster speed are obtained.In addition,the low-voltage bandgap reference needed by the frequency divider is specifically designed to provide a 1.0 V output.According to the design demand,the circuit is fabricated in 0.18μm standard CMOS process,and the measured results show that its operating frequency range is 1.1-2.5 GHz.The dual-modulus divider dissipates 1.1 mA from a 1.8 V power supply.The temperature coefficient of the reference voltage circuit is 8.3 ppm/℃ when the temperature varies from-40 to + 125 ℃.By comparison,the dual-modulus divide designed in this paper can possess better performance and flexibility.

  14. β-Type titanium alloys for spinal fixation surgery with high Young's modulus variability and good mechanical properties.

    Science.gov (United States)

    Liu, Huihong; Niinomi, Mitsuo; Nakai, Masaaki; Cho, Ken

    2015-09-01

    Along with a high strength, ductility, and work hardening rate, a variable Young's modulus is crucial for materials used as implant rods in spinal fixation surgery. The potential in this context of Ti-(9,8,7)Cr-0.2O (mass%) alloys is reported herein. The microstructural and mechanical properties of the alloys were systematically examined as a function of their chromium content, and the ion release of the optimized alloy was investigated to assess its suitability as an implant material. In terms of the deformation-induced ω-phase transformation required for a variable Young's modulus, the balance between β-phase stability and athermal ω-phase content is most favorable in the Ti-9Cr-0.2O alloy. In addition, this composition affords a high tensile strength (>1000MPa), elongation at break (∼20%), and work hardening rate to solution-treated (ST) samples. These excellent properties are attributed to the combined effects of deformation-induced ω-phase transformation, deformation twinning, and dislocation gliding. Furthermore, the ST Ti-9Cr-0.2O alloy proves resistant to metal ion release in simulated body fluid. This combination of a good biocompatibility, variable Young's modulus and a high strength, ductility, and work hardening rate is ideal for spinal fixation applications. Extensive efforts have been devoted over the past decades to developing β-type titanium alloys with low Young's moduli for biomedical applications. In spinal fixation surgery however, along with excellent mechanical properties, the spinal-support materials should possess high Young's modulus for showing small springback during surgery to facilitate manipulation but low Young's modulus close to bone once implanted to avoid stress shielding. None of currently used metallic biomaterials can satisfy these abovementioned requirements. In the present study, we have developed a novel alloy, Ti-9Cr-0.2O. Remarkably variable Young's modulus and excellent mechanical properties can be achieved in this

  15. Very high cell density perfusion of CHO cells anchored in a non-woven matrix-based bioreactor.

    Science.gov (United States)

    Zhang, Ye; Stobbe, Per; Silvander, Christian Orrego; Chotteau, Véronique

    2015-11-10

    Recombinant Chinese Hamster Ovary (CHO) cells producing IgG monoclonal antibody were cultivated in a novel perfusion culture system CellTank, integrating the bioreactor and the cell retention function. In this system, the cells were harbored in a non-woven polyester matrix perfused by the culture medium and immersed in a reservoir. Although adapted to suspension, the CHO cells stayed entrapped in the matrix. The cell-free medium was efficiently circulated from the reservoir into- and through the matrix by a centrifugal pump placed at the bottom of the bioreactor resulting in highly homogenous concentrations of the nutrients and metabolites in the whole system as confirmed by measurements from different sampling locations. A real-time biomass sensor using the dielectric properties of living cells was used to measure the cell density. The performances of the CellTank were studied in three perfusion runs. A very high cell density measured as 200 pF/cm (where 1 pF/cm is equivalent to 1 × 10(6)viable cells/mL) was achieved at a perfusion rate of 10 reactor volumes per day (RV/day) in the first run. In the second run, the effect of cell growth arrest by hypothermia at temperatures lowered gradually from 37 °C to 29 °C was studied during 13 days at cell densities above 100 pF/cm. Finally a production run was performed at high cell densities, where a temperature shift to 31 °C was applied at cell density 100 pF/cm during a production period of 14 days in minimized feeding conditions. The IgG concentrations were comparable in the matrix and in the harvest line in all the runs, indicating no retention of the product of interest. The cell specific productivity was comparable or higher than in Erlenmeyer flask batch culture. During the production run, the final harvested IgG production was 35 times higher in the CellTank compared to a repeated batch culture in the same vessel volume during the same time period.

  16. Crack prevention of highly bent metal thin films in woven electronic textiles

    Science.gov (United States)

    Kinkeldei, T.; Cherenack, K.; Zysset, C.; Woo, N. C.; Tröster, G.

    2011-08-01

    Recent smart textile fabrication methods that are aimed at increasing the integration of electronics with textiles have involved fabricating micro-electronic components directly at the yarn level. Our approach to creating smart textiles is to fabricate thin-film devices and interconnects on plastic strips to create `e-fibers' and weave them into a textile using a commercial weaving machine. e-Fibers are exposed to bending radii as small as 165 μm during weaving. If patterned interconnect lines and device layers on the surface of the e-fiber are not designed correctly, they will crack due to the high strain and lose their electronic functionality. Brittle sensor and transistor device layers may be protected locally using rigid encapsulation materials, but cracking remains an issue for long metal interconnect lines which require flexibility. We investigated two strain-control methods to prevent the thin-film interconnect lines from cracking during weaving: (1) patterning the metal interconnect lines with a geometric design to slow propagation and merging of cracks and (2) encapsulation of interconnect lines to shift the deposited films to the neutral plain of the substrate. The mechanical behavior of interconnect lines exposed to tensile bending was studied by measuring the change in interconnect resistance versus bending radii ranging from 5 mm to 50 μm. The critical bending radius, XC, defined as the radius at which the normalized interconnect resistance changes to 1.1 (indicating the onset of film rupturing) was 150 μm for standard interconnect lines. Patterned interconnect lines had a radius XC of 115 μm while encapsulated interconnect lines never reached this critical bending radius and showed a maximum resistance change of 1.02 at 100 μm. These results show that it is possible to design interconnect lines with reduced cracking behavior when exposed to high strain during commercial weaving.

  17. Nanocrystalline β-Ti alloy with high hardness, low Young's modulus and excellent in vitro biocompatibility for biomedical applications.

    Science.gov (United States)

    Xie, Kelvin Y; Wang, Yanbo; Zhao, Yonghao; Chang, Li; Wang, Guocheng; Chen, Zibin; Cao, Yang; Liao, Xiaozhou; Lavernia, Enrique J; Valiev, Ruslan Z; Sarrafpour, Babak; Zoellner, Hans; Ringer, Simon P

    2013-08-01

    High strength, low Young's modulus and good biocompatibility are desirable but difficult to simultaneously achieve in metallic implant materials for load bearing applications, and these impose significant challenges in material design. Here we report that a nano-grained β-Ti alloy prepared by high-pressure torsion exhibits remarkable mechanical and biological properties. The hardness and modulus of the nano-grained Ti alloy were respectively 23% higher and 34% lower than those of its coarse-grained counterpart. Fibroblast cell attachment and proliferation were enhanced, demonstrating good in vitro biocompatibility of the nano-grained Ti alloy, consistent with demonstrated increased nano-roughness on the nano-grained Ti alloy. Results suggest that the nano-grained β-Ti alloy may have significant application as an implant material in dental and orthopedic applications.

  18. Interface characterization by pull-out test between high modulus polyethylene fibre and an unsaturated polyester resin

    OpenAIRE

    P. Masse; Cavrot, J.; François, P.; Lefebvre, J.; Escaig, B.

    1993-01-01

    The observation of the pull-out conditions for a monofilament outside a matrix has been applied to a wide variety of organic or inorganic materials, as a direct method of interface characterization. In the case of High Modulus PolyEthylene (HMPE) it has been demonstrated that oxygen plasma treatments or gamma irradiation modify the fibre surface properties and improve the adhesion between the fibre and a resin. In this study, the effect of different plasma treatment times and the irradiation ...

  19. Assessment of dynamic modulus of high density polypropylene waste fiber reinforcement in asphalt concrete

    Directory of Open Access Journals (Sweden)

    Hassan S. OTUOZE

    2015-12-01

    Full Text Available Traditional asphalt tests like Hveem and Marshall tests are at best mere characterization than effective test of pavement field performance because of complex viscoelastic behavior of asphalt. Mechanical properties otherwise called simple performance tests (SPT are performance criteria of asphalt. Dynamic modulus among other SPT’s like permanent deformation, fatigue cracking, thermal cracking, moisture susceptibility, shear and friction properties; determines stress-strain to time-temperature relationships that imparts on strength, service life and durability. The test followed the recommendations of NCHRP 1-37a (2004 and mixes were prepared using 0, 0.5, 1.0 and 1.5% HDPP contents. The parameters tested for dynamic modulus, /E*/, are stiffness, recoverable strain (ε, and phase angle (ξ. Time – temperature superposition (TTS called master curve was fitted using sigmoidal curve to interpolate the parameters beyond measured data set so as to observe the viscoelastic behavior outside the physical properties. The performance of 0.5% HDPP asphalt is better enhanced than the conventional asphalt to improve upon strength, service and durability.

  20. The Effect of High RAP and High Asphalt Binder Content on the Dynamic Modulus and Fatigue Resistance of Asphalt Concrete

    OpenAIRE

    Tomlinson, Christopher

    2013-01-01

    This thesis investigates the effects of using various percentages of RAP and asphalt binder contents on the dynamic modulus and fatigue resistance of asphalt concrete. Two RAP percentages (20% and 40%) and three binder percentages (plant-mixed, plant-mixed + 0.5%, and plant-mixed + 1.0%) were evaluated. A Superpave gyratory compactor and an asphalt vibratory compactor were used to prepare dynamic modulus samples and fatigue beam samples at 7% air voids. Three replicate samples for each percen...

  1. Field investigation of low-temperature cracking and stiffness moduli on selected roads with conventional and high modulus asphalt concrete

    Science.gov (United States)

    Judycki, Józef; Jaczewski, Mariusz; Ryś, Dawid; Pszczoła, Marek; Jaskuła, Piotr; Glinicki, Adam

    2017-09-01

    High Modulus Asphalt Concrete (HMAC) was introduced in Poland as a one of the solutions to the problem of rutting, type of deterioration common in the 1990s. After first encouraging trials in 2002 HMAC was widely used for heavily loaded national roads and motorways. However some concerns were raised about low-temperature cracking of HMAC. This was the main reason of the studies presented in this article were started. The article presents the comparison of performance of pavements constructed in typical contract conditions with the road bases made of HMAC and conventional asphalt concrete (AC). The field investigation was focused on the number of low-temperature cracks, bearing capacity (based on FWD test) of road sections localized in coldest region of Poland. Also load transfer efficiency of selected low-temperature cracks was assessed. FWD test confirmed lower deflections of pavements with HMAC and two times higher stiffness modulus of asphalt courses in comparison to pavements constructed with conventional AC mixtures. Relation of stiffness of asphalt layers and amount of low-temperature cracks showed that the higher stiffness modulus of asphalt layers could lead to increase of the number of low-temperature cracks. FWD test results showed that the load transfer efficiency of low-temperature cracks on pavements with HMAC presents very low values, very close to lack of load transfer. It was surprising as section with HMAC road base were aged from 2 to 5 years and presented very good bearing capacity.

  2. Development of a Highly Portable Plate Loading Device and In Situ Modulus Measurements in Weak Rock Masses

    Science.gov (United States)

    Kallu, Raj R.; Keffeler, Evan R.; Watters, Robert J.; Warren, Sean N.

    2016-02-01

    In recent years, underground mines in Nevada are increasingly exploiting in weak mineralized zones at greater depths that are intensely fractured and highly altered. The mechanical behavior of these rock masses ranges between weak rock and very stiff soil. A common limitation for design of underground mining excavations in these types of rock masses is absence of in situ geotechnical data. This limitation is generally overcome by estimating in situ mechanical behavior from empirical relationships so that the continuum-based numerical methods can be used to evaluate ground support designs. Because of the cost, time, and specialized equipment involved, historically in situ tests have not been performed in these underground mines. Predictive rock mass modulus relationships that are currently available in the literature are derived from field testing of predominantly good-quality rock masses. Consequently, there is limited confidence in using these models for rock masses with Rock Mass Ratings less than 45. In order to overcome some of these limitations, a portable plate loading device (PPLD) was designed and fabricated. The PPLD allows one to perform low cost and relatively quick in situ deformability tests to be performed on weak rock masses in underground mines. Test procedures and data reduction methods were developed to limit potential sources of error associated with the PPLD test. A total of fourteen plate loading tests were performed in weak rock masses at two different active underground mines in Nevada, USA. The resulting the test data were compared to eight published empirical rock mass modulus relationships to determine which, if any, of these relationships are sufficiently accurate for estimating modulus in similar geotechnical conditions. Only two of these relationships were found to be sufficient for first-order estimations of in situ modulus.

  3. High Frequency Acoustic Microscopy for the Determination of Porosity and Young's Modulus in High Burnup Uranium Dioxide Nuclear Fuel

    Science.gov (United States)

    Marchetti, Mara; Laux, Didier; Cappia, Fabiola; Laurie, M.; Van Uffelen, P.; Rondinella, V. V.; Wiss, T.; Despaux, G.

    2016-06-01

    During irradiation UO2 nuclear fuel experiences the development of a non-uniform distribution of porosity which contributes to establish varying mechanical properties along the radius of the pellet. Radial variations of both porosity and elastic properties in high burnup UO2 pellet can be investigated via high frequency acoustic microscopy. For this purpose ultrasound waves are generated by a piezoelectric transducer and focused on the sample, after having travelled through a coupling liquid. The elastic properties of the material are related to the velocity of the generated Rayleigh surface wave (VR). A UO2 pellet with a burnup of 67 GWd/tU was characterized using the acoustic microscope installed in the hot cells of the JRC-ITU at a 90 MHz frequency, with methanol as coupling liquid. VR was measured at different radial positions. A good agreement was found, when comparing the porosity values obtained via acoustic microscopy with those determined using SEM image analysis, especially in the areas close to the centre. In addition, Young's modulus was calculated and its radial profile was correlated to the corresponding burnup profile and to the hardness radial profile data obtained by Vickers micro-indentation.

  4. Mechanical Behavior and Analytical Modeling of Melt-Infiltrated SiC/SiC Woven Composite

    Science.gov (United States)

    Lang, J.; Sankar, J.; Kelkar, A. D.; Bhatt, R. T.; Baaklini, G.; Lua, J.

    1998-01-01

    The desirable properties in ceramic matrix composites (CMCs), such as high temperature strength, corrosion resistance, high toughness, low density, or good creep resistance have led to increased use of CMCs in high-speed engine structural components and structures that operate in extreme temperature and hostile aero-thermo-chemical environments. Ceramic matrix composites have been chosen for turbine material in the design of 21st century civil propulsion systems to achieve high fuel economy, improved reliability, extended life, and reduced cost. Most commercial CMCs are manufactured using a chemical vapor infiltration (CVI) process. However, a lower cost fabrication known as melt-infiltration process is also providing CMCs marked for use in hot sections of high-speed civil transports. Limited samples of a SiC/SiC melt-infiltrated woven composites are being investigated at room and elevated temperature below and above matrix cracking. These samples show graceful failure and toughness at room temperature with a reduction in strength and modulus at elevated temperatures. A generic finite element model is also being developed to predict monotonic and cyclic loading behavior of the woven composite. Use of the initial test data from the woven composite is being used for the development of the analytical model. This model is the first of a iterative process leading towards the development the model's capability to predict behavior at room and elevated temperature for monotonic and cyclic loading. The purpose of this paper is to report on the material and mechanical findings of the SiC/SiC melt-infiltrated woven composite and progress on the development of the finite element model.

  5. Flexural performance of woven hybrid composites

    Science.gov (United States)

    Maslinda, A. B.; Majid, M. S. Abdul; Dan-mallam, Y.; Mazawati, M.

    2016-07-01

    This paper describes the experimental investigation of the flexural performance of natural fiber reinforced polymer composites. Hybrid composites consist of interwoven kenaf/jute and kenaf/hemp fibers was prepared by infusion process using epoxy as polymer matrix. Woven kenaf, jute and hemp composites were also prepared for comparison. Both woven and hybrid composites were subjected to three point flexural test. From the result, bending resistance of hybrid kenaf/jute and kenaf/hemp composites was higher compared to their individual fiber. Hybridization with high strength fiber such as kenaf enhanced the capability of jute and hemp fibers to withstand bending load. Interlocking between yarns in woven fabric make pull out fibers nearly impossible and increase the flexural performance of the hybrid composites.

  6. Silorane- and high filled-based"low-shrinkage" resin composites: shrinkage, flexural strength and modulus

    Directory of Open Access Journals (Sweden)

    Cesar Augusto Galvão Arrais

    2013-04-01

    Full Text Available This study compared the volumetric shrinkage (VS, flexural strength (FS and flexural modulus (FM properties of the low-shrinkage resin composite Aelite LS (Bisco to those of Filtek LS (3M ESPE and two regular dimethacrylate-based resin composites, the microfilled Heliomolar (Ivoclar Vivadent and the microhybrid Aelite Universal (Bisco. The composites (n = 5 were placed on the Teflon pedestal of a video-imaging device, and VS was recorded every minute for 5 min after 40 s of light exposure. For the FS and FM tests, resin discs (0.6 mm in thickness and 6.0 mm in diameter were obtained (n = 12 and submitted to a piston-ring biaxial test in a universal testing machine. VS, FS, and FM data were submitted to two-way repeated measures and one-way ANOVA, respectively, followed by Tukey's post-hoc test (a = 5%. Filtek LS showed lower VS than did Aelite LS, which in turn showed lower shrinkage than did the other composites. Aelite Universal and Filtek LS exhibited higher FS than did Heliomolar and Aelite LS, both of which exhibited the highest FM. No significant difference in FM was noted between Filtek LS and Aelite Universal, while Heliomolar exhibited the lowest values. Aelite LS was not as effective as Filtek LS regarding shrinkage, although both low-shrinkage composites showed lower VS than did the other composites. Only Filtek LS exhibited FS and FM comparable to those of the regular microhybrid dimethacrylate-based resin composite.

  7. Voids' System in the Woven Composite Structure

    Institute of Scientific and Technical Information of China (English)

    Pavla VOZKOVA

    2006-01-01

    Composites are common material constructions for high-tech use now. Mechanical properties of woven reinforced composites are influenced by voids inside the structure.Voids could be classified to the two sections. Long and thin cracks are more dangerous than pores. It is important to find relations between preparation and place of occurrence of voids. This paper classifies defects according to rise mechanism, point of occurrence, orientation, size and affect to the properties. Image analysis was used for observing samples. Future work would be oriented not only to observing real samples, but also to calculate mechanical properties from real and ideal structures in 3D woven reinforced composites.

  8. Experimental determination of bulk modulus of 14Å tobermorite using high pressure synchrotron X-ray diffraction

    KAUST Repository

    Oh, Jae Eun

    2012-02-01

    Using a diamond anvil cell, 14 Å tobermorite, a structural analogue of calcium silicate hydrates (C-S-H), was examined by high-pressure synchrotron X-ray diffraction up to 4.8 GPa under hydrostatic conditions. The bulk modulus of 14 Å tobermorite was calculated, K o = 47 GPa. Comparison of the current results with previous high pressure studies on C-S-H(I) indicates that: (1) the compression behavior of the lattice parameters a and b of 14 Å tobermorite and C-S-H(I) are very similar, implying that both materials may have very similar Ca-O layers, and also implying that an introduction of structural defects into the Ca-O layers may not substantially change in-plane incompressibility of the ab plane of 14 Å tobermorite; and (2) the bulk modulus values of 14 Å tobermorite and C-S-H(I) are dominated by the incompressibility of the lattice parameter c, which is directly related to the interlayer spacing composed of dreierketten silicate chains, interlayer Ca, and water molecules. © 2011 Elsevier Ltd. All rights reserved.

  9. A β-type TiNbZr alloy with low modulus and high strength for biomedical applications

    Directory of Open Access Journals (Sweden)

    Qingkun Meng

    2014-04-01

    Full Text Available The effect of thermo-mechanical treatment on the mechanical properties of a novel β-type Ti–36Nb–5Zr (wt% alloy has been investigated. The solution treated alloy consists of β and α″ phases and exhibits a two-stage yielding with a low yield stress (around 100 MPa. After cold rolling at a reduction of 87.5% and subsequent annealing treatment at 698 K for 25 min, a fine microstructure with nanosized α precipitates distributed in small β grains as well as high density of dislocations was obtained to achieve a yield strength of 720 MPa and a ultimate tensile strength of 860 MPa. In spite of the formation of α precipitates, the β-stabilizers are not enriched in the parent β matrix due to the short duration and low temperature of the thermal treatment, resulting in a low chemical stability of β phase. The low stability of β phase and the small volume fraction of α precipitates produce a low Young׳s modulus of 48 GPa. Such an excellent combination of low elastic modulus and high strength in mechanical properties indicates great potential for biomedical applications.

  10. Aβ-type TiNbZr alloy with low modulus and high strength for biomedical applications

    Institute of Scientific and Technical Information of China (English)

    Qingkun Meng; Shun Guo; Qing Liu; Liang Hu; Xinqing Zhao

    2014-01-01

    The effect of thermo-mechanical treatment on the mechanical properties of a novelβ-type Ti-36Nb-5Zr (wt%) alloy has been investigated. The solution treated alloy consists of β and α″phases and exhibits a two-stage yielding with a low yield stress (around 100 MPa). After cold rolling at a reduction of 87.5% and subsequent annealing treatment at 698 K for 25 min, a fine microstructure with nanosized α precipitates distributed in smallβgrains as well as high density of dislocations was obtained to achieve a yield strength of 720 MPa and a ultimate tensile strength of 860 MPa. In spite of the formation ofαprecipitates, theβ-stabilizers are not enriched in the parentβmatrix due to the short duration and low temperature of the thermal treatment, resulting in a low chemical stability ofβphase. The low stability ofβphase and the small volume fraction ofαprecipitates produce a low Young's modulus of 48 GPa. Such an excellent combination of low elastic modulus and high strength in mechanical properties indicates great potential for biomedical applications.

  11. Dynamic mechanical analysis and high strain-rate energy absorption characteristics of vertically aligned carbon nanotube reinforced woven fiber-glass composites

    Science.gov (United States)

    The dynamic mechanical behavior and energy absorption characteristics of nano-enhanced functionally graded composites, consisting of 3 layers of vertically aligned carbon nanotube (VACNT) forests grown on woven fiber-glass (FG) layer and embedded within 10 layers of woven FG, with polyester (PE) and...

  12. Woven Light Emitting Display

    OpenAIRE

    Kašurina, I

    2013-01-01

    Electrotextiles represent a huge potential in creating a new generation of flexible textile platforms for electronic systems and smart garments. In this research of electrotextile fabrication weaving method was used. Fully or partly replacing traditional (non-conductive) textile yarns with conductive textile yarns, it is possible to get woven conductive textile material or fabric circuit. In the paper weaving method is considered for electro textile design and process of ...

  13. Isothermal bulk modulus and its first pressure derivative of NaC1 at high pressure and high temperature

    Institute of Scientific and Technical Information of China (English)

    Song Ting; Sun Xiao-Wei; Liu Zi-Jiang; Li Ji1an-Feng; Tian Jun-Hong

    2012-01-01

    The isothermal bulk modulus and its first pressure derivative of NaCl are investigated using the classical molecular dynamics method and the quasi-harmonic Debye model.To ensure faithful molecular dynamics simulations,two types of potentials,the shell-model (SM) potential and the two-body rigid-ion Born-Mayer-Huggins-Fumi-Tosi (BMHFT)potential,are fully tested.Compared with the SM potential based simulation,the molecular dynamics simulation with the BMHFT potential is very successful in reproducing accurately the measured bulk modulus of NaC1. Particular attention is paid to the prediction of the isothermal bulk modulus and its first pressure derivative using the reliable potential and to the comparison of the SM and the BMHFT potentials based molecular dynamics simulations with the quasi-harmonic Debye model.The properties of NaCl in the pressure range of 0-30 GPa at temperatures up to the melting temperature of 1050 K are investigated.

  14. The influence of removing sizing on strength and stiffness of conventional and high modulus E-glass fibres

    DEFF Research Database (Denmark)

    Petersen, Helga Nørgaard; Kusano, Yukihiro; Brøndsted, Povl

    2016-01-01

    Two types of E-glass fibres, a conventional and a high modulus where the last one in the following will be denoted as ECR-glass fibre, were investigated regarding density, diameter, stiffness and strength. The fibres were analysed as pristine and after sizing removal treatments. The sizing...... was removed by either burning at 565◦C or soxhlet extraction with acetone. It was found that the density and the stiffness increased after removing the sizing by the two removal treatments whereas the diameter did not change significantly. The strength of the fibres decreased after burning as the sizing......, protecting against water and fibre-fibre damage, had been removed. The strength of the fibres after extraction was not significantly different from the strength of the pristine fibres despite removing the sizing. This indicates that the bonded part of sizing is still protecting the glass fibre surface....

  15. The complex Young's modulus of skeletal muscle fibre segments in the high frequency range determined from tension transients.

    Science.gov (United States)

    De Winkel, M E; Blangé, T; Treijtel, B W

    1993-06-01

    Stiffness measurements of muscle fibres are often based on application of a length change at one end of the muscle fibre and recording of the following tension change at the other end. In this study a method is developed to determine in the high frequency range (up to 40 kHz) the complex Young's modulus of skeletal muscle fibre as a function of frequency from the tension transient, following a rapid stepwise length change completed within 40 microseconds. For this purpose both a new mechanical moving part of the displacement generating system and a force transducer with a high natural frequency (70 kHz) had to be developed. In addition to stiffness measurements of a silk fibre to test the displacement generating system and the method of analysis, stiffness of skeletal muscle fibres in relaxed and rigor state have been measured. The complex Young's moduli of relaxed muscle fibres as well as muscle fibres in rigor state are frequency dependent. In both cases the complex Young's modulus increases smoothly with increasing frequency over a range of 250 Hz up to 40 kHz. The phase angles of the responses remained almost constant at a value of 0.3 radians for a fibre in rigor and 0.6 radians for a relaxed fibre. This leads to the conclusion that for muscle fibres in rigor state the recovery in the tension response to a step length change shows a continuous distribution of relaxation times rather than a few discrete ones. Results of our stiffness measurements are compared with results obtained from current viscoelastic models used to describe stiffness of muscle fibre in this frequency range.(ABSTRACT TRUNCATED AT 250 WORDS)

  16. The Rupture Behaviour Of Woven Fabrics Containing Kevlar Fibres

    Science.gov (United States)

    Mao, N.; Qu, J.; Darley, M.; Lingard, S.

    2012-07-01

    Woven fabrics containing high performance fibres are frequently used in spacecraft structures and the rupture behaviour of these fabrics heavily influences the performance of its final products. However, the initiation and propagation of a ruptured fracture in the woven fabrics is not clear and the interpretation of the results from different tear testing methods varies. Currently there is a lack of knowledge about both the characteristics of tear propagation woven fabrics containing high performance fibres such as Kevlar and the influence of the fabric structural parameters on the rupture behaviour of the fabrics; this knowledge gap creates difficulties for the engineering design and selection of suitable fabric materials to meet specific requirements in each application case involving such woven fabrics. In this paper, the tear propagations in a polyurethane-coated woven fabric containing Kevlar fibres based on two different tear testing standards are examined; the mechanism of tear propagation in woven fabrics and the influences of tear testing design on the interpretation of the results from different tear testing methods are discussed. It is expected that the results will guide both the engineering design of Kevlar woven fabric structures and the evaluation of the fabric performance.

  17. Elastic modulus and flexural strength comparisons of high-impact and traditional denture base acrylic resins

    Directory of Open Access Journals (Sweden)

    Nour M. Ajaj-ALKordy

    2014-01-01

    Conclusion: Within the limitations of this study, it can be concluded that the high-impact acrylic resin is a suitable denture base material for patients with clinical fracture of the acrylic denture.

  18. Optimisation of a high speed rotating composite drive shaft using a genetic algorithm - Hybrid high modulus-high resistance carbon solutions

    CERN Document Server

    Montagnier, Olivier

    2011-01-01

    This study deals with the optimisation of subcritical and supercritical laminated composite drive shafts, based on a genetic algorithm. The first part focuses on the modelling of a composite drive shaft. Flexural vibrations in a simply supported composite drive shaft mounted on viscoelastic supports, including shear effects are studied. In particular, an analytic stability criterion is developed to ensure the integrity of the system. The torsional strength is then computed with the maximum stress criterion, assuming the coupling effects to be null. Torsional buckling of thin walled composite tubes is modelled using a combination between laminate theory and Fl\\"ugge theory. In the second part, the genetic algorithm is developed. The last part presents a comparative study between various composite materials solutions on a helicopter tail rotor driveline. In particular, hybrid tubes consisting of high modulus and high resistance carbon/epoxy plies are studied. These solutions make it possible to replace the conv...

  19. Preparation of High Modulus Poly(Ethylene Terephthalate: Influence of Molecular Weight, Extrusion, and Drawing Parameters

    Directory of Open Access Journals (Sweden)

    Jian Min Zhang

    2017-01-01

    Full Text Available Poly(ethylene terephthalate (PET which is one of the most commercially important polymers, has for many years been an interesting candidate for the production of high performance fibres and tapes. In current study, we focus on investigating the effects of the various processing variables on the mechanical properties of PET produced by a distinctive process of melt spinning and uniaxial two-stage solid-state drawing (SSD. These processing variables include screw rotation speed during extrusion, fibre take-up speed, molecular weight, draw-ratio, and drawing temperature. As-spun PET production using a single-screw extrusion process was first optimized to induce an optimal polymer microstructure for subsequent drawing processes. It was found that less crystallization which occurred during this process would lead to better drawability, higher draw-ratio, and mechanical properties in the subsequent SSD process. Then the effect of drawing temperature (DT in uniaxial two-stage SSD process was studied to understand how DT (

  20. Stochastic Nonlinear Response of Woven CMCs

    Science.gov (United States)

    Kuang, C. Liu; Arnold, Steven M.

    2013-01-01

    It is well known that failure of a material is a locally driven event. In the case of ceramic matrix composites (CMCs), significant variations in the microstructure of the composite exist and their significance on both deformation and life response need to be assessed. Examples of these variations include changes in the fiber tow shape, tow shifting/nesting and voids within and between tows. In the present work, the influence of scale specific architectural features of woven ceramic composite are examined stochastically at both the macroscale (woven repeating unit cell (RUC)) and structural scale (idealized using multiple RUCs). The recently developed MultiScale Generalized Method of Cells methodology is used to determine the overall deformation response, proportional elastic limit (first matrix cracking), and failure under tensile loading conditions and associated probability distribution functions. Prior results showed that the most critical architectural parameter to account for is weave void shape and content with other parameters being less in severity. Current results show that statistically only the post-elastic limit region (secondary hardening modulus and ultimate tensile strength) is impacted by local uncertainties both at the macro and structural level.

  1. “路宝”高模量外掺剂的性能及应用%Performance and Application of "Lubao" High Modulus Admixture

    Institute of Scientific and Technical Information of China (English)

    赵冬明

    2012-01-01

    介绍了“路宝”高模量外掺剂的原材料、生产工艺、技术指标,阐述了“路宝”高模量沥青混合料的性能及应用情况,对其经济效益和社会效益进行了分析。%Raw material, production technology and technical indexes of "Lubao" high modulus admixture are introduced. The performance and application of "Lubao" high modulus asphalt mixture are elaborated and its eco- nomic benefits and social benefits are analyzed.

  2. High Oil-absorptive Composites Prepared from Non-woven Fiber and Sponges with 4-tert- buty1styrene-EPDM-divinylbenzene Graft Polymer

    Institute of Scientific and Technical Information of China (English)

    Zhou Meihua(周美华); Cho Won-Jei

    2001-01-01

    4-tert-butylstyrene-EPDM-divinylbenzene graft terpolymer (PBED) was prepared by graft cross-polymerization in toluene using BPO as an initiator. The gel-PBED and solPBED were isolated from extraction of tetrahydrofuran (THF), and then they were identified by IR spectroscopy. The maximum oil-absorptivity of gel-PBED produced from the optinum reaction conditions was 8 420% but its swelling rate was very low. The highest oil-absorptivity of photocrosslinked sol-PBED film was 5 800%. Although its oil absorbency was not as high as gel-PBED' s, swelling rate was higher than that of gelPBED and was suitable for commercial purpose. After swelling in oil, neither gel PBED nor photocrosslinked sol-PBED film having high oil-absorptivity had sufficient mechanical strength to be taken out of oil wholly. As is known, composite technique is one of the useful methods for reinforcing them. Fibers, sponges and non-woven cloths were used as reinforcers or supporters in this work. Oil-absorptivities and swelling kinetics were evaluated by method ASTM (F726 - 81 ) and an experimental equation. The mechanical properties and the morphologies of some composites were measured by tensile tester and SEM , respectively.

  3. ELASTIC BEHAVIOR ANALYSIS OF 3D ANGLE-INTERLOCK WOVEN CERAMIC COMPOSITES

    Institute of Scientific and Technical Information of China (English)

    Chang Yanjun; Jiao Guiqiong; Wang Bo; Liu Wei

    2006-01-01

    A micromechanical model for elastic behavior analysis of angle-interlock woven ceramic composites is proposed in this paper. This model takes into account the actual fabric structure by considering the fiber undulation and continuity in space, the cavities between adjacent yarns and the actual cross-section geometry of the yarn. Based on the laminate theory, the elastic properties of 3D angle-interlock woven ceramic composites are predicted. Different numbers of interlaced wefts have almost the same elastic moduli. The thickness of ceramic matrix has little effect on elastic moduli. When the undulation ratio increases longitudinal modulus decreases and the other Young's moduli increase. Good agreement between theoretical predictions and experimental results demonstrates the feasibility of the proposed model in analyzing the elastic properties of3D angle-interlock woven ceramic composites. The results of this paper verify the fact that the method of analyzing polyester matrix composites is suitable for woven ceramic composites.

  4. Construction of a high modulus asphalt (HiMA) trial section Ethekwini: South Africa's first practical experience with design, manufacturing and paving of HiMA

    CSIR Research Space (South Africa)

    Nkgapele, M

    2012-07-01

    Full Text Available A trial section was paved with the recently introduced High Modulus Asphalt (HiMA) technology on South Coast road in eThekwini (Durban). The trial section forms part of an effort to transfer HiMA technology to South Africa, in an initiative aimed...

  5. Failure in Three-Dimensional Woven Composites Subjected to Quasi-Static and Dynamic Indentation

    Science.gov (United States)

    2013-09-12

    composites, High strain rate testing, Impact behavior, Interlaminar shear strength, Short beam shear strength, Textile composites Bhavani V. Sankar...propagation in plain woven laminates and 3D orthogonal woven composites during short beam shear tests were analyzed using FEA. Two kinds of 3D woven...delamination damage caused by such impacts the characterization of delamination damage in laminated composites becomes critical to creating safe designs. 3D

  6. Numerical Modeling for Springback Predictions by Considering the Variations of Elastic Modulus in Stamping Advanced High-Strength Steels (AHSS)

    Science.gov (United States)

    Kim, Hyunok; Kimchi, Menachem

    2011-08-01

    This paper presents a numerical modeling approach for predicting springback by considering the variations of elastic modulus on springback in stamping AHSS. Various stamping tests and finite-element method (FEM) simulation codes were used in this study. The cyclic loading-unloading tensile tests were conducted to determine the variations of elastic modulus for dual-phase (DP) 780 sheet steel. The biaxial bulge test was used to obtain plastic flow stress data. The non-linear reduction of elastic modulus for increasing the plastic strain was formulated by using the Yoshida model that was implemented in FEM simulations for springback. To understand the effects of material properties on springback, experiments were conducted with a simple geometry such as U-shape bending and the more complex geometry such as the curved flanging and S-rail stamping. Different measurement methods were used to confirm the final part geometry. Two different commercial FEM codes, LS-DYNA and DEFORM, were used to compare the experiments. The variable elastic modulus improved springback predictions in U-shape bending and curved flanging tests compared to FEM with the constant elastic modulus. However, in S-rail stamping tests, both FEM models with the isotropic hardening model showed limitations in predicting the sidewall curl of the S-rail part after springback. To consider the kinematic hardening and Bauschinger effects that result from material bending-unbending in S-rail stamping, the Yoshida model was used for FEM simulation of S-rail stamping and springback. The FEM predictions showed good improvement in correlating with experiments.

  7. Studies on the mechanical properties of woven jute fabric reinforced poly(l-lactic acid composites

    Directory of Open Access Journals (Sweden)

    G.M. Arifuzzaman Khan

    2016-01-01

    Full Text Available Development of ecofriendly biocomposites to replace non-biodegradable synthetic fiber composites is the main objective of this study. To highlight the biocomposites as a perfect replacement, the plain woven jute fabric (WJF reinforced poly(l-lactic acid (PLLA composites were prepared by the hot press molding method. The influence of woven structure and direction on the mechanical properties i.e. tensile, flexural and impact properties was investigated. The average tensile strength (TS, tensile modulus (TM, flexural strength (FS, flexural modulus (FM, and impact strength (IS of untreated woven jute composite (in warp direction were improved about 103%, 211%, 95.2%, 42.4% and 85.9%, respectively and strain at maximum tensile stress for composite samples was enhanced by 11.7%. It was also found that the strengths and modulus of composites in warp direction are higher than those in weft direction. WJF composites in warp and weft directions presented superior mechanical properties than non-woven jute fabric (NWJF composites. Chemical treatment of jute fabric through benzoylation showed a positive effect on the properties of composites. Morphological studies by SEM demonstrated that better adhesion between the treated fabric and PLLA was achieved.

  8. Determination of the bulk modulus of hydroxycancrinite, a possible zeolitic precursor in geopolymers, by high-pressure synchrotron X-ray diffraction

    KAUST Repository

    Oh, Jae Eun

    2011-11-01

    Crystalline zeolitic materials, such as hydroxycancrinite, hydroxysodalite, herschelite and nepheline, are often synthesized from geopolymerization using fly-ash and solutions of NaOH at high temperatures. Comprised mainly of 6-membered aluminosilicate rings that act as basic building units, their crystal structures may provide insight into the reaction products formed in NaOH-activated fly ash-based geopolymers. Recent research indicates that the hydroxycancrinite and hydroxysodalite may play an important role as possible analogues of zeolitic precursor in geopolymers. Herein is reported a high pressure synchrotron study of the behavior of hydroxycancrinite exposed to pressures up to 6.1 GPa in order to obtain its bulk modulus. A refined equation of state for hydroxycancrinite yielded a bulk modulus of Ko = 46 ± 5 GPa (assuming Ko′ = 4.0) for a broad range of applied pressure. When low pressure values are excluded from the fit and only the range of 2.5 and 6.1 GPa is considered, the bulk modulus of hydroxycancrinite was found to be Ko = 46.9 ± 0.9 GPa (Ko′ = 4.0 ± 0.4, calculated). Comparison with the literature shows that all zeolitic materials possessing single 6-membered rings (i.e., hydroxycancrinite, sodalite and nepheline) have similar bulk moduli. © 2011 Elsevier Ltd. All rights reserved.

  9. Formable woven preforms based on in situ reinforced thermoplastic fibers

    Energy Technology Data Exchange (ETDEWEB)

    Robertson, C.G.; Souza, J.P. de; Baird, D.G. [Virginia Polytechnic Institute & State Univ., Blacksburg, VA (United States)

    1995-12-01

    Blends of Vectra B950 (VB) and polypropylene (PP) were spun into fibers utilizing a dual extrusion process for use in formable fabric prepregs. Fibers of 50/50 weight composition were processed up to fiber draw ratios of 106. The tensile modulus of these fibers showed positive deviation from the rule of mixtures for draw ratios greater than 40, and the tensile modulus and strength properties did not level off within the range of draw ratios investigated. The fibers, pre-wetted with polypropylene, were woven into fabrics that were subsequently impregnated with polypropylene sheet to form composites. The tensile mechanical properties of these composites were nearly equivalent to those of long glass fiber reinforced polypropylene. At temperatures between 240 and 280{degrees}C, composites of 6.3 wt.% VB proved formable with elongation to break values in excess of 20%. Impregnated fabric composites were successfully thermoformed without noticeable fiber damage, and a combined fabric impregnation / thermoforming process was developed.

  10. Tensile strength of woven yarn kenaf fiber reinforced polyester composites

    Directory of Open Access Journals (Sweden)

    A.E. Ismail

    2015-12-01

    Full Text Available This paper presents the tensile strength of woven kenaf fiber reinforced polyester composites. The as-received yarn kenaf fiber is weaved and then aligned into specific fiber orientations before it is hardened with polyester resin. The composite plates are shaped according to the standard geometry and uni-axially loaded in order to investigate the tensile responses. Two important parameters are studied such as fiber orientations and number of layers. According to the results, it is shown that fiber orientations greatly affected the ultimate tensile strength but it is not for modulus of elasticity for both types of layers. It is estimated that the reductions of both ultimate tensile strength and Young’s modulus are in the range of 27.7-30.9% and 2.4-3.7% respectively, if the inclined fibers are used with respect to the principal axis.

  11. Characterization of High Temperature Modulus of Elasticity of Lightweight Foamed Concrete under Static Flexural and Compression: An Experimental Investigations

    Directory of Open Access Journals (Sweden)

    Md Azree Othuman Mydin

    2012-09-01

    Full Text Available This paper focused on an experimental works that have been performed to examine the young’s modulus of foamed concrete at elevated temperatures up to 600°C. Foamed concrete of 650 and 1000 kg/m3 density were cast and tested under compression and bending. The experimental results of this study consistently demonstrated that the loss in stiffness for cement based material like foamed concrete at elevated temperatures occurs predominantly after about 95°C, regardless of density. This indicates that the primary mechanism causing stiffness degradation is microcracking, which occurs as water expands and evaporates from the porous body. As expected, reducing the density of LFC reduces its strength and stiffness. However, for LFC of different densities, the normalised strength-temperature and stiffness-temperature relationships are very similar.

  12. Shear Behavior of 3D Woven Hollow Integrated Sandwich Composites: Experimental, Theoretical and Numerical Study

    Science.gov (United States)

    Zhou, Guangming; Liu, Chang; Cai, Deng'an; Li, Wenlong; Wang, Xiaopei

    2016-11-01

    An experimental, theoretical and numerical investigation on the shear behavior of 3D woven hollow integrated sandwich composites was presented in this paper. The microstructure of the composites was studied, then the shear modulus and load-deflection curves were obtained by double lap shear tests on the specimens in two principal directions of the sandwich panels, called warp and weft. The experimental results showed that the shear modulus of the warp was higher than that of the weft and the failure occurred in the roots of piles. A finite element model was established to predict the shear behavior of the composites. The simulated results agreed well with the experimental data. Simultaneously, a theoretical method was developed to predict the shear modulus. By comparing with the experimental data, the accuracy of the theoretical method was verified. The influence of structural parameters on shear modulus was also discussed. The higher yarn number, yarn density and dip angle of the piles could all improve the shear modulus of 3D woven hollow integrated sandwich composites at different levels, while the increasing height would decrease the shear modulus.

  13. A fully woven touchpad sensor based on soft capacitor fibers

    CERN Document Server

    Gu, Jian Feng; Skorobogatiy, Maksim

    2011-01-01

    A novel, highly flexible capacitor fiber (with 100 nF m-1 typical capacitance per length) having a multilayer periodic structure of dielectric and conductive polymer composite films is fabricated by drawing technique. The fiber is used to build a woven touchpad sensor. Then, we study the influence of the fiber length, capacitance and volume resistivity on the touch sensing performance. A theoretical ladder network model of a fiber network is developed. A fully woven textile sample incorporating one-dimension array of the capacitor fibers is fabricated. Finally we show that such an array functions as a two-dimensional touch sensor.

  14. Nanocrystalline β-Ti alloy with high hardness, low Young's modulus and excellent in vitro biocompatibility for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Kelvin Y. [Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, NSW 2006 (Australia); School of Aerospace, Mechanical and Mechatronics Engineering, The University of Sydney, Sydney, NSW 2006 (Australia); Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD 21218 (United States); Wang, Yanbo, E-mail: yanbo.wang@sydney.edu.au [School of Aerospace, Mechanical and Mechatronics Engineering, The University of Sydney, Sydney, NSW 2006 (Australia); Zhao, Yonghao [School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China); Chang, Li; Wang, Guocheng; Chen, Zibin; Cao, Yang [School of Aerospace, Mechanical and Mechatronics Engineering, The University of Sydney, Sydney, NSW 2006 (Australia); Liao, Xiaozhou, E-mail: xiaozhou.liao@sydney.edu.au [School of Aerospace, Mechanical and Mechatronics Engineering, The University of Sydney, Sydney, NSW 2006 (Australia); Lavernia, Enrique J. [Department of Chemical Engineering and Materials Science, University of California, Davis, CA 95616 (United States); Valiev, Ruslan Z. [Institute of Physics of Advanced Materials, Ufa State Aviation Technical University, K. Marksa 12, Ufa 450000 (Russian Federation); Sarrafpour, Babak; Zoellner, Hans [The Cellular and Molecular Pathology Research Unit, Department of Oral Pathology and Oral Medicine, Faculty of Dentistry, The University of Sydney, Westmead Centre for Oral Health, Westmead Hospital, NSW 2145 (Australia); Ringer, Simon P. [Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, NSW 2006 (Australia); School of Aerospace, Mechanical and Mechatronics Engineering, The University of Sydney, Sydney, NSW 2006 (Australia)

    2013-08-01

    High strength, low Young's modulus and good biocompatibility are desirable but difficult to simultaneously achieve in metallic implant materials for load bearing applications, and these impose significant challenges in material design. Here we report that a nano-grained β-Ti alloy prepared by high-pressure torsion exhibits remarkable mechanical and biological properties. The hardness and modulus of the nano-grained Ti alloy were respectively 23% higher and 34% lower than those of its coarse-grained counterpart. Fibroblast cell attachment and proliferation were enhanced, demonstrating good in vitro biocompatibility of the nano-grained Ti alloy, consistent with demonstrated increased nano-roughness on the nano-grained Ti alloy. Results suggest that the nano-grained β-Ti alloy may have significant application as an implant material in dental and orthopedic applications. - Highlights: • A bulk nanocrystalline β-Ti alloy was produced by high-pressure torsion processing. • Excellent mechanical properties for biomedical implants were obtained. • Enhanced in vitro biocompatibility was also demonstrated.

  15. Determination and Temperature Dependence of Plateau Modulus for Polymerization of Propylene to Isotactic Polypropylene with Ultra-high Molecular Weight under Catalysis of Ziegler-Natta Catalyst

    Institute of Scientific and Technical Information of China (English)

    DING Jian; DING Xue-jia; XU Ri-wei; YU Ding-sheng

    2005-01-01

    The viscoelastic behavior of isotactic polypropylene with ultra-high molecular weight (UHPPH) and broad molecular weight distribution(MWD), produced in the presence of Ziegler-Natta catalyst, was investigated by means of oscillatory rheometry at 180 and 200 ℃, whose loss modulus(G") plots at 180 and 200 ℃versus the natural logarithm of angular frequency(ω) present a pronounced maximum at 34.35 and 69.21 rad/s, respectively, and do not show a maximum peak at 0. 01-100 rad/s for Ziegler-Natta catalyzing ethylenepropylene random copolymerization (PPR) with a conventional molecular weight and broad MWD. The fact indicates that the high molecular weight is responsible for a maximum peak of G"(ω) vs. lnω curves for UHPPH. This makes it possible to determine the plateau modulus (G0N) of UHPPH from a certain experimental temperature G"(ω) curve directly. For UHPPH, the G0N determined to be 4. 28×105 and 3. 62×105 Pa at 180and 200 ℃, respectively, decreases with the increase of temperature and is independent of the molecular weight, which directly confirms reputation theoretical prediction that the G0N has no relation to the molecular weight.

  16. Evaluation of Young’s modulus of MgB2 filaments in composite wires for the superconducting links for the high-luminosity LHC upgrade

    Science.gov (United States)

    Sugano, Michinaka; Ballarino, Amalia; Bartova, Barbora; Bjoerstad, Roger; Gerardin, Alexandre; Scheuerlein, Christian

    2016-02-01

    MgB2 wire is a promising superconductor for the superconducting links for the high-luminosity upgrade of the large Hadron collider at CERN. The mechanical properties of MgB2 must be fully quantified for the cable design, and in this study, we evaluate the Young’s modulus of MgB2 filaments in wires with a practical level of critical current. The Young’s moduli of MgB2 filaments by two different processes, in situ and ex situ, were compared. Two different evaluation methods were applied to an in situ MgB2 wire, a single-fiber tensile test and a tensile test after removing Monel. In addition, the Young’s modulus of the few-micron-thick Nb-Ni reaction layer in an ex situ processed wire was evaluated using a nanoindentation testing technique to improve the accuracy of analysis based on the rule of mixtures. The Young’s moduli of the in situ and ex situ MgB2 wires were in the range of 76-97 GPa and no distinct difference depending on the fabrication process was found.

  17. submitter Evaluation of Young’s modulus of MgB2 filaments in composite wires for the superconducting links for the high-luminosity LHC upgrade

    CERN Document Server

    Sugano, Michinaka; Bartova, Barbora; Bjoerstad, Roger; Gerardin, Alexandre; Scheuerlein, Christian

    2015-01-01

    MgB2 wire is a promising superconductor for the superconducting links for the high-luminosity upgrade of the large Hadron collider at CERN. The mechanical properties of MgB2 must be fully quantified for the cable design, and in this study, we evaluate the Young's modulus of MgB2 filaments in wires with a practical level of critical current. The Young's moduli of MgB2 filaments by two different processes, in situ and ex situ, were compared. Two different evaluation methods were applied to an in situ MgB2 wire, a single-fiber tensile test and a tensile test after removing Monel. In addition, the Young's modulus of the few-micron-thick Nb–Ni reaction layer in an ex situ processed wire was evaluated using a nanoindentation testing technique to improve the accuracy of analysis based on the rule of mixtures. The Young's moduli of the in situ and ex situ MgB2 wires were in the range of 76–97 GPa and no distinct difference depending on the fabrication process was found.

  18. An anisotropic constitutive model with biaxial-tension coupling for woven composite reinforcements

    Science.gov (United States)

    Yao, Yuan; Huang, Xiaoshuang; Peng, Xiongqi; Gong, Youkun

    2016-10-01

    Based on fiber reinforced continuum mechanics theory, an anisotropic hyperelastic constitutive model with biaxial tension coupling for woven composite reinforcements is developed. Experimental data from literature are used to identify material parameters in the constitutive model for a specific balanced plain woven fabric. The developed model is validated by comparing numerical results with experimental biaxial tension data under different stretch ratios and picture-frame shear data, demonstrating that the developed constitutive model is highly suitable to characterize the highly non-linear and strongly anisotropic mechanical behaviors of woven composite reinforcements under large deformation.

  19. MAGNETIC WOVEN FABRICS - PHYSICAL AND MAGNETIC PROPERTIES

    Directory of Open Access Journals (Sweden)

    GROSU Marian C

    2015-05-01

    Full Text Available A coated material is a composite structure that consists of at least two components: base material and coating layer. The purpose of coating is to provide special properties to base material, with potential to be applied in EMI shielding and diverse smart technical fields. This paper reports the results of a study about some physical and magnetic properties of coated woven fabrics made from cotton yarns with fineness of 17 metric count. For this aim, a plain woven fabric was coated with a solution hard magnetic polymer based. As hard magnetic powder, barium hexaferrite (BaFe12O19 was selected. The plain woven fabric used as base has been coated with five solutions having different amounts of hard magnetic powder (15% - 45% in order to obtain five different magnetic woven fabrics. A comparison of physical properties regarding weight (g/m2, thickness (mm, degree of charging (% and magnetic properties of magnetic woven samples were presented. Saturation magnetizing (emu/g, residual magnetizing (emu/g and coercive force (kA/m of pure hard magnetic powder and woven fabrics have been studied as hysteresis characteristics. The magnetic properties of the woven fabrics depend on the mass percentage of magnetic powder from coating solution. Also, the residual magnetism and coercive field of woven fabrics represents only a part of bulk barium hexafferite residual magnetism and coercive field.

  20. Microacoustic Imaging Technique for Bulk Microstructure Characterization of Woven CFRC Materials

    Institute of Scientific and Technical Information of China (English)

    Songping; Guo; Enming; Liu; Feifei; Legang; V.M.Levin; Petronyuk

    2007-01-01

    In short wavelength case ultrasound propagation through woven carbon fiber-rein-forced composite (CFRC) materials essentially depends on their microstructure.Fiber bundle and weaving ply can be considered as basic structural elements of woven CFRC laminates.These structural units provide effective reflectors when ultra-short impulse high frequency ultrasound impinges on woven laminates.The reflection coefficient R0 achieves level of 3%-15% at ply-ply interface,0.2-0.4 in resin pocket region.This magnitude of reflection coefficient offers reasonable acoustic contrast to see packing,lay-up and resin pockets in woven laminate body by acoustic imaging methods.Microacoustic imaging technique is based on time-resolved echoes from reflections in woven CFRC laminates.A focal system with low aperture angle is used to generate 20-40 probe ultrasonic pulse wave.Its spatial resolution is up to 60mm at 50MHz in woven CFRC laminate.The results presented in this paper demonstrates the possibility and potentiality of characterization of microstrueture of woven CFRC laminates.Packing,lay-up,weaving nature,fiber bundle,resin pocket as well as their topology are exhibited clearly in the acoustic images by using microaeoustic technique.

  1. Jacquard-woven photonic bandgap fiber displays

    CERN Document Server

    Sayed, Imran; Skorobogatiy, Maksim

    2010-01-01

    We present an overview of photonic textile displays woven on a Jacquard loom, using newly discovered polymer photonic bandgap fibers that have the ability to change color and appearance when illuminated with ambient or transmitted light. The photonic fiber can be thin (smaller than 300 microns in diameter) and highly flexible, which makes it possible to weave in the weft on a computerized Jacquard loom and develop intricate double weave structures together with a secondary weft yarn. We demonstrate how photonic crystal fibers enable a variety of color and structural patterns on the textile, and how dynamic imagery can be created by balancing the ambient and emitted radiation. Finally, a possible application in security ware for low visibility conditions is described as an example.

  2. Cytotoxiciteitsanalyse van wondafdekmaterialen en non-woven verpakkingsmaterialen voor sterilisatie

    NARCIS (Netherlands)

    Geffen MF van; Machielsen JCA; Orzechowski TJH; Asten JAAM van; LGM

    1994-01-01

    Non-wovens gebruikt als verpakkingsmateriaal voor stoomsterilisatie en non-wovens/wovens gebruikt voor wondbedekking zijn in-vitro onderzocht op cytotoxiciteit. Aanleiding van het onderzoek was een incident waarbij non-wovens gebruikt voor sterilisatie van het in-vitro fertilisatie instrumentari

  3. Highly effective permeability and antifouling performances of polypropylene non-woven fabric membranes modified with graphene oxide by inkjet printing and immersion coating methods.

    Science.gov (United States)

    Zhao, Chuan-Qi; Xu, Xiao-Chen; Li, Rui-Yun; Chen, Jie; Yang, Feng-Lin

    2013-01-01

    In the current study, graphene oxide (GO)-modified polypropylene non-woven fabric (PP-NWF) membranes were prepared via inkjet printing and immersion coating methods. Scanning electron microscopy, Fourier transform infrared spectroscopy, contact angle measurements, pure water permeation (JPWP) and protein adsorption were tested to evaluate the impact of the GO nanosheet on the characteristics and performance of modified PP-NWF membranes. The results showed that the exfoliated GO nanosheets uniformly deposited on the membrane surface and firmly embedded into the interlaced fibers, resulting in the improvement of membrane hydrophilicity, permeability and antifouling properties comparing with original PP-NWF membranes. The GO-printed and GO-coated membranes had 113 and 188% higher fluxes, and 70.95 and 75.74% lower protein adsorptions than the original PP-NWF membranes, respectively. After cross-linked treatment, ultrasound processing was conducted to evaluate the stability of the modified PP-NWF membranes. The results demonstrated that there was almost no decrease in permeation after ultrasonic treatment indicating that the cross-linking treatment could enhance the immobilization of the GO nanosheets on and into the modified membranes.

  4. A β-type TiNbZr alloy with low modulus and high strength for biomedical applications

    OpenAIRE

    Qingkun Meng; Shun Guo; Qing Liu; Liang Hu; Xinqing Zhao

    2014-01-01

    The effect of thermo-mechanical treatment on the mechanical properties of a novel β-type Ti–36Nb–5Zr (wt%) alloy has been investigated. The solution treated alloy consists of β and α″ phases and exhibits a two-stage yielding with a low yield stress (around 100 MPa). After cold rolling at a reduction of 87.5% and subsequent annealing treatment at 698 K for 25 min, a fine microstructure with nanosized α precipitates distributed in small β grains as well as high density of dislocations was obtai...

  5. Graphite/Ultra-High Modulus Polyethylene Hybrid Fiber Composites with Epoxy and Polyethylene Matrices for Cosmic Radiation Shielding

    Science.gov (United States)

    2003-01-01

    One of the most significant technical challenges in long-duration space missions is that of protecting the crew from harmful radiation. Protection against such radiation on a manned Mars mission will be of vital importance both during transit and while on the surface of the planet. The development of multifunctional materials that serve as integral structural members of the space vehicle and provide the necessary radiation shielding for the crew would be both mission enabling and cost effective. Additionally, combining shielding and structure could reduce total vehicle mass. Hybrid laminated composite materials having both ultramodulus polyethylene (PE) and graphite fibers in epoxy and PE matrices could meet such mission requirements. PE fibers have excellent physical properties, including the highest specific strength of any known fiber. Moreover, the high hydrogen (H) content of polyethylene makes the material an excellent shielding material for cosmic radiation. When such materials are incorporated into an epoxy or PE matrix a very effective shielding material is expected. Boron (B) may be added to the matrix resin or used as a coating to further increase the shielding effectiveness due to B s ability to slow thermal neutrons. These materials may also serve as micrometeorites shields due to PE s high impact energy absorption properties. It should be noted that such materials can be fabricated by existing equipment and methods. It is the objective of this work therefore to: (a) perform preliminary analysis of the radiation transport within these materials; (b) fabricate panels for mechanical property testing before and after radiation exposure. Preliminary determination on the effectiveness of the combinations of material components on both shielding and structural efficiency will be made.

  6. Graphite/Ultra-High Modulus Polyethylene Hybrid Fiber Composites with Epoxy and Polyethylene Matrices for Cosmic Radiation Shielding

    Science.gov (United States)

    2003-01-01

    One of the most significant technical challenges in long-duration space missions is that of protecting the crew from harmful radiation. Protection against such radiation on a manned Mars mission will be of vital importance both during transit and while on the surface of the planet. The development of multifunctional materials that serve as integral structural members of the space vehicle and provide the necessary radiation shielding for the crew would be both mission enabling and cost effective. Additionally, combining shielding and structure could reduce total vehicle mass. Hybrid laminated composite materials having both ultramodulus polyethylene (PE) and graphite fibers in epoxy and PE matrices could meet such mission requirements. PE fibers have excellent physical properties, including the highest specific strength of any known fiber. Moreover, the high hydrogen (H) content of polyethylene makes the material an excellent shielding material for cosmic radiation. When such materials are incorporated into an epoxy or PE matrix a very effective shielding material is expected. Boron (B) may be added to the matrix resin or used as a coating to further increase the shielding effectiveness due to B s ability to slow thermal neutrons. These materials may also serve as micrometeorites shields due to PE s high impact energy absorption properties. It should be noted that such materials can be fabricated by existing equipment and methods. It is the objective of this work therefore to: (a) perform preliminary analysis of the radiation transport within these materials; (b) fabricate panels for mechanical property testing before and after radiation exposure. Preliminary determination on the effectiveness of the combinations of material components on both shielding and structural efficiency will be made.

  7. Nanostructured bacterial cellulose-poly(4-styrene sulfonic acid) composite membranes with high storage modulus and protonic conductivity.

    Science.gov (United States)

    Gadim, Tiago D O; Figueiredo, Andrea G P R; Rosero-Navarro, Nataly C; Vilela, Carla; Gamelas, José A F; Barros-Timmons, Ana; Neto, Carlos Pascoal; Silvestre, Armando J D; Freire, Carmen S R; Figueiredo, Filipe M L

    2014-05-28

    The present study reports the development of a new generation of bio-based nanocomposite proton exchange membranes based on bacterial cellulose (BC) and poly(4-styrene sulfonic acid) (PSSA), produced by in situ free radical polymerization of sodium 4-styrenesulfonate using poly(ethylene glycol) diacrylate (PEGDA) as cross-linker, followed by conversion of the ensuing polymer into the acidic form. The BC nanofibrilar network endows the composite membranes with excellent mechanical properties at least up to 140 °C, a temperature where either pure PSSA or Nafion are soft, as shown by dynamic mechanical analysis. The large concentration of sulfonic acid groups in PSSA is responsible for the high ionic exchange capacity of the composite membranes, reaching 2.25 mmol g(-1) for a composite with 83 wt % PSSA/PEGDA. The through-plane protonic conductivity of the best membrane is in excess of 0.1 S cm(-1) at 94 °C and 98% relative humidity (RH), decreasing to 0.042 S cm(-1) at 60% RH. These values are comparable or even higher than those of ionomers such as Nafion or polyelectrolytes such as PSSA. This combination of electric and viscoelastic properties with low cost underlines the potential of these nanocomposites as a bio-based alternative to other polymer membranes for application in fuel cells, redox flow batteries, or other devices requiring functional proton conducting elements, such as sensors and actuators.

  8. 高模量沥青面层合理结构形式的有限元研究%Definite Element Study on Reasonable Structure Form of High Modulus Asphalt Pavement

    Institute of Scientific and Technical Information of China (English)

    王先伟

    2012-01-01

    本文根据以往的经验提出了三种高模量沥青路面的结构形式,并从应力、应变和弯沉值的角度对高模量沥青面层结构进行分析,从而得出了高模量沥青混凝土路面的合理结构形式,为相关的沥青路面设计提供了一个新的分析方法。%This article provides three type of high modulus asphalt pavement structure form based on previous experience. It analyses high modulus asphalt pavement structure form from stress, strain and deflection value. A reasonable structure form of high modulus asphalt pavement is given, which also provides a new method to design asphalt pavement.

  9. Improved Strength and Toughness of Carbon Woven Fabric Composites with Functionalized MWCNTs

    Directory of Open Access Journals (Sweden)

    Eslam Soliman

    2014-06-01

    Full Text Available This investigation examines the role of carboxyl functionalized multi-walled carbon nanotubes (COOH-MWCNTs in the on- and off-axis flexure and the shear responses of thin carbon woven fabric composite plates. The chemically functionalized COOH-MWCNTs were used to fabricate epoxy nanocomposites and, subsequently, carbon woven fabric plates to be tested on flexure and shear. In addition to the neat epoxy, three loadings of COOH-MWCNTs were examined: 0.5 wt%, 1.0 wt% and 1.5 wt% of epoxy. While no significant statistical difference in the flexure response of the on-axis specimens was observed, significant increases in the flexure strength, modulus and toughness of the off-axis specimens were observed. The average increase in flexure strength and flexure modulus with the addition of 1.5 wt% COOH-MWCNTs improved by 28% and 19%, respectively. Finite element modeling is used to demonstrate fiber domination in on-axis flexure behavior and matrix domination in off-axis flexure behavior. Furthermore, the 1.5 wt% COOH-MWCNTs increased the toughness of carbon woven composites tested on shear by 33%. Microstructural investigation using Fourier Transform Infrared Spectroscopy (FTIR proves the existence of chemical bonds between the COOH-MWCNTs and the epoxy matrix.

  10. Modulus and yield stress of drawn LDPE

    Science.gov (United States)

    Thavarungkul, Nandh

    Modulus and yield stress were investigated in drawn low density polyethylene (LDPE) film. Uniaxially drawn polymeric films usually show high values of modulus and yield stress, however, studies have normally only been conducted to identify the structural features that determine modulus. In this study small-angle x-ray scattering (SAXS), thermal shrinkage, birefringence, differential scanning calorimetry (DSC), and dynamic mechanical thermal analysis (DMTA) were used to examine, directly and indirectly, the structural features that determine both modulus and yield stress, which are often closely related in undrawn materials. Shish-kebab structures are proposed to account for the mechanical properties in drawn LDPE. The validity of this molecular/morphological model was tested using relationships between static mechanical data and structural and physical parameters. In addition, dynamic mechanical results are also in line with static data in supporting the model. In the machine direction (MD), "shish" and taut tie molecules (TTM) anchored in the crystalline phase account for E; whereas crystal lamellae with contributions from "shish" and TTM determine yield stress. In the transverse direction (TD), the crystalline phase plays an important roll in both modulus and yield stress. Modulus is determined by crystal lamellae functioning as platelet reinforcing elements in the amorphous matrix with an additional contributions from TTM and yield stress is determined by the crystal lamellae's resistance to deformation.

  11. Laminate mechanics for balanced woven fabrics

    NARCIS (Netherlands)

    Akkerman, Remko

    2006-01-01

    Laminate mechanics equations are presented for composites with balanced woven fabric reinforcements. It is shown that mimicking these textile composites with equivalent transversely isotropic (‘unidirectional’) layers requires disputable manipulations. Various micromechanics predictions of textile

  12. Development of high-modulus low-shrinkage polyester industrial yarn%高模量低收缩涤纶工业丝的开发

    Institute of Scientific and Technical Information of China (English)

    季永忠

    2013-01-01

    A high-modulus low-shrinkage polyester industrial yarn was prepared from bright polyester chip with the intrinsic viscosity of 0.67 dL/g by high-speed spinning process subsequently to solid-state polycondensation. The effects of spinning conditions on the fiber properties were discussed. The results showed that the improvement of the modulus and dimension stability (DS value) of polyester industrial yarn would be beneficial from controlling the intrinsic viscosity of oil-free filament not less than 0.95 dL/g, spinning speed 3 400 m/min and spinneret draft ratio about 300 and rationally decreasing the post-heating temperature or insulation zone length. The obtained 1 677 dtex polyester industrial yarn had the breaking strength of 7.6 cN/dtex, elongation at break 10.8% , dry hot shrinkage 3.1%, constant load elongation 5.3% and DS value 8.4%.%采用特性黏数0.67 dL/g的大有光涤纶切片,通过固相缩聚后高速纺丝,生产高模量低收缩涤纶工业丝,讨论了纺丝工艺条件对纤维性能的影响.结果表明:控制涤纶无油丝特性黏数大于等于0.95 dL/g,纺丝速度3 400 m/min,喷丝头拉伸倍数约300,适当降低后加热器温度或缩短隔热区长度,有利于提高涤纶工业丝的模量和尺寸稳定性(DS值);生产的167dtex涤纶工业丝断裂强度7.6 cN/dtex,断裂伸长率10.8%,干热收缩率3.1%,定负荷伸长5.3%,DS值8.4%.

  13. Development Of 3D Woven Fabric Based Pressure Switch

    Directory of Open Access Journals (Sweden)

    Shaker Khubab

    2015-06-01

    Full Text Available This paper introduces a 3D woven fabric-based approach for the development of pressure switch. A fabric substrate, being elastic and extendable is very useful in addition to its high breaking strength and low cost. The developed resistive-type switch is based on the multilayer interlock 3D fabrics. In the top and bottom layers, certain number of conductive yarns are woven separated by cotton yarns in both transversal and thickness direction. Application of pressure makes the layers of conductive yarn to come in contact, resulting in a short circuit, which may be recorded using multi-meters. Removing the pressure cause the connection points to separate away and it depends on the weave design. Such switch can be used as an on/off switch for usage in security systems, can be sewn into carpets and wearable garments for a number of purposes.

  14. Debonding characteristics of adhesively bonded woven Kevlar composites

    Science.gov (United States)

    Mall, S.; Johnson, W. S.

    1988-01-01

    The fatigue damage mechanism of an adhesively bonded joint between fabric reinforced composite adherends was investigated with cracked-lap-shear specimens. Two bonded systems were studied: fabric Kevlar 49/5208 epoxy adherends bonded together with either EC 3445 or FM-300 adhesive. For each bonded system, two specimen geometries were tested. In all specimens tested, fatigue damage occurred in the form of cyclic debonding; however, the woven Kevlar specimens gave significantly slower debond growth rates and higher fracture toughness than previously found in the nonwoven adherend specimens. The surfaces for the woven adherends were not smooth; rather, they had regular crests (high spots) and troughs (low spots) due to the weave pattern. Radiographs of the specimens and examination of their failure surfaces revealed that fiber bridging occurred between the crests of the two adherends in the debonded region. The observed improvements in debond growth resistance and static fracture toughness are attributed to this bridging.

  15. Elastic Modulus Evolution and Behavior of Si/Mullite/BSAS-Based Environmental Barrier Coatings Exposed to High Temperature in Water Vapor Environment

    Science.gov (United States)

    Cojocaru, C. V.; Kruger, S. E.; Moreau, C.; Lima, R. S.

    2011-01-01

    Si-based ceramics (e.g., SiC and Si3N4) are known as promising high-temperature structural materials in various components where metals/alloys reached their ultimate performances (e.g., advanced gas turbine engines and structural components of future hypersonic vehicles). To alleviate the surface recession that Si-based ceramics undergo in a high-temperature environmental attack (e.g., H2O vapor), appropriate refractory oxides are engineered to serve as environmental barrier coatings (EBCs). The current state-of-the-art EBCs multilayer system comprises a silicon (Si) bond coat, mullite (3Al2O3·2SiO2) interlayer and (1 - x)BaO· xSrO·Al2O3·2SiO2, 0 ≤ x ≤ 1 (BSAS) top coat. In this article, the role of high-temperature exposure (1300 °C) performed in H2O vapor environment (for time intervals up to 500 h) on the elastic moduli of air plasma sprayed Si/mullite/BSAS layers deposited on SiC substrates was investigated via depth-sensing indentation. Laser-ultrasonics was employed to evaluate the E values of as-sprayed BSAS coatings as an attempt to validate the indentation results. Fully crystalline, crack-free, and near-crack-free as-sprayed EBCs were engineered under controlled deposition conditions. The absence of phase transformation and stability of the low elastic modulus values (e.g., ~60-70 GPa) retained by the BSAS top layers after harsh environmental exposure provides a plausible explanation for the almost crack-free coatings observed. The relationships between the measured elastic moduli of the EBCs and their microstructural behavior during the high-temperature exposure are discussed.

  16. Deployable robotic woven wire structures and joints for space applications

    Science.gov (United States)

    Shahinpoor, MO; Smith, Bradford

    1991-01-01

    Deployable robotic structures are basically expandable and contractable structures that may be transported or launched to space in a compact form. These structures may then be intelligently deployed by suitable actuators. The deployment may also be done by means of either airbag or spring-loaded typed mechanisms. The actuators may be pneumatic, hydraulic, ball-screw type, or electromagnetic. The means to trigger actuation may be on-board EPROMS, programmable logic controllers (PLCs) that trigger actuation based on some input caused by the placement of the structure in the space environment. The actuation may also be performed remotely by suitable remote triggering devices. Several deployable woven wire structures are examined. These woven wire structures possess a unique form of joint, the woven wire joint, which is capable of moving and changing its position and orientation with respect to the structure itself. Due to the highly dynamic and articulate nature of these joints the 3-D structures built using them are uniquely and highly expandable, deployable, and dynamic. The 3-D structure naturally gives rise to a new generation of deployable three-dimensional spatial structures.

  17. Cytotoxiciteitsanalyse van wondafdekmaterialen en non-woven verpakkingsmaterialen voor sterilisatie

    OpenAIRE

    Geffen MF van; Machielsen JCA; Orzechowski TJH; Asten JAAM van; LGM

    1994-01-01

    Non-wovens gebruikt als verpakkingsmateriaal voor stoomsterilisatie en non-wovens/wovens gebruikt voor wondbedekking zijn in-vitro onderzocht op cytotoxiciteit. Aanleiding van het onderzoek was een incident waarbij non-wovens gebruikt voor sterilisatie van het in-vitro fertilisatie instrumentarium embryotoxisch bleken. Om de aanwezigheid van migrerende cytotoxische stoffen aan te tonen zijn extracten van de materialen in een aantal in-vitro testen onderzocht. Evaluatie met cytotoxiciteitspara...

  18. Modeling of 3D Woven Composites Containing Multiple Delaminations

    Science.gov (United States)

    2012-08-20

    researchers 3D woven composites shows better damage tolerance than laminated textile composites without z-yarns such as plain woven composites even...modeling of quasi-static short beam shear test of plain woven laminated composites. Cohesive elements were used in regions where transverse cracks and...Title ABSTRACT In this paper we present FE modeling of quasi-static short beam shear test of plain woven laminated composites. Cohesive elements were

  19. 49 CFR 178.518 - Standards for woven plastic bags.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Standards for woven plastic bags. 178.518 Section... PACKAGINGS Non-bulk Performance-Oriented Packaging Standards § 178.518 Standards for woven plastic bags. (a) The following are identification codes for woven plastic bags: (1) 5H1 for an unlined or...

  20. Mechanical properties and fabrication of small boat using woven glass/sugar palm fibres reinforced unsaturated polyester hybrid composite

    Science.gov (United States)

    Misri, S.; Leman, Z.; Sapuan, S. M.; Ishak, M. R.

    2010-05-01

    In recent years, sugar palm fibre has been found to have great potential to be used as fibre reinforcement in polymer matrix composites. This research investigates the mechanical properties of woven glass/sugar palm fibres reinforced unsaturated polyester hybrid composite. The composite specimens made of different layer of fibres such as strand mat, natural and hand woven of sugar palm fibres. The composites were fabricated using a compression moulding technique. The tensile and impact test was carried out in accordance to ASTM 5083 and ASTM D256 standard. The fibre glass boat is a familiar material used in boat industry. A lot of research on fabrication process such as lay-up, vacuum infusion mould and resin transfer mould has been conducted. Hybrid material of sugar palm fibre and fibre glass was used in fabricating the boat. This research investigates the method selection for fabrication of small boat application of natural fibre composites. The composite specimens made of different layer of fibres; woven glass fibre, strand mat, natural and hand woven of woven sugar palm fibres were prepared. The small boat were fabricated using a compression moulding and lay up technique. The results of the experiment showed that the tensile strength, tensile modulus, elongation at break value and impact strength were higher than the natural woven sugar palm fibre. The best method for fabricating the small boat was compression moulding technique. As a general conclusion, the usage of glass fibre had improved the tensile properties sugar palm fibre composites and compression moulding technique is suitable to be used in making a small boat application of natural fibre composites.

  1. Elastic modulus of cetacean auditory ossicles.

    Science.gov (United States)

    Tubelli, Andrew A; Zosuls, Aleks; Ketten, Darlene R; Mountain, David C

    2014-05-01

    In order to model the hearing capabilities of marine mammals (cetaceans), it is necessary to understand the mechanical properties, such as elastic modulus, of the middle ear bones in these species. Biologically realistic models can be used to investigate the biomechanics of hearing in cetaceans, much of which is currently unknown. In the present study, the elastic moduli of the auditory ossicles (malleus, incus, and stapes) of eight species of cetacean, two baleen whales (mysticete) and six toothed whales (odontocete), were measured using nanoindentation. The two groups of mysticete ossicles overall had lower average elastic moduli (35.2 ± 13.3 GPa and 31.6 ± 6.5 GPa) than the groups of odontocete ossicles (53.3 ± 7.2 GPa to 62.3 ± 4.7 GPa). Interior bone generally had a higher modulus than cortical bone by up to 36%. The effects of freezing and formalin-fixation on elastic modulus were also investigated, although samples were few and no clear trend could be discerned. The high elastic modulus of the ossicles and the differences in the elastic moduli between mysticetes and odontocetes are likely specializations in the bone for underwater hearing.

  2. Thermal Testing of Woven TPS Materials in Extreme Entry Environments

    Science.gov (United States)

    Gonzales, G.; Stackpoole, M.

    2014-01-01

    NASAs future robotic missions to Venus and outer planets, namely, Saturn, Uranus, Neptune, result in extremely high entry conditions that exceed the capabilities of current mid density ablators (PICA or Avcoat). Therefore mission planners assume the use of a fully dense carbon phenolic heatshield similar to what was flown on Pioneer Venus and Galileo. Carbon phenolic (CP) is a robust TPS however its high density and thermal conductivity constrain mission planners to steep entries, high heat fluxes, high pressures and short entry durations, in order for CP to be feasible from a mass perspective. In 2012 the Game Changing Development Program in NASAs Space Technology Mission Directorate funded NASA ARC to investigate the feasibility of a Woven Thermal Protection System to meet the needs of NASAs most challenging entry missions. The high entry conditions pose certification challenges in existing ground based test facilities. Recent updates to NASAs IHF and AEDCs H3 high temperature arcjet test facilities enable higher heatflux (2000 Wcm2) and high pressure (5 atm) testing of TPS. Some recent thermal tests of woven TPS will be discussed in this paper. These upgrades have provided a way to test higher entry conditions of potential outer planet and Venus missions and provided a baseline against carbon phenolic material. The results of these tests have given preliminary insight to sample configuration and physical recession profile characteristics.

  3. Artificial nanograting woven by self-assembled nanowires.

    Science.gov (United States)

    Liu, Feng-Qi; Shao, Ye; Huang, Xiu-Qi; Wang, Zhan-Guo

    2005-10-01

    We report on a new simple route to realize a high resolution nanograting. By adopting an InAlGaAs matrix and strain-compensated technique, we have proved that a uniform self-assembled InAs nanowire array can be fabricated by molecular beam epitaxy (MBE). A nanograting woven by self-assembled semiconductor nanowires shows a conspicuous diffraction feature. The good agreement between the theoretical and experimental values of diffraction peak positions indicates that a uniform nanowire array is a promising nanograting. This simple one-step MBE growth method will open exciting opportunities for the field of clever optics design.

  4. Influence of Warp Yarn Tension on Cotton Greige and Dyed Woven Fabric Prosperities

    Directory of Open Access Journals (Sweden)

    Uzma Syed

    2013-01-01

    Full Text Available Fabric properties such as pilling and abrasion resistance and tensile strength vary when greige fabric is processed further. The quality of dyed fabric depends on the quality of greige fabric. Cotton Plain and Twill weave fabrics were woven at three different warp yarn tension and then dyed using monochlorotriazine, Drimerene Red Cl-5B dye gives difference in fabric properties. The ASTM, American International Standards were used to determine the greige and dyed fabric properties. It has been observed fabric woven at proper loom setting or warp yarn tension have high strength, less pilling and abrasion tendency as compared to fabric woven at variant warp yarn tension. Moreover, fabric tenacity is decreased after dyeing whereas, slight difference in pilling and abrasion values is observed after dyeing than that of greige fabric.

  5. Elastic moduli, damping and modulus of rupture changes in a high alumina refractory castable due to different types of thermal shock

    Directory of Open Access Journals (Sweden)

    Pereira, A. H. A.

    2012-06-01

    Full Text Available The work herein verifies the changes of the elastic moduli, damping and modulus of rupture (MOR of a high alumina refractory castable due to heating, cooling and heating-cooling thermal shock damage. Twelve prismatic specimens were prepared for the tests and divided into four groups. The thermal shocks were performed on three groups, each containing three specimens having abrupt temperature changes of 1100°C during heating in the first group, during cooling in the second and during heating followed by cooling in the third group. The fourth group, which was taken as a reference did not receive any thermal shock. The elastic moduli were measured after each thermal shock cycle. After 10 cycles, the MOR, the damping and the damping dependence on excitation amplitude were measured at room temperature for all specimens. The elastic moduli showed a similar decrease and the damping a similar increase due to the cooling and heating-cooling thermal shocks. The heating thermal shocks caused no significant changes on the elastic moduli and damping. However, the MOR appeared to be sensitive to the heating thermal shock. This work also shows that the damping for the studied refractory castable is non-linear (i.e., amplitude of excitation sensitive and that this non-linearity increases when the damage level rises.

    En este trabajo se investigaron las alteraciones de los módulos elásticos dinámicos, del amortiguamiento y del módulo de rotura (MOR de un material refractario moldeable de alta alúmina después de recibir choques térmicos de calentamiento, enfriamiento y calentamiento seguido de enfriamiento (calentamiento-enfriamiento. Para ello se prepararon doce cuerpos prismáticos dividiéndolos en cuatro grupos. Los choques térmicos se le aplicaron a sólo tres grupos, cada uno con tres muestras. Al primer grupo se le aplicó un cambio brusco de temperatura de 1100 °C en calentamiento, en enfriamiento al segundo grupo y calentamiento seguido

  6. Microscopic origin of volume modulus inflation

    Energy Technology Data Exchange (ETDEWEB)

    Cicoli, Michele [ICTP, Strada Costiera 11, Trieste 34014 (Italy); Dipartimento di Fisica e Astronomia, Università di Bologna, via Irnerio 46, 40126 Bologna (Italy); INFN, Sezione di Bologna, via Irnerio 46, 40126 Bologna (Italy); Muia, Francesco [Dipartimento di Fisica e Astronomia, Università di Bologna, via Irnerio 46, 40126 Bologna (Italy); INFN, Sezione di Bologna, via Irnerio 46, 40126 Bologna (Italy); Pedro, Francisco Gil [Departamento de Fisica Teórica UAM and Instituto de Fisica Teórica UAM/CSIC, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid (Spain)

    2015-12-21

    High-scale string inflationary models are in well-known tension with low-energy supersymmetry. A promising solution involves models where the inflaton is the volume of the extra dimensions so that the gravitino mass relaxes from large values during inflation to smaller values today. We describe a possible microscopic origin of the scalar potential of volume modulus inflation by exploiting non-perturbative effects, string loop and higher derivative perturbative corrections to the supergravity effective action together with contributions from anti-branes and charged hidden matter fields. We also analyse the relation between the size of the flux superpotential and the position of the late-time minimum and the inflection point around which inflation takes place. We perform a detailed study of the inflationary dynamics for a single modulus and a two moduli case where we also analyse the sensitivity of the cosmological observables on the choice of initial conditions.

  7. Microscopic Origin of Volume Modulus Inflation

    CERN Document Server

    Cicoli, Michele; Pedro, Francisco Gil

    2015-01-01

    High-scale string inflationary models are in well-known tension with low-energy supersymmetry. A promising solution involves models where the inflaton is the volume of the extra dimensions so that the gravitino mass relaxes from large values during inflation to smaller values today. We describe a possible microscopic origin of the scalar potential of volume modulus inflation by exploiting non-perturbative effects, string loop and higher derivative perturbative corrections to the supergravity effective action together with contributions from anti-branes and charged hidden matter fields. We also analyse the relation between the size of the flux superpotential and the position of the late-time minimum and the inflection point around which inflation takes place. We perform a detailed study of the inflationary dynamics for a single modulus and a two moduli case where we also analyse the sensitivity of the cosmological observables on the choice of initial conditions.

  8. Tensile Properties of Co-Woven-Knitted Fabric Reinforced Composites%机织针织复合结构增强复合材料的拉伸性能

    Institute of Scientific and Technical Information of China (English)

    徐艳华; 袁新林; 胡红

    2011-01-01

    经纬纱和针织纱分别使用玻璃纤维和高强涤纶编织新型机织针织复合织物作为增强体,采用真空辅助树脂传递模塑(VARTM)工艺制作聚乙烯树脂复合材料.对该新型复合材料的横向、纵向和斜向拉伸性能进行测试,并对拉伸应力-应变特征曲线及其拉伸断裂形态进行分析.研究表明:该类复合材料具有较好的拉伸性能,横向和纵向的拉伸性能均优于斜向,其拉伸断裂都为脆性断裂.研究结果为该新型织物增强复合材料的应用提供了必要的基础.%A novel co-woven-knitted fabric was produced using glass filaments as warp and weft inserted yarns and high tenacity polyester as stitch yarn and used for reinforcing the co-woven-knitted composites by Vacuum Assisted Resin Transfer Molding(VARTM) process.Tensile tests were carried out in the course, wale and bias directions.The mechanical properties of the composites were investigated by analyzing the stress-strain curves and the damage modes.The results revealed that the tensile strength and the elastic modulus in the course and wale directions were all better than in the bias direction, and the damage modes were the brittle fracture.These provided a basis for the application of the co-woven-knitted reinforced composites.

  9. Numerical Tools for Composite Woven Fabric Preforming

    Directory of Open Access Journals (Sweden)

    Abel Cherouat

    2013-01-01

    Full Text Available An important step in the manufacturing processes of thin composite components is the layingup of the reinforcement onto the mould surface. The prediction of the angular distortion of the reinforcement during draping and the changes in fibre orientation are essential for the understanding of the manufacture process and the evaluation of the mechanical properties of the composite structures. This paper presents an optimization-based method for the simulation of the forming processes of woven fabric reinforced composites. Two different approaches are proposed for the simulation of the draping of woven fabric onto complex geometries: geometrical and mechanical approaches. The geometrical approach is based on a fishnet model. It is well adapted to predimensioning fabrics and to give a suitable quantification of the resulting flat patterns. The mechanical approach is based on a mesostructural model. It allows us to take into account the mechanical properties of fibres and resin and the various dominating mode of deformation of woven fabrics during the forming process. Some numerical simulations of the forming process are proposed and compared with the experimental results in order to demonstrate the efficiency of our approaches.

  10. Present and future of non-woven fabric technology

    Energy Technology Data Exchange (ETDEWEB)

    Tsuji, Issei (Idemitsu Kosan Co. Ltd., Tokyo, (Japan))

    1989-07-01

    Non-woven fabrics which had been in the background as an auxiliary material is now on the surface as such disposable household merchandise as paper diapers, disposable pocket warmes and wet tissue, etc. rapidly get popular. The non-wovens show a large variety of performances according to the difference of the raw materials and the method of manufacture. What is important in the future is the technology of 'order-made' non-wovens, i.e., the complex texturing and the post-fabrication technology. This report describes on the following items: Definition and concept of non-woven fabrics. Market and applications. Production method (Wet process and dry process, bonding and entangling). Type and features (staple type, needle punched type, stitch bonded type, spun bond type, and wet type). Future trends. Reciprocal process. Melt-blown non-woven fabric. Spun-lace non-woven fabric. 5 refs., 3 figs., 4 tabs.

  11. Principle and Method for Structural Design of Digital Woven Fabric

    Institute of Scientific and Technical Information of China (English)

    ZHOU Jiu; NG Frankie

    2006-01-01

    Digital woven textiles are one of the latest research areas of digital textiles. The key of research on design of digital woven fabrics lies in structural design. Nowadays, the application of digital design technology has fundamentally changed the concept of structural design of woven fabric,giving rise to design methods and effects that were deemed impossible before. A study has been carried out to analyze the nature of woven structures and the methods of structural design. This paper proposes an innovative principle and method of structural design under digital design concept, on which the design of digital gamut weaves and establishment of weave-database were presented to meet the requirement of balanced interlacement. It is envisaged that the results of this study will enhance future research in creation of digital woven fabrics, with particular emphasis on digital jacquard fabrics. Meanwhile, this study is also laid the foundation for the intelligent design of woven textile.

  12. Road Performance of High Modulus Asphalt Concrete Additive Calcium Sulfate Whisker%硫酸钙晶须高模量沥青混凝土的路用性能

    Institute of Scientific and Technical Information of China (English)

    王修山

    2011-01-01

    从路用性能出发,对3种混合料进行试验,对比研究了新型高模量无机改性剂硫酸钙晶须在沥青混合料中的应用效果.结果显示:硫酸钙晶须改性的高模量沥青混合料可以在不降低混合料低温性能的同时,有效地提高混合料的高温稳定性、水稳性和抗疲劳性能,可行性分析证明:酸钙晶须高模量沥青混凝土路用性能良好,并且有着较高的经济效益与社会效益.%The application effect of high modulus asphalt concrete additive calcium sulfate whisker in the asphalt mixtures is studied on the basis of road performance. Three mixtures are involved in the experiment and a comparative study of test results are carried out. The results show that the high modulus of asphalt mixture which is modified by calcium sulfate whisker can effectively improve the high temperature stability, water stability and anti-fatigue performance; at the same time, it doesn't decrease the mixture low temperature performance. Finally, the feasibility analysis shows that: the road performance of calcium whisker high modulus asphalt concrete pavement is good and it has high economic and social benefits.

  13. Immobilized photocatalyst on stainless steel woven meshes assuring efficient light distribution in a solar reactor

    NARCIS (Netherlands)

    El-Kalliny, A.S.; Ahmed, S.F.; Rietveld, L.C.; Appel, P.W.

    2014-01-01

    An immobilized TiO2 photocatalyst with a high specific surface area was prepared on stainless steel woven meshes in order to be used packed in layers for water purification. Immobilization of such a complex shape needs a special coating technique. For this purpose, dip coating and electrophoretic de

  14. 75 FR 38459 - Certain Woven Electric Blankets From the People's Republic of China: Final Determination of Sales...

    Science.gov (United States)

    2010-07-02

    ... Antidumping Investigations involving Non-Market Economy Countries,'' which states: \\23\\ See Certain Woven... International Trade Administration Certain Woven Electric Blankets From the People's Republic of China: Final... Department'') has determined that certain woven electric blankets (``woven electric blankets'') from...

  15. Elastic modulus of viral nanotubes

    Science.gov (United States)

    Zhao, Yue; Ge, Zhibin; Fang, Jiyu

    2008-09-01

    We report an experimental and theoretical study of the radial elasticity of tobacco mosaic virus (TMV) nanotubes. An atomic force microscope tip is used to apply small radial indentations to deform TMV nanotubes. The initial elastic response of TMV nanotubes can be described by finite-element analysis in 5nm indentation depths and Hertz theory in 1.5nm indentation depths. The derived radial Young’s modulus of TMV nanotubes is 0.92±0.15GPa from finite-element analysis and 1.0±0.2GPa from the Hertz model, which are comparable with the reported axial Young’s modulus of 1.1GPa [Falvo , Biophys. J. 72, 1396 (1997)].

  16. SPLITTING MODULUS FINITE ELEMENT METHOD FOR ORTHOGONAL ANISOTROPIC PLATE BENGING

    Institute of Scientific and Technical Information of China (English)

    党发宁; 荣廷玉; 孙训方

    2001-01-01

    Splitting modulus variational principle in linear theory of solid mechanics was introduced, the principle for thin plate was derived, and splitting modulus finite element method of thin plate was established too. The distinctive feature of the splitting model is that its functional contains one or more arbitrary additional parameters, called splitting factors,so stiffness of the model can be adjusted by properly selecting the splitting factors. Examples show that splitting modulus method has high precision and the ability to conquer some illconditioned problems in usual finite elements. The cause why the new method could transform the ill-conditioned problems into well-conditioned problem, is analyzed finally.

  17. Elastic modulus of phases in Ti–Mo alloys

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Wei-dong [State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan 410083 (China); Liu, Yong, E-mail: yonliu11@aliyun.com [State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan 410083 (China); Wu, Hong; Song, Min [State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan 410083 (China); Zhang, Tuo-yang [Metallurgical Engineering, University of Utah, Salt Lake City, UT 84112 (United States); Lan, Xiao-dong; Yao, Tian-hang [State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan 410083 (China)

    2015-08-15

    In this work, a series of binary Ti–Mo alloys with the Mo contents ranging from 3.2 to 12 at.% were prepared using non-consumable arc melting. The microstructures were investigated by X-ray diffraction and transmission electron microscope, and the elastic modulus was evaluated by nanoindentation testing technique. The evolution of the volume fractions of ω phase was investigated using X-ray photoelectron spectroscopy. The results indicated that the phase constitution and elastic modulus of the Ti–Mo alloys are sensitive to the Mo content. Ti–3.2Mo and Ti–8Mo alloys containing only α and β phases, respectively, have a low elastic modulus. In contrast, Ti–4.5Mo, Ti–6Mo, Ti–7Mo alloys, with different contents of ω phase, have a high elastic modulus. A simple micromechanical model was used to calculate the elastic modulus of ω phase (E{sub ω}), which was determined to be 174.354 GPa. - Highlights: • Ti–Mo alloys with the Mo contents ranging from 3.2 to 12 at.% were investigated. • XPS was used to investigate the volume fractions of ω phase. • The elastic modulus of Ti–Mo alloys is sensitive to the Mo content. • The elastic modulus of ω phase was determined to be 174.354 GPa.

  18. Computational modelling of buckling of woven fabrics

    CSIR Research Space (South Africa)

    Anandjiwala, RD

    2006-02-01

    Full Text Available generalized model of a plain woven fabric and subsequently for modifying Huang’s extension analysis. Although, Kang et al have utilized Huang’s bilinearity in their model, the obvious inconsistency of applying the classical beam theory to the textile problem... couple which influences the behaviour of textile materials, such as yarns and fabrics. This implies that M a = 0 and B = B*. When substituting these values in Equations (4) to (16) equations are obtained that are similar to the buckling of a strut...

  19. 75 FR 51482 - Woven Electric Blankets From China

    Science.gov (United States)

    2010-08-20

    ... publishing the notice in the Federal Register of March 11, 2010 (75 FR 11557). The hearing was held in... COMMISSION Woven Electric Blankets From China Determination On the basis of the record \\1\\ developed in the... United States is materially injured by reason of imports from China of woven electric blankets,...

  20. Adsorption of proteins from plasma at polyester non-wovens

    NARCIS (Netherlands)

    Klomp, A.J.A.; Engbers, G.H.M.; Mol, J.; Terlingen, J.G.A.; Feijen, J.

    1999-01-01

    Polyester non-wovens in filters for the removal of leukocytes from platelet concentrates (PCs) must be platelet compatible. In PC filtration, the adsorption of proteins at the plasma–non-woven interface can be of great importance with respect to the yield of platelets. Unmodified and radio frequency

  1. Impact Performance of 3D Integrated Cellular Woven Composite Panel

    Institute of Scientific and Technical Information of China (English)

    TIAN Wei; ZHU Cheng-yan

    2006-01-01

    This paper studied the impact resistance of 3D integrated cellular woven composite panel under persudo-static impact,comprised the test result with property of typical 3D woven composites, analyzed some parameters that maybe affect composites' impact resistance and at last used SEM to observe the damage process and mechanism of samples. The result shows that the impact resistance of 3D integrated cellular woven composites is much better than the performance of typical 3D woven composites; it is an active method to improve the impact resistance of composites that developing preform with cellular on the basis of typical 3D woven structure; for different 3D integrated cellular woven structure, the value of absorbed-energy is incrensing with the hollow percentage; tiny deformation will not emerge on samples until the acting force gets to 85% of the maximum;similar with typical 3D woven composites, the delaminated phenomenon of 3D integrated cellular woven composites is also unapparent during impact process.

  2. Representation of 3D Woven Structures by Parametric Method

    Institute of Scientific and Technical Information of China (English)

    DING Xin; YI Hong-lei

    2005-01-01

    A parametric method is developed to quantitatively represent the microstructure of 3D woven structures. Different binding patterns, such as angle interlock and orthogonal interlock with through-thickness or layer-to-layer bindings, are classified. A unit cell of 3D woven structure is defined with four constituent yarn systems represented by nine structural parameters. A mapping relationship between the 3D woven structure and corresponding representative parameters is thus established. The study indicates that four out of the nine parameters are necessary to represent a 3D woven structure with an angle interlock binding, and that five parameters are required to describe a 3D woven structure with an orthogonal interlock binding. Once the structural parameters are determined, the pattern of 3D woven structures can be unambiguously identified, and vice versa. In addition to the purpose of structure presentation, the method can be further used as a means for designing 3D woven structure to meet the performance requirements of 3D woven composites.

  3. Thermal properties of hemp fibre non-woven materials

    Science.gov (United States)

    Freivalde, Liga; Kukle, Silvija; Russell, Stephen

    2013-12-01

    This review considers the thermal properties analysis of hemp fiber non-woven materials made by three different manufacturing technologies - thermal bonding, needle-punching and hydro-entanglement. For non-wovens development two hemp fibers cultivars grown in Latvia were used - Purini and Bialobrzeskie. Thermal resistance, conductivity and the effects of several parameters on thermal performance are revised.

  4. Influence of the Testing Gage Length on the Strength, Young's Modulus and Weibull Modulus of Carbon Fibres and Glass Fibres

    Directory of Open Access Journals (Sweden)

    Luiz Claudio Pardini

    2002-10-01

    Full Text Available Carbon fibres and glass fibres are reinforcements for advanced composites and the fiber strength is the most influential factor on the strength of the composites. They are essentially brittle and fail with very little reduction in cross section. Composites made with these fibres are characterized by a high strength/density ratio and their properties are intrisically related to their microstructure, i.e., amount and orientation of the fibres, surface treatment, among other factors. Processing parameters have an important role in the fibre mechanical behaviour (strength and modulus. Cracks, voids and impurities in the case of glass fibres and fibrillar misalignments in the case of carbon fibres are created during processing. Such inhomogeneities give rise to an appreciable scatter in properties. The most used statistical tool that deals with this characteristic variability in properties is the Weibull distribution. The present work investigates the influence of the testing gage length on the strength, Young's modulus and Weibull modulus of carbon fibres and glass fibres. The Young's modulus is calculated by two methods: (i ASTM D 3379M, and (ii interaction between testing equipment/specimen The first method resulted in a Young modulus of 183 GPa for carbon fibre, and 76 GPa for glass fibre. The second method gave a Young modulus of 250 GPa for carbon fibre and 50 GPa for glass fibre. These differences revelead differences on how the interaction specimen/testing machine can interfere in the Young modulus calculations. Weibull modulus can be a tool to evaluate the fibre's homogeneity in terms of properties and it is a good quality control parameter during processing. In the range of specimen gage length tested the Weibull modulus for carbon fibre is ~ 3.30 and for glass fibres is ~ 5.65, which indicates that for the batch of fibres tested, the glass fibre is more uniform in properties.

  5. Robust defect segmentation in woven fabrics

    Energy Technology Data Exchange (ETDEWEB)

    Sari-Sarraf, H.; Goddard, J.S. Jr.

    1997-12-01

    This paper describes a robust segmentation algorithm for the detection and localization of woven fabric defects. The essence of the presented segmentation algorithm is the localization of those events (i.e., defects) in the input images that disrupt the global homogeneity of the background texture. To this end, preprocessing modules, based on the wavelet transform and edge fusion, are employed with the objective of attenuating the background texture and accentuating the defects. Then, texture features are utilized to measure the global homogeneity of the output images. If these images are deemed to be globally nonhomogeneous (i.e., defects are present), a local roughness measure is used to localize the defects. The utility of this algorithm can be extended beyond the specific application in this work, that is, defect segmentation in woven fabrics. Indeed, in a general sense, this algorithm can be used to detect and to localize anomalies that reside in images characterized by ordered texture. The efficacy of this algorithm has been tested thoroughly under realistic conditions and as a part of an on-line fabric inspection system. Using over 3700 images of fabrics, containing 26 different types of defects, the overall detection rate of this approach was 89% with a localization accuracy of less than 0.2 inches and a false alarm rate of 2.5%.

  6. High strength and high modulus polyvinyl alcohol fiber——the optimal substitute for asbestos%高强高模聚乙烯醇纤维是替代石棉的最理想材料

    Institute of Scientific and Technical Information of China (English)

    高祖安

    2012-01-01

    综述分析了石棉及其石棉行业存在严重危害性等实际情况,对国外开发的各种石棉替代品的试验、试用和实际应用情况进行了对比。结果表明,聚乙烯醇(PVA)纤维具有高强高模、低伸长、耐酸碱、抗溶剂、耐老化、水泥粘着力好、性价比高等优良特点,以及国外近20年的基础研究和工程应用实践证明,被国际公认为替代石棉的最理想材料。最后提出在我国加快PVA纤维代替石棉的迫切性与必要性。%This paper summarizes and analyzes the serious harm to human health caused by asbestos and asbestos industry and other actual situations, then have a comparison through experiment, trial and practical application of various kinds of asbestos substitutes developed abroad. The results indicate that PVA fibers have good performances of high strength and high modulus, low elongation, acid and alkali resistant, anti-solvent, anti-aging, good cement adhesiveness, cost effective and etc. On basis of the nearly 20 years' basic research and engineering practice in abroad, PVA is considered to be the optimal substitute for asbestos. Finally the paper leads to a conclusion that it's urgent and necessary to accelerate the development of PVA alternative technology of asbestos.

  7. 2.5GHz CMOS高速双模前置分频器设计%A High-Speed Dual Modulus Prescaler Using 0.25μm CMOS Technology

    Institute of Scientific and Technical Information of China (English)

    杨文荣; 曹家麟; 冉峰; 王键

    2004-01-01

    A high-speed dual-modulus divide-by-32/33 prescaler has been developed using 0.25 μm CMOS technology. The source-coupled logic (SCL) structure is used to reduce the switching noise and to ameliorate the power-speed tradeoff. The proposed prescaler can operate at high frequency with a low-power consumption. Based on the 2.5 V, 0.25 μm CMOS model, simulation results indicate that the maximum input frequency of the prescaler is up to 3. 2 GHz. Running at 2. 5 V, the circuit consumes only 4.6 mA at an input frequency 2.5 GHz.

  8. Experimental Study on Dynamic Elasticity Modulus and Damping Ratio of Highly Weathered Rock which Covered by Loess%黄土层下覆强风化岩动弹性模量和阻尼比试验研究

    Institute of Scientific and Technical Information of China (English)

    王平; 王杰民; 刘红玫; 王谦

    2011-01-01

    A series of studies on dynamic elasticity modulus and damping ratio of highly weathered rock which covered by loess are conducted with small strain ed, using triaxial shear equipment and their dynamics properties are analyzed. The results show that the dynamic stress and strain relation of highly weathered rock is nonlinear elastic relations, and fit the model of hyperbolic type with small strain ed. Within the same strain range, the mudstone's damping ratio is greater than the red sandstone's. In the same consolidation condition, the initial elastic modulus of red sandstone is greater than the one of mudstone. The research provides experimental technology and dynamic property parameters to dynamic response analysis and seismic deformation mechanism study for highly weathered rock which covered by thick layer of loess.%运用扭剪仪对小应变εd时黄土层下覆强风化岩的动模量和阻尼比进行了系列研究,分析了其动力学特性.结果表明,在小应变情况下风化岩体的动应力与动应变关系为非线性弹性关系,基本符合双曲线型模型;在相同应变范围内,泥岩阻尼比大于红砂岩的阻尼比;在相同固结条件下,红砂岩的初始动弹模大于泥岩初始动弹模.研究为厚覆盖层黄土场地及其下覆强风化岩层、隧道、高边坡动力反应分析和地震后土体变形机理研究提供了必要试验技术和参数.

  9. Woven structured triboelectric nanogenerator for wearable devices.

    Science.gov (United States)

    Zhou, Tao; Zhang, Chi; Han, Chang Bao; Fan, Feng Ru; Tang, Wei; Wang, Zhong Lin

    2014-08-27

    To date, quite a few wearable electronics have entered the market, which are changing the life pattern of consumers. However, the limited lifetime and energy storage capacity have made rechargeable batteries the bottleneck in wearable technology, especially with the increase of number of wearable devices and their large distribution. To solve this problem, we demonstrate a woven-structured triboelectric nanogenerator (W-TENG) using commodity nylon fabric, polyester fabric, and conductive silver fiber fabric. With the advantage of being flexible, washable, breathable, wearable, and able to be triggered by a freestanding triboelectric layer, this W-TENG can move freely without any constraint and is suitable for wearable electronics. To demonstrate the potential applications of the W-TENG, the W-TENG is integrated into shoes, coats, and trousers to harvest different kinds of mechanical energy from human motion. This work presents a new approach in applying triboelectric nanogenerator to wearable devices.

  10. Experimental study of deformations of reinforced cushion by high-strength woven geotextile in closing levee%圈围工程中高强有纺土工布加筋垫层变形试验研究

    Institute of Scientific and Technical Information of China (English)

    曹国福; 徐兵; 王茂胜; 姚顺雨; 刘丽; 刘益锋

    2014-01-01

    应用大刚度、长标距、大量程的 SDW-100型位移传感器,采用500 kN/m 高强有纺土工布进行室内试验和现场试验,研究高强土工布加筋垫层的变形情况。室内拉伸试验成果表明,位移传感器在每级加荷情形下的变形量与试验机上显示变形量具有较好的一致性,说明该类型传感器用于现场加筋高强土工布的变形测试是适用的,并因此得到高强有纺土工布的变形模量为8314.4 kN/m。现场试验表明,(1)大堤底部的土工布位移曲线基本表现为盆形,中轴线下的土工布位移量最大;(2)大堤下部土工布的位移量大小与外棱体的位移方向明显相关;(3)现场试验中高强土工布的最大实测变形率为11.9%,按室内试验得到的变形模量计算出该计算高强有纺土工布的应力值为837.40 kN/m,表明按照现场实际加荷速率设计的高强有纺土工布强度值偏小;(4)施工间歇期高强土工布的应力会出现重分布现象,具体表现为大堤轴线下变形量明显减小,现场实测成果与 Plaxis 有限元计算成果规律性吻合情况较好,试验成果符合一般规律;(5)土工布的变形率与围堤上部现场施工加荷的速率关系很大,现场施工时设计单位应当提出一个加荷速率控制值;(6)当高强有纺土工布的强度一定时,土工布的伸长率相对较大有利于快速加荷施工。%By using the data acquired from laboratory and field monitoring program, this study assessed the displacements of high-strength geotextile used as basal reinforcement of a closing levee. The displacements of the geotextile were monitored by high stiffness, large gauge length and measuring range SDW-100 displacement transducers with 500 kN/m high-strength woven geotextile .The transducers were first calibrated in a multi-function test machine. The tensile test of the geotextile yielded a tensile stiffness of 8314.4 kN/m. The field

  11. Computation of Modulus of Elasticity of Concrete

    Directory of Open Access Journals (Sweden)

    Onwuka, D.O

    2013-09-01

    Full Text Available - In this presentation, a computer based method which uses a set of algebraic equations and statistical data, were used to compute concrete mixes for prescribeable elastic concrete modulus, and vice versa. The computer programs based on Simplex and Regression theories can be used to predict several mix proportions for obtaining a desired modulus of elasticity of concrete made from crushed granite rock and other materials. The modulus of elasticity of concrete predicted by these programs agreed with experimentally obtained values. The programs are easy and inexpensive to use, and give instant and accurate results. For example, if the modulus of elasticity is specified as input, the computer instantly prints out all possible concrete mix ratios that can yield concrete having the specified elastic modulus. When the concrete mix ratio is specified as input, the computer quickly prints out the elastic modulus of the concrete obtainable from a given concrete mix ratio.

  12. Study on elastic modulus of individual ferritin

    Institute of Scientific and Technical Information of China (English)

    ZHANG JinHai; CUI ChengYi; ZHOU XingFei

    2009-01-01

    The mechanical property of individual ferriUn was measured with force-volume mapping (FV) under contact mode of atomic force microscopy (AFM) in this work. The elastic modulus of individual ferritin was estimated by the Hertz mode. The estimated value of the elastic modulus of individual ferritin was about 250-800 MPs under a small deformation. In addition, the elastic modulus of individual ferritin was compared with that of the colloid gold nanoparticle.

  13. Various Expressions for Modulus of Random Convexity

    Institute of Scientific and Technical Information of China (English)

    Xiao Lin ZENG

    2013-01-01

    We first prove various kinds of expressions for modulus of random convexity by using an Lo(F,R)-valued function's intermediate value theorem and the well known Hahn-Banach theorem for almost surely bounded random linear functionals,then establish some basic properties including continuity for modulus of random convexity.In particular,we express the modulus of random convexity of a special random normed module Lo(F,X) derived from a normed space X by the classical modulus of convexity of X.

  14. Mathematical Model for Predicting the Resistivity of an Electroconductive Woven Structure

    Science.gov (United States)

    Tokarska, Magdalena

    2017-03-01

    Highly conductive woven fabrics (WF) can be used as electronic components. Resistivity is an intrinsic physical property of the conductive textile materials (CTM). The McLachlan model that describes the resistivity of a two-component macroscopic composite (TCMC) subjected to a constant external electric field was proposed to predict the resistivity of fabrics. The volume fraction of voids in material, the voids dimension, and a single morphology parameter were taken into account. The resistivity of a chosen WF was determined based on the model. Verification of the received results was carried out. In the case of four samples, the verification was confirmed by the high level of prediction being in the range of 83-88%. In the case of one sample, the verification was negative (26%). This allowed one to pay attention to the influence of compactness and irregularity of the woven structure on results received using the model.

  15. Woven Structures from Natural Fibres for Reinforcing Composites

    OpenAIRE

    Maniņš, M; Bernava, A; Strazds, G.

    2015-01-01

    The increase of production of woven structures from natural fibres for reinforced composites can be noticed in different sectors of economy. This can be explained by limited sources of raw materials and different environmental issues, as well as European Union guidelines for car manufacture [4]. This research produced 2D textile structures of hemp yarn and polypropylene yarn and tested the impact of added glass fibre yarn on the mechanical properties of the woven structures and the composites...

  16. Microwave-synthesized freestanding iron-carbon nanotubes on polyester composites of woven Kevlar fibre and silver nanoparticle-decorated graphene.

    Science.gov (United States)

    Hazarika, Ankita; Deka, Biplab K; Kim, DoYoung; Kong, Kyungil; Park, Young-Bin; Park, Hyung Wook

    2017-01-11

    We synthesized Ag nanoparticle-decorated multilayered graphene nanosheets (Ag-graphene) from graphite nanoplatelets and silver nitrate through 90-100 s of microwave exposure, without the use of any mineral acids or harsh reducing agents. Fe nanoparticle-decorated carbon nanotubes (Fe-CNTs) were grown on polypyrrole (PPy) deposited on woven Kevlar fibre (WKF), using ferrocene as a catalyst, under microwave irradiation. Fe-CNTs grown on WKF and Ag-graphene dispersed in polyester resin (PES) were combined to fabricate Ag-graphene/Fe-CNT/PPy-coated WKF/PES composites by vacuum-assisted resin transfer moulding. The combined effect of Fe-CNTs and Ag-graphene in the resulting composites resulted in a remarkable enhancement of tensile properties (a 192.56% increase in strength and 100.64% increase in modulus) as well as impact resistance (a 116.33% increase). The electrical conductivity significantly increased for Ag-graphene/Fe-CNT/PPy-coated WKF/PES composites. The effectiveness of electromagnetic interference shielding, which relies strongly on the Ag-graphene content in the composites, was 25 times higher in Ag-graphene/Fe-CNT/PPy-coated WKF/PES than in neat WKF/PES composites. The current work offers a novel route for fabricating highly promising, cost effective WKF/PES composites through microwave-assisted synthesis of Fe-CNTs and Ag-graphene.

  17. Microwave-synthesized freestanding iron-carbon nanotubes on polyester composites of woven Kevlar fibre and silver nanoparticle-decorated graphene

    Science.gov (United States)

    Hazarika, Ankita; Deka, Biplab K.; Kim, Doyoung; Kong, Kyungil; Park, Young-Bin; Park, Hyung Wook

    2017-01-01

    We synthesized Ag nanoparticle-decorated multilayered graphene nanosheets (Ag-graphene) from graphite nanoplatelets and silver nitrate through 90–100 s of microwave exposure, without the use of any mineral acids or harsh reducing agents. Fe nanoparticle-decorated carbon nanotubes (Fe-CNTs) were grown on polypyrrole (PPy) deposited on woven Kevlar fibre (WKF), using ferrocene as a catalyst, under microwave irradiation. Fe-CNTs grown on WKF and Ag-graphene dispersed in polyester resin (PES) were combined to fabricate Ag-graphene/Fe-CNT/PPy-coated WKF/PES composites by vacuum-assisted resin transfer moulding. The combined effect of Fe-CNTs and Ag-graphene in the resulting composites resulted in a remarkable enhancement of tensile properties (a 192.56% increase in strength and 100.64% increase in modulus) as well as impact resistance (a 116.33% increase). The electrical conductivity significantly increased for Ag-graphene/Fe-CNT/PPy-coated WKF/PES composites. The effectiveness of electromagnetic interference shielding, which relies strongly on the Ag-graphene content in the composites, was 25 times higher in Ag-graphene/Fe-CNT/PPy-coated WKF/PES than in neat WKF/PES composites. The current work offers a novel route for fabricating highly promising, cost effective WKF/PES composites through microwave-assisted synthesis of Fe-CNTs and Ag-graphene.

  18. Microwave-synthesized freestanding iron-carbon nanotubes on polyester composites of woven Kevlar fibre and silver nanoparticle-decorated graphene

    Science.gov (United States)

    Hazarika, Ankita; Deka, Biplab K.; Kim, DoYoung; Kong, Kyungil; Park, Young-Bin; Park, Hyung Wook

    2017-01-01

    We synthesized Ag nanoparticle-decorated multilayered graphene nanosheets (Ag-graphene) from graphite nanoplatelets and silver nitrate through 90–100 s of microwave exposure, without the use of any mineral acids or harsh reducing agents. Fe nanoparticle-decorated carbon nanotubes (Fe-CNTs) were grown on polypyrrole (PPy) deposited on woven Kevlar fibre (WKF), using ferrocene as a catalyst, under microwave irradiation. Fe-CNTs grown on WKF and Ag-graphene dispersed in polyester resin (PES) were combined to fabricate Ag-graphene/Fe-CNT/PPy-coated WKF/PES composites by vacuum-assisted resin transfer moulding. The combined effect of Fe-CNTs and Ag-graphene in the resulting composites resulted in a remarkable enhancement of tensile properties (a 192.56% increase in strength and 100.64% increase in modulus) as well as impact resistance (a 116.33% increase). The electrical conductivity significantly increased for Ag-graphene/Fe-CNT/PPy-coated WKF/PES composites. The effectiveness of electromagnetic interference shielding, which relies strongly on the Ag-graphene content in the composites, was 25 times higher in Ag-graphene/Fe-CNT/PPy-coated WKF/PES than in neat WKF/PES composites. The current work offers a novel route for fabricating highly promising, cost effective WKF/PES composites through microwave-assisted synthesis of Fe-CNTs and Ag-graphene. PMID:28074877

  19. Geometrical Modeling of Woven Fabrics Weavability-Limit New Relationships

    Directory of Open Access Journals (Sweden)

    Dalal Mohamed

    2017-03-01

    Full Text Available The weavability limit and tightness for 2D and 3D woven fabrics is an important factor and depends on many geometric parameters. Based on a comprehensive review of the literature on textile fabric construction and property, and related research on fabric geometry, a study of the weavability limit and tightness relationships of 2D and 3D woven fabrics was undertaken. Experiments were conducted on a representative number of polyester and cotton woven fabrics which have been woven in our workshop, using three machines endowed with different insertion systems (rapier, projectiles and air jet. Afterwards, these woven fabrics have been analyzed in the laboratory to determine their physical and mechanical characteristics using air permeability-meter and KES-F KAWABATA Evaluation System for Fabrics. In this study, the current Booten’s weavability limit and tightness relationships based on Ashenhurst’s, Peirce’s, Love’s, Russell’s, Galuszynskl’s theory and maximum-weavability is reviewed and modified as new relationships to expand their use to general cases (2D and 3D woven fabrics, all fiber materiel, all yarns etc…. The theoretical relationships were examined and found to agree with experimental results. It was concluded that the weavability limit and tightness relationships are useful tools for weavers in predicting whether a proposed fabric construction was weavable and also in predicting and explaining their physical and mechanical properties.

  20. Factors Influencing Anti-ultraviolet Performance of Undyed-woven Fabrics

    Institute of Scientific and Technical Information of China (English)

    ZHOU Rong; DING Xin

    2005-01-01

    Main factors influencing anti-ultraviolet performance of woven fabrics are investigated. By means of detailed arrangement of sample design, sample making, testing and analyzing, it shows that fiber materials, fabric compactness, fabric weave and yarn type are the four important factors influencing anti-UV performance of woven fabric, but with different effects. Among them fiber material is the most important factor. For the common fiber materials used, it shows that the anti-UV performance of polyester is comparatively better than others. Once fiber material is determined, fabric with medium float weave and high compactness can offer a good anti-UV performance.The anti-UV performance of fabric with "anti-UV" filament yarn is better than that with "anti-UV" staple yarn. The anti-UV property of fabrics with untwisted filament yarns is better than that with twist counterparts.

  1. Study of Performance of Hybrid yarns (Hemp/ Polypropylene/ Glass Woven Reinforcements

    Directory of Open Access Journals (Sweden)

    Maris Manins

    2015-06-01

    Full Text Available This study examines the performance of reinforcements of 100 tex hemp yarns and hybrid yarns reinforcements with same hemp yarns and glass fibres’ (136 Tex in warp direction (25 % or 50 % interwoven with hemp yarns. The industrial loom CTБ-175 and craftsman’s loom, plain weaving technique for production of reinforcements with surface density in range of 91-246 g/m2 were used in the production. Tensile strength of hemp reinforcement on warp direction is 241.7N-279.8N and tensile modulus 218.48MPa-271.24MPa.The measurement of fabric thickness and physical-mechanical properties of reinforcements were carried out according to ISO 5084:1996 and LVS EN ISO 13934-1-2001 standards. One and two layer composites of woven reinforcements of hemp and polypropylene yarns were produced with Laboratory Press LP_S_50/SASTM. The surface density of one layer composite is 311.2 g/m2 and 608.4 g/m2 of two layers composite. The tensile strength of same composites is 303.1N and 599.5N, the tensile stress is 35.66 MPa and 40.65 MPa. The elastic modulus of one layer composites is 908.2 MPa and 1152.5MPa for two layers composite. The mechanical properties of composites were established according to ISO 527-5:2009 standard.

  2. Mechanical Characterization of CFRP Woven Laminates between Room Temperature and 4K

    Science.gov (United States)

    Kumagai, Susumu; Shindo, Yasuhide; Horiguchi, Katsumi; Takeda, Tomo

    In order to evaluate the mechanical properties of T800H/3633 CFRP woven laminates for cryogenic tankage in RLV, tensile and in-plane shear tests were performed at room temperature, liquid nitrogen temperature (77K) and liquid helium temperature (4K). The tensile tests were conducted in accordance with ASTM D 3039 and JIS K 7073. Tensile strength and modulus were evaluated for both the warp and fill directions. A problem was encountered with obtaining acceptable failure of the specimens. We could not achieve failure in the test section. This problem was avoided by using dogbone shaped specimens. A two-dimensional finite element analysis was also used to study the stress distributions within the specimens and to interpret the experimental measurements. The in-plane shear modulus and shear strength were measured by tensile tests on the ±45° specimens (ASTM D 3518 and JIS K 7079). The effects of temperature on the stress-strain responses in tension and in-plane shear are examined. Fracture topography of specimens is also investigated and interpreted.

  3. Micro-mechanics based damage mechanics for 3D Orthogonal Woven Composites: Experiment and Numerical Modelling

    KAUST Repository

    Saleh, Mohamed Nasr

    2016-01-08

    Damage initiation and evolution of three-dimensional (3D) orthogonal woven carbon fibre composite (3DOWC) is investigated experimentally and numerically. Meso-scale homogenisation of the representative volume element (RVE) is utilised to predict the elastic properties, simulate damage initiation and evolution when loaded in tension. The effect of intra-yarns transverse cracking and shear diffused damage on the in-plane transverse modulus and shear modulus is investigated while one failure criterion is introduced to simulate the matrix damage. The proposed model is based on two major assumptions. First, the effect of the binder yarns, on the in-plane properties, is neglected, so the 3DOWC unit cell can be approximated as a (0o/90o) cross-ply laminate. Second, a micro-mechanics based damage approach is used at the meso-scale, so damage indicators can be correlated, explicitly, to the density of cracks within the material. Results from the simulated RVE are validated against experimental results along the warp (0o direction) and weft (90o direction). This approach paves the road for more predictive models as damage evolution laws are obtained from micro mechanical considerations and rely on few well-defined material parameters. This largely differs from classical damage mechanics approaches in which the evolution law is obtained by retrofitting experimental observations.

  4. Characterising the loading direction sensitivity of 3D woven composites: Effect of z-binder architecture

    KAUST Repository

    Saleh, Mohamed Nasr

    2016-08-29

    Three different architectures of 3D carbon fibre woven composites (orthogonal, ORT; layer-to-layer, LTL; angle interlock, AI) were tested in quasi-static uniaxial tension. Mechanical tests (tensile in on-axis of warp and weft directions as well as 45 degrees off-axis) were carried out with the aim to study the loading direction sensitivity of these 3D woven composites. The z-binder architecture (the through-thickness reinforcement) has an effect on void content, directional fibre volume fraction, mechanical properties (on-axis and off-axis), failure mechanisms, energy absorption and fibre rotation angle in off-axis tested specimens. Out of all the examined architectures, 3D orthogonal woven composites (ORT) demonstrated a superior behaviour, especially when they were tested in 45 degrees off-axis direction, indicated by high strain to failure (similar to 23%) and high translaminar energy absorption (similar to 40 MJ/m(3)). The z-binder yarns in ORT architecture suppress the localised damage and allow larger fibre rotation during the fibre

  5. Tactile Sensing System Based on Arrays of Graphene Woven Microfabrics: Electromechanical Behavior and Electronic Skin Application.

    Science.gov (United States)

    Yang, Tingting; Wang, Wen; Zhang, Hongze; Li, Xinming; Shi, Jidong; He, Yijia; Zheng, Quan-shui; Li, Zhihong; Zhu, Hongwei

    2015-11-24

    Nanomaterials serve as promising candidates for strain sensing due to unique electromechanical properties by appropriately assembling and tailoring their configurations. Through the crisscross interlacing of graphene microribbons in an over-and-under fashion, the obtained graphene woven fabric (GWF) indicates a good trade-off between sensitivity and stretchability compared with those in previous studies. In this work, the function of woven fabrics for highly sensitive strain sensing is investigated, although network configuration is always a strategy to retain resistance stability. The experimental and simulation results indicate that the ultrahigh mechanosensitivity with gauge factors of 500 under 2% strain is attributed to the macro-woven-fabric geometrical conformation of graphene, which induces a large interfacial resistance between the interlaced ribbons and the formation of microscale-controllable, locally oriented zigzag cracks near the crossover location, both of which have a synergistic effect on improving sensitivity. Meanwhile, the stretchability of the GWF could be tailored to as high as over 40% strain by adjusting graphene growth parameters and adopting oblique angle direction stretching simultaneously. We also demonstrate that sensors based on GWFs are applicable to human motion detection, sound signal acquisition, and spatially resolved monitoring of external stress distribution.

  6. Fabrication of Biomedical Titanium Alloys with High Strength and Low Modulus by Means of Powder Metallurgy%粉末冶金法合成高强低模超细晶医用钛合金

    Institute of Scientific and Technical Information of China (English)

    李元元; 邹黎明; 杨超

    2012-01-01

    为探寻有效的高强低模医用钛合金制备方法,采用机械合金化方法制备了不同Fe含量的(Ti69.7Nb23.7Zr4.9Ta1.7)100-xFex非晶/纳米晶合金粉末,随后采用放电等离子烧结-非晶晶化法得到了高强低模的超细晶钛基复合材料.结果表明:(1)机械合金化过程中,Fe含量对合金的非晶形成能力影响显著,文中实验条件下,只有当x增大至10时才能形成全非晶相的非晶粉末;(2)Fe含量也明显影响合成的块体钛合金的力学性能,合成的不同Fe含量合金中,只有(Ti69.7Nb23.7Zr4.9Ta1.7)94 Fe6合金具有高强度和显著塑性,其压缩屈服强度为2425 MPa,断裂强度为2650 MPa,断裂应变为0.0691,平均弹性模量仅为52 GPa,接近第三代生物医用钛合金的最低值.将所合成的超细晶钛合金与常用的两种生物钛合金(Ti-6Al-4V和Ti-13Nb-13Zr)进行抗摩擦磨损性能对比,发现所合成的钛合金具有最佳的耐磨性.%In order to explore an effective method to fabricate biomedical Ti alloy with high strength and low modulus, amorphous/nanocrystallized (Ti69.7Nb23.7Zr4.9Ta1.7) 100_x.Fe;c alloy powders with different Fe contents were synthesized via mechanical alloying, and, subsequently, ultrafine-grained Ti-based composites with high strength and low modulus were fabricated via the spark plasma sintering-amorphous crystallization. The results show that, during the performed mechanical alloying, Fe content significantly affects the glass-forming ability of the alloy system, concretely, fully amorphous structure forms only when x reaches 10; and that Fe content also has an obvious effect on the mechanical properties of the bulk composites, only the bulk composite at a x value of 6 possesses high strength and distinct plasticity, with the corresponding compressive yield stress, fracture stress and fracture strain respectively being 2425 MPa, 2650 MPa and 0. 069 1, and with an average elastic modulus of 52 GPa that is close to the minimum

  7. Structural Design and Mechanical Analysis of Full-Depth High Modulus Asphalt Concrete Pavement%全厚式高模量沥青混凝土路面结构设计及力学分析

    Institute of Scientific and Technical Information of China (English)

    李涛; 刘宁; 张涛

    2013-01-01

    The pavement special program PADS is used to calculate the three kinds of asphalt concrete pavement structure thickness which are full-depth high modulus, full-depth ordinary and semi-rigid base asphalt concrete pavement, respectively. The 3-D element model of asphalt concrete pavement structure is built based on the elastic mechanics to evaluate the design bottom stress state under loads. The rutting of the three kinds of pavement is determined by using asphalt concrete pavement permanent deformation prediction method in MEPDG of the United States. Also, their fatigue life is calculated. The results show that the full-depth high modulus asphalt concrete pavement structure is able to effectively decrease the thickness of the pavement structure, at the same time exhibits the best overall performance in rutting resistance and fatigue properties.%利用路面专用程序PADS计算全厚式高模量、全厚式普通和半刚性基层3种沥青混凝土路面结构厚度;根据弹性层状理论体系,建立了上述3种沥青混凝土路面结构三维有限元模型,对路面结构在荷载作用下的设计层层底应力状态进行对比分析;应用美国MEPDG推荐的沥青混凝土路面永久变形预估方法对沥青混凝土路面结构进行车辙预估,并对其疲劳寿命进行了计算.结果表明,全厚式高模量沥青混凝土路面结构能够有效减薄路面结构厚度,是抗车辙性能及疲劳性能综合最优的路面结构类型.

  8. Using non-woven polypropylene covers in potato production: a review

    Directory of Open Access Journals (Sweden)

    Wanda Wadas

    2016-09-01

    Full Text Available This paper analyzes the effect of non-woven polypropylene covers on plant growth and development, frost protection, tuber yield and quality and the economic effectiveness in early potato production. A high income from early potato production is possible under conditions assuring early setting and rapid gain of tuber yield and its marketing when the price is highest. The application of non-woven polypropylene covers accelerates plant emergence by 28 days and the growth and development of plants in the later period, and results in an earlier new potato harvest by up to 2-3 weeks. It also increases the tuber yield and reduces the yield variability in all years. Accelerating plant growth using non-woven polypropylene covers affects not only tuber yield quantity, but also contributes to improvement of the tuber quality, especially by an increase in dry matter, potassium and phosphorus content of tubers and decrease nitrate concentration. Such a method of potato production requires higher incurred input. Increasing the production inputs is effective when the value of the tuber yield increase obtained as a result of plant covering is higher than the costs incurred. A higher productive effect of covering is usually obtained in years with a cold spring and a very early potato harvest date. A considerable tuber yield increase in cultivation under non-woven polypropylene cover results in decreased unit costs and, consequently, the cost-effectiveness of production is higher than without covering. In conditions favouring rapid potato growth, the production costs of 1 kg tuber under cover are higher, which makes production less profitable than cultivation without plant covering.

  9. Modulus-Pressure Equation for Confined Fluids

    CERN Document Server

    Gor, Gennady Y; Shen, Vincent K; Bernstein, Noam

    2016-01-01

    Ultrasonic experiments allow one to measure the elastic modulus of bulk solid or fluid samples. Recently such experiments have been carried out on fluid-saturated nanoporous glass to probe the modulus of a confined fluid. In our previous work [J. Chem. Phys., (2015) 143, 194506], using Monte Carlo simulations we showed that the elastic modulus $K$ of a fluid confined in a mesopore is a function of the pore size. Here we focus on modulus-pressure dependence $K(P)$, which is linear for bulk materials, a relation known as the Tait-Murnaghan equation. Using transition-matrix Monte Carlo simulations we calculated the elastic modulus of bulk argon as a function of pressure and argon confined in silica mesopores as a function of Laplace pressure. Our calculations show that while the elastic modulus is strongly affected by confinement and temperature, the slope of the modulus versus pressure is not. Moreover, the calculated slope is in a good agreement with the reference data for bulk argon and experimental data for ...

  10. Multifunctional non-woven fabrics of interfused graphene fibres.

    Science.gov (United States)

    Li, Zheng; Xu, Zhen; Liu, Yingjun; Wang, Ran; Gao, Chao

    2016-11-30

    Carbon-based fibres hold promise for preparing multifunctional fabrics with electrical conductivity, thermal conductivity, permeability, flexibility and lightweight. However, these fabrics are of limited performance mainly because of the weak interaction between fibres. Here we report non-woven graphene fibre fabrics composed of randomly oriented and interfused graphene fibres with strong interfibre bonding. The all-graphene fabrics obtained through a wet-fusing assembly approach are porous and lightweight, showing high in-plane electrical conductivity up to ∼2.8 × 10(4 )S m(-1) and prominent thermal conductivity of ∼301.5 W m(-1 )K(-1). Given the low density (0.22 g cm(-3)), their specific electrical and thermal conductivities set new records for carbon-based papers/fabrics and even surpass those of individual graphene fibres. The as-prepared fabrics are further used as ultrafast responding electrothermal heaters and durable oil-adsorbing felts, demonstrating their great potential as high-performance and multifunctional fabrics in real-world applications.

  11. Comparative Study of 3-Dimensional Woven Joint Architectures for Composite Spacecraft Structures

    Science.gov (United States)

    Jones, Justin S.; Polis, Daniel L.; Rowles, Russell R.; Segal, Kenneth N.

    2011-01-01

    The National Aeronautics and Space Administration (NASA) Exploration Systems Mission Directorate initiated an Advanced Composite Technology (ACT) Project through the Exploration Technology Development Program in order to support the polymer composite needs for future heavy lift launch architectures. As an example, the large composite structural applications on Ares V inspired the evaluation of advanced joining technologies, specifically 3D woven composite joints, which could be applied to segmented barrel structures needed for autoclave cured barrel segments due to autoclave size constraints. Implementation of these 3D woven joint technologies may offer enhancements in damage tolerance without sacrificing weight. However, baseline mechanical performance data is needed to properly analyze the joint stresses and subsequently design/down-select a preform architecture. Six different configurations were designed and prepared for this study; each consisting of a different combination of warp/fill fiber volume ratio and preform interlocking method (Z-fiber, fully interlocked, or hybrid). Tensile testing was performed for this study with the enhancement of a dual camera Digital Image Correlation (DIC) system which provides the capability to measure full-field strains and three dimensional displacements of objects under load. As expected, the ratio of warp/fill fiber has a direct influence on strength and modulus, with higher values measured in the direction of higher fiber volume bias. When comparing the Z-fiber weave to a fully interlocked weave with comparable fiber bias, the Z-fiber weave demonstrated the best performance in two different comparisons. We report the measured tensile strengths and moduli for test coupons from the 6 different weave configurations under study.

  12. Flexural modulus identification of thin polymer sheets

    Science.gov (United States)

    Gluhihs, S.; Kovalovs, A.; Tishkunovs, A.; Chate, A.

    2011-06-01

    The method of determination of the flexural Young's modulus is based on a solution to the problem of compression of a thin-walled cylindrical specimen by two parallel planes (TWCS method). This method was employed to calculate the flexural modulus for PET polymer compositions. The flexural modules received by TWCS method were verified by comparing the experimentally measured eigenfrequencies by Polytec vibrometer with numerical results from ANSYS program.

  13. Flexural modulus identification of thin polymer sheets

    Energy Technology Data Exchange (ETDEWEB)

    Gluhihs, S; Kovalovs, A; Tishkunovs, A; Chate, A, E-mail: s_gluhih@inbox.lv [Riga Technical University, Institute of Materials and Structures, Azenes 16/22, LV-1048, Riga (Latvia)

    2011-06-23

    The method of determination of the flexural Young's modulus is based on a solution to the problem of compression of a thin-walled cylindrical specimen by two parallel planes (TWCS method). This method was employed to calculate the flexural modulus for PET polymer compositions. The flexural modules received by TWCS method were verified by comparing the experimentally measured eigenfrequencies by Polytec vibrometer with numerical results from ANSYS program.

  14. Comparative Studies on the Mechanical Properties of Nonwoven- and Woven-Flax-Fiber-Reinforced Poly(Butylene Adipate-Co-Terephthalate)-Based Composite Laminates

    Science.gov (United States)

    Phongam, N.; Dangtungee, R.; Siengchin, S.

    2015-03-01

    Textile biocomposites made from woven- and nonwoven-flax-fiber-reinforced poly(butylene adipate-co-terephthalate) (PBAT) were prepared by compression molding using the film stacking method, and their tensile strength and stiffness, flexural strength and modulus, and impact strength were determined experimentally. The PBAT-based composites were subjected to water absorption tests. The mechanical properties of pure PBAT and the textile composites were compared, and the influence of flax weave styles on the properties were evaluated. The biocomposite reinforced with 4 × 4-plain weave fibers showed the highest strength and stiffness compared with those of the other textile biocomposites and pure PBAT.

  15. ABSORBENCY CHARACTERISTICS OF PESHTAMALS: TRADITIONAL TURKISH WOVEN CLOTHES

    Directory of Open Access Journals (Sweden)

    KESKIN Reyhan

    2014-05-01

    Full Text Available Absorbency of textiles is defined as the ability of taking in a fluid in the manner of a sponge. Absorbency is required for comfort properties in so me clothes such as sportswear and underwear clothing, for drying properties in napkins, towels and bathrobes, for health concerns in some medical textiles such as bandages, gauze and absorbent cotton, and for cleaning properties in washclothes and mops. In this study five different fabric samples (three woven 100% cotton fabrics A, B and P respectively at plain, twill, and peshtamal weaving patterns and two 100% cotton terry towels T1 and T2 were tested. The absorbency properties of the samples were evaluated according to the droplet test, sinking time test and wicking height tests (pottasium chromate test. Peshtamal samples showed better absorbency results than plain and twill weaves and lower but close results to towel samples according to the droplet test, sinking time test and wicking height tests. The absorbency properties of peshtamals showed results close to towel samples. The void content of peshtamals is higher than plain and twill samples but closer and lower than towel samples. The good absorbency results of peshtamals might be due to the void content of peshtamals which is higher than plain and twill samples but closer and lower than towel samples. Peshtamals which are good in absorbency and light in weight might be used widespreadly in daily life for their high absorbency, and on travel for weight saving purposes.

  16. Modeling the Stress Strain Behavior of Woven Ceramic Matrix Composites

    Science.gov (United States)

    Morscher, Gregory N.

    2006-01-01

    Woven SiC fiber reinforced SiC matrix composites represent one of the most mature composite systems to date. Future components fabricated out of these woven ceramic matrix composites are expected to vary in shape, curvature, architecture, and thickness. The design of future components using woven ceramic matrix composites necessitates a modeling approach that can account for these variations which are physically controlled by local constituent contents and architecture. Research over the years supported primarily by NASA Glenn Research Center has led to the development of simple mechanistic-based models that can describe the entire stress-strain curve for composite systems fabricated with chemical vapor infiltrated matrices and melt-infiltrated matrices for a wide range of constituent content and architecture. Several examples will be presented that demonstrate the approach to modeling which incorporates a thorough understanding of the stress-dependent matrix cracking properties of the composite system.

  17. Interlaminar fracture in woven carbon/epoxy laminates

    Directory of Open Access Journals (Sweden)

    Paulo N.B. Reis

    2014-10-01

    Full Text Available This paper describes an experimental study developed to characterize the mode I and mode II fracture toughness of carbon/epoxy woven composites, using DCB and ENF tests, respectively. The laminates were manufactured using an epoxy resin and twelve woven balanced bi-directional layers of carbon fibres, all of them with the same orientation (0/90º. Significant instantaneous delaminations were observed particularly for the DCB specimen, which were responsible for an oscillatory behaviour of GI versus crack length. The maximum values obtained for GIC and GIIC were 281 and 1800 J/m2, respectively.

  18. Woven coronary artery: a case report and review of literature.

    Science.gov (United States)

    Kursaklioglu, Hurkan; Iyisoy, Atila; Celik, Turgay

    2006-10-26

    Woven coronary artery is an extremely rare and clearly undefined coronary malformation. Up to now, very few cases have been reported. In this anomaly, epicardial coronary artery are branched into thin channels at any segment of the coronary artery and then these longitudinal twisted thin channels merge again as the main coronary lumen. This anomaly is regarded as a benign condition since there is completely normal blood flow after the distal segment of the abnormal coronary artery. In this case report, we present a 48-year-old male patient with a woven coronary artery anomaly in the circumflex artery and who had been followed up for 5 years.

  19. Determination of Modulus of Elasticity and Shear Modulus by the Measurement of Relative Strains

    Science.gov (United States)

    Labašová, Eva

    2016-12-01

    This contribution is focused on determining the material properties (Young modulus and shear modulus) of the testing samples. The theoretical basis for determining material properties are the knowledge of linear elasticity and strength. The starting points are dependencies among the modulus of elasticity, shear modulus, normal stress and relative strain. The relative strains of the testing samples were obtained by measuring predefined load conditions using a strain-gauge bridge and the universal measurement system Quantum X MX 840. The integration of these tasks into the teaching process enhances practical and intellectual skills of students at secondary level technical universities.

  20. Comparative study on the mechanical properties of banana and sisal woven rovings polyester composites

    Directory of Open Access Journals (Sweden)

    A. Faizur Rahman

    2014-03-01

    Full Text Available Natural fiber polymer composites are widely used in many applications. Banana and sisal woven rovings reinforced polyester composites were manufactured by hand lay-up technique. The woven rovings were modified chemically by alkali treatment to enhance the mechanical properties. Tensile strength, flexural strength and impact strength were evaluated for 5%, 10%, 15% and 20% volume fractions of both woven rovings. The results of banana and sisal woven rovings composites were compared and it indicated that sisal woven rovings with higher volume fractions reveals better mechanical strength.

  1. Impact Damage of 3D Orthogonal Woven Composite Circular Plates

    Science.gov (United States)

    Ji, Changgan; Sun, Baozhong; Qiu, Yiping; Gu, Bohong

    2007-11-01

    The damages of 3D orthogonal woven composite circular plate under quasi-static indentation and transverse impact were tested with Materials Test System (MTS) and modified split Hopkinson bar (SHPB) apparatus. The load vs. displacement curves during quasi-static penetration and impact were obtained to study the energy absorption of the composite plate. The fluctuation of the impact stress waves has been unveiled. Differences of the load-displacement curves between the quasi-static and impact loading are discussed. This work also aims at establishing a unit-cell model to analyze the damage of composites. A user material subroutine which named VUMAT for characterizing the constitutive relationship of the 3-D orthogonal woven composite and the damage evolution is incorporated with a finite element code ABAQUS/Explicit to simulate the impact damage process of the composite plates. From the comparison of the load-displacement curves and energy absorption curves of the composite plate between experimental and FEM simulation, it is shown that the unit-cell model of the 3D woven composite and the VUMAT combined with the ABAQUS/Explicit can calculate the impact responses of the circular plate precisely. Furthermore, the model can also be extended to simulate the impact behavior of the 3D woven composite structures.

  2. 75 FR 11557 - Woven Electric Blankets From China

    Science.gov (United States)

    2010-03-11

    ... permitted by section 201.8 of the Commission's rules, as amended, 67 FR 68036 (November 8, 2002). Even where... specified in II (C) of the Commission's Handbook on Electronic Filing Procedures, 67 FR 68168, 68173... COMMISSION Woven Electric Blankets From China AGENCY: United States International Trade Commission....

  3. On sound absorption and thermal properties of non-wovens

    OpenAIRE

    Chen Jin-Jing; Yu Hong-Qin; Guo Zheng; You Jin-Zhang; Song Wen-Fang

    2015-01-01

    Non-woven is widely used as auxiliary materials of automobile industry due to its excellent sound absorption capability and good thermal property. The paper concludes that its density greatly affects sound absorption and thermal resistance, and an aluminum evaporated film can enhance the thermal resistance.

  4. On sound absorption and thermal properties of non-wovens

    Directory of Open Access Journals (Sweden)

    Chen Jin-Jing

    2015-01-01

    Full Text Available Non-woven is widely used as auxiliary materials of automobile industry due to its excellent sound absorption capability and good thermal property. The paper concludes that its density greatly affects sound absorption and thermal resistance, and an aluminum evaporated film can enhance the thermal resistance.

  5. Woven TPS Enabling Missions Beyond Heritage Carbon Phenolic

    Science.gov (United States)

    Stackpoole, Margaret M.; Venkatapathy, Ethiraj; Feldman, Jay D.

    2013-01-01

    NASAs Office of the Chief Technologist (OCT) Game Changing Division recently funded an effort to advance a Woven TPS (WTPS) concept. WTPS is a new approach to producing TPS architectures that uses precisely engineered 3D weaving techniques to customize material characteristics needed to meet specific missions requirements for protecting space vehicles from the intense heating generated during atmospheric entry. Using WTPS, sustainable, scalable, mission-optimized TPS solutions can be achieved with relatively low life cycle costs compared with the high costs and long development schedules currently associated with material development and certification. WTPS leverages the mature state-of-the-art weaving technology that has evolved from the textile industry to design TPS materials with tailorable performance. Currently, missions anticipated encountering heat fluxes in the range of 1500 4000 Wcm2 and pressures greater than 1.5 atm are limited to using fully dense Carbon Phenolic. However, fully dense carbon phenolic is only mass efficient at higher heat fluxes g(reater than 4000 Wcm2), and current mission designs suffer this mass inefficiency for lack of an alternative mid-density TPS. WTPS not only bridges this mid-density TPS gap but also offers a replacement for carbon phenolic, which itself requires a significant and costly redevelopment effort to re-establish its capability for use in the high heat flux missions recently prioritized in the NRC Decadal survey, including probe missions to Venus, Saturn and Neptune. This presentation will overview the WTPS concept and present some results from initial testing completed comparing WTPS architectures to heritage carbon phenolic.

  6. Revisiting Fermat's Factorization for the RSA Modulus

    CERN Document Server

    Gupta, Sounak

    2009-01-01

    We revisit Fermat's factorization method for a positive integer $n$ that is a product of two primes $p$ and $q$. Such an integer is used as the modulus for both encryption and decryption operations of an RSA cryptosystem. The security of RSA relies on the hardness of factoring this modulus. As a consequence of our analysis, two variants of Fermat's approach emerge. We also present a comparison between the two methods' effective regions. Though our study does not yield a new state-of-the-art algorithm for integer factorization, we believe that it reveals some interesting observations that are open for further analysis.

  7. Dual-skinned polyamide/poly(vinylidene fluoride)/cellulose acetate membranes with embedded woven

    KAUST Repository

    Duong, Phuoc H.H.

    2016-08-31

    We propose multilayer membranes including (i) a thin selective polyamide (PA) layer prepared via interfacial polymerization, (ii) a poly (vinylidene fluoride) (PVDF) asymmetric porous support with high adhesion to the PA layer and high mechanical strength, (iii) a strong woven fabric, and (iv) fouling resistant porous cellulose acetate (CA) layer. The PA layer rejects solutes of the draw solution. The PVDF/woven fabric/CA (PVDF/CA) integrated layer performs as a mechanical support with unique properties for forward osmosis (FO) applications. It consists of a modified PVDF top layer suitable for the deposition of a PA layer and a highly hydrophilic bottom layer (CA) with a tunable pore size to minimize foulant deposition and intrusion onto and into the support. The experimental results using bovine serum albumin (BSA) as a model foulant show that the presence of the CA layer at the bottom of the FO membrane (PA/PVDF/CA) reduces 75% fouling propensity compared to the simple FO membrane made of PVDF, woven fabric and PA (PA/PVDF). Fouling tests with 2000 ppm oily feed faced the bottom of the FO membranes further indicate the superiority of the PA/PVDF/CA membrane compared to the PA/PVDF membrane. Moreover, the bottom CA layer can be adjusted with a flexible range of pore size, varied from sub-micron to sub-nanometer depending on the feed composition. The newly developed multilayer FO membrane has comparable performance to the state-of-the-art membrane with added tailored fouling resistance for specific wastewater feeds.

  8. Multigene Genetic Programming for Estimation of Elastic Modulus of Concrete

    Directory of Open Access Journals (Sweden)

    Alireza Mohammadi Bayazidi

    2014-01-01

    Full Text Available This paper presents a new multigene genetic programming (MGGP approach for estimation of elastic modulus of concrete. The MGGP technique models the elastic modulus behavior by integrating the capabilities of standard genetic programming and classical regression. The main aim is to derive precise relationships between the tangent elastic moduli of normal and high strength concrete and the corresponding compressive strength values. Another important contribution of this study is to develop a generalized prediction model for the elastic moduli of both normal and high strength concrete. Numerous concrete compressive strength test results are obtained from the literature to develop the models. A comprehensive comparative study is conducted to verify the performance of the models. The proposed models perform superior to the existing traditional models, as well as those derived using other powerful soft computing tools.

  9. 75 FR 53632 - Narrow Woven Ribbons With Woven Selvedge From Taiwan and the People's Republic of China...

    Science.gov (United States)

    2010-09-01

    ...-made fibers (whether artificial or synthetic, including but not limited to nylon, polyester, rayon...[eacute], fringes, embroidery, buttons, glitter, sequins, laminates, and/or adhesive backing; Have wire... or without wire running lengthwise along the longitudinal edges of the ribbon; (8) Narrow woven...

  10. Damage Tolerance Testing of a NASA TransHab Derivative Woven Inflatable Module

    Science.gov (United States)

    Edgecombe, John; delaFuente, Horacio; Valle, Gerard

    2009-01-01

    Current options for Lunar habitat architecture include inflatable habitats and airlocks. Inflatable structures can have mass and volume advantages over conventional structures. However, inflatable structures carry different inherent risks and are at a lower Technical Readiness Level (TRL) than more conventional metallic structures. One of the risks associated with inflatable structures is in understanding the tolerance to induced damage. The Damage Tolerance Test (DTT) is designed to study the structural integrity of an expandable structure. TransHab (Figure 1) was an experimental inflatable module developed at the NASA/Johnson Space Center in the 1990 s. The TransHab design was originally envisioned for use in Mars Transits but was also studied as a potential habitat for the International Space Station (ISS). The design of the TransHab module was based on a woven design using an Aramid fabric. Testing of this design demonstrated a high level of predictability and repeatability with analytical predictions of stresses and deflections. Based on JSC s experience with the design and analysis of woven inflatable structures, the Damage Tolerance Test article was designed and fabricated using a woven design. The DTT article was inflated to 45 psig, representing 25% of the ultimate burst pressure, and one of the one-inch wide longitudinal structural members was severed by initiating a Linear Shaped Charge (LSC). Strain gage measurements, at the interface between the expandable elements (straps) and the nonexpandable metallic elements for pre-selected longitudinal straps, were taken throughout pressurization of the module and strap separation. Strain gage measurements show no change in longitudinal strap loading at the bulkhead interface after strap separation indicating loads in the restraint layer were re-distributed local to the damaged area due to the effects of friction under high internal pressure loading. The test completed all primary objectives with better than

  11. Experimental and Theoretical Study of Young Modulus in Micromachined Polysilicon Films

    Institute of Scientific and Technical Information of China (English)

    丁建宁; 孟永钢; 温诗铸

    2002-01-01

    The elastic modulus is a very important mechanical property in micromachined structures. Several design issues such as resonant frequencies and stiffness in the micromachined structures are related to the elastic modulus. In addition, the accuracy of results from finite element models is highly dependent upon the elastic modulus. In this study, the Young modulus of micromachined thin polysilicon films has been investigated with a new tensile test machine using a magnetic-solenoid force actuator with linear response, low hysteresis, no friction and direct electrical control. The tensile test results show that the measured average value of Young modulus for a typical sample, (164±1.2) GPa, falls within the theoretical bounds of the texture model. These results will provide more reliable design of polysilicon microelectromechanical systems (MEMS).

  12. Resilient modulus characteristics of soil subgrade with geopolymer additive in peat

    Science.gov (United States)

    Zain, Nasuhi; Hadiwardoyo, Sigit Pranowo; Rahayu, Wiwik

    2017-06-01

    Resilient modulus characteristics of peat soil are generally very low with high potential of deformation and low bearing capacity. The efforts to improve the peat subgrade resilient modulus characteristics is required, one among them is by adding the geopolymer additive. Geopolymer was made as an alternative to replace portland cement binder in the concrete mix in order to promote environmentally friendly, low shrinkage value, low creep value, and fire resistant material. The use of geopolymer to improve the mechanical properties of peat as a road construction subgrade, hence it becomes important to identify the effect of geopolymer addition on the resilient modulus characteristics of peat soil. This study investigated the addition of 0% - 20% geopolymer content on peat soil derived from Ogan Komering Ilir, South Sumatera Province. Resilient modulus measurement was performed by using cyclic triaxial test to determine the resilience modulus model as a function of deviator stresses and radial stresses. The test results showed that an increase in radial stresses did not necessarily lead to an increase in modulus resilient, and on the contrary, an increase in deviator stresses led to a decrease in modulus resilient. The addition of geopolymer in peat soil provided an insignificant effect on the increase of resilient modulus value.

  13. Investigation of Effects of Material Architecture on the Elastic Response of a Woven Ceramic Matrix Composite

    Science.gov (United States)

    Goldberg, Robert K.; Bonacuse, Peter J.; Mital, Subodh K.

    2012-01-01

    To develop methods for quantifying the effects of the microstructural variations of woven ceramic matrix composites on the effective properties and response of the material, a research program has been undertaken which is described in this paper. In order to characterize and quantify the variations in the microstructure of a five harness satin weave, CVI SiC/SiC, composite material, specimens were serially sectioned and polished to capture images that detailed the fiber tows, matrix, and porosity. Open source quantitative image analysis tools were then used to isolate the constituents and collect relevant statistics such as within ply tow spacing. This information was then used to build two dimensional finite element models that approximated the observed section geometry. With the aid of geometrical models generated by the microstructural characterization process, finite element models were generated and analyses were performed to quantify the effects of the microstructure and its variation on the effective stiffness and areas of stress concentration of the material. The results indicated that the geometry and distribution of the porosity appear to have significant effects on the through-thickness modulus. Similarly, stress concentrations on the outer surface of the composite appear to correlate to regions where the transverse tows are separated by a critical amount.

  14. Studies on the flexural and thermomechanical properties of woven carbon/nanoclay-epoxy laminates

    Energy Technology Data Exchange (ETDEWEB)

    Chowdhury, F.H. [Center for Advanced Materials, Tuskegee University, Tuskegee, AL 36088 (United States); Hosur, M.V. [Center for Advanced Materials, Tuskegee University, Tuskegee, AL 36088 (United States)]. E-mail: mhosur@gmail.com; Jeelani, S. [Center for Advanced Materials, Tuskegee University, Tuskegee, AL 36088 (United States)

    2006-04-15

    A systematic study was carried out to investigate the effects of nanoclay particles on flexural and thermal properties of woven carbon fiber reinforced polymer matrix composites. Different weight percentages of Nanomer[reg] I-28E nanoclay, a surface modified montmorillonite mineral, were dispersed in SC-15 epoxy using sonication route. The nanophased epoxy was then used to manufacture 6000 fiber tow-plain weave carbon/epoxy nanocomposites using vacuum assisted resin infusion molding (VARIM) process. Effect of post curing on these samples was also investigated. Three-point bend flexure and dynamic mechanical analysis (DMA) studies were carried out on eight and three layered samples, respectively. Maximum improvements in flexural strength and modulus were found for 2 wt.% nanoclay reinforced composites. Failure surface analysis of flexure samples was carried out by scanning electron microscopy (SEM) analysis. Dynamic mechanical analysis showed enhancement in thermomechanical properties. Glass transition temperature, T {sub g} of room temperature cured and thermally post cured samples showed an improvement of about 9 and 13 deg. C, respectively for 2 wt.% nanoclay loading.

  15. Plasma penetration depth and mechanical properties of atmospheric plasma-treated 3D aramid woven composites

    Energy Technology Data Exchange (ETDEWEB)

    Chen, X.; Yao, L.; Xue, J.; Zhao, D.; Lan, Y.; Qian, X. [Key Laboratory of Textile Science and Technology, Donghua University, Ministry of Education (China); Department of Textile Materials Science and Product Design, College of Textiles, Donghua University, Shanghai 201620 (China); Wang, C.X. [Key Laboratory of Textile Science and Technology, Donghua University, Ministry of Education (China); Department of Textile Materials Science and Product Design, College of Textiles, Donghua University, Shanghai 201620 (China); College of Textiles and Clothing, Yancheng Institute of Technology, Jiangsu 224003 (China); Qiu, Y. [Key Laboratory of Textile Science and Technology, Donghua University, Ministry of Education (China); Department of Textile Materials Science and Product Design, College of Textiles, Donghua University, Shanghai 201620 (China)], E-mail: ypqiu@dhu.edu.cn

    2008-12-30

    Three-dimensional aramid woven fabrics were treated with atmospheric pressure plasmas, on one side or both sides to determine the plasma penetration depth in the 3D fabrics and the influences on final composite mechanical properties. The properties of the fibers from different layers of the single side treated fabrics, including surface morphology, chemical composition, wettability and adhesion properties were investigated using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), contact angle measurement and microbond tests. Meanwhile, flexural properties of the composites reinforced with the fabrics untreated and treated on both sides were compared using three-point bending tests. The results showed that the fibers from the outer most surface layer of the fabric had a significant improvement in their surface roughness, chemical bonding, wettability and adhesion properties after plasma treatment; the treatment effect gradually diminished for the fibers in the inner layers. In the third layer, the fiber properties remained approximately the same to those of the control. In addition, three-point bending tests indicated that the 3D aramid composite had an increase of 11% in flexural strength and 12% in flexural modulus after the plasma treatment. These results indicate that composite mechanical properties can be improved by the direct fabric treatment instead of fiber treatment with plasmas if the fabric is less than four layers thick.

  16. Structural relaxation monitored by instantaneous shear modulus

    DEFF Research Database (Denmark)

    Olsen, Niels Boye; Dyre, Jeppe; Christensen, Tage Emil

    1998-01-01

    This paper reports on aging of the silicone oil MS704 for sudden changes of temperature from 210.5 to 209.0 K and from 207.5 to 209.0 K studied by continuously monitoring the instantaneous shear modulus G [infinity]. The results are interpreted within the Tool-Narayanaswamy formalism with a reduc...

  17. Loading Rate for Modulus of Rupture Test

    Institute of Scientific and Technical Information of China (English)

    QUMing; ZHANGYong-fang

    1996-01-01

    Relationship among load rate,strain rate and stress rate for modulus of ruptue test,the way of applying load with stress rate using both hydraulic compression testing machine and nechanical compression testing machine have been described.The test results are identical with selected strain rate loading and stress rate loading.

  18. Determination of Young's modulus by nanoindentation

    Institute of Scientific and Technical Information of China (English)

    MA Dejun; Chung Wo Ong; LIU Jianmin; HE Jiawen

    2004-01-01

    A methodology for determining Young's modulus of materials by non-ideally sharp indentation has been developed. According to the principle of the same area-to-depth ratio, a non-ideally pyramidal indenter like a Berkovich one can be approximated by a non-ideally conical indenter with a spherical cap at the tip. By applying dimensional and finite element analysis to the non-ideally conical indentation, a set of approximate one-to-one relationships between the ratio of nominal hardness/reduced Young's modulus and the ratio of elastic work/total work, which correspond to different tip bluntness, have been revealed. The nominal hardness is defined as the maximum indentation load divided by the cross-section area of the conical indenter specified at the maximum indentation depth. As a consequence, Young's modulus can be determined from a nanoindentation test only using the maximum indentation load and depth, and the work done during loading and unloading processes. The new method for determining Young's modulus is referred to as "pure energy method". The validity of the method was examined by performing indentation tests on five materials. The experimental results and the standard reference values are in good agreement, indicating that the proposed pure energy method is a promising substitution for the most widely used analysis models at present.

  19. 聚合物涂层对高模量碳纤维表面性能的影响%Effects of polymer coating on the properties of high modulus carbon fiber

    Institute of Scientific and Technical Information of China (English)

    刘占清; 张学军; 康素梅; 田艳红

    2012-01-01

    In order to improve the surface properties of carbon fibers and the interface properties of carbon fiber/resin composites,high modulus carbon fibers(HMCF) were treated with the polymer coating.The influence of the content of latent curing agent(LCA) in the coating layer on the carbon fiber surface properties and interface properties of carbon fiber/resin composites were studied.The results show that the polymer coating may have chemical reaction with carbon fiber or resin by IR analysis.SEM and DMTA also show polymer coating can improve the interfacical properties of carbon fiber/resin composites.The amount of LCA in the coating layer is the crucial factor to improve interfacial properties of carbon fiber/resin composites.When the content of the LCA is 20%,the interlaminar shear strength(ILSS) of the sized HMCF/epoxy resin composites is improved to 77.9 MPa,increased by 8.6% compared with that of the composites reinforced by unsized HMCF.%为改善碳纤维表面性能以及碳纤维/树脂复合材料的界面性能,对PAN基高模量碳纤维(HMCF)表面进行聚合物涂层处理。研究了不同潜伏性固化剂含量的聚合物涂层对HMCF表面以及碳纤维/树脂复合材料的界面性能的影响。IR分析表明,聚合物涂层与纤维或树脂基体发生了化学反应。扫描电镜和动态机械热分析的结果也说明,聚合物涂层能够提高HMCF/树脂复合材料的界面性能。潜伏性固化剂的含量是影响纤维/树脂复合材料的界面性能的关键因素。潜伏性固化剂含量为20%的聚合物涂层涂覆后的HMCF/树脂复合材料的层间剪切强度显著提高,达到了77.9MPa,较未涂覆聚合物涂层的HMCF/树脂复合材料提高了8.6%。

  20. Some Modulus and Normal Structure in Banach Space

    Directory of Open Access Journals (Sweden)

    Zhanfei Zuo

    2009-01-01

    Full Text Available We present some sufficient conditions for which a Banach space X has normal structure in terms of the modulus of U-convexity, modulus of W∗-convexity, and the coefficient R(1,X, which generalized some well-known results. Furthermore the relationship between modulus of convexity, modulus of smoothness, and Gao's constant is considered, meanwhile the exact value of Milman modulus has been obtained for some Banach space.

  1. Comparison of Failure Modes in 2-D and 3-D Woven Carbon Phenolic Systems

    Science.gov (United States)

    Rossman, Grant A.; Stackpoole, Mairead; Feldman, Jay; Venkatapathy, Ethiraj; Braun, Robert D.

    2013-01-01

    NASA Ames Research Center is developing Woven Thermal Protection System (WTPS) materials as a new class of heatshields for entry vehicles (Stackpoole). Currently, there are few options for ablative entry heatshield materials, none of which is ideally suited to the planetary probe missions currently of interest to NASA. While carbon phenolic was successfully used for the missions Pioneer Venus and Galileo (to Jupiter), the heritage constituents are no longer available. An alternate carbon phenolic would need to be qualified for probe missions, which is most efficient at heat fluxes greater than those currently of interest. Additional TPS materials such as Avcoat and PICA are not sufficiently robust for the heat fluxes required. As a result, there is a large TPS gap between the materials efficient at very high conditions (carbon phenolic) and those that are effective at low-moderate conditions (all others). Development of 3D Woven TPS is intended to fill this gap, targeting mid-density weaves that could with withstand mid-range heat fluxes between 1100 W/sq cm and 8000 W/sq cm (Venkatapathy (2012). Preliminary experimental studies have been performed to show the feasibility of WTPS as a future mid-range TPS material. One study performed in the mARC Jet Facility at NASA Ames Research Center characterized the performance of a 3D Woven TPS sample and compared it to 2D carbon phenolic samples at ply angles of 0deg, 23.5deg, and 90deg. Each sample contained similar compositions of phenolic and carbon fiber volume fractions for experimental consistency. The goal of this study was to compare the performance of the TPS materials by evaluating resulting recession and failure modes. After exposing both samples to similar heat flux and pressure conditions, the 2D carbon phenolic laminate was shown to experience significant delamination between layers and further pocketing underneath separated layers. The 3D Woven TPS sample did not experience the delamination or pocketing

  2. Measure of the magnitude of Young's modulus in whisker-like samples of the Bi-based high-Tc materials Bi sub 2 Sr sub 2 CaCu sub 2 O sub x and Bi sub 2 Sr sub 2 Ca sub 2 Cu sub 3 O sub x

    Energy Technology Data Exchange (ETDEWEB)

    Tritt, T.M.; Ehrlich, A.C.; Gillespie, D.J. (Materials Physics Branch, Naval Research Lab., Washington, DC (USA)); Marone, M.; Chen Xinfen; Skove, M.J.; Tessema, G.X. (Clemson Univ., Dept. of Physics, SC (USA)); Franck, J.P.; Jung, J. (Univ. of Alberta, Dept. of Physics, Edmonton, AB (Canada))

    1991-08-01

    We have measured Young's modulus in ribbon-like whisker samples of the high-Tc materials: Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub x} and Bi{sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub x}. This is the first direct measurement of Young's modulus for whiskers of any of the high Tc materials. We used a stress-strain probe that applies an axial force (uniaxial stress) to the whisker-like sample and simultaneously measures the corresponding sample elongation. The slope of the resulting stress-strain curve yields the magnitude of Young's modulus (Y). We found these Bi based high-Tc materials to be soft with Y {approx equal} 20 GPa for Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub x} and Y {approx equal} 25 GPa for Bi{sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub x}. (orig.).

  3. Space charge relaxation in polyetherimides by the electric modulus formalism

    Science.gov (United States)

    Mudarra, M.; Belana, J.; Cañadas, J. C.; Diego, J. A.; Sellarès, J.; Díaz-Calleja, R.; Sanchís, M. J.

    2000-10-01

    Dynamic electrical analysis shows that at high temperatures (above the glass transition temperature), the electrical properties of polyetherimide are strongly influenced by space charge. In this article we have studied the relaxation of space charge in two commercial varieties of polyetherimide: Ultem 1000 and Ultem 5000. Their conductive properties were determined by dynamic electrical analysis, using the electric modulus formalism. The complex part of the electric modulus was fitted to Coelho's model which considers ohmic conductivity and diffusion as the prevailing charge transport mechanisms. The complex part of the electric modulus exhibits a peak in the low frequency range that can be associated with space charge. A good agreement between experimental and calculated data is observed after the fitting process to Coelho's model. Differences in the electrode behavior were required: blocking electrode conditions in the case of Ultem 5000 and partially blocking electrode for Ultem 1000. In both cases the conductivity determined is thermally activated and it increases with the temperature due to an increasing mobility, as their carrier densities do not vary significantly in the temperature range studied.

  4. NONLINEAR MICRO-MECHANICAL MODEL FOR PLAIN WOVEN FABRIC

    Institute of Scientific and Technical Information of China (English)

    ZhangYitong; XieYuxin

    2003-01-01

    The warp yarns and weft yarns of plain woven fabric which, being the principal axes of material of fabric, are orthogonal in the original configuration, but are obliquely crossed in the deformed configuration in general. The orthotropic constitutive model is unsuitable for fabric. In the oblique principal axes system the relations between loaded stress vectors and stress tensor are investigated, the stress fields of micro-weaving structures of fabric due to pure shear are carefully studied and, finally, a nonlinear micro-mechanical model for plain woven fabric is proposed. This model can accurately describe the nonlinear mechanical behavior of fabric observed in experiments. Under the assumption of small deformation and linearity of mechanical properties of fabric the model will degenerate into the existing linear model.

  5. INCREMENTAL MICRO-MECHANICAL MODEL OF PLAIN WOVEN FABRIC

    Institute of Scientific and Technical Information of China (English)

    ZhangYitong; HaoYongjiang; LiCuiyu

    2004-01-01

    Warp yarns and weft yarns of plain woven fabric are the principal axes of material of fabric. They are orthogonal in their original configuration, but are obliquely crisscross in deformed configuration in general. In this paper the expressions of incremental components of strain tensor are derived, the non-linear model of woven fabric is linearized physically and its geometric non-linearity survives. The convenience of determining the total deformation is shown by the choice of the coordinate system of the principal axes of the material, with the convergence of the incremental methods illustrated by examples. This incremental model furnishes a basis for numerical simulations of fabric draping and wrinkling based oll the micro-mechanical model of fabric.

  6. A Wear Geometry Model of Plain Woven Fabric Composites

    Directory of Open Access Journals (Sweden)

    Gu Dapeng

    2014-09-01

    Full Text Available The paper g describes a model meant for analysis of the wear geometry of plain woven fabric composites. The referred model consists of a mathematical description of plain woven fabric based on Peirce’s model coupled with a stratified method for the solution of the wear geometry. The evolutions of the wear area ratio of weft yarn, warp yarn and matrix resin on the worn surface are simulated by MatLab software in combination of warp and weft yarn diameters, warp and weft yarn-to-yarn distances, fabric structure phases (SPs. By comparing theoretical and experimental results from the PTFE/Kevlar fabric wear experiment, it can be concluded that the model can present a trend of the component area ratio variations along with the thickness of fabric, but has a inherently large error in quantitative analysis as an idealized model.

  7. Mechanical properties of non-woven glass fiber geopolymer composites

    Science.gov (United States)

    Rieger, D.; Kadlec, J.; Pola, M.; Kovářík, T.; Franče, P.

    2017-02-01

    This experimental research focuses on mechanical properties of non-woven glass fabric composites bound by geopolymeric matrix. This study investigates the effect of different matrix composition and amount of granular filler on the mechanical properties of final composites. Matrix was selected as a metakaolin based geopolymer hardened by different amount of potassium silicate activator. The ceramic granular filler was added into the matrix for investigation of its impact on mechanical properties and workability. Prepared pastes were incorporated into the non-woven fabrics by hand roller and final composites were stacked layer by layer to final thickness. The early age hardening of prepared pastes were monitored by small amplitude dynamic rheology approach and after 28 days of hardening the mechanical properties were examined. The electron microscopy was used for detail description of microstructural properties. The imaging methods revealed good wettability of glass fibers by geopolymeric matrix and results of mechanical properties indicate usability of these materials for constructional applications.

  8. Smart Woven Fabrics With Portable And Wearable Vibrating Electronics

    Directory of Open Access Journals (Sweden)

    Özdemir Hakan

    2015-06-01

    Full Text Available The portable and wearable instrumented fabrics capable of measuring biothermal variable is essential for drivers, especially long-distance drivers. Here we report on portable and wearable devices that are able to read the temperature of human body within the woven fabric. The sensory function of the fabric is achieved by temperature sensors, soldered on conductive threads coated with cotton. The presence of stainless steel wires gives these materials conductive properties, enabling the detection of human body temperature and transmitting the signal form sensors to the motors on the fabric. When body temperature decreases, hardware/software platforms send a signal to the vibration motors in order to stimulate the driver. The ‘smart woven fabric’-sensing architecture can be divided into two parts: a textile platform, where portable and wearable devices acquire thermal signals, and hardware/software platforms, to which a sensor sends the acquired data, which send the signals to the vibration motors.

  9. Elastic bending modulus of monolayer graphene

    Energy Technology Data Exchange (ETDEWEB)

    Lu Qiang; Huang Rui [Department of Aerospace Engineering and Engineering Mechanics, University of Texas, Austin, TX 78712 (United States); Arroyo, Marino [Department of Applied Mathematics 3, LaCaN, Universitat Politecnica de Catalunya (UPC), Barcelona 08034 (Spain)

    2009-05-21

    An analytic formula is derived for the elastic bending modulus of monolayer graphene based on an empirical potential for solid-state carbon atoms. Two physical origins are identified for the non-vanishing bending stiffness of the atomically thin graphene sheet, one due to the bond-angle effect and the other resulting from the bond-order term associated with the dihedral angles. The analytical prediction compares closely with ab initio energy calculations. Pure bending of graphene monolayers into cylindrical tubes is simulated by a molecular mechanics approach, showing slight nonlinearity and anisotropy in the tangent bending modulus as the bending curvature increases. An intrinsic coupling between bending and in-plane strain is noted for graphene monolayers rolled into carbon nanotubes. (fast track communication)

  10. Tow Architecture and Mechanical Properties of 3-D Woven Composites

    Science.gov (United States)

    2010-06-01

    images were processed using AMIRA, then converted into finite element models using two different procedures. The first was using CATIA to further...Processed woven fabric as assembled within CATIA ; (a) raw tow import; (b) unit cell after geometric smoothing and trimming 23 Figure 27...0.4% found in composites. 1 NRECON, Skyscan. 2 3-D CREATOR, Skyscan. 3 AMIRA® 4.1.1, Visage Imaging. 4 CATIA ® V5R18, Dassault Systemes. © 2010 CRC

  11. Ultrasound - A new approach for non-woven scaffolds investigation

    Science.gov (United States)

    Khramtsova, E. A.; Morokov, E. S.; Lukanina, K. I.; Grigoriev, T. E.; Petronyuk, Y. S.; Levin, V. M.

    2016-05-01

    In this study we verified the method of impulse acoustic microscopy as a tool for scaffold evaluation in tissue engineering investigation. Cellulose diacetate (CDA) non-woven 3D scaffold was used as a model object. Scanning electron microscopy and optical microscopy were used as reference methods in order to realize feasibility of acoustic microscopy method in a regenerative medicine field. Direct comparison of the different methods was carried out.

  12. Three-Axis Distributed Fiber Optic Strain Measurement in 3D Woven Composite Structures

    Science.gov (United States)

    Castellucci, Matt; Klute, Sandra; Lally, Evan M.; Froggatt, Mark E.; Lowry, David

    2013-01-01

    Recent advancements in composite materials technologies have broken further from traditional designs and require advanced instrumentation and analysis capabilities. Success or failure is highly dependent on design analysis and manufacturing processes. By monitoring smart structures throughout manufacturing and service life, residual and operational stresses can be assessed and structural integrity maintained. Composite smart structures can be manufactured by integrating fiber optic sensors into existing composite materials processes such as ply layup, filament winding and three-dimensional weaving. In this work optical fiber was integrated into 3D woven composite parts at a commercial woven products manufacturing facility. The fiber was then used to monitor the structures during a VARTM manufacturing process, and subsequent static and dynamic testing. Low cost telecommunications-grade optical fiber acts as the sensor using a high resolution commercial Optical Frequency Domain Reflectometer (OFDR) system providing distributed strain measurement at spatial resolutions as low as 2mm. Strain measurements using the optical fiber sensors are correlated to resistive strain gage measurements during static structural loading. Keywords: fiber optic, distributed strain sensing, Rayleigh scatter, optical frequency domain reflectometry

  13. Three-axis distributed fiber optic strain measurement in 3D woven composite structures

    Science.gov (United States)

    Castellucci, Matt; Klute, Sandra; Lally, Evan M.; Froggatt, Mark E.; Lowry, David

    2013-03-01

    Recent advancements in composite materials technologies have broken further from traditional designs and require advanced instrumentation and analysis capabilities. Success or failure is highly dependent on design analysis and manufacturing processes. By monitoring smart structures throughout manufacturing and service life, residual and operational stresses can be assessed and structural integrity maintained. Composite smart structures can be manufactured by integrating fiber optic sensors into existing composite materials processes such as ply layup, filament winding and three-dimensional weaving. In this work optical fiber was integrated into 3D woven composite parts at a commercial woven products manufacturing facility. The fiber was then used to monitor the structures during a VARTM manufacturing process, and subsequent static and dynamic testing. Low cost telecommunications-grade optical fiber acts as the sensor using a high resolution commercial Optical Frequency Domain Reflectometer (OFDR) system providing distributed strain measurement at spatial resolutions as low as 2mm. Strain measurements using the optical fiber sensors are correlated to resistive strain gage measurements during static structural loading.

  14. Fibonacci difference sequence spaces for modulus functions

    Directory of Open Access Journals (Sweden)

    Kuldip Raj

    2015-05-01

    Full Text Available In the present paper we introduce Fibonacci difference sequence spaces l(F, Ƒ, p, u and  l_∞(F, Ƒ, p, u by using a sequence of modulus functions and a new band matrix F. We also make an effort to study some inclusion relations, topological and geometric properties of these spaces. Furthermore, the alpha, beta, gamma duals and matrix transformation of the space l(F, Ƒ, p, u are determined.

  15. Shear modulus of neutron star crust

    CERN Document Server

    Baiko, D A

    2011-01-01

    Shear modulus of solid neutron star crust is calculated by thermodynamic perturbation theory taking into account ion motion. At given density the crust is modelled as a body-centered cubic Coulomb crystal of fully ionized atomic nuclei of one type with the uniform charge-compensating electron background. Classic and quantum regimes of ion motion are considered. The calculations in the classic temperature range agree well with previous Monte Carlo simulations. At these temperatures the shear modulus is given by the sum of a positive contribution due to the static lattice and a negative $\\propto T$ contribution due to the ion motion. The quantum calculations are performed for the first time. The main result is that at low temperatures the contribution to the shear modulus due to the ion motion saturates at a constant value, associated with zero-point ion vibrations. Such behavior is qualitatively similar to the zero-point ion motion contribution to the crystal energy. The quantum effects may be important for li...

  16. Positive-plate gauntlets - the non-woven fabric solution

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, A.L. [Amer-Sil, Kehlen (Luxembourg)

    1998-05-18

    The tubular positive plate has undergone a gradual change in design that has progressed from single tube assembly to the gauntlet concept. The latest step in gauntlet development is the introduction of non-woven fabrics. These latest fabrics offer many advantages to the tubular battery. The advantages are both of a technical as well as of an economic nature. On the technical side, these non-woven fabrics offer structures which are very porous and yet have relatively small pore sizes. This combination of characteristics results in excellent positive active-material retention and low electrical resistance. The surface finish and physical characteristics of the non-woven fabrics also have an impact on the different plate-manufacturing techniques. But the one of the greatest benefits of this type of positive-plate gauntlet is its contribution to an improvement of the electrical output of the cycling battery both in terms of higher capacity (due to the lower electrical resistance) and to longer cycle life (due to the finer pore structure). (orig.)

  17. Influence of Warp Yarn Tension on Cotton Woven Fabric Structures

    Directory of Open Access Journals (Sweden)

    Uzma Syed

    2013-01-01

    Full Text Available Control of the warp and weft yarn tension is an important factor. In this research, effect of warp yarn tension variations on the quality of greige and dyed woven fabrics was investigated. Six fabric samples (three Plain and three Twill weaves were woven on shuttle loom at varied warp yarn tension. The fabric samples were then pre-treated and dyed (Drimarene Red Cl 5B, 3% owf using laboratory singeing machine and HT dyeing machine. Greige fabric quality such as fabric inspection, fabric length, fabric width, GSM (Gram per Square Meter, EPI (Ends per Inch, PPI (Picks per Inch, and dyed fabric quality such as L*, a*, b*, C, h o , (K/S ?max and fastness properties were assessed according to the standard. It has been observed that fabric samples, both Plain and Twill weave; woven at improper warp yarns tension gives rejected greige fabric quality and 1-7% lower (K/S 550nm values as compared to the fabric weave at requisite warp yarn tension such as 38-39cN for Plain fabric and 78cN for Twill fabric for 42x38 and 64x36 tex construction. Hence, among other weave faults, warp yarn tension variation has influence on the greige fabric quality as well as caused improper and uneven dyeing behavior.

  18. Performance evaluation of a non-woven lithium ion battery separator prepared through a paper-making process

    Science.gov (United States)

    Huang, Xiaosong

    2014-06-01

    Porous separator functions to electrically insulate the negative and positive electrodes yet communicate lithium ions between the two electrodes when infiltrated with a liquid electrolyte. The separator must fulfill numerous requirements (e.g. permeability, wettability, and thermal stability) in order to optimize the abuse tolerance and electrochemical performance of a battery. Non-woven mat separators have advantages such as high porosity and heat resistance. However, their applications in lithium ion batteries are very limited as their inadequate pore structures could cause accelerated battery performance degradation and even internal short. This work features the development of thermally stable non-woven composite separators using a low cost paper-making process. The composite separators offer significantly improved thermal dimensional stability and exhibit superior wettability by the liquid electrolyte compared to a conventional polypropylene separator. The open porous structures of the non-woven composite separators also resulted in high effective ionic conductivities. The electrochemical performance of the composite separators was tested in coin cells. Stable cycle performances and improved rate capabilities have been observed for the coin cells with these composite separators.

  19. Precipitation Coating of Monazite on Woven Ceramic Fibers: 1. Feasibility (Postprint)

    Science.gov (United States)

    2007-02-01

    AFRL-ML-WP-TP-2006-480 PRECIPITATION COATING OF MONAZITE ON WOVEN CERAMIC FIBERS: I. FEASIBILITY (POSTPRINT) Geoff E. Fair, Randall S. Hay...GRANT NUMBER 4. TITLE AND SUBTITLE PRECIPITATION COATING OF MONAZITE ON WOVEN CERAMIC FIBERS: I. FEASIBILITY (POSTPRINT) 5c. PROGRAM ELEMENT...08 Aug 2006. Paper contains color. 14. ABSTRACT Monazite coatings were deposited on woven cloths and tows of NextelTM 610 fibers by heterogeneous

  20. Effect of Elastic Modulus on Biomechanical Properties of Lumbar Interbody Fusion Cage

    Institute of Scientific and Technical Information of China (English)

    Yue Zhu; Fusheng Li; Shujun Li; Yulin Hao; Rui Yang

    2009-01-01

    This work focuses on the influence of elastic modulus on biomechanical properties of lumbar interbody fusion cages by selecting two titanium alloys with different elastic modulus.They were made by a new β type alloy with chemical composition of Ti-24Nb-4Zr-7.6Sn having low Young's modulus ~50 GPa and by a conventional biomedical alloy Ti-6Al-4V having Young's modulus ~110 GPa.The results showed that the designed cages with low modulus (LMC) and high modulus (HMC) can keep identical compression load ~9.8 kN and endure fatigue cycles higher than 5× 106 without functional or mechanical failure under 2.0 kN axial compression.The anti-subsidence ability of both group cages were examined by axial compression of thoracic spine specimens (T9~T10) dissected freshly from the calf with averaged age of 6 months.The results showed that the LMC has better anti-subsidence ability than the HMC (p<0.05).The above results suggest that the cage with low elastic modulus has great potential for clinical applications.

  1. Composite polymer electrolyte membranes supported by non-woven fabrics for lithium-ion polymer batteries

    Institute of Scientific and Technical Information of China (English)

    TANG Dingguo; LIU Jianhong; QI Lu; CHEN Hui; CI Yunxiang

    2005-01-01

    Poly(vinylidene fluoride-co-hexafluoropropyle- ne) (PVDF-HFP) is one of the most popular polymers for polymer electrolyte membranes because of its excellent operating characteristics and superior electrochemical properties. The electrochemical performances of polymer electrolyte membrane can be enhanced by evenly dispersing nano-meter SiO2 particles in the polymer. In this paper, non-woven fabrics were immersed in the mixed solution of PVDF-HFP/ SiO2/butanone/butanol/plasticizer, and then dried in a vacuum oven to remove the solvents and the plasticizer and to make porous composite polymer electrolyte membranes. The prepared composite membranes supported by non-woven fabrics boast good mechanical strength and excellent electrochemical properties: the electrochemical stability window is 4.8 V vs. Li+/Li, and the ionic conductivity is 3.35×10-4 S/cm (around 60% of that of a common PE membrane) at room temperature. The lithium-ion polymer battery assembled by the composite membrane exhibits high rate capability and excellent cycling performance.

  2. The Effect of Penetrator Geometry on the Dynamic Response of Woven Graphite/Epoxy Composites

    Science.gov (United States)

    Wosu, Sylvanus N.; Xie, Qiaoyun

    2014-03-01

    The primary focus on this paper is to study the high energy penetration/perforation damage propagation of composite plates using the perforation split Hopkinson pressure bar. The objectives include: investigation of propagation of penetration and surface crack damage in the vicinity perforation threshold velocity; investigation of energy absorption and strain intensity profiling; and quantitative analysis of the interactive effects of penetrator geometry and sample thickness on the perforation damage of woven graphite-epoxy composite plates. The results show that strain rate increased with damage energy threshold levels and decreased with sample thickness from below to above the perforation limit velocity on the average. There was a significant difference between penetrator geometries on a specimen strain rate, and penetrator size other than shape was a more important factor. As the size of the penetrator increased, the perforation energy thresholds increased accordingly. Thus, for the same energy level, the larger penetrator delivered more energy to the target. The mode of perforation failure was localized with obliquely shaped cracks for the woven specimens. It was conceivable that the cracks first initiate at the point of intersections of the weave and move in both directions. These results would provide some instructions in building, designing, and evaluating protective structures that undergo any penetration type of impact.

  3. Modeling of Ultrasonic Testing of Woven Fabric Laminates: a Microstructure Approach

    Science.gov (United States)

    Hegemann, J.; Peiffer, A.; Van Den Broucke, B.; Baier, H.

    2009-03-01

    New complex materials constitute new challenges for the well established nondestructive ultrasonic testing (UT) methods. In aeronautic industry Carbon Fiber Reinforced Plastics (CFRP) with a high level of inner inhomogeneity are used. New construction methods of these materials lead to manufacturing problems that cannot be monitored satisfactorily yet. Therefore a consolidated knowledge of the materials and of the interactions during testing is necessary. Modeling is a promising tool to improve the understanding of physical backgrounds and thus, to reduce testing costs. In this work UT of three-dimensional models of woven fabrics on microstructure level is simulated for the first time. Therefore, model generation and simulation performance are performed separately. The inner geometry of laminates made of woven fabrics is modeled using the software module WiseTex, a textile pre-processor developed by the Catholic University of Leuven, Belgium. In these models the wave propagation is numerically calculated using the Elastodynamic Finite Integration Technique (EFIT) implemented with C++. The calculations are performed for fully orthotropic and heterogeneous media. The resolution of the investigated inner structure is in the range of micrometers depending on the frequency range. The possibility of introducing defects in the structure is shown. The influence of the interfaces between carbon fiber rovings, matrix and defects on the wave propagation is investigated. Finally comparisons of the results with experimental data are presented.

  4. Tensile Behavior Analysis on Different Structures of 3D Glass Woven Perform for Fibre Reinforced Composites

    Directory of Open Access Journals (Sweden)

    Mazhar Hussain Peerzada

    2013-01-01

    Full Text Available Three common 3D (Three Dimensional Glass woven structures were studied to analyze the tensile behavior. Each type of strand (Warp, weft and binder of 3D woven structure was studied in detail. Crimp percentage of those strands was measured by crimp meter. Standard size samples of each 3D woven structure were cut in warp and weft direction and were stretched by Instron Tensile testing computerized machine. Results reveal that hybrid possesses lowest crimp in core strands and higher strength in warp as well as weft direction. Layer to layer woven structure appeared with lower strength and higher strain value due to highest crimp percentage in core strands.

  5. Woven Thermal Protection System (WTPS) a Novel Approach to Meet NASA's Most Demanding Reentry Missions

    Science.gov (United States)

    Stackpoole, Mairead

    2014-01-01

    NASA's future robotic missions to Venus and outer planets, namely, Saturn, Uranus, Neptune, result in extremely high entry conditions that exceed the capabilities of current mid-density ablators (PICA or Avcoat). Therefore mission planners assume the use of a fully dense carbon phenolic heat shield similar to what was flown on Pioneer Venus and Galileo. Carbon phenolic (CP) is a robust Thermal Protection System (TPS) however its high density and thermal conductivity constrain mission planners to steep entries, high heat fluxes, pressures and short entry durations, in order for CP to be feasible from a mass perspective. The high entry conditions pose certification challenges in existing ground based test facilities. In 2012 the Game Changing Development Program in NASA's Space Technology Mission Directorate funded NASA ARC to investigate the feasibility of a Woven Thermal Protection System (WTPS) to meet the needs of NASA's most challenging entry missions. This presentation will summarize maturation of the WTPS project.

  6. New multitarget constant modulus array for CDMA systems

    Institute of Scientific and Technical Information of China (English)

    Zhang Jidong; Zheng Baoyu

    2006-01-01

    A new multitarget constant modulus array is proposed for CDMA systems based on least squares constant modulus algorithm. The new algorithm is called pre-despreading decision directed least squares constant modulus algorithm (DDDLSCMA). In the new algorithm, the pre-despreading is first applied for multitarget arrays to remove some multiple access signals, then the despreaded signal is processed by the algorithm which united the constant modulus algorithm and decision directed method. Simulation results illustrate the good performance for the proposed algorithm.

  7. The instantaneous shear modulus in the shoving model

    DEFF Research Database (Denmark)

    Dyre, J. C.; Wang, W. H.

    2012-01-01

    We point out that the instantaneous shear modulus G∞ of the shoving model for the non-Arrhenius temperature dependence of viscous liquids’ relaxation time is the experimentally accessible highfrequency plateau modulus, not the idealized instantaneous affine shear modulus that cannot be measured...

  8. Influence of Fibre Architecture on Impact Damage Tolerance in 3D Woven Composites

    Science.gov (United States)

    Potluri, P.; Hogg, P.; Arshad, M.; Jetavat, D.; Jamshidi, P.

    2012-10-01

    3D woven composites, due to the presence of through-thickness fibre-bridging, have the potential to improve damage tolerance and at the same time to reduce the manufacturing costs. However, ability to withstand damage depends on weave topology as well as geometry of individual tows. There is an extensive literature on damage tolerance of 2D prepreg laminates but limited work is reported on the damage tolerance of 3D weaves. In view of the recent interest in 3D woven composites from aerospace as well as non-aerospace sectors, this paper aims to provide an understanding of the impact damage resistance as well as damage tolerance of 3D woven composites. Four different 3D woven architectures, orthogonal, angle interlocked, layer-to-layer and modified layer-to-layer structures, have been produced under identical weaving conditions. Two additional structures, Unidirectional (UD) cross-ply and 2D plain weave, have been developed for comparison with 3D weaves. All the four 3D woven laminates have similar order of magnitude of damage area and damage width, but significantly lower than UD and 2D woven laminates. Damage Resistance, calculated as impact energy per unit damage area, has been shown to be significantly higher for 3D woven laminates. Rate of change of CAI strength with impact energy appears to be similar for all four 3D woven laminates as well as UD laminate; 2D woven laminate has higher rate of degradation with respect to impact energy. Undamaged compression strength has been shown to be a function of average tow waviness angle. Additionally, 3D weaves exhibit a critical damage size; below this size there is no appreciable reduction in compression strength. 3D woven laminates have also exhibited a degree of plasticity during compression whereas UD laminates fail instantly. The experimental work reported in this paper forms a foundation for systematic development of computational models for 3D woven architectures for damage tolerance.

  9. EFFECT OF DISPERSION OF MICA IN MATRIX ON YOUNG'S MODULUS OF MICA FILLED POLYETHYLENE

    Institute of Scientific and Technical Information of China (English)

    XU Xi; GONG Xiaoyi

    1991-01-01

    The correlation between Young's modulus of mica-filled high density polyethylene (HDPE), low density polyethylene(LDPE) and the state of dispersion of plasma-treated mica in the polymer matrices was studied. The modulus and the number average diameter of mica aggregates in matrix were determined with tensile testing and image analysis respectively. The interface structure of the filler/matrix and the bulk structure of matrix were examined through the dielectric spectrometry,differential scanning calorimetry (DSC) and dynamic viscoelastic spectrometry. The results show that the Young's modulus of the filled polyethylene depends to a great extent upon the state of dispersion of filler in matrix, but it is independent of the interface structure and bulk structure. The better the dispersion, the higher the Young's modulus.

  10. Low modulus Ti–Nb–Hf alloy for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    González, M., E-mail: Marta.Gonzalez.Colominas@upc.edu [Department of Materials Science and Metallurgy, Universitat Politècnica de Catalunya (UPC), Avda. Diagonal 647, 08028 Barcelona (Spain); Materials Science, Elisava Escola Superior de Disseny i Enginyeria de Barcelona, La Rambla 30-32, 08002 Barcelona (Spain); Peña, J. [Department of Materials Science and Metallurgy, Universitat Politècnica de Catalunya (UPC), Avda. Diagonal 647, 08028 Barcelona (Spain); Materials Science, Elisava Escola Superior de Disseny i Enginyeria de Barcelona, La Rambla 30-32, 08002 Barcelona (Spain); Gil, F.J.; Manero, J.M. [Department of Materials Science and Metallurgy, Universitat Politècnica de Catalunya (UPC), Avda. Diagonal 647, 08028 Barcelona (Spain); Ciber-BBN (Spain)

    2014-09-01

    β-Type titanium alloys with a low elastic modulus are a potential strategy to reduce stress shielding effect and to enhance bone remodeling in implants used to substitute failed hard tissue. For biomaterial application, investigation on the mechanical behavior, the corrosion resistance and the cell response is required. The new Ti25Nb16Hf alloy was studied before and after 95% cold rolling (95% C.R.). The mechanical properties were determined by tensile testing and its corrosion behavior was analyzed by potentiostatic equipment in Hank's solution at 37 °C. The cell response was studied by means of cytotoxicity evaluation, cell adhesion and proliferation measurements. The stress–strain curves showed the lowest elastic modulus (42 GPa) in the cold worked alloy and high tensile strength, similar to that of Ti6Al4V. The new alloy exhibited better corrosion resistance in terms of open circuit potential (E{sub OCP}), but was similar in terms of corrosion current density (i{sub CORR}) compared to Ti grade II. Cytotoxicity studies revealed that the chemical composition of the alloy does not induce cytotoxic activity. Cell studies in the new alloy showed a lower adhesion and a higher proliferation compared to Ti grade II presenting, therefore, mechanical features similar to those of human cortical bone and, simultaneously, a good cell response. - Highlights: • Presents low elastic modulus and high strength and elastic deformability. • Exhibits good biocompatibility in terms of cytotoxicity and cell response. • Corrosion resistance of this alloy is good, similar to that of Ti grade II. • Potential candidate for implants used to substitute failed hard tissue.

  11. Woven Thermal Protection System Based Heat-shield for Extreme Entry Environments Technology (HEEET)

    Science.gov (United States)

    Ellerby, Donald; Venkatapathy, Ethiraj; Stackpoole, Margaret; Chinnapongse, Ronald; Munk, Michelle; Dillman, Robert; Feldman, Jay; Prabhu, Dinesh; Beerman, Adam

    2013-01-01

    NASA's future robotic missions utilizing an entry system into Venus and the outer planets, namely, Saturn, Uranus, Neptune, result in extremely high entry conditions that exceed the capabilities of state of the art low to mid density ablators such as PICA or Avcoat. Therefore mission planners typically assume the use of a fully dense carbon phenolic heat shield similar to what was flown on Pioneer Venus and Galileo. Carbon phenolic is a robust TPS material however its high density and relatively high thermal conductivity constrain mission planners to steep entries, with high heat fluxes and pressures and short entry durations, in order for CP to be feasible from a mass perspective. The high entry conditions pose challenges for certification in existing ground based test facilities and the longer-term sustainability of CP will continue to pose challenges. In 2012 the Game Changing Development Program (GCDP) in NASA's Space Technology Mission Directorate funded NASA ARC to investigate the feasibility of a Woven Thermal Protection System (WTPS) to meet the needs of NASA's most challenging entry missions. This project was highly successful demonstrating that a Woven TPS solution compares favorably to CP in performance in simulated reentry environments and provides the opportunity to manufacture graded materials that should result in overall reduced mass solutions and enable a much broader set of missions than does CP. Building off the success of the WTPS project GCDP has funded a follow on project to further mature and scale up the WTPS concept for insertion into future NASA robotic missions. The matured WTPS will address the CP concerns associated with ground based test limitations and sustainability. This presentation will briefly discuss results from the WTPS Project and the plans for WTPS maturation into a heat-shield for extreme entry environment.

  12. Investigation of woven composites as potential cryogenic tank materials

    Science.gov (United States)

    Islam, Md. S.; Melendez-Soto, E.; Castellanos, A. G.; Prabhakar, P.

    2015-12-01

    In this paper, carbon fiber and Kevlar® fiber woven composites were investigated as potential cryogenic tank materials for storing liquid fuel in spacecraft or rocket. Towards that end, both carbon and Kevlar® fiber composites were manufactured and tested with and without cryogenic exposure. The focus was on the investigation of the influence of initial cryogenic exposure on the degradation of the composite. Tensile, flexural and inter laminar shear strength (ILSS) tests were conducted, which indicate that Kevlar® and carbon textile composites are potential candidates for use under cryogenic exposure.

  13. 78 FR 12716 - Laminated Woven Sacks From the People's Republic of China: Negative Final Determination of...

    Science.gov (United States)

    2013-02-25

    ... method either to an exterior ply of plastic film such as biaxially-oriented polypropylene (``BOPP'') or...: Laminated Woven Sacks From the People's Republic of China, 73 FR 45941 (August 7, 2008); see also Laminated Woven Sacks From the People's Republic of China: Countervailing Duty Order, 73 FR 45955 (August 7,...

  14. Woven Coronary Artery Disease Successfully Managed with Percutaneous Coronary Intervention: A New Case Report

    OpenAIRE

    Yakup Alsancak; Burak Sezenoz; Sedat Turkoglu; Adnan Abacı

    2015-01-01

    Woven coronary artery is relatively rare and can be complicated in both acute and chronic phases. A few case reports have been published until now. Herein we report a case with right woven coronary artery managed with drug-eluted stent implantation without complication.

  15. Woven Coronary Artery Disease Successfully Managed with Percutaneous Coronary Intervention: A New Case Report.

    Science.gov (United States)

    Alsancak, Yakup; Sezenoz, Burak; Turkoglu, Sedat; Abacı, Adnan

    2015-01-01

    Woven coronary artery is relatively rare and can be complicated in both acute and chronic phases. A few case reports have been published until now. Herein we report a case with right woven coronary artery managed with drug-eluted stent implantation without complication.

  16. Woven Coronary Artery Disease Successfully Managed with Percutaneous Coronary Intervention: A New Case Report

    Directory of Open Access Journals (Sweden)

    Yakup Alsancak

    2015-01-01

    Full Text Available Woven coronary artery is relatively rare and can be complicated in both acute and chronic phases. A few case reports have been published until now. Herein we report a case with right woven coronary artery managed with drug-eluted stent implantation without complication.

  17. 40 CFR 430.120 - Applicability; description of the tissue, filter, non-woven, and paperboard from purchased pulp...

    Science.gov (United States)

    2010-07-01

    ... tissue, filter, non-woven, and paperboard from purchased pulp subcategory. 430.120 Section 430.120... PULP, PAPER, AND PAPERBOARD POINT SOURCE CATEGORY Tissue, Filter, Non-Woven, and Paperboard From Purchased Pulp Subcategory § 430.120 Applicability; description of the tissue, filter, non-woven,...

  18. Low-modulus PMMA bone cement modified with castor oil.

    Science.gov (United States)

    López, Alejandro; Hoess, Andreas; Thersleff, Thomas; Ott, Marjam; Engqvist, Håkan; Persson, Cecilia

    2011-01-01

    Some of the current clinical and biomechanical data suggest that vertebroplasty causes the development of adjacent vertebral fractures shortly after augmentation. These findings have been attributed to high injection volumes as well as high Young's moduli of PMMA bone cements compared to that of the osteoporotic cancellous bone. The aim of this study was to evaluate the use of castor oil as a plasticizer for PMMA bone cements. The Young's modulus, yield strength, maximum polymerization temperature, doughing time, setting time and the complex viscosity curves during curing, were determined. The cytotoxicity of the materials extracts was assessed on cells of an osteoblast-like cell line. The addition of up to 12 wt% castor oil decreased yield strength from 88 to 15 MPa, Young's modulus from 1500 to 446 MPa and maximum polymerization temperature from 41.3 to 25.6°C, without affecting the setting time. However, castor oil seemed to interfere with the polymerization reaction, giving a negative effect on cell viability in a worst-case scenario.

  19. If mechanics of cells can be described by elastic modulus in AFM indentation experiments?

    Science.gov (United States)

    Sokolov, Igor; Dokukin, Maxim; Guz, Nataliia; Kalaparthi, Vivekanand

    2014-03-01

    We study the question if cells, being highly heterogeneous objects, can be described with an elastic modulus (the Young's modulus) in a self-consistent way. We analyze the elastic modulus using indentation done with AFM of human cervical epithelial cells. Both sharp (cone) and dull AFM probes were used. The indentation data collected were processed through different elastic models. The cell was considered as a homogeneous elastic medium which had either smooth spherical boundary (Hertz/Sneddon models) or the boundary covered with a layer of glycocalyx and membrane protrusions (``brush'' models). Validity of these approximations was investigated. Specifically, we tested the independence of the elastic modulus of the indentation depth, which is assumed in these models. We demonstrate that only one model shows consistency with treating cells as homogeneous elastic medium, the bush model when processing the indentation data collected with the dull probe. The elastic modulus demonstrates strong depth dependence in all other three models. We conclude that it is possible to describe the elastic properties of the cell body by means of an effective elastic modulus in a self-consistent way when using the brush model to analyze data collected with a dull AFM probe.

  20. Multiphase composites with extremal bulk modulus

    DEFF Research Database (Denmark)

    Gibiansky, L. V.; Sigmund, Ole

    2000-01-01

    This paper is devoted to the analytical and numerical study of isotropic elastic composites made of three or more isotropic phases. The ranges of their effective bulk and shear moduli are restricted by the Hashin-Shtrikman-Walpole (HSW) bounds. For two-phase composites, these bounds are attainable......, that is, there exist composites with extreme bulk and shear moduli. For multiphase composites, they may or may not be attainable depending on phase moduli and volume fractions. Sufficient conditions of attainability of the bounds and various previously known and new types of optimal composites...... are described. Most of our new results are related to the two-dimensional problem. A numerical topology optimization procedure that solves the inverse homogenization problem is adopted and used to look for two-dimensional three-phase composites with a maximal effective bulk modulus. For the combination...

  1. Mechanical Testing of Carbon Based Woven Thermal Protection Materials

    Science.gov (United States)

    Pham, John; Agrawal, Parul; Arnold, James O.; Peterson, Keith; Venkatapathy, Ethiraj

    2013-01-01

    Three Dimensional Woven thermal protection system (TPS) materials are one of the enabling technologies for mechanically deployable hypersonic decelerator systems. These materials have been shown capable of serving a dual purpose as TPS and as structural load bearing members during entry and descent operations. In order to ensure successful structural performance, it is important to characterize the mechanical properties of these materials prior to and post exposure to entry-like heating conditions. This research focuses on the changes in load bearing capacity of woven TPS materials after being subjected to arcjet simulations of entry heating. Preliminary testing of arcjet tested materials [1] has shown a mechanical degradation. However, their residual strength is significantly more than the requirements for a mission to Venus [2]. A systematic investigation at the macro and microstructural scales is reported here to explore the potential causes of this degradation. The effects of heating on the sizing (an epoxy resin coating used to reduce friction and wear during fiber handling) are discussed as one of the possible causes for the decrease in mechanical properties. This investigation also provides valuable guidelines for margin policies for future mechanically deployable entry systems.

  2. High Strength/High Modulus Aromatic Heterocyclic ABA Block Copolymers

    Science.gov (United States)

    1987-05-01

    stream and when condensed with 3,4- diaminotoluene , a quantitative yield of the model imidazole oligomer was obtained. HS’ NH$CII+. HCO2 -(jCO 2 H PPA...isolated by precipitation into water . Composition of the (B) blocks could be varied by the weight of AB-monomer used in the copolymer- izations. Intrinsic...outlet N2 stream through a barium hydroxide solution. The dark solution was poured into water to give a colorless precipitate. With the aid of a

  3. Evaluation on mechanical properties of woven aloevera and sisal fibre hybrid reinforced epoxy composites

    Indian Academy of Sciences (India)

    A Shadrach Jeya Sekaran; K Palani Kumar; K Pitchandi

    2015-09-01

    Natural fibres as reinforcement in polymer composite for making low-cost materials are growing day by day. Researcher’s main attention is to apply appropriate technology to utilize these natural fibres as effectively and economically as possible to produce good quality fibre-reinforced polymer composites for various engineering applications. In this research, the experiments of tensile, flexural and impact tests were carried out for woven aloevera and sisal fibre hybrid-reinforced epoxy composites. The hand layup method of fabrication was employed in preparing the composites. The surface morphology of the composites was examined through scanning electron microscope. Due to the low-density and high-specific properties of sisal fibre composites, it offer cost savings when compared with synthetic fibres. Hence it has very good implications in the automotive and transportation industry.

  4. Effective thermal conductivity of wire-woven bulk Kagome sandwich panels

    Directory of Open Access Journals (Sweden)

    Xiaohu Yang

    2014-01-01

    Full Text Available Thermal transport in a highly porous metallic wire-woven bulk Kagome (WBK is numerically and analytically modeled. Based on topology similarity and upon introducing an elongation parameter in thermal tortuosity, an idealized Kagome with non-twisted struts is employed. Special focus is placed upon quantifying the effect of topological anisotropy of WBK upon its effective conductivity. It is demonstrated that the effective conductivity reduces linearly as the porosity increases, and the extent of the reduction is significantly dependent on the orientation of WBK. The governing physical mechanism of anisotropic thermal transport in WBK is found to be the anisotropic thermal tortuosity caused by the intrinsic anisotropic topology of WBK.

  5. Hybrid composite laminates reinforced with Kevlar/carbon/glass woven fabrics for ballistic impact testing.

    Science.gov (United States)

    Randjbaran, Elias; Zahari, Rizal; Jalil, Nawal Aswan Abdul; Majid, Dayang Laila Abang Abdul

    2014-01-01

    Current study reported a facile method to investigate the effects of stacking sequence layers of hybrid composite materials on ballistic energy absorption by running the ballistic test at the high velocity ballistic impact conditions. The velocity and absorbed energy were accordingly calculated as well. The specimens were fabricated from Kevlar, carbon, and glass woven fabrics and resin and were experimentally investigated under impact conditions. All the specimens possessed equal mass, shape, and density; nevertheless, the layers were ordered in different stacking sequence. After running the ballistic test at the same conditions, the final velocities of the cylindrical AISI 4340 Steel pellet showed how much energy was absorbed by the samples. The energy absorption of each sample through the ballistic impact was calculated; accordingly, the proper ballistic impact resistance materials could be found by conducting the test. This paper can be further studied in order to characterise the material properties for the different layers.

  6. Hybrid Composite Laminates Reinforced with Kevlar/Carbon/Glass Woven Fabrics for Ballistic Impact Testing

    Directory of Open Access Journals (Sweden)

    Elias Randjbaran

    2014-01-01

    Full Text Available Current study reported a facile method to investigate the effects of stacking sequence layers of hybrid composite materials on ballistic energy absorption by running the ballistic test at the high velocity ballistic impact conditions. The velocity and absorbed energy were accordingly calculated as well. The specimens were fabricated from Kevlar, carbon, and glass woven fabrics and resin and were experimentally investigated under impact conditions. All the specimens possessed equal mass, shape, and density; nevertheless, the layers were ordered in different stacking sequence. After running the ballistic test at the same conditions, the final velocities of the cylindrical AISI 4340 Steel pellet showed how much energy was absorbed by the samples. The energy absorption of each sample through the ballistic impact was calculated; accordingly, the proper ballistic impact resistance materials could be found by conducting the test. This paper can be further studied in order to characterise the material properties for the different layers.

  7. The features of finite-element modeling of a structural element of flexible woven composites

    Directory of Open Access Journals (Sweden)

    Dmitry A. Kozhanov

    2016-03-01

    Full Text Available The features of finite-element modeling of both an element itself and its behavior under uniaxial tension have been demonstrated with a structural element of flexible woven composites. The main components of the material, such as reinforcing fabric and material's matrix were examined in modeling. The reinforcing fabric is a plain weave. These yarns were taken as an elastic material. The matrix of the material was considered to be a soft polymer with the possible occurrence of irreversible elastic-plastic deformations. Moreover, the possible occurrence of damages in the structure of the material under high loads was taken into account in modeling. The fields of stresses and strains were built; the zones of the material's internal damages under uniaxial tension were demonstrated. The risk zones of weave were revealed.

  8. An integrated computational materials engineering method for woven carbon fiber composites preforming process

    Science.gov (United States)

    Zhang, Weizhao; Ren, Huaqing; Wang, Zequn; Liu, Wing K.; Chen, Wei; Zeng, Danielle; Su, Xuming; Cao, Jian

    2016-10-01

    An integrated computational materials engineering method is proposed in this paper for analyzing the design and preforming process of woven carbon fiber composites. The goal is to reduce the cost and time needed for the mass production of structural composites. It integrates the simulation methods from the micro-scale to the macro-scale to capture the behavior of the composite material in the preforming process. In this way, the time consuming and high cost physical experiments and prototypes in the development of the manufacturing process can be circumvented. This method contains three parts: the micro-scale representative volume element (RVE) simulation to characterize the material; the metamodeling algorithm to generate the constitutive equations; and the macro-scale preforming simulation to predict the behavior of the composite material during forming. The results show the potential of this approach as a guidance to the design of composite materials and its manufacturing process.

  9. Low modulus Ti-Nb-Hf alloy for biomedical applications.

    Science.gov (United States)

    González, M; Peña, J; Gil, F J; Manero, J M

    2014-09-01

    β-Type titanium alloys with a low elastic modulus are a potential strategy to reduce stress shielding effect and to enhance bone remodeling in implants used to substitute failed hard tissue. For biomaterial application, investigation on the mechanical behavior, the corrosion resistance and the cell response is required. The new Ti25Nb16Hf alloy was studied before and after 95% cold rolling (95% C.R.). The mechanical properties were determined by tensile testing and its corrosion behavior was analyzed by potentiostatic equipment in Hank's solution at 37°C. The cell response was studied by means of cytotoxicity evaluation, cell adhesion and proliferation measurements. The stress-strain curves showed the lowest elastic modulus (42GPa) in the cold worked alloy and high tensile strength, similar to that of Ti6Al4V. The new alloy exhibited better corrosion resistance in terms of open circuit potential (EOCP), but was similar in terms of corrosion current density (iCORR) compared to Ti grade II. Cytotoxicity studies revealed that the chemical composition of the alloy does not induce cytotoxic activity. Cell studies in the new alloy showed a lower adhesion and a higher proliferation compared to Ti grade II presenting, therefore, mechanical features similar to those of human cortical bone and, simultaneously, a good cell response.

  10. Shear modulus of the hadron-quark mixed phase

    CERN Document Server

    Johnson-McDaniel, Nathan K

    2012-01-01

    Robust arguments predict that a hadron-quark mixed phase may exist in the cores of some "neutron" stars. Such a phase forms a crystalline lattice with a shear modulus higher than that of the crust due to the high density and charge separation, even allowing for the effects of charge screening. This may lead to strong continuous gravitational-wave emission from rapidly rotating neutron stars and gravitational-wave bursts associated with magnetar flares and pulsar glitches. We present the first detailed calculation of the shear modulus of the mixed phase. We describe the quark phase using the bag model plus first-order quantum chromodynamics corrections and the hadronic phase using relativistic mean-field models with parameters allowed by the most massive pulsar. Most of the calculation involves treating the "pasta phases" of the lattice via dimensional continuation, and we give a general method for computing dimensionally continued lattice sums including the Debye model of charge screening. We compute all the ...

  11. Interfacial Modulus Mapping during Structural Transformation in Shape Memory Alloys

    Science.gov (United States)

    Wan, Jianfeng; Cui, Shushan; Zhang, Jihua; Rong, Yonghua

    2017-10-01

    Through the modified phase-field model the local soft mode mechanism of nucleation during martensitic transformation was confirmed in shape memory alloys. It was discovered that the modulus loss (8 pct) depended on the martensitic nucleation exceeding the loss (1 pct) during the martensitic growth. The elastic modulus and the stress across the martensite/parent interface differed from those across the martensitic twin boundary. The modulus losses in systems with three variants, two variants, and one variant were compared.

  12. Predictive Models for Modulus of Rupture and Modulus of Elasticity of Particleboard Manufactured in Different Pressing Conditions

    Science.gov (United States)

    Tiryaki, Sebahattin; Aras, Uğur; Kalaycıoğlu, Hülya; Erişir, Emir; Aydın, Aytaç

    2017-07-01

    Determining the mechanical properties of particleboard has gained a great importance due to its increasing usage as a building material in recent years. This study aims to develop artificial neural network (ANN) and multiple linear regression (MLR) models for predicting modulus of rupture (MOR) and modulus of elasticity (MOE) of particleboard depending on different pressing temperature, pressing time, pressing pressure and resin type. Experimental results indicated that the increased pressing temperature, time and pressure in manufacturing process generally improved the mechanical properties of particleboard. It was also seen that ANN and MLR models were highly successful in predicting the MOR and MOE of particleboard under given conditions. On the other hand, a comparison between ANN and MLR revealed that the ANN was superior compared to the MLR in predicting the MOR and MOE. Finally, the findings of this study are expected to provide beneficial insights for practitioners to better understand usability of such composite materials for engineering applications and to better assess the effects of pressing conditions on the MOR and MOE of particleboard.

  13. Composition and Properties of Thermo-regulated Non-woven Fabrics

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    A series of non-woven fabrics were fabricated by blending 50 - 80wt% of thermoregulated fibres containing n-eicosane,n-nonadecane or n-octadecane with 0 - 40wt% PET fibres and 0- 20wt% PP fibres. The phase change properties,thermal conductivity, thermal resistance, heat flux and inner temperature difference between wool felt and thethermoregulated non-woven fabrics of the non-woven fabrics were measreed respectively. The thermo-regulated non-woven fabrics absorb heat at 25- 34℃ and release heat at 1025℃. The measured highest enthalpy of the non-woven is approximately 18J/g. During a heating process, heat flux of the non-woven fabrics is composed of three parts: heat absorbed by the cold textile touching the hot plate, heat transmitted from the hot plate to the cold plate, and the heat absorbed by PCM from the hot plate during the phase change process. The measured maximum inner temperature difference in a temperature rising process between the wool felt and the thermo-regulated non-woven fabric is approximately 8℃. The inner temperature difference (Tr-Ts>0) lasts 16 - 45 min. By contrary, the measured maximum inner temperature difference in the temperature decreasing process is approximately - 6. 5℃. The inner temperature difference (Tr-Ts<0) lasts 16 - 50 min. The temperatureregulation properties are obviously observed.

  14. Young’s modulus of [111] germanium nanowires

    Directory of Open Access Journals (Sweden)

    M. Maksud

    2015-11-01

    Full Text Available This paper reports a diameter-independent Young’s modulus of 91.9 ± 8.2 GPa for [111] Germanium nanowires (Ge NWs. When the surface oxide layer is accounted for using a core-shell NW approximation, the YM of the Ge core approaches a near theoretical value of 147.6 ± 23.4 GPa. The ultimate strength of a NW device was measured at 10.9 GPa, which represents a very high experimental-to-theoretical strength ratio of ∼75%. With increasing interest in this material system as a high-capacity lithium-ion battery anode, the presented data provide inputs that are essential in predicting its lithiation-induced stress fields and fracture behavior.

  15. Young’s modulus of [111] germanium nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Maksud, M.; Palapati, N. K. R.; Subramanian, A., E-mail: asubramanian@vcu.edu [Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, Virginia 23284 (United States); Yoo, J. [Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Harris, C. T. [Center for Integrated Nanotechnologies, Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)

    2015-11-01

    This paper reports a diameter-independent Young’s modulus of 91.9 ± 8.2 GPa for [111] Germanium nanowires (Ge NWs). When the surface oxide layer is accounted for using a core-shell NW approximation, the YM of the Ge core approaches a near theoretical value of 147.6 ± 23.4 GPa. The ultimate strength of a NW device was measured at 10.9 GPa, which represents a very high experimental-to-theoretical strength ratio of ∼75%. With increasing interest in this material system as a high-capacity lithium-ion battery anode, the presented data provide inputs that are essential in predicting its lithiation-induced stress fields and fracture behavior.

  16. Effects of the ratio of hardness to Young's modulus on the friction and wear behavior of bilayer coatings

    Science.gov (United States)

    Ni, Wangyang; Cheng, Yang-Tse; Lukitsch, Michael J.; Weiner, Anita M.; Lev, Lenoid C.; Grummon, David S.

    2004-11-01

    We present a study of the effects of the ratio of hardness to Young's modulus on the friction and wear behavior of layered composite coatings. Layered coating structures with the same surface coating but different interlayers were prepared by physical vapor deposition. We found that the ratio of hardness to Young's modulus plays an important role in determining the friction coefficient and wear resistance of layered composite coatings. A low friction coefficient and high wear resistance can be achieved in structures with high ratio of hardness to Young's modulus and moderately high hardness.

  17. Minimal subfamilies and the probabilistic interpretation for modulus on graphs

    CERN Document Server

    Albin, Nathan

    2016-01-01

    The notion of $p$-modulus of a family of objects on a graph is a measure of the richness of such families. We develop the notion of minimal subfamilies using the method of Lagrangian duality for $p$-modulus. We show that minimal subfamilies have at most $|E|$ elements and that these elements carry a weight related to their "importance" in relation to the corresponding $p$-modulus problem. When $p=2$, this measure of importance is in fact a probability measure and modulus can be thought as trying to minimize the expected overlap in the family.

  18. THREE-DIMENSIONAL OF CRINKLES EFFECTS USING MULTILAYER WOVEN FABRICS CONTAINING SPANDEX

    Directory of Open Access Journals (Sweden)

    ElSayed ElNashar

    2016-07-01

    Full Text Available Development of the wrinkled fabrics depends on geometry and relaxation behavior of the multilayer woven fabrics. After bleaching and relaxation, the new shapes and sizes of crinkles were recorded. The results prove that the manner of fabric deformation during relaxation depends upon the multilayer fabrics structure. The quantities of the crinkles on the fabric are related to the float length type. Multilayer woven fabrics with longer float length show higher crinkled, and its deformation behavior is non-linear. Thus, connected deformations are closely related to the stretch potential and influence multilayer woven fabrics draping and fitting of the garment. For this purpose, we have postulated new model for the relationship between fabric geometry and stretch potential. The suggested hypotheses make it possible to predict mathematically the crinkle of multilayer woven fabrics and prediction of suitable-sett of warp and weft. The area covering value was chosen as suitable model for description of multilayer woven fabrics structure. The study was divided into two parts, the first presents the relationship between fabric geometry of the relaxation behavior whereas the second investigated the influence of multilayer woven fabrics stretch potential on the relaxation ability of bleached fabric. Three variants of cumulative parameter of a crinkle woven fabrics structure were introduced. The realistic models based on a better approach of geometry and material properties will be created in order to investigate the numerical analysis performance of the mechanical properties of crinkle woven fabrics. A correlation between calculated values of structural parameters crinkle multilayer woven fabrics values was evaluated.

  19. The Effect of Temperature and Nanoclay on the Low Velocity and Ballistic Behavior of Woven Glass-Fiber Reinforced Composites

    Science.gov (United States)

    Patrin, Lauren

    The objective of this research was to study the effect of nanoclay and temperature on the behavior of woven glass-fabric reinforced epoxy composite under low velocity and ballistic impacts. The materials used in manufacturing the composite were S2 (6181) glass-fibers, epoxy resin (EPON 828), hardener (Epikure 3230), nanoclay and Heloxy 61 modifier. The nanoclay addition was 0%, 1%, 3% and 5% by weight, with respect to the resin. All specimens were manufactured at the City College facilities using vacuum infusion. Tensile tests were conducted to characterize the material and obtain the Young's modulus, ultimate stress, failure strain, Poisson's ratio, shear modulus and shear strength and their variation with nanoclay percentage and temperature. The tests were conducted at room temperature (21°C/70°F), -54°C (-65°F), -20°C (-4°F), 49°C (120°F) and 71°C (160°F). Next composite specimens with 0%, 1%, 3% and 5% nanoclay by weight, with respect to the resin, were subjected to low velocity impact at the previously specified temperatures to determine dynamic force, displacement and energy correlations. The extent of damage was studied using the ultrasound technique. Then ballistic tests were conducted on the nanoclay infused specimens at room temperature to obtain the ballistic limit (V50) and the damage behavior of the composite. The dynamic finite element analysis (FEA) software LS-DYNA was used to model and simulate the results of low velocity impact tests. Good agreement was obtained between experimental and numerical (FEA) results. Analytical analyses were undertaken to compare the results from the tensile experiments. The finite element analysis (FEA) allowed for further analytical comparison of the results. The FEA platform used was LS-DYNA due to its proficient dynamic and damage capabilities in composite materials. The FEA was used to model and simulate the low velocity impacts and compare the results to experiments.

  20. Mesoscopic Strains Maps in Woven Composite Laminas During Off-axis Tension

    Directory of Open Access Journals (Sweden)

    Nicoletto G.

    2010-06-01

    Full Text Available The mechanics of woven carbon-fiber reinforced plastic (CFRP composites is influenced by the complex architecture of the reinforcement phase. Computational (i.e. finite element based approaches have been used increasingly to model not only the global laminate stiffness, but also damage evolution and laminate strength. The modeling combines the identification of the architectural unit cell (UC, the selection of suitable constitutive models of the different phases, the creation of a fine discretization of the UC in finite elements, the application of an incremental solution procedure that solves iteratively for the stresses and strains in the UC, [1]. The experimental validation of computational models is carried out mainly at the macroscopical level, i.e. simulation of the macroscopic stress-strain curve. Damage, however, is a localized, straindependent phenomenon and therefore only accurate strain distribution within the UC (at the mesolevel can identify critical conditions in terms of damage location, extension and evolution. The validation of computational damage procedures is a key task and full-field optical strain analysis methods appear the ideal instrument. However, only limited examples of direct finte element method (FEM vs experimental strain correlation are found because of the limited sensitivity and spatial resolution of some techniques and the complexity and applicative difficulty of others. The aim of the present paper is to present the application of the digital image correlation (DIC technique, [2], to the full-field strain analysis at the mesoscopic level (i.e. within the UC of a woven CFRP lamina when the direction of loading forms an angle to the material direction. The material under consideration is a woven carbon fiber reinforced epoxy composite. Orthogonal yarns, each made of of several thousand fibers, are woven according the twill-weave architecture is shown in Fig. 1a. Single-ply laminas were manufactured and tested to

  1. Influence of Kind of Weft Yarn on Properties of the Seersucker Woven Fabrics

    Directory of Open Access Journals (Sweden)

    Matusiak Małgorzata

    2016-12-01

    Full Text Available Seersucker woven fabrics create a unique 3D woven structure. Such 3D structure is usually received on loom by an application of two warps of different tension. However, a kind of the weft yarn also significantly influences the structure and properties of the seersucker woven fabric. The paper presents an investigation of the seersucker fabrics made of the same set of warps and different weft yarns. The mechanical properties of the investigated fabrics were measured by means of the standardized testing methods. The structure of the fabric was assessed using the 3D laser scanning.

  2. Study of the indoor decontamination using nanocoated woven polyester fabric

    Science.gov (United States)

    Memon, Hafeezullah; Kumari, Naveeta; Jatoi, Abdul Wahab; Khoso, Nazakat Ali

    2016-11-01

    This research primarily deals with the photocatalytic degradation of methanol in indoor air using nanocoated indoor textiles used for curtains as household textiles. The woven polyester was coated by titanium dioxide by sol gel method, using silicon-based binder. The characterization of the coating has been done using scanning electron microscopy (SEM) image analysis, energy dispersive analysis using X-ray (EDAX) and Fourier transform infrared spectroscopy (FTIR). The DIY instrument providing the similar environment as of indoor was designed to assess the performance of the degradation of formaldehyde under UV light. The photocatalytic degradation rate was measured using the absorption value of the solutions obtained in the result of liquid chromatography of test solution and reagent solution. Different amount of dosages (1-3 %) and different time period of coatings (half hour to 3 h) have been evaluated for optimization.

  3. Chiral braided and woven composites: design, fabrication, and electromagnetic characterization

    Science.gov (United States)

    Wheeland, Sara; Bayatpur, Farhad; Amirkhizi, Alireza V.; Nemat-Nasser, Sia

    2011-04-01

    This work presents a new chiral composite composed of copper wires braided with Kevlar and nylon to form conductive coils integrated among structural fiber. To create a fabric, these braids were woven with plain Kevlar fiber. This yielded a composite with all coils possessing the same handedness, producing a chiral material. The electromagnetic response of this fabric was first simulated using a finite element full-wave simulation. For the electromagnetic measurement, the sample was placed between two lens-horn antennas connected to a Vector Network Analyzer. The frequency response of the sample was scanned between 5.5 and 8GHz. The measured scattering parameters were then compared to those of the simulated model. The measured parameters agreed well with the simulation results, showing a considerable chirality within the measured frequency band. The new composite combines the strength and durability of traditional composites with an electromagnetic design to create a multifunctional material.

  4. An Investigation on Different Physical Properties of Cotton Woven Fabrics

    Directory of Open Access Journals (Sweden)

    Shilpi Akter

    2017-01-01

    Full Text Available In this study, “An Investigation on Different Physical Properties of Cotton Woven Fabrics”, some sample fabrics were produced with plain, 2/2 twill, 3/1 twill and 4-end satin weave structure using four different weft counts. By means of regression, the correlation coefficient and correlation between different properties of fabrics were investigated. The findings of this study revealed that the crease recovery angle and the bending length are inversely proportional to each other. It was also found that with the increasing of weft yarn counts lead to a decreasing in stiffness, abrasion resistance and increasing in crease recovery angle. The pilling and wrinkle recovery affected very low by the increase of weft yarn count and for the variation of weave structure. Plain weave was superior to other structures in stiffness where as twill weave showed higher crease recovery.

  5. Investigation of Circular Woven Composite Preforms for Composite Pipes

    Directory of Open Access Journals (Sweden)

    Amid Hooman

    2016-06-01

    Full Text Available The main traditional technique for commercial manufacturing of composite pipes is filament winding in which the winding angle and the discontinuity of the structure (caused by starting and ending points of the winding process are two important matters of concern. In the present study, circular woven fabric with its orthogonal net-shaped continuous structure was produced from polyester yarns. Fabric was wet with epoxy and hand lay-up was used to manufacture the composite pipes. Composite pipes were subjected to internal hydrostatic pressure and their burst strength was recorded. In addition, tensile strength of flat laminas was assessed in the warp and weft directions. We estimated and analysed the failure strength of composite pipes using Tresca’s failure criterion and Finite Element (FE modeling. The experimental burst strength was almost 23% more than the FE model and 77% more than the theoretical estimate.

  6. Creep Burst Testing of a Woven Inflatable Module

    Science.gov (United States)

    Selig, Molly M.; Valle, Gerard D.; James, George H.; Oliveras, Ovidio M.; Jones, Thomas C.; Doggett, William R.

    2015-01-01

    A woven Vectran inflatable module 88 inches in diameter and 10 feet long was tested at the NASA Johnson Space Center until failure from creep. The module was pressurized pneumatically to an internal pressure of 145 psig, and was held at pressure until burst. The external environment remained at standard atmospheric temperature and pressure. The module burst occurred after 49 minutes at the target pressure. The test article pressure and temperature were monitored, and video footage of the burst was captured at 60 FPS. Photogrammetry was used to obtain strain measurements of some of the webbing. Accelerometers on the test article measured the dynamic response. This paper discusses the test article, test setup, predictions, observations, photogrammetry technique and strain results, structural dynamics methods and quick-look results, and a comparison of the module level creep behavior to the strap level creep behavior.

  7. Modelling the Shear-Tension Coupling of Woven Engineering Fabrics

    Directory of Open Access Journals (Sweden)

    F. Abdiwi

    2013-01-01

    Full Text Available An approach to incorporate the coupling between the shear compliance and in-plane tension of woven engineering fabrics, in finite-element-based numerical simulations, is described. The method involves the use of multiple input curves that are selectively fed into a hypoelastic constitutive model that has been developed previously for engineering fabrics. The selection process is controlled by the current value of the in-plane strain along the two fibre directions using a simple algorithm. Model parameters are determined from actual experimental data, measured using the Biaxial Bias Extension test. An iterative process involving finite element simulations of the experimental test is used to normalise the test data for use in the code. Finally, the effectiveness of the method is evaluated and shown to provide qualitatively good predictions.

  8. Mechanical Characterization of 3D Woven Carbon Composite

    Science.gov (United States)

    2017-09-18

    iii List of Tables……………………………………………………………...……..…………. iii Introduction ………………………………………………………………………………….. 1 Panels...Properties…………………………………………………………………………………….6 1 DISTRIBUTION A. Approved for public release: distribution unlimited. Introduction 3D woven composites... polymer -design 8 DISTRIBUTION A. Approved for public release: distribution unlimited. Appendix I 0 10000 20000

  9. Residual Tensile Property of Plain Woven Jute Fiber/Poly(Lactic Acid Green Composites during Thermal Cycling

    Directory of Open Access Journals (Sweden)

    Hideaki Katogi

    2016-07-01

    Full Text Available This study investigated the residual tensile properties of plain woven jute fiber reinforced poly(lactic acid (PLA during thermal cycling. Temperature ranges of thermal cycling tests were 35–45 °C and 35–55 °C. The maximum number of cycles was 103 cycles. The quasi-static tensile tests of jute fiber, PLA, and composite were conducted after thermal cycling tests. Thermal mechanical analyses of jute fiber and PLA were conducted after thermal cycling tests. Results led to the following conclusions. For temperatures of 35–45 °C, tensile strength of composite at 103 cycles decreased 10% compared to that of composite at 0 cycles. For temperatures of 35–55 °C, tensile strength and Young’s modulus of composite at 103 cycles decreased 15% and 10%, respectively, compared to that of composite at 0 cycles. Tensile properties and the coefficient of linear expansion of PLA and jute fiber remained almost unchanged after thermal cycling tests. From observation of a fracture surface, the length of fiber pull out in the fracture surface of composite at 103 cycles was longer than that of composite at 0 cycles. Therefore, tensile properties of the composite during thermal cycling were decreased, probably because of the decrease of interfacial adhesion between the fiber and resin.

  10. ON A GENERALIZED MODULUS OF CONVEXITY AND UNIFORM NORMAL STRUCTURE

    Institute of Scientific and Technical Information of China (English)

    Yang Changsen; Wang Fenghui

    2007-01-01

    In this article, the authors study a generalized modulus of convexity, δ(α)(∈).Certain related geometrical properties of this modulus are analyzed. Their main result is that Banach space X has uniform normal structure if there exists ∈, 0 ≤∈≤1, such that δ(α)(1 + ∈) > (1 - α)∈.

  11. Regulating the modulus of a chiral liquid crystal polymer network by light.

    Science.gov (United States)

    Kumar, Kamlesh; Schenning, Albertus P H J; Broer, Dirk J; Liu, Danqing

    2016-04-01

    We report a novel way to modulate the elastic modulus of azobenzene containing liquid crystal networks (LCNs) by exposure to light. The elastic modulus can cycle between different levels by controlling the illumination conditions. Exposing the polymer network to UV light near the trans absorption band of azobenzene gives a small reduction of the glass transition temperature thereby lowering the modulus. The addition of blue light addressing the cis absorption band surprisingly amplifies this effect. The continuous oscillatory effects of the trans-to-cis isomerization of the azobenzene overrule the overall net cis conversion. The influence on the chain dynamics of the network is demonstrated by dynamic mechanical thermal analysis which shows a large shift of the glass transition temperature and a modulus decrease by more than two orders of magnitude. The initial high modulus and the glassy state are recovered within a minute in the dark by switching off the light sources, despite the observation that azobenzene is still predominantly in its cis state. Based on these new findings, we are able to create a shape memory polymer LCN film at room temperature using light.

  12. Calculation of Effective Material Strengths for 3D Woven Hybrid Preforms and Composites Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The design concepts being considered for Heatshield for Extreme Entry Environment Technology (HEEET) rely on the use of 3D woven carbon fiber preforms. Therefore,...

  13. Calibration of 3D Woven Preform Design Code for CMC Materials Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Mechanical and thermal performance of CMC components benefit from low part count, integrally fabricated designs of 3D woven reinforcement. The advantages of these...

  14. Strike-through of moist contamination by woven and nonwoven surgical materials.

    Science.gov (United States)

    Laufman, H; Eudy, W W; Vandernoot, A M; Harris, C A; Liu, D

    1975-06-01

    A test is described which correlates the stress of stretching surgical gown and drape material with moist bacterial strike-through. By application of this test to a number of woven and nonwoven surgical gown and drape materials, it was found that not all of these materials, either woven or nonwoven, are impermeable to moist contamination for equal periods of time. Nonwoven disposable materials now in use range from those which remain impermeable to moist bacterial permeation through all tests while some remain impermeable for limited periods of time, and others almost immediately permeable to moist bacterial penetration. The same situation holds for woven materials. Under conditions of our test, Quarpel treated Pima tight-woven cotton cloth was impermeable to moist bacterial strike-through, through up to 75 washing and sterilizing cyclings, while ordinary linen and untreated Pima cloth permitted bacterial permeation almost immediately. These results have significance in lengthy wet surgical operations.

  15. Integration of Complex Geometry, 3D Woven Preforms via Innovative Stitching Technique Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Thick, 3D woven carbon/phenolic composites offer potential improvement over legacy thermal protection systems (TPS) for re-entry vehicle heat shield applications....

  16. Calculation of Effective Material Strengths for 3D Woven Hybrid Preforms and Composites Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Current NASA programs, such as Adaptable, Deployable Entry and Placement Technology (ADEPT) and Woven Thermal Protection Systems (WTPS) are looking to fill a gap in...

  17. Woven right coronary artery: a case report and review of the literature.

    Science.gov (United States)

    Iyisoy, Atila; Celik, Turgay; Yuksel, U Cagdas; Isik, Ersoy

    2010-07-01

    Woven coronary artery is an extremely rare and is still not a clearly defined coronary anomaly in which epicardial coronary artery is divided into multiple thin channels at any segment of the coronary artery, and subsequently, these multiple channels merge again in a normal conduit. A few cases have been reported till now. In this case report, we present a 58-year-old male with a woven right coronary artery.

  18. Rail Shear and Short Beam Shear Properties of Various 3-Dimensional (3-D) Woven Composites

    Science.gov (United States)

    2016-01-01

    ARL-TR-7576 ● JAN 2016 US Army Research Laboratory Rail Shear and Short Beam Shear Properties of Various 3 - Dimensional ( 3 -D...2016 US Army Research Laboratory Rail Shear and Short Beam Shear Properties of Various 3 - Dimensional ( 3 -D) Woven Composites by Mark...Properties of Various 3 - Dimensional Woven Composites 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Mark Pankow

  19. A Model of Temperature-Dependent Young's Modulus for Ultrahigh Temperature Ceramics

    Directory of Open Access Journals (Sweden)

    Weiguo Li

    2011-01-01

    Full Text Available Based on the different sensitivities of material properties to temperature between ultrahigh temperature ceramics (UHTCs and traditional ceramics, the original empirical formula of temperature-dependent Young's modulus of ceramic materials is unable to describe the temperature dependence of Young's modulus of UHTCs which are used as thermal protection materials. In this paper, a characterization applied to Young's modulus of UHTC materials under high temperature which is revised from the original empirical formula is established. The applicable temperature range of the characterization extends to the higher temperature zone. This study will provide a basis for the characterization for strength and fracture toughness of UHTC materials and provide theoretical bases and technical reserves for the UHTC materials' design and application in the field of spacecraft.

  20. Prediction of representative deformation modulus of longwall panel roof rock strata using Mamdani fuzzy system

    Institute of Scientific and Technical Information of China (English)

    Mohammad Rezaei; Mostafa Asadizadeh; Abbas Majdi; Mohammad Farouq Hossaini

    2015-01-01

    Deformation modulus is the important parameter in stability analysis of tunnels, dams and mining struc-tures. In this paper, two predictive models including Mamdani fuzzy system (MFS) and multivariable regression analysis (MVRA) were developed to predict deformation modulus based on data obtained from dilatometer tests carried out in Bakhtiary dam site and additional data collected from longwall coal mines. Models inputs were considered to be rock quality designation, overburden height, weathering, unconfined compressive strength, bedding inclination to core axis, joint roughness coefficient and fill thickness. To control the models performance, calculating indices such as root mean square error (RMSE), variance account for (VAF) and determination coefficient (R2) were used. The MFS results show the significant prediction accuracy along with high performance compared to MVRA results. Finally, the sensitivity analysis of MFS results shows that the most and the least effective parameters on deformation modulus are weathering and overburden height, respectively.

  1. Determination of elastic modulus and residual stress of plasma-sprayed tungsten coating on steel substrate

    Energy Technology Data Exchange (ETDEWEB)

    You, J.H. [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, Boltzmann Street 2, 85748 Garching (Germany)]. E-mail: jeong-ha.you@ipp.mpg.de; Hoeschen, T. [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, Boltzmann Street 2, 85748 Garching (Germany); Lindig, S. [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, Boltzmann Street 2, 85748 Garching (Germany)

    2006-01-01

    Plasma-sprayed tungsten, which is a candidate material for the first wall armour, shows a porous, heterogeneous microstructure. Due to its characteristic morphology, the properties are significantly different from those of its dense bulk material. Measurements of the elastic modulus of this coating have not been reported in the literature. In this work Young's modulus of highly porous plasma-sprayed tungsten coatings deposited on steel (F82H) substrates was measured. For the fabrication of the coating system the vacuum plasma-spray process was applied. Measurements were performed by means of three-point and four-point bending tests. The obtained modulus values ranged from 53 to 57 GPa. These values could be confirmed by the test result of a detached coating strip, which was 54 GPa. The applied methods produced consistent results regardless of testing configurations and specimen sizes. The errors were less than 1%. Residual stress of the coating was also estimated.

  2. Determination of elastic modulus and residual stress of plasma-sprayed tungsten coating on steel substrate

    Science.gov (United States)

    You, J. H.; Höschen, T.; Lindig, S.

    2006-01-01

    Plasma-sprayed tungsten, which is a candidate material for the first wall armour, shows a porous, heterogeneous microstructure. Due to its characteristic morphology, the properties are significantly different from those of its dense bulk material. Measurements of the elastic modulus of this coating have not been reported in the literature. In this work Young's modulus of highly porous plasma-sprayed tungsten coatings deposited on steel (F82H) substrates was measured. For the fabrication of the coating system the vacuum plasma-spray process was applied. Measurements were performed by means of three-point and four-point bending tests. The obtained modulus values ranged from 53 to 57 GPa. These values could be confirmed by the test result of a detached coating strip, which was 54 GPa. The applied methods produced consistent results regardless of testing configurations and specimen sizes. The errors were less than 1%. Residual stress of the coating was also estimated.

  3. Analysis of Road Base Uniformity via the Deviation of Modulus of Asphalt Mixtures

    Institute of Scientific and Technical Information of China (English)

    ZHI Yufeng; ZHANG Xiaoning

    2007-01-01

    The modulus deviation of base material calculated from the data of falling weight deflectometer (FWD) was used to evaluate the uniformity of road base so as to reflect the construction quality. Four parameters,the repeatability standard deviation of the data in the same driveway, the reproducibility standard deviation of the data in the different driveway, the consistency statistics value of the data in the different driveway, and the consistency statistics value of the data in the same driveway, were introduced for the construction uniformity analysis. The experimental result shows that the materials modulus calculated from FWD has a highly correlative relationship with the uniformity of road base.

  4. Automatic measurement for dimensional changes of woven fabrics based on texture

    Science.gov (United States)

    Liu, Jihong; Jiang, Hongxia; Liu, X.; Chai, Zhilei

    2014-01-01

    Dimensional change or shrinkage is an important functional attribute of woven fabrics that affects their basic function and price in the market. This paper presents a machine vision system that evaluates the shrinkage of woven fabrics by analyzing the change of fabric construction. The proposed measurement method has three features. (i) There will be no stain of shrinkage markers on the fabric specimen compared to the existing measurement method. (ii) The system can be used on fabric with reduced area. (iii) The system can be installed and used as a laboratory or industrial application system. The method processed can process the image of the fabric and is divided into four steps: acquiring a relative image from the sample of the woven fabric, obtaining a gray image and then the segmentation of the warp and weft from the fabric based on fast Fourier transform and inverse fast Fourier transform, calculation of the distance of the warp or weft sets by gray projection method and character shrinkage of the woven fabric by the average distance, coefficient of variation of distance and so on. Experimental results on virtual and physical woven fabrics indicated that the method provided could obtain the shrinkage information of woven fabric in detail. The method was programmed by Matlab software, and a graphical user interface was built by Delphi. The program has potential for practical use in the textile industry.

  5. Compressive Behavior of 3D Woven Composite Stiffened Panels: Experimental and Numerical Study

    Science.gov (United States)

    Zhou, Guangming; Pan, Ruqin; Li, Chao; Cai, Deng'an; Wang, Xiaopei

    2017-08-01

    The structural behavior and damage propagation of 3D woven composite stiffened panels with different woven patterns under axial-compression are here investigated. The panel is 2.5D interlock woven composites (2.5DIWC), while the straight-stiffeners are 3D woven orthogonal composites (3DWOC). They are coupled together with the Z-fibers from the stiffener passing straight thought the thickness of the panel. A "T-shape" model, in which the fiber bundle structure and resin matrix are drawn out to simulate the real situation of the connection area, is established to predict elastic constants and strength of the connection region. Based on Hashin failure criterion, a progressive damage model is carried out to simulate the compressive behavior of the stiffened panel. The 3D woven composite stiffened panels are manufactured using RTM process and then tested. A good agreement between experimental results and numerical predicted values for the compressive failure load is obtained. From initial damage to final collapse, the panel and stiffeners will not separate each other in the connection region. The main failure mode of 3D woven composite stiffened panels is compressive failure of fiber near the loading end corner.

  6. Temperature effect on elastic modulus of thin films and nanocrystals

    Science.gov (United States)

    Liang, Lihong; Li, Meizhi; Qin, Fuqi; Wei, Yueguang

    2013-02-01

    The stability of nanoscale devices is directly related to elasticity and the effect of temperature on the elasticity of thin films and nanocrystals. The elastic instability induced by rising temperature will cause the failure of integrated circuits and other microelectronic devices in service. The temperature effect on the elastic modulus of thin films and nanocrystals is unclear although the temperature dependence of the modulus of bulk materials has been studied for over half a century. In this paper, a theoretical model of the temperature-dependent elastic modulus of thin films and nanocrystals is developed based on the physical definition of the modulus by considering the size effect of the related cohesive energy and the thermal expansion coefficient. Moreover, the temperature effect on the modulus of Cu thin films is simulated by the molecular dynamics method. The results indicate that the elastic modulus decreases with increasing temperature and the rate of the modulus decrease increases with reducing thickness of thin films. The theoretical predictions based on the model are consistent with the results of computational simulations, semi-continuum calculations and the experimental measurements for Cu, Si thin films and Pd nanocrystals.

  7. The bulk modulus of cubic spinel selenides: an experimental and theoretical study

    DEFF Research Database (Denmark)

    Waskowska, A.; Gerward, Leif; Olsen, J.S.

    2009-01-01

    It is argued that mainly the selenium sublattice determines the overall compressibility of the cubic spinel selenides, AB2Se4, and that the bulk modulus for these compounds is about 100GPa. The hypothesis is supported by experiments using high-pressure X-ray diffraction and synchrotron radiation...

  8. Sensitive determination of the Young's modulus of thin films by polymeric microcantilevers

    DEFF Research Database (Denmark)

    Colombi, Paolo; Bergese, Paolo; Bontempi, Elza;

    2013-01-01

    A method for the highly sensitive determination of the Young's modulus of TiO2 thin films exploiting the resonant frequency shift of a SU-8 polymer microcantilever (MC) is presented. Amorphous TiO2 films with different thickness ranging from 10 to 125 nm were grown at low temperature (90 °C) with...

  9. Modulus of Elasticity and Thermal Expansion Coefficient of ITO Film

    Energy Technology Data Exchange (ETDEWEB)

    Carter, Austin D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Elhadj, S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-06-24

    The purpose of this experiment was to determine the modulus of elasticity (E) and thermal expansion coefficient (α) of RF sputtered Indium Tin Oxide (ITO) as a function of temperature (T), and to collect ITO film stress data. In order to accomplish that goal, the Toho FLX-2320-S thin film stress measurement machine was used to collect both single stress and stress-temperature data for ITO coated fused silica and sapphire substrates. The stress measurement function of the FLX-2320-S cannot be used to calculate the elastic modulus of the film because the Stoney formula incorporates the elastic modulus of the substrate, rather than of the film itself.

  10. On the relationship between indentation hardness and modulus, and the damage resistance of biological materials.

    Science.gov (United States)

    Labonte, David; Lenz, Anne-Kristin; Oyen, Michelle L

    2017-07-15

    indentation is a widespread tool for characterising the mechanical properties of biological materials. Here, we show that the ratio between indentation hardness and modulus is approximately constant in biological materials. A simple elastic-plastic series deformation model is employed to rationalise part of this correlation, and criteria for a meaningful comparison of indentation hardness across biological materials are proposed. The ratio between indentation hardness and modulus emerges as the key parameter characterising the relative amount of irreversible deformation during indentation. Despite their comparatively high hardness to modulus ratio, biological materials are susceptible to quasiplastic deformation, due to their high toughness: quasi-plastic deformation is hence hypothesised to be a frequent yet poorly understood phenomenon, highlighting an important area of future research. Copyright © 2017 Acta Materialia Inc. All rights reserved.

  11. Comparison of mechanical and ultrasound elastic modulus of ovine tibial cortical bone.

    Science.gov (United States)

    Grant, Caroline A; Wilson, Lance J; Langton, Christian; Epari, Devakar

    2014-07-01

    Finite element models of bones can be created by deriving geometry from an X-ray CT scan. Material properties such as the elastic modulus can then be applied using either a single or set of homogeneous values, or individual elements can have local values mapped onto them. Values for the elastic modulus can be derived from the CT density values using an elasticity versus density relationship. Many elasticity-density relationships have been reported in the literature for human bone. However, while ovine in vivo models are common in orthopaedic research, no work has been done to date on creating FE models of ovine bones. To create these models and apply relevant material properties, an ovine elasticity-density relationship needs to be determined. Using fresh frozen ovine tibias the apparent density of regions of interest was determined from a clinical CT scan. The bones were the sectioned into cuboid samples of cortical bone from the regions of interest. Ultrasound was used to determine the elastic modulus in each of three directions - longitudinally, radially and tangentially. Samples then underwent traditional compression testing in each direction. The relationships between apparent density and both ultrasound, and compression modulus in each direction were determined. Ultrasound testing was found to be a highly repeatable non-destructive method of calculating the elastic modulus, particularly suited to samples of this size. The elasticity-density relationships determined in the longitudinal direction were very similar between the compression and ultrasound data over the density range examined. A clear difference was seen in the elastic modulus between the longitudinal and transverse directions of the bone samples, and a transverse elasticity-density relationship is also reported.

  12. Dyeing of Polyester Woven Fabric with Disperse Dye Using Conventional and Microwave Technique

    Directory of Open Access Journals (Sweden)

    Uzma Syed

    2014-07-01

    Full Text Available Polyester fabric is generally dyed using high temperature dyeing technique and carrier. Both techniques require high energy consumption while few carriers are toxic in nature. In this study, 100% polyester woven fabric was dyed by microwave and conventional dyeing technique with disperse dye; Foron Blue RD GLN by an exhaust method for short dyeing cycle (15 and 30 min. The fabric samples were dyed using conventional high temperature dyeing technique using recommended recipe. Moreover, samples were also dyed using microwave technique with recommended recipe and by the addition of salt and urea, pre-treatment with caustic and organic solvent for improving the dye uptake value and fastness properties. The dyeing assessment; (K/S?max value by Datacolor spectrophotometer, dye uniformity by optical microscope and washing fastness by grey scale were measured. It has been observed that over conventional dyeing method, microwave irradiation dyed sample gives almost 70% high (K/S?max value and uniform dye penetration and good to very good washing fastness property. In addition, microwave dyeing gives excellent dyeing behavior at short dyeing cycle; 15 min; hence saves energy and sustainable dyeing process

  13. 不同环境温度下铝球弹丸高速撞击编织物防护屏试验研究%Experimental Investigation of Woven Bumper Shield Impacted by a High-velocity Aluminum Sphere at Different Ambient Temperature

    Institute of Scientific and Technical Information of China (English)

    管公顺; 蒲东东; 哈跃; 庞宝君

    2015-01-01

    利用二级轻气炮发射2017铝球弹丸,在两种环境温度下高速撞击编织物单防护屏结构和填充式结构,研究环境温度对铝网、玄武岩纤维布、Kevlar纤维布防护结构高速撞击损伤与防护特性的影响。用于模拟空间碎片的铝球弹丸直径为3.97 mm,撞击速度为1.47~4.47 km/s,撞击角度为0°,环境温度分别为293 K和393 K。结果表明:当撞击条件相同时,在较高环境温度中,单防护屏结构的编织物防护屏及填充式结构的编织物填充层的撞击穿孔尺寸均增大,三种编织物单防护屏结构的高速撞击防护能力下降,铝网及玄武岩纤维布填充式结构的高速撞击防护性能降低,Kevlar纤维布填充式结构的高速撞击防护性能提高。%A two-stage light gas gun is used to launch 2017-T4 Al-sphere projectiles impacting on single-wall bumper shield and stuffed bumper shield of woven at two kinds of ambient temperature. The effect of ambient temperature on damage and protection characteristic of Al-mesh, Basalt fiber cloth and Kevlar fiber cloth bumpers are studied. The diameter of projectile used to simulate space debris is 3.97 mm. Impact velocities of Al-spheres are varied between 1.47 km/s and 4.47 km/s. The impact angle is 0°. Ambient temperatures are 293 K and 393 K respectively. The results indicated that perforation size of woven bumper of single-wall bumper shield and woven stuffed wall of stuffed bumper shield increased at higher ambient temperature for the same impact condition. At the same time, the protection performance of all single-wall bumper shields of three woven bumpers degraded along with the rising of the ambient temperature, the protection performance of Al-mesh, Basalt fiber cloth stuffed bumper shields degraded and the protection performance of Kevlar fiber cloth stuffed bumper shield enhanced at higher ambient temperature.

  14. The Simulating of the Woven Fabric Visual System

    Institute of Scientific and Technical Information of China (English)

    DENG Zhongmin; LU Hongmei; ZHU Lili

    2006-01-01

    With Visual C++6.0 as the language, following the traditional waterfall model and the software engineering theory, utilizing the technique of the dialog box, picture synthesis in VC, the writers present the developing of the woven fabric CAD system under the environment of Windows98. The system includes weave designing, yarn simulating, color matching, handling hand sample fabric and the testing effect.The basic methods and effect evaluation have been discussed and developed for the weave designing, yarn appearance simulating and fabric color matching, as well as handling hand sample states the image processing, such as DIB(Device-independent bitmap);meanwhile, the developed system has been tested and run in actual design and textile mill trials. The operated results show that the system runs steadily, efficiently and smart, it can be widely used in yarn and fabric design by using with the merits of convenience, celerity and nicety in shortening the developing periods of product; additionally, it provides in fact a new approach to technical design for textile mills.

  15. Performance of polymer gears reinforced with sisal woven rovings

    Directory of Open Access Journals (Sweden)

    A. Faizur Rahman

    2014-12-01

    Full Text Available Polymer gears find a common place in many industries and applications. In general, carbon fibre and glass fibres are used as reinforcement in polymer gears. This current research focuses on developing and testing the temperature and wear performance of Polyester spur gears reinforced with Sisal Woven Rovings (SWRP . Volume fractions (Vf such as 5% (SWRP/A, 10% (SWRP/B, 15% (SWRP/C and 20% (SWRP/D of gear specimens were prepared and tested for temperature and wear effects. Gears were tested up to 1.4 x 106 cycles. Gear tooth damages are recorded through optical photographs. The result reveals that the temperature and wear performance of SWRP/A and SWRP/B gears were low compared to SWRP/D gears.A small amount of wear damages were observed in SWRP/C gears. No damages were occurred in SWRP/D gears upto 1.4 x 106 cycles and also it was observed that the temperature and wear rate were found to be 15 % and 36 % lesser in SWRP/D gears when compared to SWRP/A gears.

  16. Damage in woven CFRP laminates under impact loading

    Directory of Open Access Journals (Sweden)

    Silberschmidt V.V.

    2012-08-01

    Full Text Available Carbon fibre-reinforced polymer (CFRP composites used in sports products can be exposed to different in-service conditions such as large dynamic bending deformations caused by impact loading. Composite materials subjected to such loads demonstrate various damage modes such as matrix cracking, delamination and, ultimately, fabric fracture. Damage evolution affects both in-service properties and performance of CFRP that can deteriorate with time. These failure modes need adequate means of analysis and investigation, the major approaches being experimental characterisation and numerical simulations. This research deals with a deformation behaviour and damage in composite laminates due to dynamic bending. Experimental tests are carried out to characterise the behaviour of a woven CFRP material under large-deflection dynamic bending in impact tests carried out to obtain the force-time and absorbed energy profiles for CFRP laminates. Damage in the impacted laminates is analysed using optical microscopy. Numerical simulations are performed to study the deformation behaviour and damage in CFRP for cases of large-deflection bending based on three-dimensional finite-element models implemented in the commercial code Abaqus/Explicit. Multiple layers of bilinear cohesive-zone elements are employed to model the initiation and progression of inter-ply delamination observed in the microscopy studies. The obtained results of simulations show good agreement with experimental data.

  17. Quantifying Effects of Voids in Woven Ceramic Matrix Composites

    Science.gov (United States)

    Goldsmith, Marlana B.; Sankar, Bhavani V.; Haftka, Raphael T.; Goldberg, Robert K.

    2013-01-01

    Randomness in woven ceramic matrix composite architecture has been found to cause large variability in stiffness and strength. The inherent voids are an aspect of the architecture that may cause a significant portion of the variability. A study is undertaken to investigate the effects of many voids of random sizes and distributions. Response surface approximations were formulated based on void parameters such as area and length fractions to provide an estimate of the effective stiffness. Obtaining quantitative relationships between the properties of the voids and their effects on stiffness of ceramic matrix composites are of ultimate interest, but the exploratory study presented here starts by first modeling the effects of voids on an isotropic material. Several cases with varying void parameters were modeled which resulted in a large amount of variability of the transverse stiffness and out-of-plane shear stiffness. An investigation into a physical explanation for the stiffness degradation led to the observation that the voids need to be treated as an entity that reduces load bearing capabilities in a space larger than what the void directly occupies through a corrected length fraction or area fraction. This provides explanation as to why void volume fraction is not the only important factor to consider when computing loss of stiffness.

  18. Raman spectroscopy of thin-film silicon on woven polyester

    Energy Technology Data Exchange (ETDEWEB)

    Lind, Helena; Wilson, John [Department of Physics, School of Engineering and Physical Sciences, Heriot-Watt University, Riccarton, Edinburgh EH14 4AS (United Kingdom); Mather, Robert [Power Textiles Limited, Upland House, Ettrick Road, Selkirk TD7 5AJ (United Kingdom)

    2011-12-15

    Thin-film silicon deposited by plasma-enhanced chemical vapour deposition (PECVD), encompasses both hydrogenated amorphous silicon (a-Si:H) and 'nanocrystalline silicon' (nc-Si), the latter being a two-phase mixture of discrete nanocrystallites in an amorphous matrix. It is distinguished from a-Si:H by a characteristic Raman spectrum. As the film structure moves from amorphous to more crystalline, the Raman TO phonon spectral region no longer consists of a broad amorphous peak at {proportional_to}480 cm{sup -1} but instead has an obvious narrower peak located at higher wavenumber. The accepted signature peak for nc-Si lies between these two and most probably arises from the hexagonal, wurtzite structure of the nanocrystals. Here we use Raman spectroscopy to show how the structure of thin-film silicon on woven polyester is influenced by the substrate as well as by the deposition conditions. We find that the rough surface of the textile substrate enables nc-Si formation, provided that the correct deposition conditions are employed and that the substrate temperature does not exceed 210 C. Although the gas mixture is the dominant parameter for determining the film structure, and input power also has a significant effect, we find that a specific combination of these interrelated parameters is essential to control the final structure. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  19. Woven Glass Fiber Composites with Aligned Carbon Nanotube Sheet Interlayers

    Directory of Open Access Journals (Sweden)

    Hardik Bhanushali

    2016-01-01

    Full Text Available This investigation describes the design, fabrication, and testing of woven glass fiber reinforced epoxy matrix laminates with aligned CNT sheets integrated between plies in order to improve the matrix dominated through thickness properties such as the interlaminar fracture toughness at ply interfaces. Using aligned CNT sheets allows for a concentration of millimeter long CNTs at the most likely point of laminate failure. Mode I and Mode II interlaminar fracture toughness of various CNT modified samples were investigated using double cantilever beam (DCB and end notched flexure (ENF experiments, respectively. Short beam strength (SBS and in-plane tensile properties of the CNT modified samples were also investigated. Moderate improvement was observed in Mode I and Mode II fracture toughness at crack initiation when aligned CNT sheets with a basis weight of 0.354 g/m2 were used to modify the ply interface. No compromise in the in-plane mechanical properties of the laminate was observed and very little improvement was observed in the shear related short beam strength of the CNT modified laminates as compared to the control samples. Integration of aligned CNT sheets into the composite laminate imparted in-plane and through thickness electrical properties into the nonconductive glass fiber reinforced epoxy composite laminates.

  20. Mechanical and dynamic mechanical behaviour of novel glass–natural fibre intra-ply woven polyester composites

    Indian Academy of Sciences (India)

    M RAJESH; JEYARAJ PITCHAIMANI

    2017-07-01

    A novel intra-ply woven fabric polyester composite with glass fibre yarns in one direction and natural fibre yarns in another direction of basket-type woven fabric has been investigated for mechanical and dynamic mechanical characteristics. Individual glass fibre woven fabric, natural fibres woven fabric and intraplynatural fibres woven fabric composites are also investigated for the comparison purpose. Results reveal that the intra-ply woven fabric hybridization enhances impact and damping properties of the composite significantly than the tensile and flexural properties. Intra-ply woven fabrics with glass fibre yarns in warp direction and jute fibre yarns in weft direction (WGWJ) exhibit better impact properties compared with woven fabric with other combinations. Dynamic mechanical analysis results reveal that intra-ply woven fabric composite with glass fibreyarns in warp direction and jute and banana fibre yarns in weft direction (WGWJAB) gives higher damping characteristics due to the multi-level interaction between fibre–fibre and fibre–matrix interactions.

  1. 无纺布再利用在妇科诊查中的应用研究%The application of non-woven fabrics recycling in gynecological

    Institute of Scientific and Technical Information of China (English)

    罗云香; 刘新凤

    2011-01-01

    目的 探讨无纺布再利用在妇科诊查中的应用效果.方法 将1920张无纺布回收进行高压蒸汽灭菌,返妇科门诊作检查臀垫使用,研究其灭菌、阻菌效果及成本构成.结果 无纺布灭菌包的当天、15天、30天的细菌培养结果均为阴性;回收返消毒的无纺布与传统妇科检查臀垫的费用比为1∶l4.4.结论 无纺布再利用在妇科诊查中费用低廉,经济环保,值得推广应用.%Objective To probe the application effect of the non-woven fabric recycling in gynecological treatment process. Methods A field study is conducted at a gynecological treatment center. 1920 pieces of non-woven fabrics were recycled by high pressure steam bacteria-killing and reused in gynecological treatment process as protective pad to study the bacteriostatic and blocking effect and cost construction of them. Results The results of bacterial culture were negative which tested on the first day and the Fifteenth day and the thirtieth day of non-woven fabrics that were packed sterilized. The cost ratio is Conclusion The non-woven fabrics recycling in gynecological treatment process is low cost and environment-friendly which deserve more extensive application in clinic.

  2. Preparation and characterization of activated carbon fiber (ACF) from cotton woven waste

    Science.gov (United States)

    Zheng, Jieying; Zhao, Quanlin; Ye, Zhengfang

    2014-04-01

    In this study, the activated carbon fibers (ACFs) were prepared using cotton woven waste as precursor. The cotton woven waste was first partly dissolved by 80% phosphoric acid and then was pre-soaked in 7.5% diammonium hydrogen phosphate solution. Finally, carbonization and activation were proceeded to get ACF. The optimum preparation conditions, including carbonization temperature, carbonization time, activation temperature and activation time, were chosen by orthogonal design. Nitrogen adsorption/desorption test was conducted to characterize the prepared ACF's pore structure. Fourier transform infrared spectroscopy (FTIR) analysis, X-ray photoelectron spectroscopy (XPS) and environmental scanning electron microscope (ESEM) were employed to characterize its chemical properties and morphology. Adsorption of oilfield wastewater was used to evaluate its adsorption properties. The results show that the prepared ACF is in the form of fiber, with the sectional diameters of 11.7 × 2.6 μm and the surface area of 789 m2/g. XPS results show that carbon concentration of the prepared ACF is higher than that of the commercial ACF. When the prepared ACF dosage is 6 g/L, over 80% of COD and over 70% of chrominance can be removed after 24 h of adsorption at 18 °C. We demonstrated the catalytic growth of m-axial InxGa1-xN (0.10 ≤ x ≤ 0.17) nanocolumn arrays with high crystallinity on silicon substrates using metal-organic chemical vapor deposition with trimethylindium (TMIn), triethylgallium (TEGa), and ammonia as precursors. The high quality of InGaN nanocolumns (NCs) were believed to be due to the utilization of TEGa that achieved less carbon impurities and offered more comparable vapor pressure with that of TMIn at low temperature. In addition, these NCs were grown in non-polar m-axis, which the internal electric field of the InGaN that often deteriorates the device performances might be able to be eliminated. Furthermore, the bandgap of this InGaN can be modulated from

  3. 无纺布应用于污水处理的研究现状%Research Of Non-woven Fabrics Used In Sewage Treatment

    Institute of Scientific and Technical Information of China (English)

    王志坚

    2013-01-01

      无纺布作为一种新型的过滤材料,具有独特的结构,体现出了良好的过滤能力,因此在污水处理领域得到越来越广泛的关注和应用。同时无纺布可以与很多污水处理工艺联用,不仅提高了出水水质,还克服了膜生物反应器造价高、能耗大等缺点。总结了国内外一些针对无纺布以及无纺布与其他工艺联用的研究,并获得了实际的运行参数。%Non-woven as a new type of filter material has a unique structure, reflect better filtering capabilities, so more and more attention and application in the field of sewage treatment has been attracted. Nonwovens can associate with many wastewater treatment processes, not only to improve the water quality, but also to overcome the high cost, energy consumption and other shortcomings of membrane bioreactor. Research on non-woven fabrics and non-woven fabrics associate with other processes at home and abroad are summarized, also get some actual operating parameters .

  4. Reduction in the modulus of elasticity in orthodontic wires.

    Science.gov (United States)

    Goldberg, A J; Vanderby, R; Burstone, C J

    1977-10-01

    The modulus of elasticity of stainless steel orthodontic wires was found to be 20% below the normally assumed range of 19.3 to 20.0 x 10(4) MPa (28.0 to 29.0 x 10(6) psi). Use of the latter value can result in significant computational errors in orthodontic applicance mechanics. The lower modulus was attributed to severe cold drawing.

  5. Elastic modulus of posts and the risk of root fracture.

    Science.gov (United States)

    Meira, Josete B C; Espósito, Camila O M; Quitero, Mayra F Z; Poiate, Isis A V P; Pfeifer, Carmem Silvia C; Tanaka, Carina B; Ballester, Rafael Y

    2009-08-01

    The definition of an optimal elastic modulus for a post is controversial. This work hypothesized that the influence of the posts' elastic modulus on dentin stress concentration is dependent on the load direction. The objective was to evaluate, using finite element analysis, the maximum principal stress (sigma(max)) on the root, using posts with different elastic modulus submitted to different loading directions. Nine 3D models were built, representing the dentin root, gutta-percha, a conical post and the cortical bone. The softwares used were: MSC.PATRAN2005r2 (preprocessing) and MSC.Marc2005r2 (processing). Load of 100 N was applied, varying the directions (0 degrees, 45 degrees and 90 degrees) in relation to the post's long axis. The magnitude and direction of the sigma(max) were recorded. At the 45 degrees and 90 degrees loading, the highest values of sigma(max) were recorded for the lowest modulus posts, on the cervical region, with a direction that suggests debonding of the post. For the 0 degrees loading, the highest values of sigma(max) were recorded for higher modulus posts, on the apical region, and the circumferential direction suggests vertical root fracture. The hypothesis was accepted: the effect of the elastic modulus on the magnitude and direction of the sigma(max) generated on the root was dependent on the loading direction.

  6. An Evaluation of 3D Woven Orthogonal Composites' Potential in the Automotive Supply Chain

    Science.gov (United States)

    Taylor, Dalia

    The automotive supply chain and its management can be a very complex process and comprises a long dynamic and complex network that consists of four primary segments: original equipment manufacturers (OEMs), first tier suppliers, sub tiers suppliers, and infrastructure suppliers. During the analysis of the current automotive industry it was identified that textile industry importance is considerable increasing as a part of the global automotive supply chain, because textile products are used for interior, exterior and even suspension parts and components. Automotive industry has an increasing demand for higher quality exterior panels with better functional properties and reduced weight. One of the main potentials for this demand is based on the three-dimensional woven composites technology innovations which can replace an existing technology. The new role of the textile industry could make important changes in the automotive supply chain industry, such as: changes in the size of the supply chain, the time to the market and the position of textile industry in the automotive supply chain structure. 3D composite materials from high performance fibers, such as glass and carbon, have been used for automotive applications in a limited way due to the low production rate and the lack of research and development. This research will contribute to the understanding of textile composites in transportation and the textile parameters that affect the performance characteristics of these materials. The research examines the performance characteristics of lighter and stronger 3D woven fabric composites made from fiberglass with the aim to improve fuel efficiency by reducing the total vehicle weight while maintaining safety standards. The performance characteristics of the 3D woven fabric composite can be designed by changing different construction parameters, such as picks density, pick roving linear density, arrangements of warp and z-yarns, and the number of warp and picks layers

  7. Protozoa and metazoa relations to technological conditions of non-woven textile filters for wastewater treatment.

    Science.gov (United States)

    Spychała, Marcin; Sowińska, Aleksandra; Starzyk, Justyna; Masłowski, Adam

    2015-01-01

    The objective of this study was a preliminary identification of basic groups of micro-organisms in the cross-sectional profile of geotextile filters for septic tank effluent (STE) treatment and their relations to technological conditions. Reactors with textile filters treating wastewater were investigated on a semi-technical scale. Filters were vertically situated and STE was filtered through them under hydrostatic pressure at a wastewater surface height of 7-20 cm. Filters were made of four layers of non-woven TS 20 geotextile of 0.9 mm thickness. Various groups of organisms were observed; the most abundant group comprised free-swimming and crawling ciliates, less abundant were stalked ciliates and the least numerous were nematodes. The individual counts of all groups of micro-organisms investigated during the study were variable according to time and space. The high abundance of Opercularia, a commonly observed genus of stalked ciliates, was related to the high efficiency of wastewater treatment and dissolved oxygen concentration of about 1.0 g/m3. Numbers of free-swimming and crawling ciliates had a tendency to decrease in relation to the depth of filter cross-sectional profile. The variability in counts of particular groups of organisms could be related to the local stress conditions. No correlation between identified organism count and total mass concentration in the cross-sectional filter profile was found.

  8. An Analytical Model for Predicting Stab Resistance of Flexible Woven Composites

    Science.gov (United States)

    Hou, Limin; Sun, Baozhong; Gu, Bohong

    2013-08-01

    Flexible woven composites have been widely used in geotextiles and light weight building structures. The stab resistance behavior of the flexible woven composite is an important factor for the application design. This paper reports an analytical model for predicting stab resistance of flexible woven composites under perpendicular stab with a blunt steel penetrator. The analytical model was established based on the microstructure and the deformation shape of the flexible woven composite under normal penetration. During the quasi-static stab penetration, the strain energies of warp and weft yarns and resins have been calculated. The stab resistance was calculated from the strain energies of the flexible woven composite. Furthermore, the contributions of the warp and weft yarns, resins to the stab resistance have been analyzed. It was found the three constituents have near the same contribution to the stab resistance. The higher value of weaving density, strength of yarns and especially the higher strength coating resins will lead the higher stab resistance. With the analytical model, the stab resistance would be expected to be designed in an efficient way with an acceptable precision.

  9. Microfibrous {beta}-TCP/collagen scaffolds mimic woven bone in structure and composition

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Shen; Zhang Xin; Cai Qing; Yang Xiaoping [Key Laboratory of Beijing City on Preparation and Processing of Novel Polymer Materials, College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029 (China); Wang Bo; Deng Xuliang, E-mail: yangxp@mail.buct.edu.c [Department of VIP Dental Service, School and Hospital of Stomatology, Peking University, Beijing 100081 (China)

    2010-12-15

    Woven bone, as the initial form of bone tissue, is always found in developing and repairing bone. It is thought of as a temporary scaffold for the deposition of osteogenic cells and the laying down of lamellar bone. Thus, we hypothesize that a matrix which resembles the architecture and components of woven bone can provide an osteoblastic microenvironment for bone cell growth and new bone formation. In this study, woven-bone-like beta-tricalcium phosphate ({beta}-TCP)/collagen scaffolds were fabricated by sol-gel electrospinning and impregnating methods. Optimization studies on sol-gel synthesis and electrospinning process were conducted respectively to prepare pure {beta}-TCP fibers with dimensions close to mineralized collagen fibrils in woven bone. The collagen-coating layer prepared by impregnation had an adhesive role that held the {beta}-TCP fibers together, and resulted in rapid degradation and matrix mineralization in in vitro tests. MG63 osteoblast-like cells seeded on the resultant scaffolds showed three-dimensional (3D) morphologies, and merged into multicellular layers after 7 days culture. Cytotoxicity test further revealed that extracts from the resultant scaffolds could promote the proliferation of MG63 cells. Therefore, the woven-bone-like matrix that we constructed favored the attachment and proliferation of MG63 cells in three dimensions. It has great potential ability to shorten the time of formation of new bone.

  10. Ballistic Impact Response of Woven Hybrid Coir/Kevlar Laminated Composites

    Directory of Open Access Journals (Sweden)

    Azrin Hani A.R

    2016-01-01

    Full Text Available The effects of different laminated hybrid composites stacking configuration subjected to ballistic impact were investigated. The hybrid composites consist of woven coir (C and woven Kevlar (K layers laminated together. The samples of woven coir were prepared using handloom device. The composites were produced by stacking the laminated woven coir and Kevlar alternately with the presence of the binder. The samples were tested under ballistic impact with different stacking configuration. The results obtained had successfully achieved the National Institute of Justice (NIJ standard level IIA with energy absorption of 435.6 kJ and 412.2 kJ under the projectile speed of between 330 m/s and 321 m/s respectively. Samples that having Kevlar layer at the front face and woven coir layer as back face achieved partial penetration during projectile impact. This orientation is proven to have good impact energy absorption and able to stop projectile at the second panel of the composites.

  11. Measurement of Young’s modulus and damping of fibers at cryogenic temperatures

    Science.gov (United States)

    Rice, Brian; Quinzi, Joseph; Lund, Lance; Ulreich, Jeffrey; Shoup, Milton

    2014-09-01

    High-yield inertial confinement fusion targets are at cryogenic temperatures and must remain stable to within 10 μm during the implosion. Young’s modulus and damping properties of fibers used to mount cryogenic targets are needed to design stable targets, but these property values do not exist in literature. A novel experimental method that tracks how target vibrations respond to an impulse is used to quantitatively measure these properties from 295 to 20 K. Young’s modulus and the critical damping ratio are measured for NicalonTM ceramic grade [silicon carbide (SiC)], Zylon®HM {poly[p-phenlyne-2,6-benzobisoxazole] (PBO)}, M5 {dimidazo-pyridinylene [dihydroxy] phenylene (PIPD)}, and polyimide fibers. This method allows one to accurately measure the properties of interest for fiber diameters as small as 12 μm at ∼20 K. Significant changes are seen in Young’s modulus for the three polymeric fibers with respect to temperature; while Young’s modulus is relatively invariant to temperature for the ceramic fiber.

  12. Strain-rate Dependence of Elastic Modulus Reveals Silver Nanoparticle Induced Cytotoxicity.

    Science.gov (United States)

    Caporizzo, Matthew Alexander; Roco, Charles M; Ferrer, Maria Carme Coll; Grady, Martha E; Parrish, Emmabeth; Eckmann, David M; Composto, Russell John

    Force-displacement measurements are taken at different rates with an atomic force microscope to assess the correlation between cell health and cell viscoelasticity in THP-1 cells that have been treated with a novel drug carrier. A variable indentation-rate viscoelastic analysis, VIVA, is employed to identify the relaxation time of the cells that are known to exhibit a frequency dependent stiffness. The VIVA agrees with a fluorescent viability assay. This indicates that dextran-lysozyme drug carriers are biocompatible and deliver concentrated toxic material (rhodamine or silver nanoparticles) to the cytoplasm of THP-1 cells. By modelling the frequency dependence of the elastic modulus, the VIVA provides three metrics of cytoplasmic viscoelasticity: a low frequency modulus, a high frequency modulus and viscosity. The signature of cytotoxicity by rhodamine or silver exposure is a frequency independent twofold increase in the elastic modulus and cytoplasmic viscosity, while the cytoskeletal relaxation time remains unchanged. This is consistent with the known toxic mechanism of silver nanoparticles, where metabolic stress causes an increase in the rigidity of the cytoplasm. A variable indentation-rate viscoelastic analysis is presented as a straightforward method to promote the self-consistent comparison between cells. This is paramount to the development of early diagnosis and treatment of disease.

  13. Correlation Between Time Change in Modulus of Short-Period Geomagnetic Variation and Seismicity in Taiwan

    Directory of Open Access Journals (Sweden)

    Kuang-Jung Chen

    2007-01-01

    Full Text Available In this study, geomagnetic data of the Lunping observatory from 1993 to 2000 are utilized for computing the amplitude variation of short-period geomagnetic total intensity data, using the complex demodulation method (CD method. In order to compare these time changes with seismicity, earthquakes that occurred within 150 km of Lunping, with magnitude ML greater than 3.0, are located. The total sum of those earthquakes, summed month by month, is correlated with the modulus. After removing seasonal effect, our results show that the modulus of periods 24, 12, and 8 hr reveals a notable change that seems to be related to the total sum of events within the whole study period. One possible precursor is found 6 months prior to the 1999 high seismicity. The modulus for the periods 24, 12, and 8 hr increased gradually from the beginning of 1999 to August 1999. After earthquake occurrence the modulus decreased again to a normal level. We propose that this notable increase might be related to a preparation process for this strong earthquake.

  14. Diameter-dependent bending modulus of individual multiwall boron nitride nanotubes.

    Science.gov (United States)

    Tanur, Adrienne E; Wang, Jiesheng; Reddy, Arava L M; Lamont, Daniel N; Yap, Yoke Khin; Walker, Gilbert C

    2013-04-25

    The mechanical properties of individual multiwall boron nitride nanotubes (MWBNNTs) synthesized by a growth-vapor-trapping chemical vapor deposition method are investigated by a three-point bending technique via atomic force microscopy. Multiple locations on suspended tubes are probed in order to determine the boundary conditions of the supported tube ends. The bending moduli (EB) calculated for 20 tubes with diameters ranging from 18 to 58 nm confirm the exceptional mechanical properties of MWBNNTs, with an average EB of 760 ± 30 GPa. For the first time, the bending moduli of MWBNNTs are observed to increase with decreasing diameter, ranging from 100 ± 20 GPa to as high as 1800 ± 300 GPa. This diameter dependence is evaluated by Timoshenko beam theory. The Young's modulus and shear modulus were determined to be 1800 ± 300 and 7 ± 1 GPa, respectively, for a trimmed data set of 16 tubes. The low shear modulus of MWBNNTs is the reason for the detected diameter-dependent bending modulus and is likely due to the presence of interwall shearing between the crystalline and faceted helical nanotube structures of MWBNNTs.

  15. Variable modulus cellular structures using pneumatic artificial muscles

    Science.gov (United States)

    Pontecorvo, Michael E.; Niemiec, Robert J.; Gandhi, Farhan S.

    2014-04-01

    This paper presents a novel variable modulus cellular structure based on a hexagonal unit cell with pneumatic artificial muscle (PAM) inclusions. The cell considered is pin-jointed, loaded in the horizontal direction, with three PAMs (one vertical PAM and two horizontal PAMs) oriented in an "H" configuration between the vertices of the cell. A method for calculation of the hexagonal cell modulus is introduced, as is an expression for the balance of tensile forces between the horizontal and vertical PAMs. An aluminum hexagonal unit cell is fabricated and simulation of the hexagonal cell with PAM inclusions is then compared to experimental measurement of the unit cell modulus in the horizontal direction with all three muscles pressurized to the same value over a pressure range up to 758 kPa. A change in cell modulus by a factor of 1.33 and a corresponding change in cell angle of 0.41° are demonstrated experimentally. A design study via simulation predicts that differential pressurization of the PAMs up to 2068 kPa can change the cell modulus in the horizontal direction by a factor of 6.83 with a change in cell angle of only 2.75°. Both experiment and simulation show that this concept provides a way to decouple the length change of a PAM from the change in modulus to create a structural unit cell whose in-plane modulus in a given direction can be tuned based on the orientation of PAMs within the cell and the pressure supplied to the individual muscles.

  16. Expression, crosslinking, and developing modulus master curves of recombinant resilin.

    Science.gov (United States)

    Khandaker, Md Shahriar K; Dudek, Daniel M; Beers, Eric P; Dillard, David A

    2017-05-01

    Resilin is a disordered elastomeric protein found in specialized regions of insect cuticles, where low stiffness and high resilience are required. Having a wide range of functions that vary among insect species, resilin operates across a wide frequency range, from 5Hz for locomotion to 13kHz for sound production. We synthesize and crosslink a recombinant resilin from clone-1 (exon-1+exon-2) of the gene, and determine the water content (approximately 80wt%) and dynamic mechanical properties, along with estimating surface energies relevant for adhesion. Dynamic moduli master curves have been developed, by applying the time-temperature superposition principle (TTSP) and time-temperature concentration superposition principle (TTCSP), and compared with reported master curves for natural resilin from locusts, dragonflies, and cockroaches. To our knowledge, this is the first time dynamic moduli master curves have been developed to explore the dynamic mechanical properties of recombinant resilin and compare with resilin behavior. The resulting master curves show that the synthetic resilin undergoes a pronounced transition with increasing ethanol concentrations, with the storage modulus increasing by approximately three orders of magnitude. Although possibly a glass transition, alternate explanations include the formation of intramolecular hydrogen bonds or that the chitin binding domain (ChBD) in exon-2 might change the secondary structure of the normally disordered exon-1 into more ordered conformations that limit deformation.

  17. Polymerization Shrinkage and Flexural Modulus of Flowable Dental Composites

    Directory of Open Access Journals (Sweden)

    Janaína Cavalcanti Xavier

    2010-09-01

    Full Text Available Linear polymerization shrinkage (LPS, flexural strength (FS and modulus of elasticity (ME of low-viscosity resin composites (Admira Flow™, Grandio Flow™/VOCO; Filtek Z350 Flow™/3M ESPE; Tetric Flow™/Ivoclar-Vivadent was evaluated using a well-established conventional micro-hybrid composite as a standard (Filtek Z250™/3M ESPE. For the measurement of LPS, composites were applied to a cylindrical metallic mould and polymerized (n = 8. The gap formed at the resin/mould interface was observed using SEM (1500×. For FS and ME, specimens were prepared according to the ISO 4049 specifications (n = 10. Statistical analysis of the data was performed with one-way ANOVA and the Tukey test. The conventional resin presented significantly lower LPS associated with high FS and ME, but only the ME values of the conventional resin differed significantly from the low-viscosity composites. The relationship between ME and LPS of low-viscosity resin composites when used as restorative material is a critical factor in contraction stress relief and marginal leakage.

  18. Influence of Chemical Surface Modification of Woven Fabrics on Ballistic and Stab Protection of Multilayer Packets

    Directory of Open Access Journals (Sweden)

    Diana GRINEVIČIŪTĖ

    2014-06-01

    Full Text Available In order to achieve enhanced protective and wear (flexibility, less bulkiness properties of ballistic and stab protecting panels the investigation of chemical surface modification of woven p-aramid fabrics was performed applying different chemical composition shear thickening fluid (STF which improves friction inside fabric structure. For the chemical treatment silicic acid and acrylic dispersion water solutions were used and influence of their different concentrations on panels’ protective properties were investigated. Results of ballistic tests of multilayer protective panel have revealed that shear thickening effect was negligible when shooting at high energy range (E > 440 J. Determination of stab resistance of p-aramid panels has shown that different chemical composition of STFs had different influence on protective properties of the panels. Application of low concentrations of silicic acid determined higher stab resistance values comparing to higher concentrations of acrylic dispersion water solutions. At this stage of research stab tests results as ballistic ones determined that STF application for multilayer p-aramid fabrics protective panels is more efficient at low strike energy levels. DOI: http://dx.doi.org/10.5755/j01.ms.20.2.3138

  19. Atmospheric pressure plasma deposition of antimicrobial coatings on non-woven textiles

    Science.gov (United States)

    Nikiforov, Anton Yu.; Deng, Xiaolong; Onyshchenko, Iuliia; Vujosevic, Danijela; Vuksanovic, Vineta; Cvelbar, Uros; De Geyter, Nathalie; Morent, Rino; Leys, Christophe

    2016-08-01

    A simple method for preparation of nanoparticle incorporated non-woven fabric with high antibacterial efficiency has been proposed based on atmospheric pressure plasma process. In this work direct current plasma jet stabilized by fast nitrogen flow was used as a plasma deposition source. Three different types of the nanoparticles (silver, copper and zinc oxide nanoparticles) were employed as antimicrobial agents. X-ray photoelectron spectroscopy (XPS) measurements have shown a positive chemical shift observed for Ag 3d 5/2 (at 368.1 eV) suggests that silver nanoparticles (AgNPs) are partly oxidized during the deposition. The surface chemistry and the antibacterial activity of the samples against Staphylococcus aureus and Escherichia coli were investigated and analyzed. It is shown that the samples loaded with nanoparticles of Ag and Cu and having the barrier layer of 10 nm characterized by almost 97% of bacterial reduction whereas the samples with ZnO nanoparticles provide 86% reduction of Staphylococcus aureus. Contribution to the topical issue "6th Central European Symposium on Plasma Chemistry (CESPC-6)", edited by Nicolas Gherardi, Ester Marotta and Cristina Paradisi

  20. UV dosimeter based on polyamide woven fabric and nitro blue tetrazolium chloride as an active compound

    Energy Technology Data Exchange (ETDEWEB)

    Kozicki, Marek, E-mail: mkozicki@mitr.p.lodz.pl [Institute of Architecture of Textiles, Technical University of Lodz, Zeromskiego 116, 90-924 Lodz (Poland); European Centre of Bio- and Nano-Technology (ECBNT), Technical University of Lodz, Zeromskiego 116, 90-924 Lodz (Poland); Sasiadek, Elzbieta [Institute of Architecture of Textiles, Technical University of Lodz, Zeromskiego 116, 90-924 Lodz (Poland); European Centre of Bio- and Nano-Technology (ECBNT), Technical University of Lodz, Zeromskiego 116, 90-924 Lodz (Poland)

    2011-10-15

    This paper reports on the preparation and features of a UV light dosimeter composed of nitro blue tetrazolium chloride (NBT) and polyamide woven fabric. This textile dosimeter is based on the conversion reaction of NBT into formazan, which was initially examined in aerated aqueous solutions through steady state UV irradiation. Irradiated solutions change their colour as a consequence of the formation of polydisperse NBT formazan particles. This was analysed in relation to the absorbed dose of UV light through UV-VIS spectrophotometry and dynamic laser light scattering measurements. When NBT substrate molecules are embedded in polyamide textile, UV irradiation leads to similar effects as in solution. However, the tinge intensity changes at much lower absorbed doses. The dependence of the tinge intensity on the absorbed dose was followed by measurements of the remission of light from the NBT-polyamide samples. Consequently, the calibration parameters were calculated such as the dose sensitivity, dose range, and quasi-linear dose range. An improvement of the NBT-polyamide samples by application of a colour levelling agent and improvement of their resistance to humidity is presented. Finally, the samples were used for estimation of absorbed UV energy distribution showing their capability as new dosimeters for in-plane high resolution radiation dose measurements. - Highlights: > Preparation of a textile dosimeter with nitro blue tetrazolium chloride is shown. > The dosimeter responds to UV light by a colour change. > 2D radiation dose measurements are possible. > PC scanners can be employed for measurements of the dosimeter.

  1. 3D Woven Structures and Their Weave Design with Changing Cross-section on Warp and Weft Direction

    Institute of Scientific and Technical Information of China (English)

    ZHU Cheng-yan

    2004-01-01

    With 3D orthogonal and pseudo-orthogonal weaves, woven sructures with lengthwise and widthwise changing cross section on one side or both sides of the structure can be constructed. The weave formation and the looming draft creation are discussed in this paper which can be used as references to manufacture woven preforms with changing cross sections.

  2. Studies on the chemical resistance and mechanical properties of natural polyalthia cerasoides woven fabric/glass hybridized epoxy composites

    CSIR Research Space (South Africa)

    Jayaramudu, J

    2015-01-01

    Full Text Available In the present work, natural Polyalthiacerasoide woven fabrics were extracted from the bark of the tree and using these woven fabrics/glass fibre as reinforcements and epoxy as matrix the hybrid composites were prepared by the hand lay-up technique...

  3. 77 FR 31182 - Final Withdrawal of Regulations Pertaining to Imports of Cotton Woven Fabric and Short Supply...

    Science.gov (United States)

    2012-05-25

    ... Pertaining to Imports of Cotton Woven Fabric and Short Supply Procedures AGENCY: Import Administration... short supply procedures. Both sets of regulations are obsolete: The tariff quota on cotton woven fabric expired in 2009, and the short supply voluntary restraints have not affected U.S. trade for over 19...

  4. Musculoskeletal symptoms as related to ergonomic factors in Iranian hand-woven carpet industry and general guidelines for workstation design.

    Science.gov (United States)

    Choobineh, Alireza; Lahmi, Mohammadali; Shahnavaz, Houshang; Jazani, Reza Khani; Hosseini, Mostafa

    2004-01-01

    Carpet weaving is a high risk occupation for developing musculoskeletal disorders (MSDs). The objectives of the present study, which was carried out in the Iranian hand-woven carpet industry, were determination of the prevalence of MSD symptoms, identification of major factors associated with MSD symptoms and development of guidelines for workstation design. 1,439 randomly selected weavers participated in this study. A questionnaire was used to collect data on MSD symptoms. The results revealed that the prevalence rates for symptoms in different body regions were high as compared to the general Iranian population (for neck, back and large joints, p loom type, working posture, daily working time and seat type. Based on the results, some general guidelines for designing weaving workstations were developed. A prototype test showed that the new workstation was acceptable for subject tests and that it improved working posture.

  5. Constitutive Theories for Woven Composite Structures Subjected to Shock Loading; Experimental Validation Using a Conical Shock Tube

    Directory of Open Access Journals (Sweden)

    David R. Hufner

    2012-01-01

    Full Text Available Woven polymer-based composites are currently used in a wide range of marine applications. These materials often exhibit highly nonlinear, rate dependent, anisotropic behavior under shock loadings. Correlation to transient response data, beyond an initial peak, is often difficult. The state of damage evolves throughout the time history and the unloading response varies based on the amount, and nature of, the accumulated damage. Constitutive theories that address the loading and unloading responses have been developed and integrated with each other. A complete theory, applicable to transient dynamic analysis, is presented. The model is implemented within the commercial finite element code, Abaqus, in the form of a user material subroutine. In this study, the conical shock tube is used to experimentally reproduce the high strain rates and fluid structure interactions typical of underwater shock loadings. The conical shock tube data is used to validate analytical model predictions. Simulation results are in good agreement with test data.

  6. Texture Dependent Young's Modulus in Austenitic Cladding

    OpenAIRE

    1988-01-01

    In Austenitic claddings of pressure vessel steel columnar grains with a 〈100〉-fiber axis oriented perpendicular to the surface have been previously observed. The fiber axis is parallel to the steepest temperature gradient. Since high temperature gradients also exist in the plane of cladding, preferred orientation should be found there.This was proved with {111}- and {220}-pole figures taken of the cladding in addition to {200}-pole figures. From these pole figures it could be concluded that t...

  7. Prediction Method for Tensile Property of Woven Fabrics in Lower Loads

    Institute of Scientific and Technical Information of China (English)

    WANG Fu-mei

    2002-01-01

    A prediction method for tensile properties of woven fabrics in lower loads was developed, where the yarns axes in the weave structure were assumed to be sine curves and the measured yarn mechanical properties and weave structure parameters were used as the input information for estimating the fabric properties. The predicted properties were compared with those measured and also with those calculated values based on Kawabata's straight line model. The results suggested that this method is a more reliable means to predict the tensile characteristics of woven fabrics.

  8. Determination of the elastic modulus of snow via acoustic measurements

    Science.gov (United States)

    Gerling, Bastian; van Herwijnen, Alec; Löwe, Henning

    2016-04-01

    The elastic modulus of snow is a key quantity from the viewpoint of avalanche research and forecasting, snow engineering or materials science in general. Since it is a fundamental property, many measurements have been reported in the literature. Due to differences in measurement methods, there is a lot of variation in the reported values. Especially values derived via computer tomography (CT) based numerical calculations using finite element methods are not corresponding to the results of other methods. The central issue is that CT based moduli are purely elastic whereas other methods may include viscoelastic deformation. In order to avoid this discrepancy we derived the elastic modulus of snow via wave propagation measurements and compared our results with CT based calculations. We measured the arrival times of acoustic pulses propagating through the snow samples to determine the P-wave velocity and in turn derive the elastic modulus along the direction of wave propagation. We performed a series of laboratory experiments to derive the P-wave modulus of snow in relation to density. The P-wave modulus ranged from 10 to 280 MPa for a snow density between 150 and 370 kg/m^3;. The moduli derived from the acoustic measurements correlated well with the CT-based values and both exhibited a power law trend over the entire density range. Encouraged by these results we used the acoustic method to investigate the temporal evolution of the elastic modulus. The rate of increase was very close to values mentioned in literature on the sintering rate of snow. Overall, our results are a first but important step towards a new measurement method to attain the elastic properties of snow.

  9. Young's modulus measurement based on surface plasmon resonance

    Science.gov (United States)

    Lotfalian, Ali; Jandaghian, Ali; Saghafifar, Hossein; Mohajerani, Ezzedin

    2017-09-01

    In this paper, Young's modulus of polymers is experimentally measured using pressure sensors based on surface plasmon polariton. Theoretical relationships of changes in polymer reflective index due to applying pressure are investigated as well as the dependence of surface plasmon to the polymer reflective index. For the purpose of investigating the effects of the layers thicknesses, numerical simulation is performed using transfer matrix. Changes in resonance angle of surface plasmon due to applying pressure are experimentally studied as well. Practically, a sample of silicon rubber, as one of the most widely-used polymers, is checked and its Young's modulus is measured as 8.1 MPa.

  10. Modulus of families of loops with applications in network analysis

    CERN Document Server

    Shakeri, Heman; Albin, Nathan; Scoglio, Caterina

    2016-01-01

    We study the structure of loops in networks using the notion of modulus of loop families. We introduce a new measure of network clustering by quantifying the richness of families of simple loops. Modulus tries to minimize the expected overlap among loops by spreading the expected link-usage optimally. We propose weighting networks using these expected link-usages to improve classical community detection algorithms. We show that the proposed method enhances the performance of certain algorithms, such as spectral partitioning and modularity maximization, on standard benchmarks.

  11. Temperature, Frequency and Young’s Modulus of a Wineglass

    Directory of Open Access Journals (Sweden)

    Amitta Miller

    2015-01-01

    Full Text Available A crystal soda-lime wineglass, heated to temperatures ranging from 25 °C to 150 °C, was tapped and the frequency recorded. It was shown that the relative change in the frequency at different temperatures can be used to determine the effect of temperature on Young’s Modulus of the glass. This simple method of tapping a wineglass is proposed as an effective way of determining the relative effect of temperature on Young’ Modulus of glass.

  12. Melt-spun shaped fibers with enhanced surface effects: fiber fabrication, characterization and application to woven scaffolds.

    Science.gov (United States)

    Park, S J; Lee, B-K; Na, M H; Kim, D S

    2013-08-01

    Scaffolds with a high surface-area-to-volume ratio (SA:V) are advantageous with regard to the attachment and proliferation of cells in the field of tissue engineering. This paper reports on the development of novel melt-spun fibers with a high SA:V, which enhanced the surface effects of a fiber-based scaffold while maintaining its mechanical strength. The cross-section of the fibers was altered to a non-circular shape, producing a higher SA:V for a similar cross-sectional area. To obtain fibers with non-circular cross-sectional shape, or shaped fibers, three different types of metal spinnerets were fabricated for the melt-spinning process, each with circular, triangular or cruciform capillaries, using deep X-ray lithography followed by nickel electroforming. Using these spinnerets, circular and shaped fibers were manufactured with biodegradable polyester, polycaprolactone. The SA:V increase in the shaped fibers was experimentally investigated under different processing conditions. Tensile tests on the fibers and indentation tests on the woven fiber scaffolds were performed. The tested fibers and scaffolds exhibited similar mechanical characteristics, due to the similar cross-sectional area of the fibers. The degradation of the shaped fibers was notably faster than that of circular fibers, because of the enlarged surface area of the shaped fibers. The woven scaffolds composed of the shaped fibers significantly increased the proliferation of human osteosarcoma MG63 cells. This approach to increase the SA:V in shaped fibers could be useful for the fabrication of programmable, biodegradable fiber-based scaffolds in tissue engineering.

  13. Quantitative photoacoustic elastography of Young's modulus in humans

    Science.gov (United States)

    Hai, Pengfei; Zhou, Yong; Gong, Lei; Wang, Lihong V.

    2017-03-01

    Elastography can noninvasively map the elasticity distribution of biological tissue, which is often altered in pathological states. In this work, we report quantitative photoacoustic elastography (QPAE), capable of measuring Young's modulus of human tissue in vivo. By combining photoacoustic elastography with a stress sensor having known stress-strain behavior, QPAE can simultaneously measure strain and stress, from which Young's modulus is calculated. We first applied QPAE to quantify the Young's modulus of tissue-mimicking agar phantoms with different concentrations. The measured values fitted well with both the empirical expectations based on the agar concentrations and those measured in independent standard compression tests. We then demonstrated the feasibility of QPAE by measuring the Young's modulus of human skeletal muscle in vivo. The data showed a linear relationship between muscle stiffness and loading. The results proved that QPAE can noninvasively quantify the absolute elasticity of biological tissue, thus enabling longitudinal imaging of tissue elasticity. QPAE can be exploited for both preclinical biomechanics studies and clinical applications.

  14. Device to measure elastic modulus of superconducting windings

    CERN Multimedia

    CERN PhotoLab

    1979-01-01

    This device was made to measure elastic modulus of the Po dipole superconducting coils. More elaborated devices, but based on the same concept, were later used to measure the apparent elastic moduli of the LHC superconducting magnet coils. See also 7903547X, 7901386.

  15. Modulus of smoothness and theorems concerning approximation on compact groups

    Directory of Open Access Journals (Sweden)

    H. Vaezi

    2003-01-01

    Full Text Available We consider the generalized shift operator defined by (Shuf(g=∫Gf(tut−1gdt on a compact group G, and by using this operator, we define “spherical” modulus of smoothness. So, we prove Stechkin and Jackson-type theorems.

  16. Impact Strength of Different Weaving Patterns of Woven Kenaf Reinforced Polyester Composites

    Science.gov (United States)

    Khalid, S. N. A.; Ismail, A. E.; Zainulabidin, M. H.

    2017-01-01

    This paper focuses on the effect of weaving patterns and orientations on the energy absorption of woven kenaf reinforced polyester composites. Kenaf fiber in the form of yarn is weaved to produce different weaving patterns such as plain, twill and basket. Three woven mats are stacked together and mixed with polyester resin before it is compressed to squeeze out any excessive resin. There is 9 different orientations are used during stacking processes. The hardened composites are cured for 24 hours before it is shaped according to specific dimensions for imp act tests. The composites are perforated with 1m/s blunted projectile. According to the experimental findings, both weaving patterns and orientations have distinct potential effects on the force-displacement diagrams. However, fiber orientations have insignificant effect for plain woven especially in the first stage of deformations. Energy absorption performances for each composite condition are calculated and then plotted against fiber orientations for different weaving patterns. It is found there is no strong relationship between energy absorption and fiber orientations. However for each case of composites, higher energy absorption is found for the composites orientated using [+40°/-15°/+40°/+75°]. Based on the fracture observation, both plain and basket-type woven composites reveal large fragmentations occurred indicating lower energy absorption performances. While for twill condition, no obvious fragmentation is observed where the impact damage around the perforated hole is uniformly distributed leading to higher capability of energy absorptions.

  17. Effects of Coupled Biaxial Tension and Shear Stresses on Decrimping Behavior in Pressurized Woven Fabrics

    Science.gov (United States)

    2007-11-02

    Fabric Forces F .., .. and Fiief Versus Aet for 3000-Denier. 1:1 TDR Plain-Woven D S P F ab ric...As did Freeston et al.,I this research found that visual inspections were insufficient for determining if the fabric specimens were initially square

  18. Direct Cost of Reprocessing Cotton-woven Surgical Drapes: a Case Study

    Directory of Open Access Journals (Sweden)

    Mariana Fexina Tomé

    2015-06-01

    Full Text Available OBJECTIVE Identify the direct cost of reprocessing double and single cotton-woven drapes of the surgical LAP package. METHOD A quantitative, exploratory and descriptive case study, performed at a teaching hospital. The direct cost of reprocessing cotton-woven surgical drapes was calculated by multiplying the time spent by professionals involved in reprocessing the unit with the direct cost of labor, adding to the cost of materials. The Brazilian currency (R$ originally used for the calculations was converted to US currency at the rate of US$0.42/R$. RESULTS The average total cost for surgical LAP package was US$9.72, with the predominance being in the cost of materials (US$8.70 or 89.65%. It is noteworthy that the average total cost of materials was mostly impacted by the cost of the cotton-woven drapes (US$7.99 or 91.90%. CONCLUSION The knowledge gained will subsidize discussions about replacing reusable cotton-woven surgical drapes for disposable ones, favoring arguments regarding the advantages and disadvantages of this possibility considering human resources, materials, as well as structural, environmental and financial resources.

  19. EFFECTS OF DYNEL FIBER BLENDING ON YARN SHRINKAGE AND WOVEN-FABRIC PROPERTIES

    Science.gov (United States)

    A 50/50 picker blend warp was woven with fillings from the various blends and twists. The fabrics were scoured and treated for water repellency . Highest...results of yarn and fabric shrinkage and air permeability. All water repellency tests were poor; fabrics with low-twist fillings were better than those

  20. STRESS - STRAIN CURVE ANALYSIS OF WOVEN FABRICS MAD E FROM COMBED YARNS TYPE WOOL

    Directory of Open Access Journals (Sweden)

    VÎLCU Adrian

    2014-05-01

    Full Text Available The paper analyses the tensile behavior of woven fabrics made from 45%Wool + 55% PES used for garments. Analysis of fabric behavior during wearing has shown that these are submitted to simple and repeated uni-axial or bi-axial tensile strains. The level of these strains is often within the elastic limit, rarely going over yielding. Therefore the designer must be able to evaluate the mechanical behavior of such fabrics in order to control the fabric behavior in the garment. This evaluation is carried out based on the tensile testing, using certain indexes specific to the stress-strain curve. The paper considers an experimental matrix based on woven fabrics of different yarn counts, different or equal yarn count for warp and weft systems and different structures. The fabrics were tested using a testing machine and the results were then compared in order to determine the fabrics’ tensile behavior and the factors of influence that affect it.From the point of view of tensile testing, the woven materials having twill weave are preferable because this type of structure is characterized by higher durability and better yarn stability in the fabric. In practice, the woven material must exhibit an optimum behavior to repeated strains, flexions and abrasions during wearing process. The analysis of fabrics tensile properties studied by investigation of stress-strain diagrams reveals that the main factors influencing the tensile strength are: yarns fineness, technological density of those two systems of yarns and the weaving type.

  1. Ballistic Impact Properties of Zr-Based Amorphous Alloy Composites Reinforced with Woven Continuous Fibers

    Science.gov (United States)

    Kim, Gyeong Su; Son, Chang-Young; Lee, Sang-Bok; Lee, Sang-Kwan; Song, Young Buem; Lee, Sunghak

    2012-03-01

    This study aims at investigating ballistic impact properties of Zr-based amorphous alloy (LM1 alloy) matrix composites reinforced with woven stainless steel or glass continuous fibers. The fiber-reinforced composites with excellent fiber/matrix interfaces were fabricated without pores and misinfiltration by liquid pressing process, and contained 35 to 41 vol pct of woven continuous fibers homogeneously distributed in the amorphous matrix. The woven-STS-continuous-fiber-reinforced composite consisted of the LM1 alloy layer of 1.0 mm in thickness in the upper region and the fiber-reinforced composite layer in the lower region. The hard LM1 alloy layer absorbed the ballistic impact energy by forming many cracks, and the fiber-reinforced composite layer interrupted the crack propagation and blocked the impact and traveling of the projectile, thereby resulting in the improvement of ballistic performance by about 20 pct over the LM1 alloy. According to the ballistic impact test data of the woven-glass-continuous-fiber-reinforced composite, glass fibers were preferentially fragmented to form a number of cracks, and the amorphous matrix accelerated the fragmentation of glass fibers and the initiation of cracks. Because of the absorption process of ballistic impact energy by forming very large amounts of cracks, fragments, and debris, the glass-fiber-reinforced composite showed better ballistic performance than the LM1 alloy.

  2. Thermal Comfort Properties of Clothing Fabrics Woven with Polyester/Cotton Blend Yarns

    Directory of Open Access Journals (Sweden)

    Özdemir Hakan

    2017-06-01

    Full Text Available In this research, thermal and water vapor resistance, components of thermal comfort of 65/35 and 33/67% polyester/ cotton (PES/CO blend fabrics woven with 2/2 twill, matt twill, cellular and diced weaves, which are commonly used for clothing, were determined. The results indicate that both the fabric construction and the constituent fiber properties affect thermal comfort properties of clothing woven fabrics. Cellular weave, which is derivative of sateen weave and diced weave, which is compound weave, has the highest thermal resistance appropriating for cold climatic conditions. On the other hand, the 2/2 twill weave and matt twill weave, which is derivative of sateen weave, depicted the lowest water vapor thermal resistance, making it convenient for hot climatic conditions. Besides, fabrics woven with 65/35% PES/CO blend yarns have higher thermal resistance, so they are suitable for cold climatic conditions. Fabrics woven with 33/67% PES/CO blend yarns have lower water vapor resistance, so they are convenient for hot climatic conditions.

  3. Carbon Nanofibers Grown on Large Woven Cloths: Morphology and Properties of Growth

    NARCIS (Netherlands)

    Koysin, V.; Bor, Teunis Cornelis; Kotanjac, Zeljko; Lefferts, Leonardus; Warnet, Laurent; Akkerman, Remko

    2016-01-01

    The morphology and chemical composition of carbon nanofibers in situ grown on a large carbon-fiber woven fabric are studied using SEM measurements, X-ray Diffraction, X-ray Flourescence, and X-ray Photoelectron Spectroscopy. Results show that nanofibers can have a density and a morphology

  4. ROLE OF RESOURCE-BASED ENTREPRENEURSHIP DEVELOPMENT TO INCREASE COMPETITIVENESS OF TRADITIONALLY WOVEN SARONG CREATIVE INDUSTRY

    Directory of Open Access Journals (Sweden)

    Zakiyah Z.

    2017-07-01

    Full Text Available The objectives of the study were to describe position of traditionally woven sarong creative industry in Donggala in business competition based on both internal aspects (strength and weakness and external ones (opportunity and threats, and role of resource-based entrepreneurship development to improve competitiveness of the traditionally woven sarong creative industry in Donggala. In order to meet the objectives, the study used SWOT and Moderating Regression Analysis (MRA. The findings showed that the strength of the Donggala woven sarong industry was the sarong had indigenous Central Sulawesi pattern, it was part of the rural society and was traditionally made. The weaknesses were the sarong pattern and design had yet been touched by modern technology, its color faded away easily during laundry and it was only sold in the local areas. The opportunities were the sarong may become alternative souvenir from Central Sulawesi and development of creative economy was widely discussed recently. The threat was there were various types and patterns of sarong in the market; and entrepreneurship was moderating variables between resource-based strategy and competitiveness of Donggala woven sarong creative industry; the level of significance was 0.001 and the R-Square was 0.803.

  5. 78 FR 39319 - Laminated Woven Sacks From China; Institution of Five-Year Reviews

    Science.gov (United States)

    2013-07-01

    ... 731-TA-1122 (Review)] Laminated Woven Sacks From China; Institution of Five-Year Reviews AGENCY... of merchandise that is within the scope of the five-year reviews, as defined by the Department of.... Former Commission employees who are seeking to appear in Commission five-year reviews are advised that...

  6. Carbon Nanofibers Grown on Large Woven Cloths: Morphology and Properties of Growth

    NARCIS (Netherlands)

    Koissin, Vitaly; Bor, Ton; Kotanjac, Zeljko; Lefferts, Leon; Warnet, Laurent; Akkerman, Remko

    2016-01-01

    The morphology and chemical composition of carbon nanofibers in situ grown on a large carbon-fiber woven fabric are studied using SEM measurements, X-ray Diffraction, X-ray Flourescence, and X-ray Photoelectron Spectroscopy. Results show that nanofibers can have a density and a morphology potentiall

  7. Exploring Concepts from Abstract Algebra Using Variations of Generalized Woven Figure Eights

    Science.gov (United States)

    Taylor, Tara; Knoll, Eva; Landry, Wendy

    2016-01-01

    Students often struggle with concepts from abstract algebra. Typical classes incorporate few ways to make the concepts concrete. Using a set of woven paper artifacts, this paper proposes a way to visualize and explore concepts (symmetries, groups, permutations, subgroups, etc.). The set of artifacts used to illustrate these concepts is derived…

  8. An experimental and theoretical study of creep in woven polymer composites

    Science.gov (United States)

    Govindarajan, S.

    The creep behavior of woven polymer composites has been investigated through both analytical and experimental methods with emphasis on the high temperature creep behavior. Experiments were carried out on composites manufactured through both autoclave (vacuum bag) and compression molding methods while the analysis included consideration of the geometry and constitution which were related to the curing cycle in a previous research. In the experimental study, composites made of epoxy-based and PMR-based composites were manufactured and tested. As these two resins have different operating temperature ranges, the experiments provided valuable information about their resistance to creep at elevated temperatures. The compression-molded PMR15 specimens were manufactured to contain different resin and void contents and were used to provide experimental data on the effects of varying constituent ratios. An automated material testing system along with a strain measurement system was designed and assembled to facilitate the experimental study. The experimental data was later analyzed using theoretical visco-elastic and geometric models. Initially an existing geometric model was used to analyze the creep behavior of the composite laminate. A modified version of this which considered the presence of voids in a Gaussian (random) distribution was developed later to consider the presence of a void-filled polymer matrix. Using the Arrhenius free energy equations, the high temperature behavior of the polymer and fibers were accounted for. Through these models, the material parameters associated with creep and other time dependent phenomena were obtained using inverse simulation on the experimental data. A new tool that extends this modeling to predict the behavior under any random loading was introduced. The modeling has been shown to successfully predict the creep and other visco-elastic behavior in the composite.

  9. On Young’s modulus of multi-walled carbon nanotubes

    Indian Academy of Sciences (India)

    K T Kashyap; R G Patil

    2008-04-01

    Carbon nanotubes (CNTs) were discovered by Iijima in 1991 as the fourth form of carbon. Carbon nanotubes are the ultimate carbon fibres because of their high Young’s modulus of ≈ 1 TPa which is very useful for load transfer in nanocomposites. In the present work, CNT/Al nanocomposites were fabricated by the powder metallurgy technique and after extrusion of the nanocomposites bright field transmission electron microscopic (TEM) studies were carried out. From the TEM images so obtained, a novel method of ascertaining the Young’s modulus of multi-walled carbon nanotubes is worked out in the present paper which turns out to be 0.9 TPa which is consistent with the experimental results.

  10. Zipping, entanglement, and the elastic modulus of aligned single-walled carbon nanotube films.

    Science.gov (United States)

    Won, Yoonjin; Gao, Yuan; Panzer, Matthew A; Xiang, Rong; Maruyama, Shigeo; Kenny, Thomas W; Cai, Wei; Goodson, Kenneth E

    2013-12-17

    Reliably routing heat to and from conversion materials is a daunting challenge for a variety of innovative energy technologies--from thermal solar to automotive waste heat recovery systems--whose efficiencies degrade due to massive thermomechanical stresses at interfaces. This problem may soon be addressed by adhesives based on vertically aligned carbon nanotubes, which promise the revolutionary combination of high through-plane thermal conductivity and vanishing in-plane mechanical stiffness. Here, we report the data for the in-plane modulus of aligned single-walled carbon nanotube films using a microfabricated resonator method. Molecular simulations and electron microscopy identify the nanoscale mechanisms responsible for this property. The zipping and unzipping of adjacent nanotubes and the degree of alignment and entanglement are shown to govern the spatially varying local modulus, thereby providing the route to engineered materials with outstanding combinations of mechanical and thermal properties.

  11. Notch Sensitivity of Woven Ceramic Matrix Composites Under Tensile Loading: An Experimental, Analytical, and Finite Element Study

    Science.gov (United States)

    Haque, A.; Ahmed, L.; Ware, T.; Jeelani, S.; Verrilli, Michael J. (Technical Monitor)

    2001-01-01

    The stress concentrations associated with circular notches and subjected to uniform tensile loading in woven ceramic matrix composites (CMCs) have been investigated for high-efficient turbine engine applications. The CMC's were composed of Nicalon silicon carbide woven fabric in SiNC matrix manufactured through polymer impregnation process (PIP). Several combinations of hole diameter/plate width ratios and ply orientations were considered in this study. In the first part, the stress concentrations were calculated measuring strain distributions surrounding the hole using strain gages at different locations of the specimens during the initial portion of the stress-strain curve before any microdamage developed. The stress concentration was also calculated analytically using Lekhnitskii's solution for orthotropic plates. A finite-width correction factor for anisotropic and orthotropic composite plate was considered. The stress distributions surrounding the circular hole of a CMC's plate were further studied using finite element analysis. Both solid and shell elements were considered. The experimental results were compared with both the analytical and finite element solutions. Extensive optical and scanning electron microscopic examinations were carried out for identifying the fracture behavior and failure mechanisms of both the notched and notched specimens. The stress concentration factors (SCF) determined by analytical method overpredicted the experimental results. But the numerical solution underpredicted the experimental SCF. Stress concentration factors are shown to increase with enlarged hole size and the effects of ply orientations on stress concentration factors are observed to be negligible. In all the cases, the crack initiated at the notch edge and propagated along the width towards the edge of the specimens.

  12. Is non-woven fabric a useful method of packaging instruments for operation theatres in resource constrained settings?

    Directory of Open Access Journals (Sweden)

    G S Devadiga

    2015-01-01

    Full Text Available Introduction: Studies have highlighted the advantages and disadvantages of woven and non-woven fabrics. The present study assessed the change in resterilisation proportion after introduction of non-woven fabric for packaging of instruments and to evaluate the cost-effectiveness of non-woven fabrics compared with woven fabrics. Materials and Methods: The present study is a secondary data analysis of resterilisation data collected from November 2009 to August 2013. We calculated the proportions (and their 95% confidence intervals of resterilisation done every month. The proportion over time was compared using a Chi-square test for trend. We used linear regression analysis to adjust for the number of surgeries performed every month. We also compared the cost of woven and non-woven fabrics. Results: Of the total 117,335 surgical packets prepared during the study period, 1900 were resterilised; thus, the overall proportion was 1.62% (95% CI: 1.55% to 1.69%. The resterilisation proportion was 8.95% (95% CI: 7.73% to 10.17% in November 2009 and was 0.38% (95% CI: 0.16% to 0.62% in August 2013 (P < 0.001. After adjusting for the total number of surgeries conducted every month, we found that the number of packets resterilised reduced every month (per month reduction: -1.97, 95% CI: -2.76 to -1.18. The total cost (initial preparation and resterilisation for 100 units of woven fabric is INR 6359.41 per month (confidence limit estimates: 6228.20 to 6430.62 and for non-woven fabric was INR 6208.50 (confidence limit estimate: INR 6194.90 to 6223.35 (P < 0.01. Conclusions: The introduction of non-woven spunbond-meltblown-spunbond fabrics did reduce the proportion of resterilisation of packaged instruments. The decline was sharp and sustained over time, even after accounting for the change in the number of procedures. Furthermore, though the switch from woven to non-woven fabric was cost-effective in our situation, it may not be directly translated to other

  13. The Improvement of the Resistance to Candida albicans and Trichophyton interdigitale of Some Woven Fabrics Based on Cotton.

    Science.gov (United States)

    Surdu, Lilioara; Stelescu, Maria Daniela; Manaila, Elena; Nicula, Gheorghe; Iordache, Ovidiu; Dinca, Laurentiu Christian; Berechet, Mariana-Daniela; Vamesu, Mariana; Gurau, Dana

    2014-01-01

    This paper presents the improvement of the antimicrobial character of woven fabrics based on cotton. The woven fabrics were cleaned in oxygen plasma and treated by padding with silver chloride and titanium dioxide particles. The existence of silver and titanium on woven fabrics was evidenced by electronic microscope images (SEM, EDAX) and by flame atomic absorption spectrophotometry. The antimicrobial tests were performed with two fungi: Candida albicans and Trichophyton interdigitale. The obtained antimicrobial effect was considerably higher compared to the raw fabrics. Treatment of dyed fabrics with a colloidal solution based on silver chloride and titanium dioxide particles does not considerably influence colour resistance of dyes.

  14. The Improvement of the Resistance to Candida albicans and Trichophyton interdigitale of Some Woven Fabrics Based on Cotton

    Science.gov (United States)

    Stelescu, Maria Daniela; Manaila, Elena; Nicula, Gheorghe; Iordache, Ovidiu; Dinca, Laurentiu Christian; Berechet, Mariana-Daniela; Vamesu, Mariana; Gurau, Dana

    2014-01-01

    This paper presents the improvement of the antimicrobial character of woven fabrics based on cotton. The woven fabrics were cleaned in oxygen plasma and treated by padding with silver chloride and titanium dioxide particles. The existence of silver and titanium on woven fabrics was evidenced by electronic microscope images (SEM, EDAX) and by flame atomic absorption spectrophotometry. The antimicrobial tests were performed with two fungi: Candida albicans and Trichophyton interdigitale. The obtained antimicrobial effect was considerably higher compared to the raw fabrics. Treatment of dyed fabrics with a colloidal solution based on silver chloride and titanium dioxide particles does not considerably influence colour resistance of dyes. PMID:25276112

  15. Bacteria in non-woven textile filters for domestic wastewater treatment.

    Science.gov (United States)

    Spychała, Marcin; Starzyk, Justyna

    2015-01-01

    The objective of this study was preliminary identification of heterotrophic and ammonia oxidizing bacteria (AOB) cell concentration in the cross-sectional profile of geotextile filters for wastewater treatment. Filters of thicknesses 3.6 and 7.2 mm, made of non-woven textile TS20, were supplied with septic tank effluent and intermittently dosed and filtered under hydrostatic pressure. The cumulative loads of chemical oxygen demand (COD) and total solids were about 1.36 and 1.06 kg/cm2, respectively. The filters under analysis reached a relatively high removal efficiency for organic pollution 70-90% for biochemical oxygen demand (BOD5) and 60-85% for COD. The ammonia nitrogen removal efficiency level proved to be unstable (15-55%). Biomass samples for dry mass identification were taken from two regions: continuously flooded with wastewater and intermittently flooded with wastewater. The culturable heterotrophic bacteria were determined as colony-forming units (CFUs) on microbiological-selective media by means of the plate method. AOB and nitrite oxidizing bacteria (NOB) were examined using the FISH technique. A relatively wide range of heterotrophic bacteria was observed from 7.4×10(5)/cm2 to 3.8×10(6)/cm2 in geotextile layers. The highest concentration of heterotrophic bacteria (3.8×10(6)/cm2) was observed in the first layer of the textile filter. AOB were identified occasionally--about 8-15% of all bacteria colonizing the last filter layer, but occasionally much higher concentrations and ammonia nitrogen efficiency were achieved. Bacteria oxidizing nitrite to nitrate were not observed. The relation of total and organic fraction of biomass to culturable heterotrophic bacteria was also found.

  16. Arcjet Testing of Woven Carbon Cloth for Use on Adaptive Deployable Entry Placement Technology

    Science.gov (United States)

    Arnold, James O.; laub, Bernard; Chen, Yih-Kang; Prabhu, Dinesh K.; Bittner, M. E.; Venkatapathy, Ethiraj

    2013-01-01

    This paper describes arcjet testing and analysis that has successfully demonstrated the viability of three dimensional woven carbon cloth for dual use in the Adaptive Deployable Entry Placement Technology (ADEPT). ADEPT is an umbrella-like entry system that is folded for stowage in the launch vehicle s shroud and deployed in space prior to reaching the atmospheric interface. A key feature of the ADEPT concept is its lower ballistic coefficient for delivery of a given payload than those for conventional, rigid body entry systems. The benefits that accrue from the lower ballistic coefficient include factor of ten reductions of deceleration forces and entry heating. The former enables consideration of new classes of scientific instruments for solar system exploration while the latter enables the design of a more efficient thermal protection system. The carbon cloth now base lined for ADEPT has a dual use in that it serves as ADEPT s thermal protection system and as the "skin" that transfers aerodynamic deceleration loads to its umbrella-like substructure. The arcjet testing described in this paper was conducted for some of the higher heating conditions for a future Venus mission using the ADEPT concept, thereby showing that the carbon cloth can perform in a relevant entry environment. The ADEPT project considered the carbon cloth to be mission enabling and was carrying it as a major risk during Fiscal Year 2012. The testing and analysis reported here played a major role in retiring that risk and is highly significant to the success and possible adoption of ADEPT for future NASA missions. Finally, this paper also describes a preliminary engineering level code, based on the arcjet data, that can be used to estimate cloth thickness for future missions using ADEPT and to predict carbon cloth performance in future arcjet tests.

  17. In-plane response and mode II fracture response of Z-pin woven laminates

    Science.gov (United States)

    Huang, Hseng-Ji

    Textile composites are proven to be an attractive choice over traditional pre-preg based composites because of reduced manufacturing costs and improved transverse mechanical properties. However, similar to traditional pre-preg composites, 2D laminates consisting of multiple layers of laminae still suffer from delamination under impact or transverse loads. Z-pin (carbon fiber of small diameter inserted in the thickness direction-z) composites are a means to provide higher through-thethickness stiffness and strength that 2D woven composites lack. In this thesis, The influences of Z-pin density and Z-pin diameter on the response of Z-pin under in-plane loads (compression) and transverse loads (mode II fracture) are examined. Both experiments and numerical simulations were performed to address the problems. Compression tests were conducted first and failure mechanism in each loading scenario was identified, through optical and mechanical measurements, during and after the tests. This was followed by the development of different numerical models of varying degree of sophistication, which include in-plane 2D models, (used to study fiber distortion and damage due to Z-pin insertion), multi-layer 2D models, (used to provide an inexpensive multi-layer model to study the effect of phase difference due to stacking consolidation), and multi-layer-multi-cell models (used to provide a full 3D multi-layer and multi-representative unit cell description). The second part of this thesis investigates the mode II fracture response under static and dynamic loading. Discrete Cohesive Zone Model (DCZM) was adopted to obtain the fracture toughness in conjunction with experimental data. In dynamic test, a crack advance gage (CAG) was designed to capture the exact time when the crack begins to propagate. By use of these CAGs, the corresponding crack propagation speed between different CAGs can be computed accordingly. These observations are supplemented through high speed optical images

  18. Pengaruh Variasisilica Fumedan Perubahan Faktor Air Semen Terhadap Modulus Elastisitas Beton

    Directory of Open Access Journals (Sweden)

    Nor Intang Setyo H.

    2005-08-01

    Full Text Available The aim of this research is to know influence of addition silica fume and variation of water cement ratio (w/c, also interaction of between both to elasticity modulus of concrete. Independent variable in this research is variation of silica fume and water cement ratio. Dependent variable is compression strength and strain for result of elasticity modulus. The sample test of cylinder concrete with diameter 15 cm and high 30 cm, with the variation of w/c 0,3 ; 0,35 ; 0,4 ; 0,45 ; and 0,5, and also variation of silica fume 0,5%, 10%, 15%, and 20% cement weight. Each treatment made by 10 samples with of volume comparison of mixer concrete 1 : 1,5 : 2,5. The result of samples test carried out 28th days of age obtained optimum rate silica fume 9,328% with w/c 0,35 giving influence to increase of concrete elasticity modulus of concrete to 4,191% of normal concrete

  19. Ballistic performance of a Kevlar-29 woven fibre composite under varied temperatures

    Science.gov (United States)

    Soykasap, O.; Colakoglu, M.

    2010-05-01

    Armours are usually manufactured from polymer matrix composites and used for both military and non-military purposes in different seasons, climates, and regions. The mechanical properties of the composites depend on temperature, which also affects their ballistic characteristics. The armour is used to absorb the kinetic energy of a projectile without any major injury to a person. Therefore, besides a high strength and lightness, a high damping capacity is required to absorb the impact energy transferred by the projectile. The ballistic properties of a Kevlar 29/polyvinyl butyral composite are investigated under varied temperatures in this study. The elastic modulus of the composite is determined from the natural frequency of composite specimens at different temperatures by using a damping monitoring method. Then, the backside deformation of composite plates is analysed experimentally and numerically employing the finite-element program Abaqus. The experimental and numeric results obtained are in good agreement.

  20. Size-Dependent Elastic Modulus and Vibration Frequency of Nanocrystals

    Directory of Open Access Journals (Sweden)

    Lihong Liang

    2011-01-01

    Full Text Available The elastic properties and the vibration characterization are important for the stability of materials and devices, especially for nanomaterials with potential and broad application. Nanomaterials show different properties from the corresponding bulk materials; the valid theoretical model about the size effect of the elastic modulus and the vibration frequency is significant to guide the application of nanomaterials. In this paper, a unified analytical model about the size-dependent elastic modulus and vibration frequency of nanocrystalline metals, ceramics and semiconductors is established based on the inherent lattice strain and the binding energy change of nanocrystals compared with the bulk crystals, and the intrinsic correlation between the elasticity and the vibration properties is discussed. The theoretical predictions for Cu, Ag, Si thin films, nanoparticles, and TiO2 nanoparticles agree with the experimental results, the computational simulations, and the other theoretical models.

  1. Ultrasonic Measurement of Elastic Modulus of Kelvin Foam

    Directory of Open Access Journals (Sweden)

    Oh Sukwon

    2016-01-01

    Full Text Available Elastic modulus of 3D-printed Kelvin foam plate is investigated by measuring the acoustic wave velocity of 1 MHz ultrasound. An isotropic tetrakaidecahedron foam of 3 mm unit cell is designed and printed layer upon layer to fablicate a Kelvin foam plate of 14mm thickness by 3D CAD/printer using ABS plastic. The Kelvin foam plate is filled completely with paraffin wax for impedance matching, so that acoustic wave may propagate through the porous foam plate. The acoustic wave velocity of the foam plate is measured using the time-of-flight (TOF method to calculate the elastic modulus of the Kelvin foam plate based on acousto-elasticity.

  2. Evaluation of Bulk Modulus of Oil System with Hydraulic Line

    Directory of Open Access Journals (Sweden)

    Bureček A.

    2013-04-01

    Full Text Available The aim of the paper is to experimentally measure and ealuate bulk modulus of oil/steel pipe system and oil/hose system. The measurement was performed using experimental device on the basis of a measured pressure difference depending on time. Bulk modulus is evaluated from pressure change with known flow and volume of line. Pressure rise is caused by valve closure at the line end. Furthermore, a mathematical model of the experimental device is created using Matlab SimHydraulics software. Time dependencies of pressure for the oil/steel pipe system and the oil/hose system are simulated on this mathematical model. The simulations are verified by experiment.

  3. Modulus stabilization in a non-flat warped braneworld scenario

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, Indrani [S.N. Bose National Centre for Basic Sciences, Department of Astrophysics and Cosmology, Kolkata (India); SenGupta, Soumitra [Indian Association for the Cultivation of Science, Department of Theoretical Physics, Kolkata (India)

    2017-05-15

    The stability of the modular field in a warped brane world scenario has been a subject of interest for a long time. Goldberger and Wise (GW) proposed a mechanism to achieve this by invoking a massive scalar field in the bulk space-time neglecting the back-reaction. In this work, we examine the possibility of stabilizing the modulus without bringing about any external scalar field. We show that instead of flat 3-branes as considered in Randall-Sundrum (RS) warped braneworld model, if one considers a more generalized version of warped geometry with de Sitter 3-brane, then the brane vacuum energy automatically leads to a modulus potential with a metastable minimum. Our result further reveals that in this scenario the gauge hierarchy problem can also be resolved for an appropriate choice of the brane's cosmological constant. (orig.)

  4. Steganography based on wavelet transform and modulus function

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In order to provide larger capacity of the hidden secret data while maintaining a good visual quality of stego-image,in accordance with the visual property that human eyes are less sensitive to strong texture,a novel steganographic method based on wavelet and modulus function is presented.First,an image is divided into blocks of prescribed size,and every block is decomposed into one-level wavelet.Then,the capacity of the hidden secret data is decided with the number of wavelet coefficients of larger magnitude.Finall,secret information is embedded by steganography based on modulus function. From the experimental results,the proposed method hides much more information and maintains a good visual quality of stego-image.Besides,the embedded data can be extracted from the stego-image without referencing the original image.

  5. CALCULATION OF THE YOUNG'S MODULUS OF AN ADSORBED POLYMER LAYER

    Institute of Scientific and Technical Information of China (English)

    Rüdiger Stark; Michael Kappl; Hans-Jürgen Butt

    2007-01-01

    Polymer layers adsorbed to a surface or in a confined environment often change their mechanical properties. There is even the possibility of solidification of the confined layer. To judge the stiffness of such a layer, we used the Hertz model to calculate the Young's modulus of the polymer layer in the confinement of AFM experiments with silicon nitride tip with a radius of curvature of R ≈ 50 nm and a glass sphere attached to the cantilever R = 5 μm. Since there is no visible indentation of the layer in the AFM experiments, the layer is either penetrated very easily, or the indentation is too small to be seen in a force curve. The latter would be the case for a polymer layer with a Young's modulus above 4×108 Pa in case of an experiment with a silicon nitride tip and 4×105 Pa in case of a glass sphere.

  6. Dual SAW sensor technique for determining mass and modulus changes.

    Science.gov (United States)

    Hietala, S L; Hietala, V M; Brinker, C J

    2001-01-01

    Surface acoustic wave (SAW) sensors, which are sensitive to a variety of surface changes, have been widely used for chemical and physical sensing. The ability to control or compensate for the many surface forces has been instrumental in collecting valid data. In cases in which it is not possible to neglect certain effects, such as frequency drift with temperature, methods such as the "dual sensor" technique have been utilized. This paper describes a novel use of a dual sensor technique, using two sensor materials (quartz and GaAs) to separate out the contributions of mass and modulus of the frequency change during gas adsorption experiments. The large modulus change in the film calculated using this technique and predicted by the Gassmann equation provide a greater understanding of the challenges of SAW sensing.

  7. A Methodology for Determination of Resilient Modulus of Asphaltic Concrete

    Directory of Open Access Journals (Sweden)

    A. Patel

    2011-01-01

    Full Text Available Resilient modulus, , is an important parameter for designing pavements. However, its determination by resorting to cyclic triaxial tests is tedious and time consuming. Moreover, empirical relationships, correlating to various other material properties (namely, California Bearing Ratio, CBR; Limerock Bearing Ratio, LBR; R-value and the Soil Support Value, SSV, give vast variation in the estimated results. With this in view, an electronic circuitry, which employs bender and extender elements (i.e., piezo-ceramic elements, was developed. Details of the circuitry and the testing methodology adopted for this purpose are presented in this paper. This methodology helps in determining the resilient modulus of the material quite precisely. Further, it is believed that this methodology would be quite useful to engineers and technologists for conducting quality check of the pavements, quite rapidly and easily.

  8. Functions of Bounded kth p-Variation and Continuity Modulus

    Directory of Open Access Journals (Sweden)

    Odalis Mejía

    2015-01-01

    Full Text Available A scale of spaces exists connecting the class of functions of bounded kth p-variation in the sense of Riesz-Merentes with the Sobolev space of functions with p-integrable kth derivative. This scale is generated by the generalized functionals of Merentes type. We prove some limiting relations for these functionals as well as sharp estimates in terms of the fractional modulus of smoothness of order k-1/p.

  9. Charged string solutions with dilaton and modulus fields

    CERN Document Server

    Cvetic, M

    1994-01-01

    We find charged, abelian, spherically symmetric solutions (in flat space-time) corresponding to the effective action of $D=4$ heterotic string theory with scale-dependent dilaton $\\p$ and modulus $\\vp$ fields. We take into account perturbative (genus-one), moduli-dependent `threshold' corrections to the coupling function $f(\\p,\\vp)$ in the gauge field kinetic term $f(\\p,\\vp) F^2_{\\m\

  10. Measuring Propellant Stress Relaxation Modulus Using Dynamic Mechanical Analyzer

    Science.gov (United States)

    2017-03-29

    P. N., Singh, P. P., and Bhattacharya, B., “Determination of Activation Energy of Relaxation Events in Composite Solid Propellants by Dynamic...Article 3. DATES COVERED (From - To) 04 August 2016 – 29 March 2017 4. TITLE AND SUBTITLE Measuring Propellant Stress Relaxation Modulus Using Dynamic...ERC 14. ABSTRACT A method for determining the stress relaxation master curve of solid rocket propellants was developed. The propellant was tested in

  11. Reaction hot-pressing and property-composition relationships of modified sialon - boron nitride hetero-modulus ceramics

    Science.gov (United States)

    Wang, Y.; Shabalin, I. L.; Zhang, L.; Zhdanov, V. B.

    2011-10-01

    Hetero-modulus ceramics (HMC) present the combination of a ceramic matrix with inclusions of a dispersed phase with considerably lower values of Young's modulus, resulting in a material with significantly advanced properties. Densified '-Si6-xAlxOxN8-x based HMC materials, with various volume contents of low-modulus α-BN phase and modifiers such as TiN or ZrO2 in sialon matrix, were prepared by high-temperature reaction hot-pressing in nitrogen atmosphere. The pristine blend composition for reaction hot-pressing consisted of mixed fine powders of Si, Al, B, Ti nitrides and Al, Zr oxides. Statistical design of 25-2 fractional factorial and third-order simplex-grid types was used for the experimental studies to estimate the effects of some technological factors on the densification of hot-pressed products and the property-composition relationships of modified HMC materials.

  12. Effect of Comonomer Ethylene on Plateau Modulus of Crystalline Ethylene-propylene Random Copolymer with Broad Molecular Weight Distribution

    Institute of Scientific and Technical Information of China (English)

    丁健; 徐日炜; 丁雪佳; 余鼎声

    2005-01-01

    Ethylene-propylene random copolymer with ultra-high molecular weight (UHPPR) and broad molecular weight distribution (MWD) was prepared with Ziegler-Natta catalyst. The viscoelastic behavior of UHPPR has been investigated by means of oscillatory rheometer at 180, 200 and 220℃. The loss modulus (G"""") curves of 180 and 200℃ present a pronounced maximum at 38.10 and 84.70r/s, respectively, For the first time, this makes it possible to directly determine the plateau modulus ( GN0 ) of crystalline ethylene-propylene random copolymer with broad MWD in a certain experimental temperature G""""(w) curve. The plateau modulus of UHPPR is 4.51×105 and 3.67×105 Paat 180 and 200℃ respectively, increasing with random incorporation of comonomer ethylene into the molecular chains and being independent of molecular weight.

  13. An effective ultrasonic strain measurement-based shear modulus reconstruction technique for superficial tissues - demonstration on in vitro pork ribs and in vivo human breast tissues

    Science.gov (United States)

    Sumi, Chikayoshi; Nakayama, Kiyoshi; Kubota, Mitsuhiro

    2000-06-01

    An effective shear modulus reconstruction technique is described which uses ultrasonic strain measurements for diagnosis of superficial tissues, i.e. our previously developed ultrasonic strain measurement and shear modulus reconstruction methods are combined and enhanced. The technique realizes very low computational load, yet yields fairly high quantitativeness, high stability and spatial resolution, and large dynamic range. The suitability of the method is demonstrated on in vitro pork ribs and in vivo human breast tissues (fibroadenoma and scirrhous carcinoma).

  14. Pengukuran Modulus Elastisitas Dinamis Batuan dengan Metode Seismik Refraksi

    Directory of Open Access Journals (Sweden)

    Ashadi Salim

    2012-12-01

    Full Text Available The seismic wave velocity in rock formation depends on the elastic modulus and mass density of rock where the wave travels. The velocity measurement of P and S waves on rock formation and the mass density in the laboratory can be used for calculating the elastic modulus of rock formation. The elastic modulus is part of rock mechanical parameter needed in geological engineering researches. The velocity measurement of P and S waves by the seismic refraction method was done on a tunnel with 11 spreads of measurement. From the resultsof the measurement, three groups of rock formation could be identified. The first is rock formation with Ed=8.890-12.68 MPa and G=3.306-4.830MPa; the second group is rock formation with Ed=8.890-12.68 MPa and G=3.306-4.830MPa; and the third group is with Ed=18.520-21.120MPa and G=6.724-7.744MP. The first group is clay formation while the second and third groups are andesitic stone formation. 

  15. Young's modulus and hardness of shark tooth biomaterials.

    Science.gov (United States)

    Whitenack, Lisa B; Simkins, Daniel C; Motta, Philip J; Hirai, Makoto; Kumar, Ashok

    2010-03-01

    To date, the majority of studies on feeding mechanics in sharks have focused on the movement of cranial components and muscle function, with little attention to tooth properties or function. Attributes related to mechanical properties, such as structural strength, may also be subjected to natural selection. Additionally it is necessary to characterize these properties in order to construct biomechanical models of tooth function. The goal of this study was to determine hardness and elastic modulus for the shark tooth materials enameloid, osteodentine, and orthodentine. Five teeth each from one carcharhiniform species, the bonnethead Sphyrna tiburo, and one lamniform, the sand tiger shark Carcharias taurus, were utilized for nanoindentation testing. Each tooth was sectioned transversely, air-dried, and polished. Both enameloid and dentine were tested on each tooth via a Berkovich diamond tip, with nine 2 microm deep indentations per material. t-Tests were used to determine if there were differences in hardness and Young's modulus between the tooth materials of the two species. There was no significant difference between the two species for the material properties of enameloid, however both hardness and Young's modulus were higher for osteodentine than for orthodentine. This may be due to differences in microanatomy and chemical composition, however this needs to be studied in greater detail. Copyright 2010 Elsevier Ltd. All rights reserved.

  16. Measurement of Elastic Modulus of Collagen Type I Single Fiber.

    Science.gov (United States)

    Dutov, Pavel; Antipova, Olga; Varma, Sameer; Orgel, Joseph P R O; Schieber, Jay D

    2016-01-01

    Collagen fibers are the main components of the extra cellular matrix and the primary contributors to the mechanical properties of tissues. Here we report a novel approach to measure the longitudinal component of the elastic moduli of biological fibers under conditions close to those found in vivo and apply it to type I collagen from rat tail tendon. This approach combines optical tweezers, atomic force microscopy, and exploits Euler-Bernoulli elasticity theory for data analysis. This approach also avoids drying for measurements or visualization, since samples are freshly extracted. Importantly, strains are kept below 0.5%, which appear consistent with the linear elastic regime. We find, surprisingly, that the longitudinal elastic modulus of type I collagen cannot be represented by a single quantity but rather is a distribution that is broader than the uncertainty of our experimental technique. The longitudinal component of the single-fiber elastic modulus is between 100 MPa and 360 MPa for samples extracted from different rats and/or different parts of a single tail. Variations are also observed in the fibril-bundle/fibril diameter with an average of 325±40 nm. Since bending forces depend on the diameter to the fourth power, this variation in diameter is important for estimating the range of elastic moduli. The remaining variations in the modulus may be due to differences in composition of the fibril-bundles, or the extent of the proteoglycans constituting fibril-bundles, or that some single fibrils may be of fibril-bundle size.

  17. Single crystal elasticity of gold up to ˜20 GPa: Bulk modulus anomaly and implication for a primary pressure scale

    Science.gov (United States)

    Yoneda, Akira; Fukui, Hiroshi; Gomi, Hitoshi; Kamada, Seiji; Xie, Longjian; Hirao, Naohisa; Uchiyama, Hiroshi; Tsutsui, Satoshi; Baron, Alfred Q. R.

    2017-09-01

    We measured the elasticity of single crystal gold (Au) and its lattice parameters under high pressure using inelastic X-ray scattering (IXS). The elastic moduli were obtained at five pressure points between 0 and 20 GPa. The pressure variation of the bulk modulus displays anomalous behavior, being nearly constant up to ˜5 GPa, and then steeply increasing at higher pressure. A similar anomaly is observed in first-principles calculations. An absolute pressure scale was derived by direct numerical integration of the bulk modulus over volume change. This yields a scale that gives slightly lower pressure values than those of previous work, about 5-10% lower at ˜20 GPa.

  18. Effect of Sea Water and Natural Ageing on Residual Strength of Epoxy Laminates, Reinforced with Glass and Carbon Woven Fabrics

    Directory of Open Access Journals (Sweden)

    Andrzej Komorek

    2016-01-01

    Full Text Available This paper reports the results of the effect of sea water, natural ageing, and cross-impact loading on flexural strength and residual flexural strength of epoxy laminates with glass woven fabrics and hybrid reinforcement with glass and carbon woven fabrics. The tests were conducted on samples with different fibre reinforcement both before and after low energy cross-impact loading. Carbon fabrics decreased residual strength of the composites.

  19. Comparative study on three dynamic modulus of elasticity and static modulus of elasticity for Lodgepole pine lumber

    Institute of Scientific and Technical Information of China (English)

    LIANG Shan-qing; FU feng

    2007-01-01

    The dynamic and static modulus of elasticity (MOE) between bluestained and non-bluestained lumber of Lodgepole pine were tested and analyzed by using three methods of Non-destructive testing (NDT), Portable Ultrasonic Non-destructive Digital Indicating Testing (Pundit), Metriguard and Fast Fourier Transform (FFT) and the normal bending method. Results showed that the dynamic and static MOE of bluestained wood were higher than those of non-bluestained wood. The significant differences in dynamic MOE and static MOE were found between bulestained and non-bluestained wood, of which, the difference in each of three dynamic MOE (Ep.the ultrasonic wave modulus of elasticity, Em, the stress wave modulus of elasticity and Ef, the longitudinal wave modulus of elasticity) between bulestained and non-bluestained wood arrived at the 0.01 significance level, whereas that in the static MOE at the 0.05 significance level. The differences in MOE between bulestained and non-bluestained wood were induced by the variation between sapwood and heartwood and the different densities of bulestained and non-bluestained wood. The correlation between dynamic MOE and static MOE was statistically significant at the 0.01 significance level. Although the dynamic MOE values of Ep, Em, Ef were significantly different, there exists a close relationship between them (arriving at the 0.01 correlation level). Comparative analysis among the three techniques indicated that the accurateness of FFT was higher than that of Pundit and Metriguard. Effect of tree knots on MOE was also investigated. Result showed that the dynamic and static MOE gradually decreased with the increase of knot number, indicating that knot number had significant effect on MOE value.

  20. Experiment Study and Interpretation on Relation between Modulus of Rock and Strain Amplitude

    Institute of Scientific and Technical Information of China (English)

    Bao Xueyang; Shi Xingjue; Wen Dan; Li Chengbo; Wang Xingzhou

    2006-01-01

    Nonlinear elasticity of the earth medium produces a numerical difference between the dynamic and the static modulus of rock. The dynamic modulus is calculated with the ultrasonic velocity measurement, the small-cycle modulus is calculated with small cycles in the load-unload experiment, the static modulus is calculated from the slope of the stress-strain curve in the large cycle, the Young' s modulus is obtained from the ratio of stress to strain in the measured point.The relationship between the modulus and the strain amplitudes is studied by changing the strain amplitude in the small cycles. The moduli obtained from different measuring methods are thus compared. The result shows that the dynamic modulus is the largest, the small-cycle modulus takes the second place, the static modulus of bigger-cycle is the third, and finally the Young's modulus is the smallest. Nonlinear modulus of rock is a function of the strain level and strain amplitude. The modulus decreases exponentially with the ascending of the strain amplitude, while increases with the ascending of the strain level. Finally, the basic concept of the P-M model is briefly introduced and the relationship between the modulus and strain amplitude is explained by the rock having different distribution densities and the different open-and-close stresses of the micro-cracks.

  1. Optimization on Impact Strength of Woven Kenaf Reinforced Polyester Composites using Taguchi Method

    Science.gov (United States)

    Khalid, S. N. A.; Ismail, A. E.; Zainulabidin, M. H.

    2017-01-01

    This paper focuses on the effect of weaving patterns and orientations on the energy absorption of woven kenaf reinforced polyester composites. Kenaf fiber in the form of yarn is weaved to produce different weaving patterns such as plain, twill and basket. Three woven mats are stacked together and mixed with polyester resin before it is compressed to squeeze out any excessive resin. There is nine different orientations are used during stacking processes by following Taguchi orthogonal arrays method. The hardened composites are cured for 24 hours before it is shaped according to specific dimensions for impact tests. The composites are perforated with 1m/s blunted projectile. According to the experimental findings, weaving pattern and orientation have distinct potential effects on value of energy absorption. The optimization using Taguchi method reveals preferable orientation of each weaving pattern composites. Based on the fracture observation, the fragmentations after optimization indicating lower distance surface fracture perforated obtained.

  2. Notched Strength of Woven Fabric Kenaf Composite Plates with Different Stacking Sequences and Hole Sizes

    Directory of Open Access Journals (Sweden)

    Hans Romayne Anders

    2016-01-01

    Full Text Available Advantages of using kenaf fibres over synthetic fibres in composites manufacturing are relatively cheap, less abrasive and hazardous during handling, and renewable materials. Current work investigates parametric effects on notched strength of woven fabric kenaf polymer composites plates with variation of lay-up types, notch sizes and plate thickness. Testing coupons are prepared using hand lay-up technique and circular notch were drilled prior to mechanical testing. Stress concentration at the notch edge promotes micro-damage event as tensile loading was applied leading to crack initiation and propagations across the plate width. It is suggested that woven fabric kenaf polymer composites are potentially used in low and medium load bearing applications.

  3. Analysis of Depth of Shade on Mercerized and Unmercerized Fabric among Different Woven Fabric Structures

    Directory of Open Access Journals (Sweden)

    Md Shamim Alam

    2016-01-01

    Full Text Available The main objective of this paper is to analyze and compare the color strengths of mercerized and unmercerized fabric among different fabric structures. In this research work Remazol reactive dye and three types of woven fabrics were used such as 20⁎20 sheeting, 30⁎30 sheeting, and herringbone. Spectrophotometer was used to find out the amount of dye which is fixed in the fabrics after soap wash. Three different woven fabrics were dyed with reactive dye (Remazol Red, Remazol Yellow, and Remazol Blue using pad dyeing method. It was found that mercerized fabric had higher depth of shade under the same dye concentration. In case of shade A (0.5% 20⁎20 sheeting showed better color strength compared to other two structures but for shade B (1.5% and shade C (4% herringbone fabric showed better dye absorptive capacity than 20⁎20 sheeting.

  4. THE DYNAMICS OF IN VITRO DEGRADATION OF NON-WOVEN POLYLACTIDE MATRICES IN MODEL BIOLOGICAL LIQUID

    Directory of Open Access Journals (Sweden)

    I. A. Khlusov

    2013-01-01

    Full Text Available The weekly in vitro degradation of fibrous-porous non-woven polylactide scaffolds made by aerodynamic formation in a turbulent gas flow has been studied with 37 °С in model RPMI-1640 medium imitated body fluid of organism. Lactate monomers released into solution exponentially and reached slowly a maximum value the end of the observation (5th week of dissolution. At the same time, reducing the concentrations of calcium and inorganic phosphorus ions in solutions contacted with tested samples (10×10×1 mm2 testified about chemical elements adsorption on artificial material. Ions exchange with biological fluids may be a basis of regulated bioactivity of fibrous-porous non-woven biodegradable material in application to intercellular matrix bioengineering for regenerative medicine

  5. If Cell Mechanics Can Be Described by Elastic Modulus: Study of Different Models and Probes Used in Indentation Experiments

    Science.gov (United States)

    Guz, Nataliia; Dokukin, Maxim; Kalaparthi, Vivekanand; Sokolov, Igor

    2014-01-01

    Here we investigated the question whether cells, being highly heterogeneous objects, could be described with the elastic modulus (effective Young’s modulus) in a self-consistent way. We performed a comparative analysis of the elastic modulus derived from the indentation data obtained with atomic force microscopy (AFM) on human cervical epithelial cells (both normal and cancerous). Both sharp (cone) and dull (2500-nm radius sphere) AFM probes were used. The indentation data were processed through different elastic models. The cell was approximated as a homogeneous elastic medium that had either 1), smooth hemispherical boundary (Hertz/Sneddon models) or 2), the boundary covered with a layer of glycocalyx and membrane protrusions (“brush” models). Consistency of these approximations was investigated. Specifically, we tested the independence of the elastic modulus of the indentation depth, which is assumed in these models. We demonstrated that only one model showed consistency in treating cells as a homogeneous elastic medium, namely, the brush model, when processing the indentation data collected with the dull AFM probe. The elastic modulus demonstrated strong depth dependence in all models: Hertz/Sneddon models (no brush taken into account), and when the brush model was applied to the data collected with sharp conical probes. We conclude that it is possible to describe the elastic properties of the cell body by means of an effective elastic modulus, used in a self-consistent way, when using the brush model to analyze data collected with a dull AFM probe. The nature of these results is discussed. PMID:25099796

  6. Application of an ancient Chinese algorithm to stab performance of woven fabrics

    Directory of Open Access Journals (Sweden)

    Wang Ping

    2016-01-01

    Full Text Available Stab damage is a common failure mode for textile products, especially for the geotextiles and geotextile-related products which are widely used in the road, airport, pipeline, and so on. In this paper, an ancient Chinese algorithm is applied to predict the stab area and stab energy of woven fabrics under stabbing load according to the load-displacement performance of the single yarn. This research proposes a novel method to analyze the stab property of the textile products.

  7. Oscillating-flow regenerator test rig: Woven screen and metal felt results

    Science.gov (United States)

    Gedeon, D.; Wood, J. G.

    1992-01-01

    We present correlating expressions, in terms of Reynolds or Peclet numbers, for friction factors, Nusselt numbers, enhanced axial conduction ratios, and overall heat flux ratios in four porous regenerator samples representative of stirling cycle regenerators: two woven screen samples and two random wire samples. Error estimates and comparison of data with others suggest our correlations are reliable, but we need to test more samples over a range of porosities before our results will become generally useful.

  8. Viscoelastic and thermal properties of woven sisal fabric reinforced natural rubber biocomposites

    CSIR Research Space (South Africa)

    John, MJ

    2009-01-01

    Full Text Available P.O. Kottayam, Kerala, India. -686 560 3 Central Power Research Institute, Polymer Laboratory, Bangalore, India-560 080. Abstract Textile- rubber biocomposites were prepared by reinforcing natural rubber with woven sisal fabric...-matrix interface. *Corresponding author E-mail: mjohn@csir.oc.za,mayajacobkunnel@yahoo.com Page 1 of 27 John Wiley & Sons, Inc. Journal of Applied Polymer Science For Peer Revie w 2 1. INTRODUCTION Developments in composite technology have...

  9. Analyze the Properties of Woven Fabric Manufactured by Hand Loom and Power Loom

    Directory of Open Access Journals (Sweden)

    L. Shafinaz

    2014-09-01

    Full Text Available The handloom weaving industry is one of the ancient cottage industries in Bangladesh. Next to agriculture, it is the second largest sources of rural employment and income. The present study is an effort to investigate the present scenario of handloom weaving industries in Bangladesh. Also the analysis the properties and present trends of local woven fabric manufactured by Hand loom and Power loom. The study is based on secondary data.

  10. Influence of Warp Yarn Tension on Cotton Greige and Dyed Woven Fabric Prosperities

    OpenAIRE

    Uzma Syed; Rafique Ahmed Jhatial

    2013-01-01

    Fabric properties such as pilling and abrasion resistance and tensile strength vary when greige fabric is processed further. The quality of dyed fabric depends on the quality of greige fabric. Cotton Plain and Twill weave fabrics were woven at three different warp yarn tension and then dyed using monochlorotriazine, Drimerene Red Cl-5B dye gives difference in fabric properties. The ASTM, American International Standards were used to determine the greige and dyed fabric properties. It has been...

  11. The Effect Of Weave Construction On Tear Strength Of Woven Fabrics

    Directory of Open Access Journals (Sweden)

    Eryuruk Selin Hanife

    2015-09-01

    Full Text Available The tear strength of a woven fabric is very important, since it is more closely related to serviceability of the fabric. Tearing strength of the fabrics depend on the mobility of the yarn within the fabric structure. In this study, the tearing strength of four types of fabrics warp rib, weft rib, ripstop and plain weave were analysed, which were produced in different densities and with filament and texturised polyester yarns.

  12. Effect of carbon nanotube addition on the wear behavior of basalt/epoxy woven composites.

    Science.gov (United States)

    Kim, M T; Rhee, K Y; Lee, B H; Kim, C J

    2013-08-01

    The effect of acid-treated carbon nanotube (CNT) addition on the wear and dynamic mechanical thermal properties of basalt/epoxy woven composites was investigated in this study. Basalt/CNT/epoxy composites were fabricated by impregnating woven basalt fibers into epoxy resin mixed with 1 wt% CNTs which were acid-treated. Wear and DMA (dynamic mechanical analyzer) tests were performed on basalt/epoxy composites and basalt/CNT/epoxy composites. The results showed that the addition of the acid-treated CNTs improved the wear properties of basalt/epoxy woven composites. Specifically, the friction coefficient of the basalt/epoxy composite was stabilized in the range of 0.5-0.6 while it fell in the range of 0.3-0.4 for basalt/CNT/epoxy composites. The wear volume loss of the basalt/CNT/epoxy composites was approximately 68% lower than that of the basalt/epoxy composites. The results also showed that the glass transition temperature of basalt/CNT/epoxy composites was higher than that of basalt/epoxy composites. The improvement of wear properties of basalt/epoxy composites by the addition of acid-treated CNTs was caused by the homogeneous load transfer between basalt fibers and epoxy matrix due to the reinforcement of CNTs.

  13. Investigating the Potential of Using Off-Axis 3D Woven Composites in Composite Joints’ Applications

    KAUST Repository

    Saleh, Mohamed Nasr

    2016-09-26

    The effect of circular notch has been evaluated for three different architectures of three-dimensional (3D) carbon fibre woven composites (orthogonal, ORT; layer-to-layer, LTL; angle interlock, AI) through open-hole quasi-static tension and double-lap bearing strength tests in the off-axis (45°) direction. Damage characterisation is monitored using Digital Image correlation (DIC) for open-hole testing and X-ray Computed Tomography (CT) for double-lap bearing strength test. The off-axis notched 3D woven composites exhibits minor reduction (less than 10 %) of the notched strength compared to the un-notched strength. DIC strain contour clearly show stress/strain localisation regions around the hole periphery and stress/strain redistribution away from the whole due to the z-binder existence, especially for ORT architecture. Up to 50 % bearing strain, no significant difference in the bearing stress/bearing strain response is observed. However when ORT architecture was loaded up to failure, it demonstrates higher strain to failure (~140 %) followed by AI (~105 %) and lastly LTL (~85 %). X-ray CT scans reveal the effect of the z-binder architecture on damage evolution and delamination resistance. The study suggests that off-axis loaded 3D woven composites, especially ORT architecture, has a great potential of overcoming the current challenges facing composite laminates when used in composite joints’ applications. © 2016 The Author(s)

  14. Polymer optical fibers integrated directly into 3D orthogonal woven composites for sensing

    Science.gov (United States)

    Hamouda, Tamer; Seyam, Abdel-Fattah M.; Peters, Kara

    2015-02-01

    This study demonstrates that standard polymer optical fibers (POF) can be directly integrated into composites from 3D orthogonal woven preforms during the weaving process and then serve as in-situ sensors to detect damage due to bending or impact loads. Different composite samples with embedded POF were fabricated of 3D orthogonal woven composites with different parameters namely number of y-/x-layers and x-yarn density. The signal of POF was not affected significantly by the preform structure. During application of resin using VARTM technique, significant drop in backscattering level was observed due to pressure caused by vacuum on the embedded POF. Measurements of POF signal while in the final composites after resin cure indicated that the backscattering level almost returned to the original level of un-embedded POF. The POF responded to application of bending and impact loads to the composite with a reduction in the backscattering level. The backscattering level almost returned back to its original level after removing the bending load until damage was present in the composite. Similar behavior occurred due to impact events. As the POF itself is used as the sensor and can be integrated throughout the composite, large sections of future 3D woven composite structures could be monitored without the need for specialized sensors or complex instrumentation.

  15. Antibacterial activity of combination of synthetic and biopolymer non-woven structures.

    Science.gov (United States)

    Bhullar, Sukhwinder K; Özsel, Burcak Kaya; Yadav, Ramesh; Kaur, Ginpreet; Chintamaneni, Meena; Buttar, Harpal S

    2015-12-01

    Fibrous structures and synthetic polymer blends offer potential usages in making biomedical devices, textiles used in medical practices, food packaging, tissue engineering, environmental applications and biomedical arena. These products are also excellent candidates for building scaffolds to grow stem cells for implantation, to make tissue engineering grafts, to make stents to open up blood vessels caused by atherosclerosis or narrowed by blood clots, for drug delivery systems for micro- to nano-medicines, for transdermal patches, and for healing of wounds and burn care. The current study was designed to evaluate the antimicrobial activity of woven and non-woven forms of nano- and macro-scale blended polymers having biocompatible and biodegradable characteristics. The antimicrobial activity of non-woven fibrous structures created with the combination of synthetic and biopolymer was assessed using Gram-negative, Gram-positive bacteria, such as Staphylococcus aureus, Proteus vulgaris, Escherichia coli and Enterobacter aerogenes using pour plate method. Structural evaluation of the fabricated samples was performed by Fourier transform infrared spectroscopy. Broad spectrum antibacterial activities were found from the tested materials consisting of polyvinyl alcohol (PVA) with chitosan and nylon-6 combined with chitosan and formic acid. The combination of PVA with chitosan was more bactericidal or bacteriostatic than that of nylon-6 combined with chitosan and formic acid. PVA combination with chitosan appears to be a broad-spectrum antimicrobial agent.

  16. Influence of the Elastane Fibre on the Woven Fabric Structural Mobility

    Directory of Open Access Journals (Sweden)

    Virginija SACEVIČIENĖ

    2011-11-01

    Full Text Available The woven fabrics structural mobility has some influence on the garment design and pattern construction. Deformation peculiarities during six textile fabrics extension were analysed in this work. Four of the tested fabrics had the elastane filaments in their structure. The method of parallelepiped shaped specimen uniaxial extension till fixed strain was used. The experiment was carrying out using a "Tinius Olsen HT10" tension machine. The specimens' deformation exceeds 14 %. The parallelepiped shape of specimen's was received by cut of its top and bottom edges with pitch of 16 degrees. The woven fabrics structure mobility was analyzed using strain-stress curves, numerical and graphical results. The results of this research work have shown that deformation peculiarities of the woven fabrics depend on their structural characteristics: density, thickness, wave and presence of elastane filaments. Taking into account the more considerable extensibility of elastane fibre the shearing phenomenon was not occurred finally during specimens' deformations. The results indicated that for the tested fabrics deformation till stated degree the force from 0.6 N till 9.4 N is necessary.http://dx.doi.org/10.5755/j01.ms.17.4.779

  17. Investigating the Potential of Using Off-Axis 3D Woven Composites in Composite Joints' Applications

    Science.gov (United States)

    Saleh, Mohamed Nasr; Wang, Ying; Yudhanto, Arief; Joesbury, Adam; Potluri, Prasad; Lubineau, Gilles; Soutis, Constantinos

    2017-04-01

    The effect of circular notch has been evaluated for three different architectures of three-dimensional (3D) carbon fibre woven composites (orthogonal, ORT; layer-to-layer, LTL; angle interlock, AI) through open-hole quasi-static tension and double-lap bearing strength tests in the off-axis (45°) direction. Damage characterisation is monitored using Digital Image correlation (DIC) for open-hole testing and X-ray Computed Tomography (CT) for double-lap bearing strength test. The off-axis notched 3D woven composites exhibits minor reduction (less than 10 %) of the notched strength compared to the un-notched strength. DIC strain contour clearly show stress/strain localisation regions around the hole periphery and stress/strain redistribution away from the whole due to the z-binder existence, especially for ORT architecture. Up to 50 % bearing strain, no significant difference in the bearing stress/bearing strain response is observed. However when ORT architecture was loaded up to failure, it demonstrates higher strain to failure ( 140 %) followed by AI ( 105 %) and lastly LTL ( 85 %). X-ray CT scans reveal the effect of the z-binder architecture on damage evolution and delamination resistance. The study suggests that off-axis loaded 3D woven composites, especially ORT architecture, has a great potential of overcoming the current challenges facing composite laminates when used in composite joints' applications.

  18. 3D-WOVEN FIBER-REINFORCED COMPOSITE FOR CAD/CAM DENTAL APPLICATION.

    Science.gov (United States)

    Petersen, Richard; Liu, Perng-Ru

    2016-05-01

    Three-dimensional (3D)-woven noncrimp fiber-reinforced composite (FRC) was tested for mechanical properties in the two principal directions of the main XY plane and compared to different Computer-Aided-Design/Computer-Aided-Machining (CAD/CAM) Dental Materials. The Dental Materials included ceramic with Vitablock Mark II®, ProCAD®, InCeram® Spinel, InCeram® Alumina and InCeram® Zirconia in addition to a resin-based 3M Corp. Paradigm® particulate-filled composite. Alternate material controls included Coors 300 Alumina Ceramic and a tungsten carbide 22% cobalt cermet. The 3D-woven FRC was vacuum assisted resin transfer molding processed as a one-depth-thickness ~19-mm preform with a vinyl-ester resin and cut into blocks similar to the commercial CAD/CAM Dental Materials. Mechanical test samples prepared for a flexural three-point span length of 10.0 mm were sectioned for minimum-depth cuts to compare machinability and fracture resistance between groups. 3D-woven FRC improved mechanical properties with significant statistical differences over all CAD/CAM Dental Materials and Coors Alumina Ceramic for flexural strength (pfracture (p<0.001), strain energy release (p<0.05), critical stress intensity factor (p<0.001) and strain (p<0.001).

  19. Evaluation of In-Situ Stiffness of Subgrade by Resilient and FWD Modulus

    OpenAIRE

    Kim, Daehyeon; Ji, Yigong; Siddiki, Nayyar Zia

    2010-01-01

    Resilient modulus has been used for characterizing the stress-strain behavior of subgrade soils subjected to traffic loadings in the design of pavements. With the recent release of the M-E Pavement Design Guide, highway agencies are further encouraged to implement the resilient modulus test to improve subgrade design. A laboratory resilient modus test and a FWD test are usually used to obtain the resilient modulus of subgrade. However, the difference in the resilient modulus obtained from the...

  20. 无纺布专用PP树脂S960的开发%Development of special PP resin S960 for non-woven fabric

    Institute of Scientific and Technical Information of China (English)

    黄启望; 陈斌

    2012-01-01

    Special resin S960 for non-woven fabric with melt flow rate (MFR) of 39.0-42.0 g/10 min was produced under the conditions of controlling appropriately the MFR of polypropylene by introducing liquid di -tert -butyl peroxide into the pelletizer, solving the difficulty in pelletizing in the production by adjusting the cooling water temperature and the cutter rotational speed, etc.in the pelletizing system, and alleviating discoloration of the product after storage for a long time by changing the formula of additives. The special resin had ash content not more than 0.015 0%, flexural modulus higher than 1 000 MPa, tensile yield stress over 30.0 MPa and isotactic index above 96.0%. The processability of the resin and the mechanical properties of the non-woven fabric were confirmed to be excellent and able to meet the customers' demand.%通过在造粒单元加入液体二叔丁基过氧化物控制聚丙烯(PP)产品的熔体流动速率(MFR)、调整造粒系统冷却水温度、切刀转速等参数来解决生产中出现的切粒困难的问题;调整助剂配方,改善制品放置时间长出现变色的问题,生产出 MFR为39.0~42.0 g/10 min的无纺布专用 PP树脂S960.产品灰分不大于0.015 0%,弯曲模量大于1 000 MPa,拉伸屈服应力大于30.0 MPa,等规指数大于96.0%.产品加工性能、无纺布力学性能良好,可满足客户使用要求.

  1. Measurement of Elastic Modulus of Collagen Type I Single Fiber.

    Directory of Open Access Journals (Sweden)

    Pavel Dutov

    Full Text Available Collagen fibers are the main components of the extra cellular matrix and the primary contributors to the mechanical properties of tissues. Here we report a novel approach to measure the longitudinal component of the elastic moduli of biological fibers under conditions close to those found in vivo and apply it to type I collagen from rat tail tendon. This approach combines optical tweezers, atomic force microscopy, and exploits Euler-Bernoulli elasticity theory for data analysis. This approach also avoids drying for measurements or visualization, since samples are freshly extracted. Importantly, strains are kept below 0.5%, which appear consistent with the linear elastic regime. We find, surprisingly, that the longitudinal elastic modulus of type I collagen cannot be represented by a single quantity but rather is a distribution that is broader than the uncertainty of our experimental technique. The longitudinal component of the single-fiber elastic modulus is between 100 MPa and 360 MPa for samples extracted from different rats and/or different parts of a single tail. Variations are also observed in the fibril-bundle/fibril diameter with an average of 325±40 nm. Since bending forces depend on the diameter to the fourth power, this variation in diameter is important for estimating the range of elastic moduli. The remaining variations in the modulus may be due to differences in composition of the fibril-bundles, or the extent of the proteoglycans constituting fibril-bundles, or that some single fibrils may be of fibril-bundle size.

  2. Connecting Jacobi elliptic functions with different modulus parameters

    Indian Academy of Sciences (India)

    Avinash Khare; Uday Sukhatme

    2004-11-01

    The simplest formulas connecting Jacobi elliptic functions with different modulus parameters were first obtained over two hundred years ago by John Landen. His approach was to change integration variables in elliptic integrals. We show that Landen’s formulas and their subsequent generalizations can also be obtained from a different approach, using which we also obtain several new Landen transformations. Our new method is based on recently obtained periodic solutions of physically interesting non-linear differential equations and remarkable new cyclic identities involving Jacobi elliptic functions.

  3. Lazy Modulus Switching for the BKW Algorithm on LWE

    DEFF Research Database (Denmark)

    Albrecht, Martin Roland; Faugère, Jean-Charles; Fitzpatrick, Robert

    2014-01-01

    algorithm for binary-LWE and other small secret variants and show that this variant reduces the complexity for solving binary-LWE. We also give estimates for the cost of solving binary-LWE instances in this setting and demonstrate the advantage of this BKW variant over standard BKW and lattice reduction...... techniques applied to the SIS problem. Our variant can be seen as a combination of the BKW algorithm with a lazy variant of modulus switching which might be of independent interest....

  4. Information-Theoretic Secure Verifiable Secret Sharing over RSA Modulus

    Institute of Scientific and Technical Information of China (English)

    QIU Gang; WANG Hong; WEI Shimin; XIAO Guozhen

    2006-01-01

    The well-known non-interactive and information-theoretic secure verifiable secret sharing scheme presented by Pedersen is over a large prime. In this paper, we construct a novel non-interactive and information-theoretic verifiable secret sharing over RSA (Rivest,Shamir,Adleman) modulus and give the rigorous security proof. It is shown how to distribute a secret among a group such that any set of k parties get no information about the secret. The presented scheme is generally applied to constructions of secure distributed multiplication and threshold or forward-secure signature protocols.

  5. Hidden Modulus in the Extended Veneziano-Yankielowicz Theory

    CERN Document Server

    Auzzi, R; Auzzi, Roberto; Sannino, Francesco

    2005-01-01

    The issue of domain walls in the recently extended Veneziano-Yankielowicz theory is investigated and we show that they have an interesting substructure. We also demonstrate the presence of a noncompact modulus. The associated family of degenerate solutions is physically due to the presence of a valley of vacua in the enlarged space of fields. This is a feature of the extended Veneziano-Yankielowicz theory. Unfortunately the above properties do not match the ones expected for the domain walls of N=1 super Yang-Mills.

  6. Simple Backdoors on RSA Modulus by Using RSA Vulnerability

    Science.gov (United States)

    Sun, Hung-Min; Wu, Mu-En; Yang, Cheng-Ta

    This investigation proposes two methods for embedding backdoors in the RSA modulus N=pq rather than in the public exponent e. This strategy not only permits manufacturers to embed backdoors in an RSA system, but also allows users to choose any desired public exponent, such as e=216+1, to ensure efficient encryption. This work utilizes lattice attack and exhaustive attack to embed backdoors in two proposed methods, called RSASBLT and RSASBES, respectively. Both approaches involve straightforward steps, making their running time roughly the same as that of normal RSA key-generation time, implying that no one can detect the backdoor by observing time imparity.

  7. A Note on Modulus-dominated SUSY-breaking

    CERN Document Server

    Maxin, James A; Nanopoulos, D V

    2009-01-01

    In models where supersymmetry-breaking is dominated by the Kahler moduli and/or the universal dilaton, the B-parameter at the unification scale should be consistent with the value of tan(beta) at the electroweak scale determined by minimization of the Higgs potential triggering REWSB. We study such models employing a self-consistent determination of the B-parameter. In particular, we study the viability of a generic model, as well as M-theory and Type IIB flux compactifications with modulus-dominated supersymmetric soft-terms from the GUT scale, M_{GUT}=2x10^{16}GeV.

  8. Environmental Effects on Long Term Displacement Data of Woven Fabric Webbings Under Constant Load for Inflatable Structures

    Science.gov (United States)

    Kenner, WInfred S.; Jones, Thomas C.; Doggett, William R.; Duncan, Quinton; Plant, James

    2015-01-01

    An experimental study of the effects of environmental temperature and humidity conditions on long-term creep displacement data of high strength Kevlar and VectranTM woven fabric webbings under constant load for inflatable structures is presented. The restraint layer of an inflatable structure for long-duration space exploration missions is designed to bear load and consists of an assembly of high strength webbings. Long-term creep displacement data of webbings can be utilized by designers to validate service life parameters of restraint layers of inflatable structures. Five groups of high-strength webbings were researched over a two year period. Each group had a unique webbing length, load rating, applied load, and test period. The five groups consisted of 1.) 6K Vectran webbings loaded to 49% ultimate tensile strength (UTS), 2.) 6K Vectran webbings loaded to 55% UTS, 3.) 12.5K Vectran webbings loaded to 22% UTS, 4.) 6K Kevlar webbings loaded to 40% and 43% UTS, and 5.) 6K Kevlar webbings loaded to 48% UTS. Results show that all webbing groups exhibit the initial two stages of three of a typical creep curve of an elastic material. Results also show that webbings exhibit unique local wave patterns over the duration of the test period. Data indicate that the local pattern is primarily generated by daily variations in relative humidity values within the test facility. Data indicate that after a three to six month period, where webbings reach a steady-state creep condition, an annual sinusoidal displacement pattern is exhibited, primarily due to variations in annual mean temperature values. Data indicates that variations in daily temperature values and annual mean humidity values have limited secondary effects on creep displacement behavior. Results show that webbings in groups 2 and 5 do not exhibit well defined annual displacement patterns because the magnitude of the applied loads cause large deformations, and data indicate that material yielding within a webbing

  9. Elastic superlattices with simultaneously negative effective mass density and shear modulus

    Science.gov (United States)

    Solís-Mora, I. S.; Palomino-Ovando, M. A.; Pérez-Rodríguez, F.

    2013-03-01

    We investigate the vibrational properties of superlattices with layers of rubber and polyurethane foam, which can be either conventional or auxetic. Phononic dispersion calculations show a second pass band for transverse modes inside the lowest band gap of the longitudinal modes. In such a band, the superlattices behave as a double-negative elastic metamaterial since the effective dynamic mass density and shear modulus are both negative. The pass band is associated to a Fabry-Perot resonance band which turns out to be very narrow as a consequence of the high contrast between the acoustic impedances of the superlattice components.

  10. Studies of P(L/D)LA 96/4 non-woven scaffolds and fibres; properties, wettability and cell spreading before and after intrusive treatment methods

    OpenAIRE

    Ellã, V.; Gomes, Manuela E.; Reis, R. L.; Tormala, P.; Kellomaki, M.

    2007-01-01

    Poly(L/D)lactide 96/4 fibres with diameters of 50 and 80 microm were produced. The smaller diameter fibres were carded and needle punched to form a non-woven mat. Fibres and non-woven mats were hydrolysed for a period of 20 weeks. Fibres and pressed non-woven discs were treated with low-temperature oxygen plasma and alkaline KOH hydrolysis and ethanol washing was used as a reference treatment. The non-wovens lost 50% of their tear strength after 8 weeks in vitro while the fibres still retaine...

  11. ECG Analysis based on Wavelet Transform and Modulus Maxima

    Directory of Open Access Journals (Sweden)

    Mourad Talbi

    2012-01-01

    Full Text Available In this paper, we have developed a new technique of P, Q, R, S and T Peaks detection using Wavelet Transform (WT and Modulus maxima. One of the commonest problems in electrocardiogram (ECG signal processing, is baseline wander removal suppression. Therefore we have removed the baseline wander in order to make easier the detection of the peaks P and T. Those peaks are detected after the QRS detection. The proposed method is based on the application of the discritized continuous wavelet transform (Mycwt used for the Bionic wavelet transform, to the ECG signal in order to detect R-peaks in the first stage and in the second stage, the Q and S peaks are detected using the R-peaks localization. Finally the Modulus maxima are used in the undecimated wavelet transform (UDWT domain in order to detect the others peaks (P, T. This detection is performed by using a varying-length window that is moving along the whole signal. For evaluating the proposed method, we have compared it to others techniques based on wavelets. In this evaluation, we have used many ECG signals taken from MIT-BIH database. The obtained results show that the proposed method outperforms a number of conventional techniques used for our evaluation.

  12. Modulus reconstruction from prostate ultrasound images using finite element modeling

    Science.gov (United States)

    Yan, Zhennan; Zhang, Shaoting; Alam, S. Kaisar; Metaxas, Dimitris N.; Garra, Brian S.; Feleppa, Ernest J.

    2012-03-01

    In medical diagnosis, use of elastography is becoming increasingly more useful. However, treatments usually assume a planar compression applied to tissue surfaces and measure the deformation. The stress distribution is relatively uniform close to the surface when using a large, flat compressor but it diverges gradually along tissue depth. Generally in prostate elastography, the transrectal probes used for scanning and compression are cylindrical side-fire or rounded end-fire probes, and the force is applied through the rectal wall. These make it very difficult to detect cancer in prostate, since the rounded contact surfaces exaggerate the non-uniformity of the applied stress, especially for the distal, anterior prostate. We have developed a preliminary 2D Finite Element Model (FEM) to simulate prostate deformation in elastography. The model includes a homogeneous prostate with a stiffer tumor in the proximal, posterior region of the gland. A force is applied to the rectal wall to deform the prostate, strain and stress distributions can be computed from the resultant displacements. Then, we assume the displacements as boundary condition and reconstruct the modulus distribution (inverse problem) using linear perturbation method. FEM simulation shows that strain and strain contrast (of the lesion) decrease very rapidly with increasing depth and lateral distance. Therefore, lesions would not be clearly visible if located far away from the probe. However, the reconstructed modulus image can better depict relatively stiff lesion wherever the lesion is located.

  13. Long Term Displacement Data of Woven Fabric Webbings Under Constant Load for Inflatable Structures

    Science.gov (United States)

    Kenner, Winfred S.; Jones, Thomas C.; Doggett, William R.; Lucy, Melvin H.; Grondin, Trevor A.; Whitley, Karen S.; Duncan, Quinton; Plant, James V.

    2014-01-01

    Inflatable modules for space applications offer weight and launch volume savings relative to current metallic modules. Limited data exist on the creep behavior of the restraint layer of inflatable modules. Long-term displacement and strain data of two high strength woven fabric webbings, Kevlar and Vectran, under constant load is presented. The creep behavior of webbings is required by designers to help determine service life parameters of inflatable modules. Four groups of different webbings with different loads were defined for this study. Group 1 consisted of 4K Kevlar webbings loaded to 33% ultimate tensile strength and 6K Vectran webbings loaded to 27% ultimate tensile strength, group 2 consisted of 6K Kevlar webbings loaded to 40% and 43% ultimate tensile strength, and 6K Vectran webbings loaded to 50% ultimate tensile strength, group 3 consisted of 6K Kevlar webbings loaded to 52% ultimate tensile strength and 6K Vectran webbings loaded to 60% ultimate tensile strength, and group 4 consisted of 12.5K Kevlar webbings loaded to 22% ultimate tensile strength, and 12.5K Vectran webbings loaded to 22% ultimate tensile strength. The uniquely designed test facility, hardware, displacement measuring devices, and test data are presented. Test data indicate that immediately after loading all webbings stretch an inch or more, however as time increases displacement values significantly decrease to fall within a range of several hundredth of an inch over the remainder of test period. Webbings in group 1 exhibit near constant displacements and strains over a 17-month period. Data acquisition was suspended after the 17th month, however webbings continue to sustain load without any local webbing damage as of the 21st month of testing. Webbings in group 2 exhibit a combination of initial constant displacement and subsequent increases in displacement rates over a 16-month period. Webbings in group 3 exhibit steady increases in displacement rates leading to webbing failure

  14. Optimization of Cr content of metastable β-type Ti-Cr alloys with changeable Young's modulus for spinal fixation applications.

    Science.gov (United States)

    Zhao, Xingfeng; Niinomi, Mitsuo; Nakai, Masaaki; Hieda, Junko; Ishimoto, Takuya; Nakano, Takayoshi

    2012-07-01

    Metallic implant rods used in spinal fixtures should have a Young's modulus that is sufficiently low to prevent stress shielding for the patient and sufficiently high to suppress springback for the surgeon. Therefore, we propose a new concept: novel biomedical titanium alloys with a changeable Young's modulus via deformation-induced ω phase transformation. In this study, the Cr content in the range of 10-14 mass% was optimized to produce deformation-induced ω phase transformation, resulting in a large increase in the Young's modulus of binary Ti-Cr alloys. The springback and cytotoxicity of the optimized alloys were also examined. Ti-(10-12)Cr alloys exhibit an increase in Young's modulus owing to deformation-induced ω phase transformation. In this case, such deformation-induced ω phase transformation occurs along with {332}(β) mechanical twinning, resulting in the maintenance of acceptable ductility with relatively high strength. Among the examined alloys, the lowest Young's modulus and largest increase in Young's modulus are obtained from the Ti-12Cr alloy. This alloy exhibits smaller springback than and comparable cytocompatibility to the biomedical Ti alloy Ti-29Nb-13Ta-4.6Zr. Copyright © 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  15. Research on Reasonable Elastic Modulus of High-strength Extruded Sheet Laid at Bridge Beam end and Used in CRTS-II Slab Track on Bridge%桥上CRTS域型板式轨道梁端高强度挤塑板的合理弹性模量研究

    Institute of Scientific and Technical Information of China (English)

    赵坪锐; 刘观; 胡佳

    2014-01-01

    依据梁端CRTS域型板式轨道的结构受力特征,采用梁模拟钢轨、轨道板和底座板,线性弹簧模拟扣件与CA砂浆的弹性作用,采用单向受压弹簧模拟滑动层与挤塑板的支撑作用,建立梁端轨道叠合梁计算模型,分析挤塑板弹性模量对无砟轨道承受轮载以及梁端位移时的受力变化规律。分析表明:由于梁端挤塑板弹性模量相对较低,列车通过时容易引起刚度不平顺、增大轨道受力,应适当提高挤塑板弹性模量;而梁端位移作用时,较大的挤塑板弹性模量则会引起较大的附加弯矩。综合考虑两方面作用,在常用32 m梁上,挤塑板弹性模量在10~50 MPa时,轨道受力状态最佳,其他梁型应根据实际梁端位移适当调整挤塑板弹性模量。%In this research, based on structural and mechanical characteristic of CRTS-II slab track at bridge beam end, a beam-track composite model at bridge beam end was established. In this model, the rail, track slab and base plate were assumed to be beam elements; the fastener and CA mortar were assumed to be linear springs so as to simulate their elastic effect;and the sliding layer and the extruded sheet were assumed to be uniaxial compression springs so as to simulate their supporting effect. Then the change rules of the action effects of both the wheel load and bridge beam end displacement were analyzed with the change of the elastic modulus of the extruded sheet. The analysis shows that: because of the lower elastic modulus of the extruded sheet, there will be uneven stiffness and increased rail stress when train passing through, so the elastic modulus of extruded sheet should be increased appropriately;and on the other hand, because of the higher elastic modulus of the extruded sheet, there will be additional bending moment when displacement angle appearing at bridge beam end. Then this research comes to the conclusion:according to a comprehensive

  16. Effect of swaging on Young׳s modulus of β Ti-33.6Nb-4Sn alloy.

    Science.gov (United States)

    Hanada, Shuji; Masahashi, Naoya; Jung, Taek Kyun; Miyake, Masahiro; Sato, Yutaka S; Kokawa, Hiroyuki

    2014-04-01

    The effect of swaging on the Young's modulus of β Ti-33.6Nb-4Sn rods was investigated by X-ray diffraction, thermography, microstructural observations, deformation simulator analysis and cyclic tensile deformation. Stress-induced α″ martensite was stabilized by swaging, dependent on the diameter reduction rate during swaging. Thermography and deformation simulator analysis revealed that swaged rods were adiabatically heated, and consequently, stress-induced α″ underwent reverse transformation. Young's modulus, which was measured by the slope of the initial portion of the stress-strain curve, decreased from 56GPa in the hot-forged/quenched rod to 44GPa in the rapidly swaged rod with a high reduction rate and to 45GPa in the gradually swaged rod with a low reduction rate. The tangent modulus, which was measured by the slope of the tangent to any point on the stress-strain curve, decreased with strain even in the linear range of the stress-strain curve of the hot-forged/quenched rod and the rapidly swaged rod, while the tangent modulus remained unchanged for the gradually swaged rod. It was found that Young's moduli in swaged β Ti-33.6Nb-4Sn rods were affected by stabilized α″ martensite. Low Young's modulus of 45GPa and high strength over 800MPa were obtained when the reverse transformation by adiabatic heating was suppressed and the stress-induced α″ was sufficiently stabilized by gradual swaging to a 75% reduction in cross section area.

  17. Mechanical properties of low modulus beta titanium alloys designed from the electronic approach.

    Science.gov (United States)

    Laheurte, P; Prima, F; Eberhardt, A; Gloriant, T; Wary, M; Patoor, E

    2010-11-01

    Titanium alloys dedicated to biomedical applications may display both clinical and mechanical biocompatibility. Based on nontoxic elements such as Ti, Zr, Nb, Ta, they should combine high mechanical resistance with a low elastic modulus close to the bone elasticity (E=20 GPa) to significantly improve bone remodelling and osseointegration processes. These elastic properties can be reached using both lowering of the intrinsic modulus by specific chemical alloying and superelasticity effects associated with a stress-induced phase transformation from the BCC metastable beta phase to the orthorhombic alpha(″) martensite. It is shown that the stability of the beta phase can be triggered using a chemical formulation strategy based on the electronic design method initially developed by Morinaga. This method is based on the calculation of two electronic parameters respectively called the bond order (B(o)) and the d orbital level (M(d)) for each alloy. By this method, two titanium alloys with various tantalum contents, Ti-29Nb-11Ta-5Zr and Ti-29Nb-6Ta-5Zr (wt%) were prepared. In this paper, the effect of the tantalum content on the elastic modulus/yield strength balance has been investigated and discussed regarding the deformation modes. The martensitic transformation beta-->alpha(″) has been observed on Ti-29Nb-6Ta-5Zr in contrast to Ti-29Nb-11Ta-5Zr highlighting the chemical influence of the Ta element on the initial beta phase stability. A formulation strategy is discussed regarding the as-mentioned electronic parameters. Respective influence of cold rolling and flash thermal treatments (in the isothermal omega phase precipitation domain) on the tensile properties has been investigated.

  18. The effects of side-artifacts on the elastic modulus of trabecular bone.

    Science.gov (United States)

    Un, Kerem; Bevill, Grant; Keaveny, Tony M

    2006-01-01

    Determining accurate density-mechanical property relationships for trabecular bone is critical for correct characterization of this important structure-function relation. When testing any excised specimen of trabecular bone, an unavoidable experimental artifact originates from the sides of the specimen where peripheral trabeculae lose their vertical load-bearing capacity due to interruption of connectivity, a phenomenon denoted here as the 'side-artifact'. We sought in this study to quantify the magnitude of such side-artifact errors in modulus measurement and to do so as a function of the trabecular architecture and specimen size. Using parametric computational analysis of high-resolution micro-CT-based finite-element models of cores of elderly human vertebral trabecular bone, a specimen-specific correction factor for the side-artifact was quantified as the ratio of the side-artifact-free apparent modulus (Etrue) to the apparent modulus that would be measured in a typical experiment (Emeasured). We found that the width over which the peripheral trabeculae were mostly unloaded was between 0.19 and 0.58 mm. The side-artifact led to an underestimation error in Etrue of over 50% in some specimens, having a mean (+/-SD) of 27+/-11%. There was a trend for the correction factor to linearly increase as volume fraction decreased (p=0.001) and as mean trabecular separation increased (perror increased substantially as specimen size decreased. Two methods used for correcting for the side-artifact were both successful in bringing Emeasured into statistical agreement with Etrue. These findings have important implications for the interpretation of almost all literature data on trabecular bone mechanical properties since they indicate that such properties need to be adjusted to eliminate the substantial effects of side-artifacts in order to provide more accurate estimates of in situ behavior.

  19. Pretreatment of Woven Jute FRP Composite and Its Use in Strengthening of Reinforced Concrete Beams in Flexure

    Directory of Open Access Journals (Sweden)

    Tara Sen

    2013-01-01

    Full Text Available Environmental awareness motivates researchers worldwide to perform studies of natural fibre reinforced polymer composites, as they come with many advantages and are primarily sustainable. The present study aims at evaluating the mechanical characteristics of natural woven jute fibre reinforced polymer (FRP composite subjected to three different pretreatments, alkali, benzyl chloride, and lastly heat treatment. It was concluded that heat treatment is one of the most suitable treatment methods for enhancing mechanical properties of jute FRP. Durability studies on Jute FRP pertaining to some common environmental conditions were also carried out such as effect of normal water and thermal aging on the tensile strength of jute FRP followed by fire flow test. The heat treated woven jute FRP composites were subsequently used for flexural strengthening of reinforced concrete beams in full and strip wrapping configurations. The study includes the effect of flexural strengthening provided by woven jute FRP, study of different failure modes, load deflection behavior, effect on the first crack load, and ultimate flexural strength of concrete beams strengthened using woven jute FRP subjected to bending loads. The study concludes that woven jute FRP is a suitable material which can be used for flexural upgradation of reinforced concrete beams.

  20. Measurement of ultimate tensile strength and Young modulus in LYSO scintillating crystals

    Energy Technology Data Exchange (ETDEWEB)

    Scalise, Lorenzo, E-mail: l.scalise@univpm.it [Dipartimento di Meccanica, Universita Politecnica delle Marche, Via Brecce Bianche, 60131 Ancona (Italy); Rinaldi, Daniele [Dipartimento di Fisica e Ingegneria dei Materiali e del Territorio, Universita Politecnica delle Marche, Via Brecce Bianche, 60131 Ancona (Italy); Istituto Nazionale di Fisica Nucleare, Section of Perugia (Italy); Davi, Fabrizio [Dipartimento di Architettura Costruzioni e Strutture, Universita Politecnica delle Marche, Via Brecce Bianche, 60131 Ancona (Italy); Paone, Nicola [Dipartimento di Meccanica, Universita Politecnica delle Marche, Via Brecce Bianche, 60131 Ancona (Italy)

    2011-10-21

    Scintillating crystals are employed in high energy physics, in medical imaging, diagnostic and security. Two mechanical properties of lutetium-yttrium oxyorthosilicate cerium-doped Lu{sub 2(1-x)}Y{sub 2x}SiO{sub 5}:Ce with x=0.1 (LYSO) crystals have been measured: the ultimate tensile stress ({sigma}{sub UTS}) and the Young elastic modulus (E). Measurements are made by means of a 4-points loading device and the experimental results account for an elastic-brittle stress-strain relation, which depends heavily on the specimen preparation and the material defects. {sigma}{sub UTS} along the [0 1 0] tensile direction ranges within 68.14 and 115.61 MPa, which, in the lowest case, is more than twice with respect to those measured for PbWO{sub 4} (PWO), exhibiting a marked difference between the annealed and the not-annealed samples. The mean elastic modulus (E), along the same direction, is E=1.80x10{sup 11} ({+-}2.15x10{sup 10}) N/m{sup 2}, with lower dispersion respect to UTS data. This type of analysis and study can be included into quality control procedures of crystals, based on samples taken out of production; such procedures can be established for industrial processing of crystals aimed to the high energy physics (calorimeters) and medical imaging (PET, etc.) applications.

  1. Size dependent elastic modulus and mechanical resilience of dental enamel.

    Science.gov (United States)

    O'Brien, Simona; Shaw, Jeremy; Zhao, Xiaoli; Abbott, Paul V; Munroe, Paul; Xu, Jiang; Habibi, Daryoush; Xie, Zonghan

    2014-03-21

    Human tooth enamel exhibits a unique microstructure able to sustain repeated mechanical loading during dental function. Although notable advances have been made towards understanding the mechanical characteristics of enamel, challenges remain in the testing and interpretation of its mechanical properties. For example, enamel was often tested under dry conditions, significantly different from its native environment. In addition, constant load, rather than indentation depth, has been used when mapping the mechanical properties of enamel. In this work, tooth specimens are prepared under hydrated conditions and their stiffnesses are measured by depth control across the thickness of enamel. Crystal arrangement is postulated, among other factors, to be responsible for the size dependent indentation modulus of enamel. Supported by a simple structure model, effective crystal orientation angle is calculated and found to facilitate shear sliding in enamel under mechanical contact. In doing so, the stress build-up is eased and structural integrity is maintained.

  2. Separation of attractors in 1-modulus quantum corrected special geometry

    CERN Document Server

    Bellucci, S; Marrani, A; Shcherbakov, A

    2008-01-01

    We study the solutions to the N=2, d=4 Attractor Equations in a dyonic, extremal, static, spherically symmetric and asymptotically flat black hole background, in the simplest case of perturbative quantum corrected cubic Special Kahler geometry consistent with continuous axion-shift symmetry, namely in the 1-modulus Special Kahler geometry described (in a suitable special symplectic coordinate) by the holomorphic Kahler gauge-invariant prepotential F=t^3+i*lambda, with lambda real. By performing computations in the ``magnetic'' charge configuration, we find evidence for interesting phenomena (absent in the classical limit of vanishing lambda). Namely, for a certain range of the quantum parameter lambda we find a ``splitting'' of attractors, i.e. the existence of multiple solutions to the Attractor Equations for fixed supporting charge configuration. This corresponds to the existence of ``area codes'' in the radial evolution of the scalar t, determined by the various disconnected regions of the moduli space, wh...

  3. Size effects of effective Young's modulus for periodic cellular materials

    Institute of Scientific and Technical Information of China (English)

    DAI GaoMing; ZHANG WeiHong

    2009-01-01

    With the wide demands of cellular materials applications in aerospace and civil engineering, research effort sacrificed for this type of materials attains nowadays a higher level than ever before. This paper is focused on the prediction methods of effective Young's modulus for periodical cellular materials. Based on comprehensive studies of the existing homogenization method (HM), the G-A meso-me-chanice method (G-A MMM) and the stretching energy method (SEM) that are unable to reflect the size effect, we propose the bending energy method (BEM) for the first time, and a comparative study of these four methods is further made to show the generality and the capability of capturing the size effect of the BEM method. Meanwhile, the underlying characteristics of each method and their relations are clarified. To do this, the detailed finite element computing and existing experimental results of hex-agonal honeycombs from the literature are adopted as the standard of comparison for the above four methods. Stretch and bending models of periodical cellular materials are taken into account, respec-tively for the comparison of stretch and flexural displacements resulting from the above methods. We conclude that the BEM has the strong ability of both predicting the effective Young's modulus and re- vealing the size effect. Such a method is also able to predict well the variations of structural displace-ments in terms of the cell size under stretching and bending loads including the non-monotonous variations for the hexagonal cell. On the contrary, other three methods can only predict the limited re- sults whenever the cell size tends to be infinitely small.

  4. Compression molding of chopped woven thermoplastic composite flakes

    NARCIS (Netherlands)

    Abdul Rasheed, Mohammed Iqbal

    2016-01-01

    Continuous fiber reinforced composites with high-performance thermoplastic polymer matrices have an enormous potential in terms of performance, production rate, cost efficiency and recyclability. The use of this relatively new class of materials by the aerospace and automotive industry has been

  5. Compression molding of chopped woven thermoplastic composite flakes

    NARCIS (Netherlands)

    Abdul Rasheed, Mohammed Iqbal

    2016-01-01

    Continuous fiber reinforced composites with high-performance thermoplastic polymer matrices have an enormous potential in terms of performance, production rate, cost efficiency and recyclability. The use of this relatively new class of materials by the aerospace and automotive industry has been grow

  6. A polylactic acid non-woven nerve conduit for facial nerve regeneration in rats.

    Science.gov (United States)

    Matsumine, Hajime; Sasaki, Ryo; Yamato, Masayuki; Okano, Teruo; Sakurai, Hiroyuki

    2014-06-01

    This study developed a biodegradable nerve conduit with PLA non-woven fabric and evaluated its nerve regeneration-promoting effect. The buccal branch of the facial nerve of 8 week-old Lewis rats was exposed, and a 7 mm nerve defect was created. A nerve conduit made of either PLA non-woven fabric (mean fibre diameter 460 nm), or silicone tube filled with type I collagen gel, or an autologous nerve, was implanted into the nerve defect, and their nerve regenerative abilities were evaluated 13 weeks after the surgery. The number of myelinated neural fibres in the middle portion of the regenerated nerve was the highest for PLA tubes (mean ± SD, 5051 ± 2335), followed by autologous nerves (4233 ± 590) and silicone tubes (1604 ± 148). Axon diameter was significantly greater in the PLA tube group (5.17 ± 1.69 µm) than in the silicone tube group (4.25 ± 1.60 µm) and no significant difference was found between the PLA tube and autograft (5.53 ± 1.93 µm) groups. Myelin thickness was greatest for the autograft group (0.65 ± 0.24 µm), followed by the PLA tube (0.54 ± 0.18 µm) and silicone tube (0.38 ± 0.12 µm) groups, showing significant differences among the three groups. The PLA non-woven fabric tube, composed of randomly-connected PLA fibres, is porous and has a number of advantages, such as sufficient strength to maintain luminal structure. The tube has demonstrated a comparable ability to induce peripheral nerve regeneration following autologous nerve transplantation.

  7. Influence of Laundering on the Quality of Sewn Cotton and Bamboo Woven Fabrics

    Directory of Open Access Journals (Sweden)

    Jurgita KOŽENIAUSKIENĖ

    2013-03-01

    Full Text Available In the presented study the effect of laundering on the quality of sewn cotton and bamboo plain woven fabrics was investigated considering both the textile parameters and the type of chemical treatment. Quality parameters of sewn cotton and bamboo woven fabrics such as: fabric strength, seam strength and seam slippage at the moment of 4 mm seam opening were evaluated before and after washing with “Tide” washing powder without softeners or with softeners: “Surcare” and “Pflege Weicspuler”. There was also determined surface density, warp and weft densities as well as thicknesses under the pressures 0.625 kPa and 3.125 kPa, and calculated the comparative thickness that was considered as softness or porosity of fabrics. Notwithstanding that both the investigated fabrics were cellulosic their behavior after laundering was different. Under the tested conditions, unwashed and laundered with or without chemical softeners cotton fabric didn’t demonstrate seam slippage. The seam slippage resistance of laundered without or with softener specimens of bamboo fabric was increased in respect to control fabric. The larger changes in seam efficiency and seam strength because of laundering were determined for bamboo woven fabric then for cotton fabric. They could be influenced by the higher changes in bamboo fabric’s structure. The highest difference between the structure parameters of both fabrics was determined for comparative thickness. It was significantly increased for cotton fabric and decreased for bamboo fabric after chemical softening comparing to untreated fabrics.DOI: http://dx.doi.org/10.5755/j01.ms.19.1.3831

  8. Preparation and characterization of activated carbon fiber (ACF) from cotton woven waste

    Energy Technology Data Exchange (ETDEWEB)

    Jieying Zheng,; Zhao, Quanlin; Ye, Zhengfang, E-mail: zhengfangye@163.com

    2014-04-01

    Highlights: • Cotton woven waste can be recycled as precursor to produce activated carbon fiber. • The optimum carbonization and activation temperature are 700 °C and 800 °C. • The prepared ACF is in the form of fiber, with the surface area of 789 m{sup 2}/g. • The prepared ACF can be used to remove over 80% of COD from oilfield wastewater. - Abstract: In this study, the activated carbon fibers (ACFs) were prepared using cotton woven waste as precursor. The cotton woven waste was first partly dissolved by 80% phosphoric acid and then was pre-soaked in 7.5% diammonium hydrogen phosphate solution. Finally, carbonization and activation were proceeded to get ACF. The optimum preparation conditions, including carbonization temperature, carbonization time, activation temperature and activation time, were chosen by orthogonal design. Nitrogen adsorption/desorption test was conducted to characterize the prepared ACF's pore structure. Fourier transform infrared spectroscopy (FTIR) analysis, X-ray photoelectron spectroscopy (XPS) and environmental scanning electron microscope (ESEM) were employed to characterize its chemical properties and morphology. Adsorption of oilfield wastewater was used to evaluate its adsorption properties. The results show that the prepared ACF is in the form of fiber, with the sectional diameters of 11.7 × 2.6 μm and the surface area of 789 m{sup 2}/g. XPS results show that carbon concentration of the prepared ACF is higher than that of the commercial ACF. When the prepared ACF dosage is 6 g/L, over 80% of COD and over 70% of chrominance can be removed after 24 h of adsorption at 18 °C.

  9. 3D Orthogonal Woven Triboelectric Nanogenerator for Effective Biomechanical Energy Harvesting and as Self-Powered Active Motion Sensors.

    Science.gov (United States)

    Dong, Kai; Deng, Jianan; Zi, Yunlong; Wang, Yi-Cheng; Xu, Cheng; Zou, Haiyang; Ding, Wenbo; Dai, Yejing; Gu, Bohong; Sun, Baozhong; Wang, Zhong Lin

    2017-08-08

    The development of wearable and large-area energy-harvesting textiles has received intensive attention due to their promising applications in next-generation wearable functional electronics. However, the limited power outputs of conventional textiles have largely hindered their development. Here, in combination with the stainless steel/polyester fiber blended yarn, the polydimethylsiloxane-coated energy-harvesting yarn, and nonconductive binding yarn, a high-power-output textile triboelectric nanogenerator (TENG) with 3D orthogonal woven structure is developed for effective biomechanical energy harvesting and active motion signal tracking. Based on the advanced 3D structural design, the maximum peak power density of 3D textile can reach 263.36 mW m(-2) under the tapping frequency of 3 Hz, which is several times more than that of conventional 2D textile TENGs. Besides, its collected power is capable of lighting up a warning indicator, sustainably charging a commercial capacitor, and powering a smart watch. The 3D textile TENG can also be used as a self-powered active motion sensor to constantly monitor the movement signals of human body. Furthermore, a smart dancing blanket is designed to simultaneously convert biomechanical energy and perceive body movement. This work provides a new direction for multifunctional self-powered textiles with potential applications in wearable electronics, home security, and personalized healthcare. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Fabrication and characterization of nanoclay modified PMR type polyimide composites reinforced with 3D woven basalt fabric

    Science.gov (United States)

    Xie, Jianfei; Qiu, Yiping

    2009-07-01

    Nanoclay modified PMR type polyimide composites were prepared from 3D orthogonal woven basalt fiber performs and nanoclay modified polyimide matrix resin, which derived from methylene dianiline (MDA), dimethyl ester of 3,3',4,4'- oxydiphthalic acid (ODPE), monomethyl ester of cis-5-norbornene-endo-2,3-dicarboxylic acid (NE) and nanoclay. The Na+-montmorillonite was organically treated using a 1:1 molar ratio mixture of dodecylamine (C12) and MDA. The rheological properties of neat B-stage PMR polyimide and 2% clay modified B-stage PMR polyimide were investigated. Based on the results obtained from the rheological tests, a two step compression molding process can be established for the composites. In the first step, the 3D fabric preforms were impregnated with polyimide resin in a vacuum oven and heated up for degassing the volatiles and by-products. In the second step, composites were compressed. The internal structure of the composites was observed by a microscope. Incorporation of 2% clay showed an improvement in the Tg and stiffness of the PMR polyimide. The resulting composites exhibited high thermal stability and good mechanical properties.

  11. Kinetics and mechanisms of oxidation of 2D woven C/SiC composites; 1: Experimental approach

    Energy Technology Data Exchange (ETDEWEB)

    Lamouroux, F.; Camus, G. (UMR 47, Pessac (France). Lab. des Composites Thermostructuraux); Thebault, J. (Societe Europeenne de Propulsion, Saint Medard-en-Jalles (France))

    1994-08-01

    The oxidation behavior of a 2D woven C/SiC composite partly protected with a SiC seal coating and heat-treated (stabilized) at 1,600 C in inert gas has been investigated through an experimental approach based on thermogravimetric analyses and optical/electron microscopy. Results of the tests, performed under flowing oxygen, have shown that the oxidation behavior of the composite material in terms of oxidation kinetics and morphological evolutions is related to the presence of thermal microcracks in the seal coating as well as in the matrix. Three different temperature domains exist. At low temperatures (< 800 C), the mechanisms of reaction between carbon and oxygen control the oxidation kinetics and are associated with a uniform degradation of the carbon reinforcement. At intermediate temperatures, (between 800 and 1,100 C), the oxidation kinetics are controlled by the gas-phase diffusion through a network of microcracks in the SiC coatings, resulting in a nonuniform degradation of the carbon phases. At high temperatures (> 1,100 C), such diffusion mechanisms are limited by sealing of the microcracks by silica; therefore, the degradation of the composite remains superficial. The study of the oxidation behavior of (i) the heat-treated composite in a lower oxygen content environment (dry air) and (ii) the as-processed (unstabilized) composite in dry oxygen confirms the different mechanisms proposed to explain the oxidation behavior of the composite material.

  12. Research and Application of the Mathematic Model for the Washing Shrinkage of Woven Fabric

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Having analyzed the relationships between washing shrinkage and weaving technique, parameters, material properties of woven fabrics and studied the shrinkage mechanism and its mathematical model of the plain fabric,researchers set up a shrinkage model of the twills and satins and proposed a method for calculating the washing shrinkage based on weaving technique and parameters of fabrics. Shrinkage experiments of silk habotai, silk twill and silk satin fabrics were performed. The results were compared with those of the theoretical computations, and it has been proven that the theoretical method is reliable.

  13. Comparison between disc and non-woven synthetic fabric filter media to prevent emitter clogging

    OpenAIRE

    Ribeiro, TAP; Paterniani, JES; Airoldi, RPS; Silva, MJM

    2008-01-01

    The aim of this research was to compare the evolution of head loss in disc (130 mu m) and non-woven synthetic fabric filter media used to filter the water in drip irrigation systems. Two forms of treatment of the irrigation water were carried out: one with a chemical product (chlorine) and the other with none. The research used two different filter media: two for each treatment together with a fertigation technique with organic products in both types of treatment. The chemical treatment of th...

  14. Low-velocity impact behavior of woven jute/poly(lactic acid) composites

    Science.gov (United States)

    Russo, Pietro; Simeoli, Giorgio; Papa, Ilaria; Acierno, Domenico; Lopresto, Valentina; Langella, Antonio

    2016-05-01

    Biocomposite laminates based on poly(lactic acid) (PLA) and woven jute fabric were obtained by film stacking and compression molding techniques. Sample laminates were systematically characterized by impact tests with a falling dart at impact energies equal to 5, 10 and 20 J. Tests showed that, investigated PLA/jute fabric plates suffer only barely visible damages at the first two levels of impact energy while they result to be perforated at 20 J as highlighted by photographic images taken on low and back side of impacted surfaces.

  15. Silverman Gail P., A woven book of knowledge. Textile iconography of Cuzco, Peru

    OpenAIRE

    Vallard, Annabel

    2014-01-01

    A woven book of knowledge est un ouvrage doublement attendu de ceux qui s’intéressent aux textiles et à leur iconographie. D’abord, il s’agit de la traduction en anglais de la version révisée de quelques-uns des articles de Gail P. Silverman qui se consacre depuis une vingtaine d’années aux textiles de Cuzco et de sa région et qui étaient connus, jusqu’alors, des seuls hispanophones. Cette publication est ainsi une porte ouverte sur les travaux de cet auteur et permettra de les diffuser auprè...

  16. LCO flutter of cantilevered woven glass/epoxy laminate in subsonic flow

    Institute of Scientific and Technical Information of China (English)

    Dayang Laila Abang Haji Abdul Majid; ShahNor Basri

    2008-01-01

    The paper presents aeroelastic characteristics of a cantilevered composite wing,idealized as a composite flat plate laminate.The composite laminate was made from woven glass fibers with epoxy matrix.The elastic and dynamic properties of the laminate were determined experimentally for aeroelastic calculations.Aeroelastic wind tunnel testing of the laminate was performed and the result showed that flutter,a dynamic instability occurred.The cantilevered laminate also displayed limit cycle amplitude,post-flutter oscillation.The experimental flutter velocity and frequency were verified by our computational analysis.

  17. Evaluation of micro-damage accumulation in holed plain-woven CFRP composite under fatigue loading

    Science.gov (United States)

    Ying, Jia; Nishikawa, Masaaki; Hojo, Masaki

    2014-03-01

    Fluorescence method was used to detect the micro-damage caused by fatigue in a plain-woven carbon fiber reinforced polymer (CFRP). Fluorescence measurement is a method which estimates micro-damage by measuring fluorescent intensity change inside materials. The principle is, larger micro-damage means larger plastic strain, thus more space in that damaged spot which allows more fluorescent dyes coming in the material. By detecting fluorescent intensity in CFRP layer by layer using confocal laser microscopy, micro-damage can be estimated. Results show that there's a good relationship between micro-damage and fluorescent intensity gradient.

  18. Fatigue behavior of carbon/epoxy composites reinforced with 3-Dimensional woven fabric

    Directory of Open Access Journals (Sweden)

    Mehmet Karahan

    2013-07-01

    Full Text Available This paper reports results of study of fatigue behavior of a non-crimp 3-dimensional woven carbon/epoxy composite in tension-tension fatigue. Infinite fatigue life limit corresponds to the load of 27.5 kN for fill direction. The damage under fatigue loading starts and develops from intersection of z-yarns and fill yarns. Since the z-yarns bonded the yarn layers, it is not seen the delaminastion damages. This indicate that for load carrying capacity and stiffness of 3-dimensional composites better than classic 2-dimensional textile composites.

  19. Attachment of Poly(l-lactide) Nanoparticles to Plasma-Treated Non-Woven Polymer Fabrics Using Inkjet Printing.

    Science.gov (United States)

    Ivanova, Tatiana V; Baier, Grit; Landfester, Katharina; Musin, Eduard; Al-Bataineh, Sameer A; Cameron, David C; Homola, Tomáš; Whittle, Jason D; Sillanpää, Mika

    2015-09-01

    Active dressings that based on fabric materials are an area of interest for the treatment of wounds. Poly(l-lactide) nanoparticles containing the antimicrobial agent octenidine can be controllably lysed by toxins released by pathogenic bacteria thus releasing antimicrobial material in response to the presence of the bacterial toxins and so counteracting the infection. We developed an integrated engineering solution that allows for the stable immobilisation of nanoparticles on non-woven fabrics. The process involves coating nanoparticles on non-woven polymer surfaces by using an inkjet printing process. In order to improve the adhesion and retention of the nanoparticles on the fabric, surface pretreatment of the non-woven fabric using plasma jet treatment can be applied to increase its surface energy. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Preparation and characterization of thermal-responsive non-woven poly (propylene) materials grafted with N-isopropylacrylamide/β-cyclodextrin

    DEFF Research Database (Denmark)

    Amiri, Setareh; Zadhoush, Ali; Mallakpour, Shadpour

    2013-01-01

    A temperature-sensitive hydrogel was successfully grafted on the surface of non-woven poly(propylene) materials. This was carried out by the application of unmodified β-cyclodextrin and N-isopropylacrylamide monomer in order to develop new functional hydrogels for textile science and technology....... Graft polymerization technique was used to graft this temperature-sensitive hydrogel on the surface of plasma-treated non-woven poly(propylene) materials. Fourier transform infrared attenuated total reflection, scanning electron microscopy and elemental analyses confirmed the presence of poly......-sensitive property with a lower critical solution temperature (33.23°C) compared to a non-grafted hydrogel. The wicking time and contact angle measurements showed an improvement of the wicking ability and hydrophilicity of modified non-woven poly(propylene) materials. This investigation facilitates the preparation...

  1. Springback prediction of titanium tube bending considering Bauschinger effect and Young's modulus variation

    Science.gov (United States)

    Ma, J.; Yang, H.; Li, H.; Tao, Z. J.; Li, G. J.

    2016-08-01

    High strength titanium bent tubes present promising usages in advanced aircraft and spacecraft to achieve lightweight and improve overall performance. However, the high ratio of yield strength to Young's modulus results in significant springback in bending, which limits their forming accuracy. In this work, the Bauschinger effect and nonlinear unloading behavior of high strength Ti-3Al-2.5V tube are experimentally investigated. Then, to describe such behaviors, the Yoshida-Uemori (Y-U) two-surface hardening model and Chord unloading model are introduced into the elastoplastic constitutive framework and numerically implemented. Taking rotary draw (RDB) bending as a case, the springback angles are predicted and analyzed by comparison with the experimental results.

  2. Effect of nanosilica on optical, electric modulus and AC conductivity of polyvinyl alcohol/polyaniline films

    Energy Technology Data Exchange (ETDEWEB)

    El-Sayed, Somyia, E-mail: somyia.elsayed@yahoo.com [Physics Department, Faculty of Science and Education, Taif University (Saudi Arabia); Physics Department, Faculty of Science, Fayoum University, 63514 El Fayoum (Egypt); Abel-Baset, Tarob; Elfadl, Azza Abou [Physics Department, Faculty of Science, Fayoum University, 63514 El Fayoum (Egypt); Hassen, Arafa [Physics Department, Faculty of Science and Education, Taif University (Saudi Arabia); Physics Department, Faculty of Science, Fayoum University, 63514 El Fayoum (Egypt)

    2015-05-01

    Nanosilica (NS) was synthesized by a sol–gel method and mixed with 0.98 polyvinyl alcohol (PVA)/0.02 polyaniline (PANI) in different amounts to produce nanocomposite films. High-resolution transmission electron microscopy (HR-TEM) revealed the average particle size of the NS to be ca. 15 nm. Scanning electron microscopy (SEM) showed that the NS was well-dispersed on the surface of the PVA/PNAI films. The Fourier transform infrared (FTIR) spectra of the samples showed a significant change in the intensity of the characteristic peak of the functional groups in the composite films with the amount of NS added. The absorbance and refractive index (n) of the composites were studied in the UV–vis range, and the optical energy band gap, E{sub g}, and different optical parameters were calculated. The dielectric loss modulus, M″ and ac conductivity, σ{sub ac}, of the samples were studied within 300–425 K and 0.1 kHz–5 MHz, respectively. Two relaxation peaks were observed in the frequency dependence of the dielectric loss modulus, M″. The behavior of σ{sub ac}(f) for the composite films indicated that the conduction mechanism was correlated barrier hopping (CBH). The results of this work are discussed and compared with those of previous studies of similar composites.

  3. Linear and nonlinear modulus surfaces in stress space, from stress-strain measurements on Berea sandstone

    Directory of Open Access Journals (Sweden)

    M. Boudjema

    2003-01-01

    Full Text Available The elastic response of many rocks to quasistatic stress changes is highly nonlinear and hysteretic, displaying discrete memory. Rocks also display unusual nonlinear response to dynamic stress changes. A model to describe the elastic behavior of rocks and other consolidated materials is called the Preisach-Mayergoyz (PM space model. In contrast to the traditional analytic approach to stress-strain, the PM space picture establishes a relationship between the quasistatic data and a number density of hysteretic mesoscopic elastic elements in the rock. The number density allows us to make quantitative predictions of dynamic elastic properties. Using the PM space model, we analyze a complex suite of quasistatic stress-strain data taken on Berea sandstone. We predict a dynamic bulk modulus and a dynamic shear modulus surface as a function of mean stress and shear stress. Our predictions for the dynamic moduli compare favorably to moduli derived from time of flight measurements. We derive a set of nonlinear elastic constants and a set of constants that describe the hysteretic behavior of the sandstone.

  4. Artificial neural network for modeling the elastic modulus of electrospun polycaprolactone/gelatin scaffolds.

    Science.gov (United States)

    Vatankhah, Elham; Semnani, Dariush; Prabhakaran, Molamma P; Tadayon, Mahdi; Razavi, Shahnaz; Ramakrishna, Seeram

    2014-02-01

    Scaffolds for tissue engineering (TE) require the consideration of multiple aspects, including polymeric composition and the structure and mechanical properties of the scaffolds, in order to mimic the native extracellular matrix of the tissue. Electrospun fibers are frequently utilized in TE due to their tunable physical, chemical, and mechanical properties and porosity. The mechanical properties of electrospun scaffolds made from specific polymers are highly dependent on the processing parameters, which can therefore be tuned for particular applications. Fiber diameter and orientation along with polymeric composition are the major factors that determine the elastic modulus of electrospun nano- and microfibers. Here we have developed a neural network model to investigate the simultaneous effects of composition, fiber diameter and fiber orientation of electrospun polycaprolactone/gelatin mats on the elastic modulus of the scaffolds under ambient and simulated physiological conditions. The model generated might assist bioengineers to fabricate electrospun scaffolds with defined fiber diameters, orientations and constituents, thereby replicating the mechanical properties of the native target tissue.

  5. The Modulus of the Complex Correlation Coefficient Between Co-Polarized Channels for Oil Spill Observation

    Science.gov (United States)

    Khenouchi, H.; Smara, Y.; Migliaccio, M.; Nunziata, F.; Buono, A.

    2016-08-01

    Sea oil pollution is a matter of great concern since it affects both the environment and human health. Recent studies demonstrated that synthetic aperture radar (SAR) polarimetry is able to provide additional information useful for environmental applications, i. e., oil spill observation. In this context, different approaches based on polarimetric SARs were developed. In this study, a dual-polarimetric feature, namely the modulus of the complex correlation coefficient between the co-polarized channels, is used to discriminate between sea oil spill and weak-damping look-alikes.The proposed approach relies on the fact that high correlation between co-polarized channels is expected over sea surface and weak-damping look- alikes due to the dominant Bragg scattering, while significantly lower correlation is expected over strong-damping oil spills since they are characterized by a no-Bragg scattering behaviour. Experimental results show that the modulus of the complex correlation between the co-polarized chan- nels can be successfully exploited for both the observation of sea oil slicks and their discrimination from weak-damping look-alikes.

  6. Estimating the bending modulus of a FtsZ bacterial-division protein filament

    Science.gov (United States)

    Cytrynbaum, Eric N.; Li, Yongnan Devin; Allard, Jun F.; Mehrabian, Hadi

    2012-01-01

    FtsZ, a cytoskeletal protein homologous to tubulin, is the principle constituent of the division ring in bacterial cells. It is known to have force-generating capacity in vitro and has been conjectured to be the source of the constriction force in vivo. Several models have been proposed to explain the generation of force by the Z ring. Here we re-examine data from in vitro experiments in which Z rings formed and constricted inside tubular liposomes, and we carry out image analysis on previously published data with which to better estimate important model parameters that have proven difficult to measure by direct means. We introduce a membrane-energy-based model for the dynamics of multiple Z rings moving and colliding inside a tubular liposome and a fluid model for the drag of a Z ring as it moves through the tube. Using this model, we estimate an effective membrane bending modulus of 500-700 pNnm. If we assume that FtsZ force generation is driven by hydrolysis into a highly curved conformation, we estimate the FtsZ filament bending modulus to be 310-390 pNnm2. If we assume instead that force is generated by the non-hydrolysis-dependent intermediate curvature conformation, we find that Bf>1400pNnm2. The former value sits at the lower end of the range of previously estimated values and, if correct, may raise challenges for models that rely on filament bending to generate force.

  7. 3D mapping of elastic modulus using shear wave optical micro-elastography

    Science.gov (United States)

    Zhu, Jiang; Qi, Li; Miao, Yusi; Ma, Teng; Dai, Cuixia; Qu, Yueqiao; He, Youmin; Gao, Yiwei; Zhou, Qifa; Chen, Zhongping

    2016-10-01

    Elastography provides a powerful tool for histopathological identification and clinical diagnosis based on information from tissue stiffness. Benefiting from high resolution, three-dimensional (3D), and noninvasive optical coherence tomography (OCT), optical micro-elastography has the ability to determine elastic properties with a resolution of ~10 μm in a 3D specimen. The shear wave velocity measurement can be used to quantify the elastic modulus. However, in current methods, shear waves are measured near the surface with an interference of surface waves. In this study, we developed acoustic radiation force (ARF) orthogonal excitation optical coherence elastography (ARFOE-OCE) to visualize shear waves in 3D. This method uses acoustic force perpendicular to the OCT beam to excite shear waves in internal specimens and uses Doppler variance method to visualize shear wave propagation in 3D. The measured propagation of shear waves agrees well with the simulation results obtained from finite element analysis (FEA). Orthogonal acoustic excitation allows this method to measure the shear modulus in a deeper specimen which extends the elasticity measurement range beyond the OCT imaging depth. The results show that the ARFOE-OCE system has the ability to noninvasively determine the 3D elastic map.

  8. Temperature Effects on Adhesive Bond Strengths and Modulus for Commonly Used Spacecraft Structural Adhesives

    Science.gov (United States)

    Ojeda, Cassandra E.; Oakes, Eric J.; Hill, Jennifer R.; Aldi, Dominic; Forsberg, Gustaf A.

    2011-01-01

    A study was performed to observe how changes in temperature and substrate material affected the strength and modulus of an adhesive bondline. Seven different adhesives commonly used in aerospace bonded structures were tested. Aluminum, titanium and Invar adherends were cleaned and primed, then bonded using the manufacturer's recommendations. Following surface preparation, the coupons were bonded with the adhesives. The single lap shear coupons were then pull tested per ASTM D 1002 Standard Test Method for Apparent Shear Strength of Single- Lap-Joint over a temperature range from -150 deg C up to +150 deg C. The ultimate strength was calculated and the resulting data were converted into B-basis design allowables. Average and Bbasis results were compared. Results obtained using aluminum adherends are reported. The effects of using different adherend materials and temperature were also studied and will be reported in a subsequent paper. Dynamic Mechanical Analysis (DMA) was used to study variations in adhesive modulus with temperature. This work resulted in a highly useful database for comparing adhesive performance over a wide range of temperatures, and has facilitated selection of the appropriate adhesive for spacecraft structure applications.

  9. Design and Weaving of Rope Woven Fabric%绳带机织物的设计与织制

    Institute of Scientific and Technical Information of China (English)

    张萍; 王克清

    2012-01-01

    探讨绳带机织物的设计与织造要点.通过对绳带机织物原料、组织、规格等进行设计,采用纹杆织机进行绳带机织物的手工织造;同时对现代机械化织制绳带机织物进行尝试和可行性分析.认为:只有对现代整经机的导纱部件、伸缩筘及定幅筘等进行扁平状改造,保证其尺寸与所选用的带经规格相吻合,并对织机的综丝和钢筘进行特殊形状的改造,合理配置工艺参数,才能最终成功织制绳带机织物.%Design and weaving key points of rope woven fabric were discussed. Raw material, fabric weave structure and specification of rope woven fabric were designed. Wasp bar loom was adopted and rope woven fabric was produced by hand-woven. Experiment and feasiblility analysis were done on modem mechanization rope woven fabric. It is considered that yam guide deveic, expansion reed and spacing reed of modern warping machine were modified to ensure the matchi to selected warp. Heald and reed of loom were modified,parameter were set rationally,finally rope woven fabric can be produced successfully.

  10. Establishing time-dependent model of deformation modulus caused by bedrock excavation rebound by inverse analysis method

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Rock rebound relaxation deformation,or even rock burst,caused by the excavation of dam base and abutment or high rock slope affects their stability and results in the fall of mechanical properties of the rock.So an inverse analysis method was proposed in this paper to establish the time-dependent model of deformation modulus caused by excavation rebound.The basic principle is based on the combination of observed data of the excavation rebound deformation of dam abutment or rock slope,and the calculated rebound deformation by FEM under ground stress at the corresponding time in the excavation process.The norm of the residuals of observed data and calculated data are taken as the objective function.Accordingly,the time-dependent model of bedrock deformation modulus can be established.The method displays its significance in the design of excavation,construction and operation management of dam base and high slope.

  11. Testing a simple method for computing directly the bulk modulus by NPT simulation: The case of polydisperse hard sphere solids

    Science.gov (United States)

    Li, Da; Xu, Hong

    2015-10-01

    The bulk modulus of hard sphere solids has been computed directly by constant pressure Monte-Carlo simulations, using the histogram of the volume fluctuations. In considering first the one-component system, we show that the method is accurate in a large range of pressures, including high-pressure regime. The method is then applied to a polydisperse solid with relatively low polydispersity index. For illustrative purpose, we took a three-component mixture with symmetric size-distribution, and we studied the solid phase (fcc crystal) of this system. Our results show that the equation of state is very sensitive to the polydispersity. Furthermore, in the high-pressure region, where no (accurate) analytical fit for the equation of state exists, our simulations are able to predict the bulk modulus of such systems.

  12. Living nanofiber yarn-based woven biotextiles for tendon tissue engineering using cell tri-culture and mechanical stimulation.

    Science.gov (United States)

    Wu, Shaohua; Wang, Ying; Streubel, Philipp N; Duan, Bin

    2017-10-15

    Non-woven nanofibrous scaffolds have been developed for tendon graft application by using electrospinning strategies. However, electrospun nanofibrous scaffolds face some obstacles and limitations, including suboptimal scaffold structure, weak tensile and suture-retention strengths, and compact structure for cell infiltration. In this work, a novel nanofibrous, woven biotextile, fabricated based on electrospun nanofiber yarns, was implemented as a tissue engineered tendon scaffold. Based on our modified electrospinning setup, polycaprolactone (PCL) nanofiber yarns were fabricated with reproducible quality, and were further processed into plain-weaving fabrics interlaced with polylactic acid (PLA) multifilaments. Nonwoven nanofibrous PCL meshes with random or aligned fiber structures were generated using typical electrospinning as comparative counterparts. The woven fabrics contained 3D aligned microstructures with significantly larger pore size and obviously enhanced tensile mechanical properties than their nonwoven counterparts. The biological results revealed that cell proliferation and infiltration, along with the expression of tendon-specific genes by human adipose derived mesenchymal stem cells (HADMSC) and human tenocytes (HT), were significantly enhanced on the woven fabrics compared with those on randomly-oriented or aligned nanofiber meshes. Co-cultures of HADMSC with HT or human umbilical vein endothelial cells (HUVEC) on woven fabrics significantly upregulated the functional expression of most tenogenic markers. HADMSC/HT/HUVEC tri-culture on woven fabrics showed the highest upregulation of most tendon-associated markers than all the other mono- and co-culture groups. Furthermore, we conditioned the tri-cultured constructs with dynamic conditioning and demonstrated that dynamic stretch promoted total collagen secretion and tenogenic differentiation. Our nanofiber yarn-based biotextiles have significant potential to be used as engineered scaffolds to

  13. Exploration in the test of splitting resilient modulus of asphalt mixture

    Science.gov (United States)

    Li, Peihong

    2017-06-01

    In terms of the non-correspondence about the bottom layer tensile stress provided by the compressive resilient modulus and the allowable tensile stress obtained by the splitting test, this paper puts forward the methods about splitting stepping testing by contrasting the compressive resilient modulus testing methods. Both the stepping load and resilient deformation are recorded. With the help of the concept of splitting stiffness modulus, the expression of splitting resilient modulus can be obtained to gain the splitting resilient testing flow. The results show that the resilient modulus which is measured by splitting stepping load can meet the design ranges of asphalt mixture and the stepping loading methods about splitting resilient modulus are worth popularizing.

  14. Production of chitosan-based non-woven membranes using the electrospinning process

    Science.gov (United States)

    Pakravan Lonbani, Mehdi

    Chitosan is a modified natural polymer mainly produced from chitin, one of the most abundant organic materials in the world. Highly porous chitosan mats present the specific physicochemical properties of the base material and also benefit from the physical characteristics of nanoporous membranes. Electrospinning is a novel technique developed long time ago and revisited recently that can generate polymeric fibers with nanometric size. The ultimate purpose of this work is to fabricate microporous non-woven chitosan membranes for wound healing dressings and heavy metal ion removal from drinking water. In this dissertation, two approaches have been utilized to prepare chitosan-based nanofibers; blending and co-axial electrospinning of chitosan solution with a readily electrospinnable solution, i.e. an aqueous solution of polyethylene oxide (PEO). Consequently, understanding the phase behavior and miscibility of aqueous acidic solutions of chitosan and PEO and their blends is of crucial importance, as any phase separation occurring during the electrospinning process greatly changes the morphology and physico-mechanical properties of the final products. First we employed the rheological approach on a well-known aqueous PEO solution to develop the experimental protocol. By comparing these critical points with that obtained from other experimental techniques, we showed that rheological measurements can sensitively detect early stages of phase separation. Subsequently the method was applied to 50 wt% aqueous acetic acid solutions of PEO, chitosan and their blends at different ratios. These solutions showed a lower critical solution temperature (LCST) phase diagram that is attributed to the existence of hydrogen bonds between active groups on chitosan and PEO backbone and the solvent. Critical decomposition temperatures for binodal and spinodal points were estimated from isochronal temperature sweep experiments. The obtained binodal temperatures confirmed that chitosan

  15. STEEL FIBER CURVATURE IN CONCRETE COMPOSITES: MODULUS PREDICTIONS USING EFFECTIVE STEEL FIBER PROPERTIES

    OpenAIRE

    Abdellatif Selmi

    2014-01-01

    Results in the literature demonstrate that substantial improvements in the mechanical behavior of concrete have been attained through the addition of steel fibers as a reinforcing phase. We have developed a model combining finite element results and micromechanical methods to determine the effective reinforcing modu-lus of hook-ended steel fibers. This effective reinforcing modulus is then used within a multiphase micro-mechanics model to predict the effective modulus of concrete reinforced w...

  16. Bending Modulus of Elasticity of the Press Forming Composite Material from Bagasse Fiber and Biodegradable Resin

    OpenAIRE

    柴田, 信一; 曹, 勇; 福本, 功; Shibata, Shin-ichi; Cao, Yong; Fukumoto, Isao

    2005-01-01

    Bending modulus of elasticity of the composite material from bagasse fiber (remains after sugar cane squeezed) and biodegradable resin was investigated in view of the content of bagasse fiber and the fiber length. The result was validated by short fiber strengthen theory. The result is as followings. Bending modulus of elasticity increased with increasing the content of bagasse fiber. The increase of Bending modulus of elasticity is predicted by short fiber strengthen theory incorporated with...

  17. Goldilocks models of higher-dimensional inflation (including modulus stabilization)

    Science.gov (United States)

    Burgess, C. P.; Enns, Jared J. H.; Hayman, Peter; Patil, Subodh P.

    2016-08-01

    We explore the mechanics of inflation within simplified extra-dimensional models involving an inflaton interacting with the Einstein-Maxwell system in two extra dimensions. The models are Goldilocks-like inasmuch as they are just complicated enough to include a mechanism to stabilize the extra-dimensional size (or modulus), yet simple enough to solve explicitly the full extra-dimensional field equations using only simple tools. The solutions are not restricted to the effective 4D regime with H ll mKK (the latter referring to the characteristic mass splitting of the Kaluza-Klein excitations) because the full extra-dimensional Einstein equations are solved. This allows an exploration of inflationary physics in a controlled calculational regime away from the usual four-dimensional lamp-post. The inclusion of modulus stabilization is important because experience with string models teaches that this is usually what makes models fail: stabilization energies easily dominate the shallow potentials required by slow roll and so open up directions to evolve that are steeper than those of the putative inflationary direction. We explore (numerically and analytically) three representative kinds of inflationary scenarios within this simple setup. In one the radion is trapped in an inflaton-dependent local minimum whose non-zero energy drives inflation. Inflation ends as this energy relaxes to zero when the inflaton finds its own minimum. The other two involve power-law scaling solutions during inflation. One of these is a dynamical attractor whose features are relatively insensitive to initial conditions but whose slow-roll parameters cannot be arbitrarily small; the other is not an attractor but can roll much more slowly, until eventually transitioning to the attractor. The scaling solutions can satisfy H > mKK, but when they do standard 4D fluctuation calculations need not apply. When in a 4D regime the solutions predict η simeq 0 and so r simeq 0.11 when ns simeq 0.96 and so

  18. Modeling and characterization of long term material behavior in polymer composites with woven fiber architecture

    Science.gov (United States)

    Gupta, Vikas

    The purpose of this research is to develop an analytical tool which, when coupled with accelerated material characterization, is capable of predicting long-term durability of polymers and their composites. Conducting creep test on each composite laminate with different fibers, fiber volume fractions, and weave architectures is impractical. Moreover, in case of thin laminates, accurately characterizing the out-of-plane matrix dominated viscoelastic response is not easily achievable. Therefore, the primary objective of this paper is to present a multi-scale modeling methodology to simulate the long-term interlaminar properties in polymer matrix woven composites and then predict the critical regions where failure is most likely to occur. A micromechanics approach towards modeling the out-of-plane viscoelastic behavior of a five-harness satin woven-fiber cross-ply composite laminate is presented, taking into consideration the weave architecture and time-dependent effects. Short-term creep tests were performed on neat resin at different test temperatures and stress levels to characterize physical aging of the resin matrix. In addition, creep and recovery experiments were conducted on un-aged resin specimens in order to characterize the pronounced stress-dependent nonlinear viscoelastic response of the PR500 resin. Two-dimensional micromechanics analysis was carried out using a test-bed finite element code, NOVA-3D, including interactions between non-linear material constitutive behavior, geometric nonlinearity, aging and environmental effects.

  19. Validating the Classical Failure Criteria for Applicability to the Notched Woven-Roving Composite Materials

    Directory of Open Access Journals (Sweden)

    Mohamed Mostafa Yousef Bassyouny Elshabasy

    2014-01-01

    Full Text Available The classical failure criteria are phenomenological theories as they ignore the actual failure mechanism and do not concentrate on the microscopic events of failure. The main objective of the current investigation is to modify the classical failure theories to comprise the essential failure mechanism (interfacial shear failure in the thin-layered woven-roving composite materials. An interfacial shear correction factor (MH6 is introduced into the nondimensional shear terms in the studied classical failure criteria. Thus the validity of applying these theories to the investigated material will be augmented. The experimental part of the current study is conducted on thin-layered circular specimens. The specimens are fabricated from two plies of fiber E-glass woven-roving fabric reinforced with polyester. The fabrics are laid to have [±45°] or [0°, 90°] fiber orientation. The specimens used are plain, where no macroscopic sources of stress concentration exist or having circular notches of five, seven, or nine mm radii. The specimens are subjected to low cycle completely reversed fatigue bending loading where the S-N and the R.D.-N curves are plotted for each group of specimens.

  20. Finite element modelling of woven composite failure modes at the mesoscopic scale: deterministic versus stochastic approaches

    Science.gov (United States)

    Roirand, Q.; Missoum-Benziane, D.; Thionnet, A.; Laiarinandrasana, L.

    2017-09-01

    Textile composites are composed of 3D complex architecture. To assess the durability of such engineering structures, the failure mechanisms must be highlighted. Examinations of the degradation have been carried out thanks to tomography. The present work addresses a numerical damage model dedicated to the simulation of the crack initiation and propagation at the scale of the warp yarns. For the 3D woven composites under study, loadings in tension and combined tension and bending were considered. Based on an erosion procedure of broken elements, the failure mechanisms have been modelled on 3D periodic cells by finite element calculations. The breakage of one element was determined using a failure criterion at the mesoscopic scale based on the yarn stress at failure. The results were found to be in good agreement with the experimental data for the two kinds of macroscopic loadings. The deterministic approach assumed a homogeneously distributed stress at failure all over the integration points in the meshes of woven composites. A stochastic approach was applied to a simple representative elementary periodic cell. The distribution of the Weibull stress at failure was assigned to the integration points using a Monte Carlo simulation. It was shown that this stochastic approach allowed more realistic failure simulations avoiding the idealised symmetry due to the deterministic modelling. In particular, the stochastic simulations performed have shown several variations of the stress as well as strain at failure and the failure modes of the yarn.

  1. Wear Behavior of Woven Roving Aramid / Epoxy Composite under Different Conditions

    Directory of Open Access Journals (Sweden)

    Asad A. Khalid

    2012-09-01

    Full Text Available Wear behavior studies of aramid woven roving /epoxy composite has been conducted. Sliding the material against smooth steel counter face under dry and  lubricated with oil conditions has been investigated. Powder of Silicon carbide has been mixed with the epoxy resin and tested also. The powder was mixed in a volumetric fraction of 10% with the epoxy resin. Four Laminates of six layers were fabricated by hand lay up  method. A pin on disc apparatus has been fabricated to conduct the sliding wear tests on specimens of (4 mm   4 mm   12 mm in size have been cut from the four laminates. The effect of sliding condition including dry, lubricated, dry with additives and lubricated with additives have been studied. Wear rate tests have been conducted at different sliding speeds and loads. Results show that the wear characteristics are influenced by the operating conditions and the construction of the composite material used. It was also found that the wear of aramid /epoxy composite onto the steel counter face were significantly reduced by using lubricant and additives but still took place.Keywords: Wear, Composite materials, Woven roving aramid, Epoxy, Additives, Lubricant.

  2. Analysis of mechanical properties anisotropy of nanomodified carbon fibre-reinforced woven composites

    Science.gov (United States)

    Ruslantsev, A. N.; Portnova, Ya M.; Tairova, L. P.; Dumansky, A. M.

    2016-10-01

    The polymer binder cracking problem arises while designing and maintaining polymer composite-based aircraft load-bearing members. Some technological methods are used to solve this problem. In particular the injection of nanoagents can block the initiation and growth of microscopic cracks. Crack propagation can also be blocked if the strain energy release is not related with fracturing. One of the possible ways for such energy release is creep. Testing of the anisotropy of the woven carbon fibre reinforced plastic elastic characteristics and creep have been conducted. The samples with different layouts have been made of woven carbon fibre laminate BMI-3/3692 with nanomodified bismaleimide matrix. This matrix has a higher glass transition temperature and improved mechanical properties. The deformation regularities have been analyzed, layer elastic characteristics have been determined. The constitutive equations describing composite material creep have been obtained and its parameters have been defined. Experimental and calculated creep curves have been plotted. It was found that the effects of rheology arise as the direction of load does not match the direction of reinforcing fibres of the material.

  3. Rate Dependent Multicontinuum Progressive Failure Analysis of Woven Fabric Composite Structures under Dynamic Impact

    Directory of Open Access Journals (Sweden)

    James Lua

    2004-01-01

    Full Text Available Marine composite materials typically exhibit significant rate dependent response characteristics when subjected to extreme dynamic loading conditions. In this work, a strain-rate dependent continuum damage model is incorporated with multicontinuum technology (MCT to predict damage and failure progression for composite material structures. MCT treats the constituents of a woven fabric composite as separate but linked continua, thereby allowing a designer to extract constituent stress/strain information in a structural analysis. The MCT algorithm and material damage model are numerically implemented with the explicit finite element code LS-DYNA3D via a user-defined material model (umat. The effects of the strain-rate hardening model are demonstrated through both simple single element analyses for woven fabric composites and also structural level impact simulations of a composite panel subjected to various impact conditions. Progressive damage at the constituent level is monitored throughout the loading. The results qualitatively illustrate the value of rate dependent material models for marine composite materials under extreme dynamic loading conditions.

  4. Impedance and modulus spectroscopic study of nano hydroxyapatite

    Science.gov (United States)

    Jogiya, B. V.; Jethava, H. O.; Tank, K. P.; Raviya, V. R.; Joshi, M. J.

    2016-05-01

    Hydroxyapatite (Ca10 (PO4)6 (OH)2, HAP) is the main inorganic component of the hard tissues in bones and also important material for orthopedic and dental implant applications. Nano HAP is of great interest due to its various bio-medical applications. In the present work the nano HAP was synthesized by using surfactant mediated approach. Structure and morphology of the synthesized nano HAP was examined by the Powder XRD and TEM. Impedance study was carried out on pelletized sample in a frequency range of 100Hz to 20MHz at room temperature. The variation of dielectric constant, dielectric loss, and a.c. conductivity with frequency of applied field was studied. The Nyquist plot as well as modulus plot was drawn. The Nyquist plot showed two semicircle arcs, which indicated the presence of grain and grain boundary effect in the sample. The typical behavior of the Nyquist plot was represented by equivalent circuit having two parallel RC combinations in series.

  5. Low elastic modulus titanium–nickel scaffolds for bone implants

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jing; Yang, Hailin; Wang, Huifeng; Ruan, Jianming, E-mail: jianming@csu.edu.cn

    2014-01-01

    The superelastic nature of repeating the human bones is crucial to the ideal artificial biomedical implants to ensure smooth load transfer and foster the ingrowth of new bone tissues. Three dimensional interconnected porous TiNi scaffolds, which have the tailorable porous structures with micro-hole, were fabricated by slurry immersing with polymer sponge and sintering method. The crystallinity and phase composition of scaffolds were studied by X-ray diffraction. The pore morphology, size and distribution in the scaffolds were characterized by scanning electron microscopy. The porosity ranged from 65 to 72%, pore size was 250–500 μm. Compressive strength and elastic modulus of the scaffolds were ∼ 73 MPa and ∼ 3GPa respectively. The above pore structural and mechanical properties are similar to those of cancellous bone. In the initial cell culture test, osteoblasts adhered well to the scaffold surface during a short time, and then grew smoothly into the interconnected pore channels. These results indicate that the porous TiNi scaffolds fabricated by this method could be bone substitute materials. - Highlights: • A novel approach for the fabrication of porous TiNi scaffolds • Macroporous structures are replicated from the polymer sponge template. • The pore characteristics and mechanical properties of TiNi scaffolds agree well with the requirement of trabecular bone. • Cytocompatibility of TiNi scaffolds is assessed, and it closely associated with pore property.

  6. Dentinogenesis imperfecta - hardness and Young's modulus of teeth.

    Science.gov (United States)

    Wieczorek, Aneta; Loster, Jolanta; Ryniewicz, Wojciech; Ryniewicz, Anna M

    2013-01-01

    Dentinogenesis imperfecta type II (DI-II) is the most common dental genetic disease with reported incidence 1 in 8000. Elasticity and hardness of the enamel of teeth are important values which are connected with their resistance to attrition. It is hypothesized that values of physical properties for healthy teeth and teeth with DI-II are different. The aim of the study was to investigate some physical properties of teeth extracted from patients with DI-II in comparison with normal teeth. The material of the study was six teeth: three lower molars, with clinical signs of DI-II, which were extracted due to complications of pulp inflammation and three other lower molars which were extracted for orthodontic reasons - well formed, without any signs of pathology. The surfaces of DI-II and normal teeth were tested on the CSM Instruments Scratch Tester machine (producer CSEM Switzerland) by Oliver and Pharr method. The indenter used was Vicker's VG-73 diamond indenter. Additionally, the Scanning Electron Microscopy (SEM) analysis of the surface of the teeth with DI-II was made. Vickers hardness of the teeth with dental pathology (DI-II) was seven times smaller, and Young's modulus six times smaller than those of healthy teeth. The parameters of hardness and elasticity of enamel of teeth with clinical diagnosis of DI-II were very much smaller than in normal teeth and because of that can be responsible for attrition.

  7. Volume modulus inflation and a low scale of SUSY breaking

    CERN Document Server

    Badziak, M

    2008-01-01

    The relation between the Hubble constant and the scale of supersymmetry breaking is investigated in models of inflation dominated by a string modulus. Usually in this kind of models the gravitino mass is of the same order of magnitude as the Hubble constant which is not desirable from the phenomenological point of view. It is shown that slow-roll saddle point inflation may be compatible with a low scale of supersymmetry breaking only if some corrections to the lowest order Kahler potential are taken into account. However, choosing an appropriate Kahler potential is not enough. There are also conditions for the superpotential, and e.g. the popular racetrack superpotential turns out to be not suitable. A model is proposed in which slow-roll inflation and a light gravitino are compatible. It is based on a superpotential with a triple gaugino condensation and the Kahler potential with the leading string corrections. The problem of fine tuning and experimental constraints are discussed for that model.

  8. Modulus spectroscopy of grain–grain boundary binary system

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Peng-Fei, E-mail: pfcheng@xpu.edu.cn [School of Science, Xi’an Polytechnic University, Xi’an 710048 (China); Song, Jiang [School of Science, Xi’an Polytechnic University, Xi’an 710048 (China); Li, Sheng-Tao; Wang, Hui [State Key Laboratory of Electrical Insulation and Power Equipment, Xi’an Jiaotong University, Xi’an 710049 (China)

    2015-02-15

    Understanding various polarization mechanisms in complex dielectric systems and specifying their physical origins are key issues in dielectric physics. In this paper, four different methods for representing dielectric properties were analyzed and compared. Depending on the details of the system under study, i.e., uniform or non-uniform, it was suggested that different representing approaches should be used to obtain more valuable information. Especially, for the grain–grain boundary binary non-uniform system, its dielectric response was analyzed in detail in terms of modulus spectroscopy (MS). Furthermore, it was found that through MS, the dielectric responses between uniform and non-uniform systems, grain and grain boundary, Maxwell–Wagner polarization and intrinsic polarization can be distinguished. Finally, with the proposed model, the dielectric properties of CaCu{sub 3}Ti{sub 4}O{sub 12} (CCTO) ceramics were studied. The colossal dielectric constant of CCTO at low frequency was attributed to the pseudo relaxation process of grain.

  9. Constraining The Hubble Parameter Using Distance Modulus - Redshift Relation

    CERN Document Server

    Onuchukwu, C C

    2015-01-01

    Using the relation between distance modulus (m-M) and redshift (z), deduced from Friedman-Robertson-Walker (FRW) metric and assuming different values of deceleration parameter (q0). We constrained the Hubble parameter (h). The estimates of the Hubble parameters we obtained using the median values of the data obtained from NASA Extragalactic Database (NED), are: h=0.7+/-0.3 for q0=0, h=0.6+/-0.3, for q0=1 and h=0.8+/-0.3, for q0=-1. The corresponding age ({\\tau}) and size (R) of the observable universe were also estimated as: {\\tau}=15+/-1 Gyrs, R=(5+/-2)x10^3 Mpc, {\\tau}=18+/-1 Gyrs, R=(6+/-2)x10^3 Mpc and {\\tau}=13+/-1 Gyrs, R=(4+/-2)x10^3 Mpc for q0=0, q0=1 and q0=-1 respectively.

  10. Evaluation of Thrust force in Drilling Woven roving Glass fibre reinforced Aluminium Sandwich laminates with TiAlN coated drill using Taguchi analysis

    Science.gov (United States)

    Ramya Devi, G.; Palanikumar, K.

    2017-05-01

    TiAlN is a high-performance coating which outshines in coarse and hard-to-machine materials like cast iron, aluminium alloys, tool steels, and nickel alloys. This paper presents the prediction and evaluation of thrust force and Torque in drilling of Woven roving Glass Fibre Reinforced Plastic and Aluminium sandwich laminate. The Prediction is based on Taguchi method. The experimental results specify that the feed rate and the drill diameter are the most significant factors affecting the thrust force, while the feed rate and spindle speed contribute the most to the surface roughness. In this study, the objective was to establish a correlation between the feed rate, spindle speed and drill diameter with the induced thrust force and Torque in drilling sandwich laminate.

  11. Regional variation in wood modulus of elasticity (stiffness) and modulus of rupture (strength) of planted loblolly pine in the United States

    Science.gov (United States)

    Antony Finto; Lewis Jordan; Laurence R. Schimleck; Alexander Clark; Ray A. Souter; Richard F. Daniels

    2011-01-01

    Modulus of elasticity (MOE), modulus of rupture (MOR), and specific gravity (SG) are important properties for determining the end-use and value of a piece of lumber. This study addressed the variation in MOE, MOR, and SG with physiographic region, tree height, and wood type. Properties were measured from two static bending samples (dimensions 25.4 mm × 25.4 mm × 406.4...

  12. Size- and temperature-dependent Young's modulus and size-dependent thermal expansion coefficient of thin films.

    Science.gov (United States)

    Zhou, Xiao-Ye; Huang, Bao-Ling; Zhang, Tong-Yi

    2016-08-21

    Nanomaterials possess a high surface/volume ratio and surfaces play an essential role in size-dependent material properties. In the present study, nanometer-thick thin films were taken as an ideal system to investigate the surface-induced size- and temperature-dependent Young's modulus and size-dependent thermal expansion coefficient. The surface eigenstress model was further developed with the consideration of thermal expansion, leading to analytic formulas of size- and temperature-dependent Young's modulus, and size-dependent thermal expansion coefficient of thin films. Molecular dynamics (MD) simulations on face-centered cubic (fcc) Ag, Cu, and Ni(001) thin films were conducted at temperatures ranging from 300 K to 600 K. The MD simulation results are perfectly consistent with the theoretical predictions, thereby verifying the theoretical approach. The newly developed surface eigenstress model will be able to attack similar problems in other types of nanomaterials.

  13. J-integral fracture toughness, Tearing modulus and tensile properties of Vitamin E stabilized radiation crosslinked UHMWPE.

    Science.gov (United States)

    Bellare, Anuj; Dorfman, Robert; Samuel, Ashwanth; Thornhill, Thomas S

    2016-08-01

    Radiation crosslinking of ultra-high molecular weight polyethylene (UHMWPE) increases its wear resistance in total joint replacement prostheses. Unfortunately, it is accompanied by a dose-dependent decrease in several mechanical properties. In this study, the tensile properties and fracture behavior of radiation crosslinked, Vitamin E stabilized UHMWPE was studied as a function of radiation dose. The Rice and Sorensen model, applicable to elastic-plastic materials, was utilized to obtain the initial crack driving force, J1c, steady state J-integral fracture toughness, Jss and the Tearing modulus. Tensile tests showed the dependence of tensile properties on radiation dose. Jss of non-crosslinked UHMWPE was higher than for crosslinked UHMWPE׳s but there was no dose dependent change in Jss whereas there was almost no change in J1c over the entire dose range. Finally, a monotonic decrease in Tearing modulus was observed with radiation dose.

  14. Young modulus, mechanical and electrical properties of isolated individual and bundled single-walled boron nitride nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Arenal, Raul; Loiseau, Annick [Laboratoire d' Etude des Microstructures (LEM), ONERA-CNRS, F-92322 Chatillon (France); Wang Mingsheng; Xu Zhi; Golberg, Dmitri, E-mail: raul.arenal@onera.fr [International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), Tsukuba 3050044 (Japan)

    2011-07-01

    The Young modulus of individual single-walled boron nitride nanotubes (SW-BNNTs) was determined using a high-resolution transmission-electron microscope (HRTEM)-atomic force microscope (AFM) set-up. The Young modulus and maximum stress for these NTs were deduced from the analysis of the stress-strain curves, and discussed as a function of the considered value for the shell thickness of an SW-BNNT. The elastic properties of bundles of SW-BNNTs were also investigated. All these experiments revealed that SW-BNNTs are very flexible. Furthermore, the electrical behavior of these SW-BNNTs was also analyzed employing a scanning tunneling microscope (STM) holder integrated with the same HRTEM. I/V curves were measured on individual tubes as well as on bundles of SW-BNNTs.

  15. 78 FR 64472 - Laminated Woven Sacks From the People's Republic of China: Final Results of Expedited First...

    Science.gov (United States)

    2013-10-29

    ... method either to an exterior ply of plastic film such as biaxially-oriented polypropylene (``BOPP'') or... (``Sunset'') Review, 78 FR 39256 (July 1, 2013). DATES: Effective Date: October 29, 2013. FOR FURTHER... polypropylene strip and/or woven polyethylene strip, regardless of the width of the strip; with or without...

  16. 78 FR 19209 - Laminated Woven Sacks From the People's Republic of China: Final Results of Antidumping Duty...

    Science.gov (United States)

    2013-03-29

    ... without an extrusion coating of polypropylene and/or polyethylene on one or both sides of the fabric... are typically used for retail packaging of consumer goods such as pet foods and bird seed. \\2\\ ``Paper... plastic coating on both sides of the fabric consisting of woven polypropylene strip and/or...

  17. 75 FR 81218 - Laminated Woven Sacks From the People's Republic of China: Preliminary Results of the Second...

    Science.gov (United States)

    2010-12-27

    ... Woven Sacks Committee and its individual members, Coating Excellence International, LLC and Polytex... extrusion coating of polypropylene and/or polyethylene on one or both sides of the fabric; laminated by any... for retail packaging of consumer goods such as pet foods and bird seed. \\4\\ ``Paper suitable for...

  18. 76 FR 14906 - Laminated Woven Sacks From the People's Republic of China: Final Results of First Antidumping...

    Science.gov (United States)

    2011-03-18

    .... \\8\\ Petitioners are the Laminated Woven Sacks Committee and its individual members, Coating...; with or without an extrusion coating of polypropylene and/or polyethylene on one or both sides of the... are typically used for retail packaging of ] consumer goods such as pet foods and bird seed....

  19. Hardness and Elastic Modulus on Six-Fold Symmetry Gold Nanoparticles

    Science.gov (United States)

    Ramos, Manuel; Ortiz-Jordan, Luis; Hurtado-Macias, Abel; Flores, Sergio; Elizalde-Galindo, José T.; Rocha, Carmen; Torres, Brenda; Zarei-Chaleshtori, Maryam; Chianelli, Russell R.

    2013-01-01

    The chemical synthesis of gold nanoparticles (NP) by using gold (III) chloride trihydrate (HAuCl∙3H2O) and sodium citrate as a reducing agent in aqueous conditions at 100 °C is presented here. Gold nanoparticles areformed by a galvanic replacement mechanism as described by Lee and Messiel. Morphology of gold-NP was analyzed by way of high-resolution transmission electron microscopy; results indicate a six-fold icosahedral symmetry with an average size distribution of 22 nm. In order to understand the mechanical behaviors, like hardness and elastic moduli, gold-NP were subjected to nanoindentation measurements—obtaining a hardness value of 1.72 GPa and elastic modulus of 100 GPa in a 3–5 nm of displacement at the nanoparticle’s surface. PMID:28809302

  20. Determination of Reliability Index and Weibull Modulus as a Measure of Hypereutectic Silumins Survival

    Directory of Open Access Journals (Sweden)

    J. Szymszal

    2007-07-01

    Full Text Available The first part of the study describes the methods used to determine Weibull modulus and the related reliability index of hypereutectic silumins containing about 17% Si, assigned for manufacture of high-duty castings to be used in automotive applications and aviation. The second part of the study discusses the importance of chemical composition, including the additions of 3% Cu, 1,5% Ni and 1,5% Mg, while in the third part attention was focussed on the effect of process history, including mould type (sand or metal as well as the inoculation process and heat treatment (solutioning and ageing applied to the cast AlSi17Cu3Mg1,5Ni1,5 alloy, on the run of Weibull distribution function and reliability index calculated for the tensile strength Rm of the investigated alloys.

  1. Microstructure, electrical conductivity and modulus spectra of CdI2 doped nanocomposite-electrolytes

    Science.gov (United States)

    Kundu, Ranadip; Roy, Debasish; Bhattacharya, Sanjib

    2017-02-01

    Ionic conductivity and dielectric behavior of Ag2O-CdI2-CdO nanocomposite system have been studied. X-ray diffraction has been carried out to obtain the crystallite sizes and the growth of CdO dispersed in glass-matrices. Total conductivity of them shows thermally activated nature. It is observed that total conductivity decreases and corresponding activation energy for conduction follows opposite behavior. The high-frequency ac conductivity may correspond to a nonrandom, correlated and sub-diffusive motion of Ag+ ions. Conductivity relaxation time is found to increase. The nature of scaling of the conductivity as well as modulus spectra indicates that the electrical relaxation of Ag+ is temperature independent but depends upon composition.

  2. Microstructure, electrical conductivity and modulus spectra of CdI{sub 2} doped nanocomposite-electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Kundu, Ranadip [Department of Engineering Sciences and Humanities, Siliguri Institute of Technology, Darjeeeling 734009, West Bengal (India); Department of Mechanical Engineering, Jadavpur University, Jadavpur, Kolkata 700032 (India); Roy, Debasish [Department of Mechanical Engineering, Jadavpur University, Jadavpur, Kolkata 700032 (India); Bhattacharya, Sanjib, E-mail: sanjib_ssp@yahoo.co.in [Department of Engineering Sciences and Humanities, Siliguri Institute of Technology, Darjeeeling 734009, West Bengal (India)

    2017-02-15

    Ionic conductivity and dielectric behavior of Ag{sub 2}O–CdI{sub 2}–CdO nanocomposite system have been studied. X-ray diffraction has been carried out to obtain the crystallite sizes and the growth of CdO dispersed in glass-matrices. Total conductivity of them shows thermally activated nature. It is observed that total conductivity decreases and corresponding activation energy for conduction follows opposite behavior. The high-frequency ac conductivity may correspond to a nonrandom, correlated and sub-diffusive motion of Ag{sup +} ions. Conductivity relaxation time is found to increase. The nature of scaling of the conductivity as well as modulus spectra indicates that the electrical relaxation of Ag{sup +} is temperature independent but depends upon composition.

  3. Experimentally-based relaxation modulus of polyurea and its composites

    Science.gov (United States)

    Jia, Zhanzhan; Amirkhizi, Alireza V.; Nantasetphong, Wiroj; Nemat-Nasser, Sia

    2016-06-01

    Polyurea is a block copolymer that has been widely used in the coating industry as an abrasion-resistant and energy-dissipative material. Its mechanical properties can be tuned by choosing different variations of diamines and diisocyanates as well as by adding various nano- and micro-inclusions to create polyurea-based composites. Our aim here is to provide the necessary experimentally-based viscoelastic constitutive relations for polyurea and its composites in a format convenient to support computational studies. The polyurea used in this research is synthesized by the reaction of Versalink P-1000 (Air Products) and Isonate 143L (Dow Chemicals). Samples of pure polyurea and polyurea composites are fabricated and then characterized using dynamic mechanical analysis (DMA). Based on the DMA data, master curves of storage and loss moduli are developed using time-temperature superposition. The quality of the master curves is carefully assessed by comparing with the ultrasonic wave measurements and by Kramers-Kronig relations. Based on the master curves, continuous relaxation spectra are calculated, then the time-domain relaxation moduli are approximated from the relaxation spectra. Prony series of desired number of terms for the frequency ranges of interest are extracted from the relaxation modulus. This method for developing cost efficient Prony series has been proven to be effective and efficient for numerous DMA test results of many polyurea/polyurea-based material systems, including pure polyurea with various stoichiometric ratios, polyurea with milled glass inclusions, polyurea with hybrid nano-particles and polyurea with phenolic microbubbles. The resulting viscoelastic models are customized for the frequency ranges of interest, reference temperature and desired number of Prony terms, achieving both computational accuracy and low cost. The method is not limited to polyurea-based systems. It can be applied to other similar polymers systems.

  4. Measurement of Young's modulus of vocal folds by indentation.

    Science.gov (United States)

    Chhetri, Dinesh K; Zhang, Zhaoyan; Neubauer, Juergen

    2011-01-01

    To assess the accuracy of the indentation method for stiffness measurements and to estimate the Young's modulus of the vocal fold using this technique. Basic science. Indentation tests were performed using a range of indenter diameters and indentation depths on single- and double-layer silicone rubber models with various cover-layer thicknesses with known geometry and Young's moduli. Measurements were repeated on intact vocal folds and isolated muscle and cover-layer samples from three cadaveric human larynges. Indentation on single-layer rubber models yielded Young's moduli with acceptable accuracy when the indentation depth was equal to or smaller than the indenter diameter, and both were smaller than the physical dimensions of the material sample. On two-layer models, the stiffness estimation was similarly influenced by indenter diameter and indentation depth, and acceptable accuracy was reached when indentation depth was much smaller than the height of the top cover layer. Measurements on midmembranous vocal fold tissue revealed location-dependent Young's moduli (in kPa) as follows: intact hemilarynx, 8.6 (range=5.3-13.1); isolated inferior medial surface cover, 7.5 (range=7-7.9); isolated medial surface cover, 4.8 (range=3.9-5.7); isolated superior surface cover, 2.9 (range=2.7-3.2); and isolated thyroarytenoid muscle, 2.0 (range=1.3-2.7). Indenter diameter, indentation depth, and material thickness are important parameters in the measurement of vocal fold stiffness using the indentation technique. Measurements on human larynges showed location-dependent differences in stiffness. The stiffness of the vocal folds was also found to be higher when the vocal fold structure was still attached to the laryngeal framework compared with that when the vocal fold was separated from the framework. Copyright © 2011 The Voice Foundation. Published by Mosby, Inc. All rights reserved.

  5. Interfacial modulus mapping of layered dental ceramics using nanoindentation

    Science.gov (United States)

    Bushby, Andrew J; P'ng, Ken MY; Wilson, Rory M

    2016-01-01

    PURPOSE The aim of this study was to test the modulus of elasticity (E) across the interfaces of yttria stabilized zirconia (YTZP) / veneer multilayers using nanoindentation. MATERIALS AND METHODS YTZP core material (KaVo-Everest, Germany) specimens were either coated with a liner (IPS e.max ZirLiner, Ivoclar-Vivadent) (Type-1) or left as-sintered (Type-2) and subsequently veneered with a pressable glass-ceramic (IPS e.max ZirPress, Ivoclar-Vivadent). A 5 µm (nominal tip diameter) spherical indenter was used with a UMIS CSIRO 2000 (ASI, Canberra, Australia) nanoindenter system to test E across the exposed and polished interfaces of both specimen types. The multiple point load – partial unload method was used for E determination. All materials used were characterized using Scanning Electron Microscopy (SEM) and X – ray powder diffraction (XRD). E mappings of the areas tested were produced from the nanoindentation data. RESULTS A significantly (P<.05) lower E value between Type-1 and Type-2 specimens at a distance of 40 µm in the veneer material was associated with the liner. XRD and SEM characterization of the zirconia sample showed a fine grained bulk tetragonal phase. IPS e-max ZirPress and IPS e-max ZirLiner materials were characterized as amorphous. CONCLUSION The liner between the YTZP core and the heat pressed veneer may act as a weak link in this dental multilayer due to its significantly (P<.05) lower E. The present study has shown nanoindentation using spherical indentation and the multiple point load - partial unload method to be reliable predictors of E and useful evaluation tools for layered dental ceramic interfaces. PMID:28018566

  6. Cellulose nanofiber/single-walled carbon nanotube hybrid non-woven macrofiber mats as novel wearable supercapacitors with excellent stability, tailorability and reliability

    Science.gov (United States)

    Niu, Qingyuan; Gao, Kezheng; Shao, Ziqiang

    2014-03-01

    Non-woven macrofiber mats are prepared by simply controlling the extrusion patterns of cellulose nanofiber/single-walled carbon nanotube suspensions in an ethanol coagulation bath, and drying in air under restricted conditions. These novel wearable supercapacitors based on non-woven macrofiber mats are demonstrated to have excellent tailorability, electrochemical stability, and damage reliability.Non-woven macrofiber mats are prepared by simply controlling the extrusion patterns of cellulose nanofiber/single-walled carbon nanotube suspensions in an ethanol coagulation bath, and drying in air under restricted conditions. These novel wearable supercapacitors based on non-woven macrofiber mats are demonstrated to have excellent tailorability, electrochemical stability, and damage reliability. Electronic supplementary information (ESI) available: Experimental, TEM image, IR spectra, and XRD spectra of cellulose nanofibers, photograph of the cellulose nanofiber/single-walled carbon nanotube suspension, cellulose nanofiber/single-walled carbon nanotube non-woven macrofiber mat and non-woven macrofiber mat wearable supercapacitors. The electrochemical performance of the CNF/SWCNT hybrid fiber wearable supercapacitor. Photograph of the non-woven macrofiber mat wearable supercapacitors integrated within textiles. See DOI: 10.1039/c3nr05929d

  7. Laser lever method in the application of young’s modulus measurement

    Science.gov (United States)

    Fan, Yingyuan; Qiu, Zhaoyun; Zhao, Renhong

    2017-06-01

    Young’s modulus of solid material is usually measured by tensile test. We adopt a new laser lever to instead of the traditional optical lever in this article. Contrast experiments with two different methods are designed to measure the steel-wire’s Young’s modulus. The results show that the new method is more accurate and efficient than the old one.

  8. Variation of Hardness and Modulus across thickness of Zr-Cu-Al Metallic Glass Ribbons

    Science.gov (United States)

    Z. Humberto Melgarejo; J.E. Jakes; J. Hwang; Y.E. Kalay; M.J. Kramer; P.M. Voyles; D.S. Stone

    2012-01-01

    We investigate through-thickness hardness and modulus of Zr50Cu45Al5 metallic glass melt-spun ribbon. Because of their thinness, the ribbons are challenging to measure, so we employ a novel nanoindentation based-method to remove artifacts caused by ribbon flexing and edge effects. Hardness and modulus...

  9. E-modulus evolution and its relation to solids formation of pastes from commercial cements

    DEFF Research Database (Denmark)

    Maia, Lino; Azenha, Miguel; Geiker, Mette;

    2012-01-01

    Models for early age E-modulus evolution of cement pastes are available in the literature, but their validation is limited. This paper provides correlated measurements of early age evolution of E-modulus and hydration of pastes from five commercial cements differing in limestone content. A recent...

  10. Estimation of the Young’s modulus of cellulose Iß by MM3 and quantum mechanics

    Science.gov (United States)

    Young’s modulus provides a measure of the resistance to deformation of an elastic material. In this study, modulus estimations for models of cellulose Iß relied on calculations performed with molecular mechanics (MM) and quantum mechanics (QM) programs. MM computations used the second generation emp...

  11. Welded-woven fabrics for use as synthetic, minimally invasive orthopaedic implants

    Science.gov (United States)

    Rodts, Timothy W.

    The treatment of osteoarthritis in healthcare today focuses on minimizing pain and retaining mobility. Osteoarthritis of the knee is a common disease and known to be associated with traumatic injuries, among other factors. An identified trend is that patients are younger and have expectations of life with the preservation of an active lifestyle. As a result, great strain is placed on the available offerings of healthcare professionals and device manufacturers alike. This results in numerous design challenges for managing pain and disease over an extended period of time. The available treatments are being extended into younger populations, which increasingly suffer traumatic knee injuries. However, these patients are not good candidates for total joint replacement. A common problem for young patients is localized cartilage damage. This can heal, but often results in a painful condition that requires intervention. A welded-woven three-dimensional polymer fabric was developed to mimic the properties of articular cartilage. A process for the laser welding reinforcement of the surface layers of three-dimensional fabrics was investigated. Confined compression creep and pin-on-disc wear studies were conducted to characterize the contribution of the surface welding reinforcement. All materials used in the studies have previously been used in orthopaedic devices or meet the requirements for United States Pharmacopeial Convention (USP) Class VI biocompatibility approval. The compressive behavior of three-dimensional fabrics was tailored by the inclusion of surface welds. The compressive properties of the welded-woven fabrics were shown to better approximate articular cartilage compressive properties than conventional woven materials. The wear performance was benchmarked against identical fabrics without welding reinforcement. The wear rates were significantly reduced and the lifespan of the fabrics was markedly improved due to surface welding. Welding reinforcement offers a

  12. Measuring permeability, Young's modulus, and stress relaxation by the beam-bending technique

    Science.gov (United States)

    Vichit-Vadakan, Wilasa

    Recent interest in the permeability of cement paste, mortars, and concrete lies in the need to gain further understanding of mechanisms affecting the durability of these materials. Conventional techniques for measuring permeability are cumbersome and often take days to complete just one measurement. This thesis proposes a new technique for measuring the permeability. The advantage of this technique is that the results are obtained in a few minutes to a few hours; moreover, there is no problem with leaks or need for high pressures. The method is particularly well suited for examining the changes in permeability and viscoelastic properties of young cement paste samples. When a saturated rod of a porous material is instantaneously deflected under three-point bending, two types of relaxation processes occur simultaneously: hydrodynamic relaxation, caused by the flow of liquid in the porous body to restore ambient pressure, and viscoelastic relaxation of the solid network. By measuring the decrease in the force required to sustain a constant deflection, it is possible to obtain the permeability and Young's modulus from the hydrodynamic relaxation function, in addition to the stress relaxation function of the sample. The exact viscoelastic solution is developed and the total relaxation is shown to be very closely approximated as the product of the hydrodynamic and stress relaxation functions. The analytical results are verified on porous VycorRTM glass saturated in various solvents, including normal alcohols, water, and glycerol. The results show excellent agreement with the theory. Consistent with observations of previous workers, the permeability is found to be influenced by the size of the solvent molecule; by assuming that the pore surfaces are covered with a monolayer of immobile solvent, the observed variation can be explained. The evolution of the permeability, Young's modulus, and stress relaxation function are reported for Type III Portland cement paste with

  13. A Prediction Method of Tensile Young's Modulus of Concrete at Early Age

    Directory of Open Access Journals (Sweden)

    Isamu Yoshitake

    2012-01-01

    Full Text Available Knowledge of the tensile Young's modulus of concrete at early ages is important for estimating the risk of cracking due to restrained shrinkage and thermal contraction. However, most often, the tensile modulus is considered equal to the compressive modulus and is estimated empirically based on the measurements of compressive strength. To evaluate the validity of this approach, the tensile Young's moduli of 6 concrete and mortar mixtures are measured using a direct tension test. The results show that the tensile moduli are approximately 1.0–1.3-times larger than the compressive moduli within the material's first week of age. To enable a direct estimation of the tensile modulus of concrete, a simple three-phase composite model is developed based on random distributions of coarse aggregate, mortar, and air void phases. The model predictions show good agreement with experimental measurements of tensile modulus at early age.

  14. Preparation and Compressive Properties of 3D Woven Sandwich Composites%三维机织夹芯复合材料的制备与压缩性能研究

    Institute of Scientific and Technical Information of China (English)

    王梦远; 曹海建; 钱坤; 袁守忍

    2013-01-01

    Using glass fiber as raw material,two systems of warp (one for the upper and lower surface,the other for the folder core layer) and one system of weft were employed to make the new 3D sandwich fabric whose meridional cross-section was a rectangle on the SU111-automatic rapier.Using the epoxy resin E-44 and the type of 9055 curing agent as the matrix system,the woven fabric was made into 3D woven sandwich composites through the hand lay-up process.The compressive properties of 3D woven sandwich composites were studied,and the relationship between structure and compressive properties was analyzed and compared with the "8"-shaped hollow composite material.The results show that the compressive strength of the "8"-shaped hollow composite material whose spacing of core material is 5 mm is better than 3D woven sandwich composites whose spacing of core material is 25 mm.But the elastic modulus of the lattar is higher than the former.The results are extremely valuable in guiding the optimization and mechanical property study on this kind of materials.%以玻璃纤维为原料,采用2个系统经纱(一个为上下表层经纱,另一个为夹芯层经纱)、1个系统纬纱,在SU111型全自动剑杆织机上制织经向截面为“口”字形的新型三维夹芯织物.以环氧树脂E-44与9055型固化剂为基体体系,采用手糊成型工艺将上述机织物复合制成三维机织夹芯复合材料.研究三维机织夹芯复合材料的压缩性能,分析材料结构与压缩性能之间的关系,并与“8”字形中空复合材料进行比较.结果表明,芯材间距为5mm的“8”字形中空复合材料的压缩强度高于芯材间距为25 mm的三维机织夹芯复合材料,但是后者的弹性模量高于前者.实验结果对该类结构材料的优化设计与力学性能研究具有极其重要的指导价值.

  15. Reaction hot-pressing and property-composition relationships of modified sialon - boron nitride hetero-modulus ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Y; Shabalin, I L [Materials and Physics Research Centre, University of Salford, Salford, Greater Manchester, M5 4WT (United Kingdom); Zhang, L [Department of Ceramic and Glass Engineering, CICECO, University of Aveiro, Aveiro 3810-193 (Portugal); Zhdanov, V B, E-mail: i.shabalin@salford.ac.uk [Department of Less-Common Metals, Ural State Technical University, Yekaterinburg 620002 (Russian Federation)

    2011-10-29

    Hetero-modulus ceramics (HMC) present the combination of a ceramic matrix with inclusions of a dispersed phase with considerably lower values of Young's modulus, resulting in a material with significantly advanced properties. Densified '-Si{sub 6-x}Al{sub x}O{sub x}N{sub 8-x} based HMC materials, with various volume contents of low-modulus {alpha}-BN phase and modifiers such as TiN or ZrO{sub 2} in sialon matrix, were prepared by high-temperature reaction hot-pressing in nitrogen atmosphere. The pristine blend composition for reaction hot-pressing consisted of mixed fine powders of Si, Al, B, Ti nitrides and Al, Zr oxides. Statistical design of 2{sup 5-2} fractional factorial and third-order simplex-grid types was used for the experimental studies to estimate the effects of some technological factors on the densification of hot-pressed products and the property-composition relationships of modified HMC materials.

  16. Metastable Zr-Nb alloys for spinal fixation rods with tunable Young's modulus and low magnetic resonance susceptibility.

    Science.gov (United States)

    Zhao, X L; Li, L; Niinomi, M; Nakai, M; Zhang, D L; Suryanarayana, C

    2017-10-15

    Good ductility, low magnetic susceptibility, and tunable Young's modulus are highly desirable properties for materials usage as spinal fixation rods. In this study, the effects of niobium content on the microstructure, magnetic susceptibility, and mechanical properties of Zr-xNb (13≤x≤23wt%) alloys were investigated. For the Zr-15Nb and Zr-17Nb alloys, a remarkable increase in Young's modulus was achieved due to the occurrence of deformation-induced ω phase transformation. This was the result of the competition of two factors associated with the Nb content: an increase of the stability of β phase and a decrease of the amount of athermal ω phase with increasing Nb content. When the Nb content was 15% or 17%, the amount of deformation-induced ω phase was maximum. Moreover, the magnetic susceptibility decreased with the deformation-induced β→ω phase transformation, and the Zr-17Nb alloy with apparent kink bands exhibited a smaller amount of springback than the Zr-15Nb alloy with {332} 〈113〉 mechanical twins. Furthermore, the ions released from the Zr-xNb alloys in accelerated immersion tests were at a very low level. The combination of low initial Young's modulus, and its remarkable variation induced by deformation, low magnetic susceptibility, good ductility, and smaller springback make the Zr-17Nb alloy a potential candidate for spinal fixation rods. For the rods of spinal fixation devices, it is important but difficult to lower the springback for bending formativeness while keeping the low initial Young's modulus for biocompatibility and lower the magnetic susceptibility for postoperative examination simultaneously. In this study, Zr-17Nb alloy was successfully developed via deformation-induced ω phase transformation during loading, simultaneously meeting the abovementioned properties for spinal fixation rods. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  17. Dielectric Behaviour of Some Woven Fabrics on the Basis of Natural Cellulosic Fibers

    Directory of Open Access Journals (Sweden)

    Florin St. C. Mustata

    2014-01-01

    Full Text Available The electrical permittivity of the weaves obtained from natural cellulosic yarns or mixed with synthetic fibers was established with capacitor method. The highest value of relative electrical permittivity in case of the woven fabric from natural cellulosic fibers has been observed at the weave made of pure hemp (13.55 and the lowest at the weave obtained from the pure jute—weave packing (1.87. Electrical permittivity value of the pure jute weave packing is comparable to that of the permittivity for the glass thread, when the work conditions are as follows: temperature 25°C and air humidity 35%. The relative electrical permittivity of the weave is depending on the degree of crimping yarns especially in the weft direction, technological density in direction of the warp and weft, and surface mass of the weave.

  18. Modelling And Analysis Of Permeability Of Anisotropic Compressed Non-Woven Filters

    Science.gov (United States)

    Prieur du Plessis, J.; Woudberg, Sonia; Le Coq, Laurence

    2010-05-01

    An existing geometrical pore-scale model for flow through isotropic spongelike media is adapted to predict flow through anisotropic non-woven glass fibre filters. Model predictions are compared to experimental results for the permeability obtained for a filter under different stages of compression to demonstrate the capability of the model to adjust to changes in porosity. The experimental data used are for a glass fibre paper with a uniform fibre diameter. The input parameters of the pore-scale model are the porosity, fibre diameter and some measure of the anisotropy between the in-plane and normal directions to the paper. Correlation between the predictions and the experimental results is satisfactory and provides confidence in the modelling procedure. It is shown that the permeability is very sensitive to changes in the level of anisotropy, i.e. the level of compression of the nonwoven material.

  19. Tensile Properties and Failure Mechanism of 3D Woven Hollow Integrated Sandwich Composites

    Science.gov (United States)

    Liu, Chang; Cai, Deng'an; Zhou, Guangming; Lu, Fangzhou

    2017-01-01

    Tensile properties and failure mechanism of 3D woven hollow integrated sandwich composites are investigated experimentally, theoretically and numerically in this paper. Firstly, the tensile properties are obtained by quasi-static tensile tests on the specimens in two principal directions of the sandwich panels, called warp and weft. The experimental results shows that the tensile performances of the warp are better than that of the weft. By observing the broken specimens, it is found that the touch parts between yarns are the main failure regions under tension. Then, a theoretical method is developed to predict the tensile properties. By comparing with the experimental data, the accuracy of the theoretical method is verified. Simultaneously, a finite element model is established to predict the tensile behavior of the composites. The numerical results agree well with the experimental data. Moreover, the simulated progressive damages show that the contact regions in the warp and weft tension are both the initial failure areas.

  20. Micro-Scale Mechanical Testing of Non-Woven Carbon Nanotube Sheets and Yarns

    Science.gov (United States)

    Magargee, J.; Morestin, F.; Cao, J.; Jones, J. S.

    2013-01-01

    Non-woven carbon nanotube (CNT) sheets and yarns were tested using a novel micro-scale mechanical testing system. CNT sheets were observed to delaminate during uniaxial testing using an adbesive gripping method, resulting from a higher proportion of load bearing in the outer sheets versus internal sheets and an apparently low interlaminar shear strength. In response to this, a new spool-grip method was used to alleviate non-uniform through-thickness stresses, circumvent premature delamination, and allow the sheet material to sustain a 72% increase in measured tensile strength. Furthermore, tension tests of CNT yarns showed that the yarn-structure was approximaiely 7 times stronger than the sheet structure, owing to a higher degree of CNT alignment in the test direction.