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Sample records for high modulus woven

  1. Increasing Mechanical Properties of 2-D-Structured Electrospun Nylon 6 Non-Woven Fiber Mats

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    Chunhui Xiang

    2016-04-01

    Full Text Available Tensile strength, Young’s modulus, and toughness of electrospun nylon 6 non-woven fiber mats were improved by increasing individual nanofiber strength and fiber–fiber load sharing. Single-walled carbon nanotubes (CNTs were used as reinforcement to increase the strength of the electrospun nylon 6 nanofibers. Young’s modulus, tensile strength, and toughness of the nylon 6 non-woven fiber mats electrospun from 20 wt % solutions increased 51%, 87%, and 136%, respectively, after incorporating 1 wt % CNTs into the nylon 6 nanofibers. Three methods were investigated to enhance fiber–fiber load sharing: increasing friction between fibers, thermal bonding, and solvent bonding. The addition of beaded nylon 6 nanofibers into the non-woven fiber mats to increase fiber-fiber friction resulted in a statistically significantly increase in Young’s modulus over comparable smooth non-woven fiber mats. After annealing, tensile strength, elongation, and toughness of the nylon 6 non-woven fiber mats electrospun from 20 wt % + 10 wt % solutions increased 26%, 28%, and 68% compared to those from 20 wt % solutions. Solvent bonding with formic acid vapor at room temperature for 30 min caused increases of 56%, 67%, and 39% in the Young’s modulus, tensile strength, and toughness of non-woven fiber mats, respectively. The increases attributed to increased individual nanofiber strength and solvent bonding synergistically resulted in the improvement of Young’s modulus of the electrospun nylon 6 non-woven fiber mats.

  2. 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.

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

    International Nuclear Information System (INIS)

    Jawaid, M.; Abdul Khalil, H.P.S.; Abu Bakar, A.

    2011-01-01

    Highlights: → Woven hybrid composites show good tensile and flexural properties. → Hybridization with 20% woven jute gives rise to sufficient modulus to composites. → Layering pattern affect mechanical properties of hybrid composites. → 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.

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

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    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.

  5. Simulation of Degraded Properties of 2D plain Woven C/SiC Composites under Preloading Oxidation Atmosphere

    Science.gov (United States)

    Chen, Xihui; Sun, Zhigang; Sun, Jianfen; Song, Yingdong

    2017-12-01

    In this paper, a numerical model which incorporates the oxidation damage model and the finite element model of 2D plain woven composites is presented for simulation of the oxidation behaviors of 2D plain woven C/SiC composite under preloading oxidation atmosphere. The equal proportional reduction method is firstly proposed to calculate the residual moduli and strength of unidirectional C/SiC composite. The multi-scale method is developed to simulate the residual elastic moduli and strength of 2D plain woven C/SiC composite. The multi-scale method is able to accurately predict the residual elastic modulus and strength of the composite. Besides, the simulated residual elastic moduli and strength of 2D plain woven C/SiC composites under preloading oxidation atmosphere show good agreements with experimental results. Furthermore, the preload, oxidation time, temperature and fiber volume fractions of the composite are investigated to show their influences upon the residual elastic modulus and strength of 2D plain woven C/SiC composites.

  6. Mechanical properties of woven banana fibre reinforced epoxy composites

    International Nuclear Information System (INIS)

    Sapuan, S.M.; Leenie, A.; Harimi, M.; Beng, Y.K.

    2006-01-01

    In this paper, the experiments of tensile and flexural (three-point bending) tests were carried out using natural fibre with composite materials (Musaceae/epoxy). Three samples prepared from woven banana fibre composites of different geometries were used in this research. From the results obtained, it was found that the maximum value of stress in x-direction is 14.14 MN/m 2 , meanwhile the maximum value of stress in y-direction is 3.398 MN/m 2 . For the Young's modulus, the value of 0.976 GN/m 2 in x-direction and 0.863 GN/m 2 in y-direction were computed. As for the case of three-point bending (flexural), the maximum load applied is 36.25 N to get the deflection of woven banana fibre specimen beam of 0.5 mm. The maximum stress and Young's modulus in x-direction was recorded to be 26.181 MN/m 2 and 2.685 GN/m 2 , respectively. Statistical analysis using ANOVA-one way has showed that the differences of results obtained from those three samples are not significant, which confirm a very stable mechanical behaviour of the composites under different tests. This shows the importance of this product and allows many researchers to develop an adequate system for producing a good quality of woven banana fibre composite which maybe used for household utilities

  7. Mechanical properties of woven banana fibre reinforced epoxy composites

    Energy Technology Data Exchange (ETDEWEB)

    Sapuan, S.M. [Department of Mechanical and Manufacturing Engineering, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia)]. E-mail: sapuan@eng.upm.my; Leenie, A. [Department of Mechanical and Manufacturing Engineering, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia); Harimi, M. [School of Engineering and Information Technology, Universiti Malaysia Sabah, 88999 Kota Kinabalu, Sabah (Malaysia); Beng, Y.K. [School of Engineering and Information Technology, Universiti Malaysia Sabah, 88999 Kota Kinabalu, Sabah (Malaysia)

    2006-07-01

    In this paper, the experiments of tensile and flexural (three-point bending) tests were carried out using natural fibre with composite materials (Musaceae/epoxy). Three samples prepared from woven banana fibre composites of different geometries were used in this research. From the results obtained, it was found that the maximum value of stress in x-direction is 14.14 MN/m{sup 2}, meanwhile the maximum value of stress in y-direction is 3.398 MN/m{sup 2}. For the Young's modulus, the value of 0.976 GN/m{sup 2} in x-direction and 0.863 GN/m{sup 2} in y-direction were computed. As for the case of three-point bending (flexural), the maximum load applied is 36.25 N to get the deflection of woven banana fibre specimen beam of 0.5 mm. The maximum stress and Young's modulus in x-direction was recorded to be 26.181 MN/m{sup 2} and 2.685 GN/m{sup 2}, respectively. Statistical analysis using ANOVA-one way has showed that the differences of results obtained from those three samples are not significant, which confirm a very stable mechanical behaviour of the composites under different tests. This shows the importance of this product and allows many researchers to develop an adequate system for producing a good quality of woven banana fibre composite which maybe used for household utilities.

  8. Elastic properties of woven bone: effect of mineral content and collagen fibrils orientation.

    Science.gov (United States)

    García-Rodríguez, J; Martínez-Reina, J

    2017-02-01

    Woven bone is a type of tissue that forms mainly during fracture healing or fetal bone development. Its microstructure can be modeled as a composite with a matrix of mineral (hydroxyapatite) and inclusions of collagen fibrils with a more or less random orientation. In the present study, its elastic properties were estimated as a function of composition (degree of mineralization) and fibril orientation. A self-consistent homogenization scheme considering randomness of inclusions' orientation was used for this purpose. Lacuno-canalicular porosity in the form of periodically distributed void inclusions was also considered. Assuming collagen fibrils to be uniformly oriented in all directions led to an isotropic tissue with a Young's modulus [Formula: see text] GPa, which is of the same order of magnitude as that of woven bone in fracture calluses. By contrast, assuming fibrils to have a preferential orientation resulted in a Young's modulus in the preferential direction of 9-16 GPa depending on the mineral content of the tissue. These results are consistent with experimental evidence for woven bone in foetuses, where collagen fibrils are aligned to a certain extent.

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

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    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. Mechanical Properties of Non-Woven Polyester Fibers and Polymer-Modified Bitumen Composites

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    V. Hadadi

    2007-12-01

    Full Text Available Blown bitumen (110/10 was mixed with heavy vacuum slops (H.V.S, 60/70 penetration grade bitumen and recycled isotactic polypropylene (iPP at different levels. The resulting resins were used to impregnate non-woven poly(ethylene terephthalate fibers to form composites. The modulus and penetration grade of the resulting bituminous resins were determined. It was found that these bituminous resins drastically affect the modulus of the composites formed by low-Young’s modulus fibers such as polyesters. Consequently, interactions between resin and fibers and the correlation length of asphalthenes (in absence of iPP and interdiffused coalescence and segregated network of asphalthenes (in presence of iPP result in a non-linear behavior of composite’s modulus. The behavior of the composites with or without iPP is controlled by resin toughness and resin interactions with the fiber through the viscosity. Comparison of the experimental composite modulus data with the theoretical modulus data revealed that the Takayanangi’s model best predicts the behavior of these composites. The adjustment factors of this model were reported and proposed as an indication of fiber-resin interaction. It was also found that the modulus of fibers is affected by toughness, viscosity and the iPP content of the bituminous resin.

  11. Static and Dynamic Mechanical Properties of Graphene Oxide-Incorporated Woven Carbon Fiber/Epoxy Composite

    Science.gov (United States)

    Adak, Nitai Chandra; Chhetri, Suman; Kim, Nam Hoon; Murmu, Naresh Chandra; Samanta, Pranab; Kuila, Tapas

    2018-03-01

    This study investigates the synergistic effects of graphene oxide (GO) on the woven carbon fiber (CF)-reinforced epoxy composites. The GO nanofiller was incorporated into the epoxy resin with variations in the content, and the CF/epoxy composites were manufactured using a vacuum-assisted resin transfer molding process and then cured at 70 and 120 °C. An analysis of the mechanical properties of the GO (0.2 wt.%)/CF/epoxy composites showed an improvement in the tensile strength, Young's modulus, toughness, flexural strength and flexural modulus by 34, 20, 83, 55 and 31%, respectively, when compared to the CF/epoxy composite. The dynamic mechanical analysis of the composites exhibited an enhancement of 56, 114 and 22% in the storage modulus, loss modulus and damping capacity (tan δ), respectively, at its glass transition temperature. The fiber-matrix interaction was studied using a Cole-Cole plot analysis.

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

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    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.

  13. 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.

  14. High energy ballistic and fracture comparison between multilayered armor systems using non-woven curaua fabric composites and aramid laminates

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    Fábio de Oliveira Braga

    2017-10-01

    Full Text Available For personal protection against high kinetic energy projectiles, multilayered armor systems (MAS are usually the best option. They combine synergistically the properties of different materials such as ceramics, composites and metals. In the present work, ballistic tests were performed to evaluate multilayered armor systems (MAS using curaua non-woven fabric epoxy composites as second layer. A comparison to a MAS using aramid (Kevlar™ fabric laminates was made. The results showed that the curaua non-woven fabric composites are suitable to the high ballistic applications, and are promising substitutes for aramid fabric laminates. Keywords: Composite, Natural fiber, Curaua fiber, Non-woven fabric, Aramid laminate, Ballistic test

  15. Effect of Reinforced Hybrid Palm Shells on Mechanical Properties of Polyurethane-Jute Woven/ Vinyl Ester Sandwich Board

    International Nuclear Information System (INIS)

    Cheng, T.S.; Nurul Ain Nanyan; Lan, D.N.U.; Leng, T.P.

    2014-01-01

    A natural fiber sandwich was constructed from palm shells/polyurethane core and jute woven/vinyl ester face sheets by the in-situ sandwich process (core and panel prepared simultaneously). The polyurethane sandwich core was reinforced by hybrid shell systems of dried palm shell (DPS) and palm kernel shell (PKS) (50P-50D, 25P-75D), and single shell system of PKS (100P) as well as 20 phr empty fruit bunch (EFB) based on hundred part of polyurethane. The sandwich face sheets are prepared by using two jute woven layers and impregnated by vinyl ester. Interlocking between DPS and polyurethane matrix was formed, which hence enhanced the mechanical properties. The interfacial adhesion between DPS, PKS, and EFB with the polyurethane binder played the important role to achieve high mechanical properties. It was found that hybrid shells exhibited high reinforcement for sandwich's performance resulting better compression (50P-50D) and flexural (25P-75D) properties. The single shell 100P showed only improvement on flexural modulus.The fracture surface morphology of sandwich under mechanical test was performed by using optical microscopy. (author)

  16. Tablet-woven and tabby-woven braids from the Czech late medieval archaeological findings

    Czech Academy of Sciences Publication Activity Database

    Březinová, Helena

    2010-01-01

    Roč. 23, - (2010), s. 47-51 ISSN 0860-0007 Institutional research plan: CEZ:AV0Z80020508 Keywords : textile fragments * tablet -woven braids * tabby-woven braids * late medieval Subject RIV: AC - Archeology, Anthropology, Ethnology

  17. A study on damage and fatigue characteristics of plain woven carbon fiber reinforced composite material(I)

    International Nuclear Information System (INIS)

    Kim, Kwang Soo; Kim, Sang Tae

    1993-01-01

    The characteristics of damage and fatigue subjected to tensile fatigue loading in plain woven carbon fiber reinforced composite material were studied. Constant amplitude load of 90% stress of notch strength was applied to each specimen, which had different initial notch length, and crack dectectvie compliance curve was determined form load-displacement data. The effective crack length(a eff ) was obtained form this compliance curve and the effective crack growth could be divided to three-steps and explained separately. After cycling the shape of fatigue crack was observed by S.E.M.. Change of elastic modulus(E N ) during fatigue cycle was explained by repeated sudden-death medel. The material constant determined by Jen-Hsu model was more useful to evaluate damage than Wang-Chim model. (Author)

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

    International Nuclear Information System (INIS)

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

    2010-01-01

    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.

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

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    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.

  20. 75 FR 11908 - Narrow Woven Ribbons With Woven Selvedge From China and Taiwan

    Science.gov (United States)

    2010-03-12

    ...)] Narrow Woven Ribbons With Woven Selvedge From China and Taiwan AGENCY: United States International Trade...(b) of the Act (19 U.S.C. 1673d(b)) to determine whether an industry in the United States is materially injured or threatened with material injury, or the establishment of an industry in the United...

  1. Basalt woven fiber reinforced vinylester composites: Flexural and electrical properties

    International Nuclear Information System (INIS)

    Carmisciano, Salvatore; Rosa, Igor Maria De; Sarasini, Fabrizio; Tamburrano, Alessio; Valente, Marco

    2011-01-01

    A preliminary comparative study of basalt and E-glass woven fabric reinforced composites was performed. The fabrics were characterized by the same weave pattern and the laminates tested by the same fiber volume fraction. Results of the flexural and interlaminar characterization are reported. Basalt fiber composites showed higher flexural modulus and apparent interlaminar shear strength (ILSS) in comparison with E-glass ones but also a lower flexural strength and similar electrical properties. With this fiber volume fraction, scanning electron microscopy (SEM) analysis of the fractured surfaces enabled a better understanding both of the failure modes involved and of points of concern. Nevertheless, the results of this study seem promising in view of a full exploitation of basalt fibers as reinforcement in polymer matrix composites (PMCs).

  2. Physical, Mechanical, and Morphological Properties of Woven Kenaf/Polymer Composites Produced Using a Vacuum Infusion Technique

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    Suhad D. Salman

    2015-01-01

    Full Text Available Nowadays, due to renewable issues, environmental concerns, and the financial problems of synthetic fibres, the development of high-performance engineering products made from natural resources is increasing all over the world. Lately, kenaf fibre has been used among many different types of natural resources in various shapes. Unidirectional long fibres or randomly oriented short fibre shapes are the most common type of kenaf fibres that have been investigated in previous works. This work characterises and evaluates the physical, mechanical, and morphological properties of plain woven kenaf fabric and its composites with three types of thermoset resin at 0°/90° and 45°/−45° orientation, in order to assess their suitability as lignocellulosic reinforced polymer composites. A vacuum infusion manufacturing technique was used to prepare the specimens with fibre weight content of 35% ± 2%. Eight specimens were prepared for each test, and five replications were adopted. A total of 78 samples were tested in this study. The results show that the composites with 0°/90° had the highest tensile, flexural strengths, and modulus. The morphological properties of composite samples were analysed through scanning electron microscopy (SEM images and these clearly demonstrated the better interfacial adhesion between the woven kenaf and the epoxy matrix.

  3. 75 FR 53711 - Narrow Woven Ribbons With Woven Selvedge From China and Taiwan

    Science.gov (United States)

    2010-09-01

    ... Woven Ribbons With Woven Selvedge From China and Taiwan Determinations On the basis of the record \\1... U.S.C. 1673d(b)) (the Act), that an industry in the United States is threatened with material injury... (19 U.S.C. 1673d(b)), that an industry in the United States is threatened with material injury by...

  4. MAGNETIC WOVEN FABRICS - PHYSICAL AND MAGNETIC PROPERTIES

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    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.

  5. Computational modelling of buckling of woven fabrics

    CSIR Research Space (South Africa)

    Anandjiwala, RD

    2006-02-01

    Full Text Available for reducing unit production cost is critically important if garment industries in developed countries are keen to improve their competitiveness vis-à-vis low labour cost countries. The mechanics of the buckling behaviour of woven fabric started... of woven fabric. INTRODUCTION The buckling, bending and drape behaviours of a woven fabric influence its performance during actual use and during the process of making-up into the end product. These properties are important, particularly when the fabric...

  6. 77 FR 32938 - Narrow Woven Ribbons With Woven Selvedge From Taiwan: Preliminary Results of Antidumping Duty...

    Science.gov (United States)

    2012-06-04

    ... ribbons subject to the order include all narrow woven fabrics, tapes, and labels that fall within this... the manufacture of typewriter or printer ribbons; (5) Narrow woven labels and apparel tapes, cut-to... 1994 U.S.C.C.A.N. 4040, 4198-99. Furthermore, ``affirmative evidence of bad faith on the part of a...

  7. Woven type smart soft composite beam with in-plane shape retention

    International Nuclear Information System (INIS)

    Wu, Renzhe; Han, Min-Woo; Lee, Gil-Yong; Ahn, Sung-Hoon

    2013-01-01

    Shape memory alloy (SMA) wire embedded composites (SMAECs) are widely used as morphing structures in small-size and high-output systems. However, conventional SMAECs cannot keep deformed shapes without additional energy. In this paper, a new kind of smart structure named the woven type smart soft composite (SSC) beam is introduced, which is not only capable of morphing, but also maintaining its deformed shape without additional energy. The woven type SSC beam consists of two parts: woven wires and matrix. The selected woven wires are nitinol (Ni–Ti) SMA wires and glass fibers, while the matrix part is polydimethylsiloxane (PDMS). In order to evaluate the performance of the woven type SSC beam in areas such as in-plane deformation, blocking force and repeatability, a beam-shape specimen is prepared of size 100 mm (length) × 8 mm (width) ×3 mm (thickness). The fabricated SSC beam achieved 21 mm deformation and 16 mm shape retention. Blocking force was measured using a dynamometer, and was about 60 mN. In the repeatability test, it recovered almost the same position when its cooling time was 90 s more. Consequently, the woven type SSC beam can be applied to bio-mimicking, soft morphing actuators, consuming less energy than traditional SMAECs. (paper)

  8. Elastic Modulus at High Frequency of Polymerically Stabilized Suspensions

    NARCIS (Netherlands)

    Nommensen, P.A.; Duits, Michael H.G.; van den Ende, Henricus T.M.; Mellema, J.

    2000-01-01

    The elastic moduli of polymerically stabilized suspensions consisting of colloidal silica particles coated with endgrafted PDMS (Mn = 80 000) in heptane, were measured as a function of concentration. And the elastic modulus at high frequency G'.. was quantitatively described by model calculations

  9. 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 non-coated...

  10. Non-Wovens as Sound Reducers

    Science.gov (United States)

    Belakova, D.; Seile, A.; Kukle, S.; Plamus, T.

    2018-04-01

    Within the present study, the effect of hemp (40 wt%) and polyactide (60 wt%), non-woven surface density, thickness and number of fibre web layers on the sound absorption coefficient and the sound transmission loss in the frequency range from 50 to 5000 Hz is analysed. The sound insulation properties of the experimental samples have been determined, compared to the ones in practical use, and the possible use of material has been defined. Non-woven materials are ideally suited for use in acoustic insulation products because the arrangement of fibres produces a porous material structure, which leads to a greater interaction between sound waves and fibre structure. Of all the tested samples (A, B and D), the non-woven variant B exceeded the surface density of sample A by 1.22 times and 1.15 times that of sample D. By placing non-wovens one above the other in 2 layers, it is possible to increase the absorption coefficient of the material, which depending on the frequency corresponds to C, D, and E sound absorption classes. Sample A demonstrates the best sound absorption of all the three samples in the frequency range from 250 to 2000 Hz. In the test frequency range from 50 to 5000 Hz, the sound transmission loss varies from 0.76 (Sample D at 63 Hz) to 3.90 (Sample B at 5000 Hz).

  11. Preparation and Characterization of Polypropylene Non-woven Fabrics Prepared by Melt-blown Spinning for Filtration Membranes

    Energy Technology Data Exchange (ETDEWEB)

    Chu, Konghee; Park, Mira; Kim, Hakyong [Chonbuk National Univ., Jeonju (Korea, Republic of); Jin, Fanlong; Park, Soojin [Inha Univ., Incheon (Korea, Republic of)

    2014-06-15

    PP non-woven fabrics were prepared by melt-blown spinning, followed by heat and plasma treatments. After heat treatment, the PP non-woven fabrics displayed decreased water flux, increased tensile strength, decreased elongation, and an average pore size of 0.7 μm. The hydrophilicity of the PP non-woven fabrics was improved by plasma treatment. The water flux of the PP non-woven fabrics increased about two fold after the plasma treatment. The particle removal efficiency was determined to be 97.2-99.4% for 1-3 μm sized particles, demonstrating a high particle removal efficiency. Polypropylene (PP) non-woven fabrics have been widely used as filtration membranes in wastewater purification with industrial applications due to their low cost, good mechanical strength, and high thermal and chemical stability. The membrane fouling behavior depends strongly on the physical and mechanical properties of the membrane, including pore size, porosity, morphology, and hydrophilicity. In general, PP non-woven fabrics have poor hydrophilicity; this has limited their application in the biomedical field. It is therefore necessary to develop PP non-woven fabrics with improved surface hydrophilicity to increase the scope of their use. Plasma treatment, an environmentally friendly alternative to traditional chemical activation, only changes the uppermost atomic layers of a membrane surface without affecting the bulk properties of the polymer.

  12. Multi Length Scale Finite Element Design Framework for Advanced Woven Fabrics

    Science.gov (United States)

    Erol, Galip Ozan

    Woven fabrics are integral parts of many engineering applications spanning from personal protective garments to surgical scaffolds. They provide a wide range of opportunities in designing advanced structures because of their high tenacity, flexibility, high strength-to-weight ratios and versatility. These advantages result from their inherent multi scale nature where the filaments are bundled together to create yarns while the yarns are arranged into different weave architectures. Their highly versatile nature opens up potential for a wide range of mechanical properties which can be adjusted based on the application. While woven fabrics are viable options for design of various engineering systems, being able to understand the underlying mechanisms of the deformation and associated highly nonlinear mechanical response is important and necessary. However, the multiscale nature and relationships between these scales make the design process involving woven fabrics a challenging task. The objective of this work is to develop a multiscale numerical design framework using experimentally validated mesoscopic and macroscopic length scale approaches by identifying important deformation mechanisms and recognizing the nonlinear mechanical response of woven fabrics. This framework is exercised by developing mesoscopic length scale constitutive models to investigate plain weave fabric response under a wide range of loading conditions. A hyperelastic transversely isotropic yarn material model with transverse material nonlinearity is developed for woven yarns (commonly used in personal protection garments). The material properties/parameters are determined through an inverse method where unit cell finite element simulations are coupled with experiments. The developed yarn material model is validated by simulating full scale uniaxial tensile, bias extension and indentation experiments, and comparing to experimentally observed mechanical response and deformation mechanisms. Moreover

  13. Modeling the Monotonic and Cyclic Tensile Stress-Strain Behavior of 2D and 2.5D Woven C/SiC Ceramic-Matrix Composites

    Science.gov (United States)

    Li, L. B.

    2018-05-01

    The deformation of 2D and 2.5 C/SiC woven ceramic-matrix composites (CMCs) in monotonic and cyclic loadings has been investigated. Statistical matrix multicracking and fiber failure models and the fracture mechanics interface debonding approach are used to determine the spacing of matrix cracks, the debonded length of interface, and the fraction of broken fibers. The effects of fiber volume fraction and fiber Weibull modulus on the damage evolution in the composites and on their tensile stress-strain curves are analyzed. When matrix multicracking and fiber/matrix interface debonding occur, the fiber slippage relative to the matrix in the debonded interface region of the 0° warp yarns is the main reason for the emergance of stress-strain hysteresis loops for 2D and 2.5D woven CMCs. A model of these loops is developed, and histeresis loops for the composites in cyclic loadings/unloadings are predicted.

  14. 75 FR 41804 - Notice of Final Determination of Sales at Less Than Fair Value: Narrow Woven Ribbons with Woven...

    Science.gov (United States)

    2010-07-19

    ... unaffiliated supplier informed the Department that it did not produce NWR but merely purchased and resold it... or set such as when packaged with other products, including but not limited to gift bags, gift boxes... ribbons with woven selvedge attached to and forming the handle of a gift bag; (7) cut-edge narrow woven...

  15. Processing and Characterization of Liquid-Phase Sintered NiTi Woven Structures

    Science.gov (United States)

    Erdeniz, Dinc; Weidinger, Ryan P.; Sharp, Keith W.; Dunand, David C.

    2018-03-01

    Porous NiTi is of interest for bone implants because of its unique combination of biocompatibility (encouraging osseointegration), high strength (to prevent fracture), low stiffness (to reduce stress shielding), and shape memory or superelasticity (to deploy an implant). A promising method for creating NiTi structures with regular open channels is via 3D weaving of NiTi wires. This paper presents a processing method to bond woven NiTi wire structures at contact points between wires to achieve structural integrity: (i) a slurry consisting of a blend of NiTi and Nb powders is deposited on the surface of the NiTi wires after the weaving operation; (ii) the powders are melted to create a eutectic liquid phase which collects at contact points; and (iii) the liquid is solidified and binds the NiTi woven structures. The bonded NiTi wire structures exhibited lower transformation temperatures compared to the as-woven NiTi wires because of Nb diffusion into the NiTi wires. A bonded woven sample was deformed in bending and showed near-complete recovery up to 6% strain and recovered nearly half of the deformation up to 19% strain.

  16. 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.

  17. The Effect of Customized Woven and Stacked Layer Orientation on Tensile and Flexural Properties of Woven Kenaf Fibre Reinforced Epoxy Composites

    Directory of Open Access Journals (Sweden)

    A. Hamdan

    2016-01-01

    Full Text Available The synthetic fibres have created some issues including risk of inhalation during fabrication process, renewability, biodegradability, and recyclability in composites industry. The usage of biocomposites as a replacement to synthetic fibres is beginning to be widespread. However, it is noted that lesser attention has been devoted to evaluating the mechanical properties of woven kenaf composites at various woven and stacked layer orientation. Thus, the research objective is to identify the effect of woven and stacked layer orientation on tensile and flexural properties of kenaf composites. Two types of fibre orientation are employed; type A contains a higher yarn density and type B contains a low yarn density. The tensile and flexural tests are conducted to analyze the mechanical properties of woven kenaf fibre composites and compare them to random chopped kenaf composites. The fracture interface between fibre and matrix epoxy is further investigated via scanning electron microscope. Type A kenaf improved up to 199% and 177% as compared to random chopped kenaf for flexural strength and tensile strength, respectively. Scanning electron microscopy analysis shows that resin matrix is properly induced into kenaf fibre gap hence giving additional strength to woven kenaf as compared to random chopped kenaf.

  18. 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.

  19. 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.

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

    Science.gov (United States)

    Jones, Justin S.; Polis, Daniel L.; 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 traditionally manufactured barrel segments. 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.

  1. 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...

  2. 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.

  3. A Study on Accelerated Thermal Aging of High Modulus Carbon/Epoxy Composite Material

    Directory of Open Access Journals (Sweden)

    Ju Min Kyung

    2015-01-01

    Full Text Available Composite materials have been used increasingly for various space applications due to the favorable characteristic of high modulus to density ratio and potential for near-zero coefficient of thermal expansion. In composite system, depending on the orientation of fibers, strength and stiffness can be changed so that the optimum structure can be accomplished. This is because the coefficient of thermal expansion (CTE of carbon fibers is negative. For spacecraft and orbiting space structure, which are thermally cycled by moving through the earth' shadow for at least 5 years, it is necessary to investigate the change of properties of the material over time. In this study, thermal aging of epoxy matrix/high modulus carbon fiber composite materials are accelerated to predict the long term creep property. Specimens are tested at various temperatures of 100~140°C with dynamic mechanical analysis to obtain creep compliances that are functions of time and temperature. Using Time Temperature Superposition method, creep compliance curves at each temperature are shifted to the reference temperature by shift factor and a master curve is generated at the reference temperature. This information is useful to predict the long term thermal aging of high modulus composite material for spacecraft application.

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

    KAUST Repository

    Saleh, Mohamed Nasr; Lubineau, Gilles; Potluri, Prasad; Withers, Philip; Soutis, Constantinos

    2016-01-01

    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.

  5. 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.

  6. Medical effects of poly-ethylene terephthalate (PET) non-woven ...

    African Journals Online (AJOL)

    In this study, bamboo activated charcoal was mixed with acrylic resin in various proportions and deposited on poly-ethylene terephthalate (PET) non-woven fabrics. A series of characterizations were carried out to estimate the performances of PET non-woven fabrics such as far infrared ray emission, heat retention, negative ...

  7. CREASING BEHAVIOR OF SOME WOVEN MATERIALS MADE FROM COMBED YARNS TYPE

    OpenAIRE

    HRISTIAN Liliana; BORDEIANU Demetra Lacramioara; OSTAFE Maria Magdalena; BŐHM-RÉVÉSZ Gabriela

    2017-01-01

    The paper analyses the behavior to creasing of some woven materials made from yarns type wool used for ready-made clothes. Factors like fibrous composition, properties of constituent fibers, wovens structure parameters, mechanical properties of warp and weft yarns and finishing treatments that influenced the recovery capacity from crease/folding were investigated experimentally through several tests which revealed their importance in the process. The creasing of woven materials made from c...

  8. Recent advancements in mechanical characterisation of 3D woven composites

    Science.gov (United States)

    Saleh, Mohamed Nasr; Soutis, Constantinos

    2017-12-01

    Three dimensional (3D) woven composites have attracted the interest of academia and industry thanks to their damage tolerance characteristics and automated fabric manufacturing. Although much research has been conducted to investigate their out-of-plane "through thickness" properties, still their in-plane properties are not fully understood and rely on extensive experimentation. To date, the literature lacks an inclusive summary of the mechanical characterisation for 3D woven composites. Therefore, the objective of this paper is to provide a comprehensive review of the available research studies on 3D woven composites mechanical characterisation, with less emphasis on the out-of-plane response, but an in-depth review of the in-plane response "un-notched vs. notched". The paper highlights the knowledge gap in the literature of 3D woven composites, suggesting opportunities for future research in this field and a room for improvement in utilising Non-Destructive Techniques (NDT), such as Digital Image Correlation (DIC), Acoustic Emission (AE) and X-ray Computed Tomography (CT), for observing damage initiation and evolution in 3D woven composites that could be used to calibrate and evaluate analytical and numerical models.

  9. 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.

  10. 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.

  11. CREASING BEHAVIOR OF SOME WOVEN MATERIALS MADE FROM COMBED YARNS TYPE

    Directory of Open Access Journals (Sweden)

    HRISTIAN Liliana

    2017-05-01

    Full Text Available The paper analyses the behavior to creasing of some woven materials made from yarns type wool used for ready-made clothes. Factors like fibrous composition, properties of constituent fibers, wovens structure parameters, mechanical properties of warp and weft yarns and finishing treatments that influenced the recovery capacity from crease/folding were investigated experimentally through several tests which revealed their importance in the process. The creasing of woven materials made from combed yarns type wool used for ready-clothes is an undesired deformation effect with temporary or permanent character, which is caused by a composed strain of bending and compression during utilization, processing or maintenance. It is manifested by the appearance of wrinkles, folds or stripes on the surface of wovens materials, thus diminishing their qualitative appearance and also their practical value. Creasing is the result of irreversible changes created through the reciprocal sliding of structural fiber components when exposed to a bending strain. Creasing is specific to oriented structures with high crystallinity (cellulosic fibers. The sliding appears because of hydrogen bond breaking which can, however, reform easy in other positions conferring a permanent character to creasing.Functional apparel will be subjected to a wide range of end uses such that a garment will be affected by intern (fibres, yarn fineness warp/weft, fabric density, thickness, fabric count and external factors (external environment - exposure to sunlight, wind, rain, cold weather conditions, fabric/human body interaction. These factors affect the performance and behaviour of functional.

  12. Failure Modes of a Unidirectional Ultra-High-Modulus Carbon-Fiber/Carbon-Matrix Composite

    National Research Council Canada - National Science Library

    Zaldivar, R

    1998-01-01

    The objective of this study was to observe the effects of various microstructural features on the in situ, room-temperature tensile fracture behavior of an ultra-high-modulus, unidirectional carbon/carbon (C/C...

  13. 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.

  14. 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.

  15. From mindtools to social mindtools: collaborative writing with Woven Stories

    CSIR Research Space (South Africa)

    Nuutinen, J

    2010-09-01

    Full Text Available . We present the concept of Woven Stories and use it as an example of an effective social mindtool. We also describe a case study in which Woven Stories software was used as an online debating forum. This case study reveals the potential inherent...

  16. Comparative Study of the Properties of some Non-Woven Diapers ...

    African Journals Online (AJOL)

    ABSTRACT: The properties of locally made non-woven diapers were studied. Four locally made non-woven absorbent pads samples namely; Always ultra absorbent pad (sample A), Dr. Brown absorbent pad (sample B),. Everyday ultra thin normal absorbent pad (sample C), and Enjoy leto absorbent pad (sample D) were ...

  17. 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

  18. Application of diffusion barriers to high modulus fibers

    Science.gov (United States)

    Veltri, R. D.; Douglas, F. C.; Paradis, E. L.; Galasso, F. S.

    1977-01-01

    Barrier layers were coated onto high-modulus fibers, and nickel and titanium layers were overcoated as simulated matrix materials. The objective was to coat the high-strength fibers with unreactive selected materials without degrading the fibers. The fibers were tungsten, niobium, and single-crystal sapphire, while the materials used as barrier coating layers were Al2O3, Y2O3, TiC, ZrC, WC with 14% Co, and HfO2. An ion-plating technique was used to coat the fibers. The fibers were subjected to high-temperature heat treatments to evaluate the effectiveness of the barrier layer in preventing fiber-metal interactions. Results indicate that Al2O3, Y2O3, and HfO2 can be used as barrier layers to minimize the nickel-tungsten interaction. Further investigation, including thermal cycling tests at 1090 C, revealed that HfO2 is probably the best of the three.

  19. 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.

  20. Physical properties of recycled PET non-woven fabrics for buildings

    Science.gov (United States)

    Üstün Çetin, S.; Tayyar, A. E.

    2017-10-01

    Recycled fibers have been commonly used in non-woven production technology for engineering applications such as textile engineering and civil engineering. Nonwovens including recycled fibers can be utilized in insulation, roofing and floor separation applications. In this study, physical performance properties such as drape, bending resistance, tensile strength, and breaking elongation values of non-woven fabrics consisting of v-PET (virgin) and r-PET (recycled) fibers in five different blend ratios are examined comparatively. The test results indicated that r-PET can be used in non-wovens for civil engineering applications such as insulation, roofing and floor separation fulfilling the acceptable quality level values.

  1. 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.

  2. 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...

  3. 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.

  4. 78 FR 29703 - Narrow Woven Ribbons With Woven Selvedge From Taiwan: Preliminary Results of Antidumping Duty...

    Science.gov (United States)

    2013-05-21

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-583-844] Narrow Woven Ribbons With... AGENCY: Import Administration, International Trade Administration, Department of Commerce. SUMMARY: The..., International Trade Administration, U.S. Department of Commerce, 14th Street and Constitution Avenue NW...

  5. 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

  6. Geometrical analysis of woven fabric microstructure based on micron-resolution computed tomography data

    Science.gov (United States)

    Krieger, Helga; Seide, Gunnar; Gries, Thomas; Stapleton, Scott E.

    2018-04-01

    The global mechanical properties of textiles such as elasticity and strength, as well as transport properties such as permeability depend strongly on the microstructure of the textile. Textiles are heterogeneous structures with highly anisotropic material properties, including local fiber orientation and local fiber volume fraction. In this paper, an algorithm is presented to generate a virtual 3D-model of a woven fabric architecture with information about the local fiber orientation and the local fiber volume fraction. The geometric data of the woven fabric impregnated with resin was obtained by micron-resolution computed tomography (μCT). The volumetric μCT-scan was discretized into cells and the microstructure of each cell was analyzed and homogenized. Furthermore, the discretized data was used to calculate the local permeability tensors of each cell. An example application of the analyzed data is the simulation of the resin flow through a woven fabric based on the determined local permeability tensors and on Darcy's law. The presented algorithm is an automated and robust method of going from μCT-scans to structural or flow models.

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

    KAUST Repository

    Phuoc, Duong; Nunes, Suzana Pereira; Chung, Tai-Shung

    2016-01-01

    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

  8. 78 FR 26614 - Narrow Woven Ribbon With Woven Selvedge From the People's Republic of China: Rescission of...

    Science.gov (United States)

    2013-05-07

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-570-952] Narrow Woven Ribbon With...; 2011-2012 AGENCY: Import Administration, International Trade Administration, Department of Commerce... Administration, International Trade Administration, U.S. Department of Commerce, 14th Street and Constitution...

  9. 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.

  10. Effect of layering sequence and chemical treatment on the mechanical properties of woven kenaf–aramid hybrid laminated composites

    International Nuclear Information System (INIS)

    Yahaya, R.; Sapuan, S.M.; Jawaid, M.; Leman, Z.; Zainudin, E.S.

    2015-01-01

    Highlights: • The mechanical properties of woven kenaf/Kevlar hybrid composites were analysed. • The layering sequences affect the mechanical properties of hybrid composites. • Treated kenaf improves the mechanical properties of hybrid composites. - Abstract: This work aims to evaluate the effect of layering sequence and chemical treatment on mechanical properties of woven kenaf–Kevlar composites. Woven kenaf–aramid hybrid laminated composites fabricated through hand lay-up techniques by arranging woven kenaf and Kevlar fabrics in different layering sequences and by using treated kenaf mat. To evaluate the effect of chemical treatment on hybrid composites, the woven kenaf mat was treated with 6% sodium hydroxide (NaOH) diluted solution and compared mechanical properties with untreated kenaf hybrid composites. Results shows that the tensile properties of hybrid composites improved in 3-layer composites compared to 4-layer composites. Hybrid composite with Kevlar as outer layers display a better mechanical properties as compared to other hybrid composites. Tensile and flexural properties of treated hybrid composites are better than non-treated hybrid composites. The fractured surface of hybrid composites was investigated by scanning electron microscopy. This study is a part of exploration of potential application of the hybrid composite in high velocity impact application

  11. Stiff, light, strong and ductile: nano-structured High Modulus Steel.

    Science.gov (United States)

    Springer, H; Baron, C; Szczepaniak, A; Uhlenwinkel, V; Raabe, D

    2017-06-05

    Structural material development for lightweight applications aims at improving the key parameters strength, stiffness and ductility at low density, but these properties are typically mutually exclusive. Here we present how we overcome this trade-off with a new class of nano-structured steel - TiB 2 composites synthesised in-situ via bulk metallurgical spray-forming. Owing to the nano-sized dispersion of the TiB 2 particles of extreme stiffness and low density - obtained by the in-situ formation with rapid solidification kinetics - the new material has the mechanical performance of advanced high strength steels, and a 25% higher stiffness/density ratio than any of the currently used high strength steels, aluminium, magnesium and titanium alloys. This renders this High Modulus Steel the first density-reduced, high stiffness, high strength and yet ductile material which can be produced on an industrial scale. Also ideally suited for 3D printing technology, this material addresses all key requirements for high performance and cost effective lightweight design.

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

    Directory of Open Access Journals (Sweden)

    Mariana Fexina Tomé

    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.

  13. 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.

  14. Microfibrous β-TCP/collagen scaffolds mimic woven bone in structure and composition

    International Nuclear Information System (INIS)

    Zhang Shen; Zhang Xin; Cai Qing; Yang Xiaoping; Wang Bo; Deng Xuliang

    2010-01-01

    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 (β-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 β-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 β-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.

  15. Experimental Young's modulus calculations

    International Nuclear Information System (INIS)

    Chen, Y.; Jayakumar, R.; Yu, K.

    1994-01-01

    Coil is a very important magnet component. The turn location and the coil size impact both mechanical and magnetic behavior of the magnet. The Young's modulus plays a significant role in determining the coil location and size. Therefore, Young's modulus study is essential in predicting both the analytical and practical magnet behavior. To determine the coil Young's modulus, an experiment has been conducted to measure azimuthal sizes of a half quadrant QSE101 inner coil under different loading. All measurements are made at four different positions along an 8-inch long inner coil. Each measurement is repeated three times to determine the reproducibility of the experiment. To ensure the reliability of this experiment, the same measurement is performed twice with a open-quotes dummy coil,close quotes which is made of G10 and has the same dimension and similar azimuthal Young's modulus as the inner coil. The difference between the G10 azimuthal Young's modulus calculated from the experiments and its known value from the manufacturer will be compared. Much effort has been extended in analyzing the experimental data to obtain a more reliable Young's modulus. Analysis methods include the error analysis method and the least square method

  16. Spatial and temporal variations of the callus mechanical properties during bone transport

    Energy Technology Data Exchange (ETDEWEB)

    Mora-Macias, J.; Reina-Romo, E.; Pajares, A.; Miranda, P.; Dominguez, J.

    2016-07-01

    Nanoindentation allows obtaining the elastic modulus and the hardness of materials point by point. This technique has been used to assess the mechanical propeties of the callus during fracture healing. However, as fas as the authors know, the evaluation of mechanical properties by this technique of the distraction and the docking-site calluses generated during bone transport have not been reported yet. Therefore, the aim of this work is using nanoindentation to assess the spatial and temporal variation of the elastic modulus of the woven bone generated during bone transport. Nanoindentation measurements were carried out using 6 samples from sheep sacrificed at different stages of the bone transport experiments. The results obtained show an important heterogeneity of the elastic modulus of the woven bone without spatial trends. In the case of temporal variation, a clear increase of the mean elastic modulus with time after surgery was observed (from 7±2GPa 35 days after surgery to 14±2GPa 525 days after surgery in the distraction callus and a similar increase in the docking site callus). Comparison with the evolution of the elastic modulus in the woven bone generated during fracture healing shows that mechanical properties increase slower in the case of the woven bone generated during bone transport. (Author)

  17. Fast, High Resolution, and Wide Modulus Range Nanomechanical Mapping with Bimodal Tapping Mode.

    Science.gov (United States)

    Kocun, Marta; Labuda, Aleksander; Meinhold, Waiman; Revenko, Irène; Proksch, Roger

    2017-10-24

    Tapping mode atomic force microscopy (AFM), also known as amplitude modulated (AM) or AC mode, is a proven, reliable, and gentle imaging mode with widespread applications. Over the several decades that tapping mode has been in use, quantification of tip-sample mechanical properties such as stiffness has remained elusive. Bimodal tapping mode keeps the advantages of single-frequency tapping mode while extending the technique by driving and measuring an additional resonant mode of the cantilever. The simultaneously measured observables of this additional resonance provide the additional information necessary to extract quantitative nanomechanical information about the tip-sample mechanics. Specifically, driving the higher cantilever resonance in a frequency modulated (FM) mode allows direct measurement of the tip-sample interaction stiffness and, with appropriate modeling, the set point-independent local elastic modulus. Here we discuss the advantages of bimodal tapping, coined AM-FM imaging, for modulus mapping. Results are presented for samples over a wide modulus range, from a compliant gel (∼100 MPa) to stiff materials (∼100 GPa), with the same type of cantilever. We also show high-resolution (subnanometer) stiffness mapping of individual molecules in semicrystalline polymers and of DNA in fluid. Combined with the ability to remain quantitative even at line scan rates of nearly 40 Hz, the results demonstrate the versatility of AM-FM imaging for nanomechanical characterization in a wide range of applications.

  18. 75 FR 41808 - Narrow Woven Ribbons With Woven Selvedge From the People's Republic of China: Final Determination...

    Science.gov (United States)

    2010-07-19

    ... Ribbon Company, Inc. (``Petitioner''); Yama; and Yangzhou Bestpak Gifts & Crafts Co., Ltd. (``Bestpak... liquid petroleum gas from the supplier to Yama's factory.\\10\\ \\10\\ See Final Analysis Memorandum for Yama... limited to gift bags, gift boxes and/ or other types of ribbon. Narrow woven ribbons subject to the...

  19. Natural asphalt modified binders used for high stiffness modulus asphalt concrete

    Science.gov (United States)

    Bilski, Marcin; Słowik, Mieczysław

    2018-05-01

    This paper presents a set of test results supporting the possibility of replacing, in Polish climate conditions, hard road 20/30 penetration grade bitumen used in the binder course and/or base course made of high stiffness modulus asphalt concrete with binders comprising of 35/50 or 50/70 penetration grade bitumens and additives in the form of natural Gilsonite or Trinidad Epuré asphalts. For the purpose of comparing the properties of the discussed asphalt binders, values of the Performance Grade have been determined according to the American Superpave system criteria.

  20. 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.

  1. Fatigue life prediction in woven carbon fabric polyester composites

    International Nuclear Information System (INIS)

    Khan, Z.; Al-Sulaiman, F.S.; Farooqi, J.K.

    1999-01-01

    An analytical model, based on stiffness degradation during fatigue loading, which has been used for fatigue life predictions in the Fiber Reinforced Plastics (FRP), is employed to examine its validity to the fatigue life predictions in the Woven Fabric Reinforced Plastics. The rate of stiffness degradation (dE/dN) has been obtained from the constant amplitude fatigue testing of 8-ply coupons made from prepreg plain-weave woven carbon-carbon fabric having a polyester resin as the matrix material. The test coupons had three different ply stacking sequences, namely, the unidirectional (0)8,and two off axis plied (0,0,+45,-45)s, and (+45,-45,0,0)s orientations. The estimated fatigue lives obtained from the damage rate function dD/dN, which in turn was a function of the stiffness degradation rate dE/dN, were compared with the experimentally observed fatigue life data. It is shown that the stiffness degradation model provides reasonably good correlation between the analytically determined fatigue lives and the experimentally observed fatigue for the plain-weave woven Carbon-Carbon Fabric Reinforced Plastic Composites. (author)

  2. 77 FR 47363 - Narrow Woven Ribbons With Woven Selvedge From the People's Republic of China: Preliminary Results...

    Science.gov (United States)

    2012-08-08

    ... fabrics, tapes, and labels that fall within this written description of the scope of the antidumping duty... of a kind used for the manufacture of typewriter or printer ribbons; (5) Narrow woven labels and..., ``affirmative evidence of bad faith on the part of a respondent is not required before the Department may make...

  3. 75 FR 56982 - Narrow Woven Ribbons With Woven Selvedge From Taiwan and the People's Republic of China: Amended...

    Science.gov (United States)

    2010-09-17

    ...: Margin Exporter or producer (percent) Taiwan Roung Shu Industry Corporation 4.37 All Others 4.37 Margin... Ribbons With Woven Selvedge From Taiwan and the People's Republic of China: Amended Antidumping Duty...: Notice of amended antidumping duty orders. FOR FURTHER INFORMATION CONTACT: Holly Phelps (Taiwan), AD/CVD...

  4. DRAPING SIMULATION OF WOVEN FABRICS

    Energy Technology Data Exchange (ETDEWEB)

    Rodgers, William [General Motors LLC; Jin, Xiaoshi [ESI Group NA; Zhu, Jiang [Optimal CAE; Wathen, Terrence [General Motors LLC; Doroudian2, Mark [ESI Group NA; Aitharaju, Venkat [General Motors LLC

    2016-09-07

    Woven fabric composites are extensively used in molding complex geometrical shapes due to their high conformability compared to other fabrics. Preforming is an important step in the overall process, where the two-dimensional fabric is draped to become the three-dimensional shape of the part prior to resin injection. During preforming, the orientation of the yarns may change significantly compared to the initial orientations. Accurate prediction of the yarn orientations after molding is important for evaluating the structural performance of the final part. This paper presents a systematic investigation of the angle changes during the preform operation for carbon fiber twill and satin weave fabrics. Preforming experiments were conducted using a truncated pyramid mold geometry designed and fabricated at the General Motors Research Laboratories. Predicted results for the yarn orientations were compared with experimental results and good agreement was observed

  5. The Layer of Kevlar Angle-interlock Woven Fabric Effect on the Tensile Properties of Composite Materials

    Science.gov (United States)

    Xie, Wan-Chen; Guo, Xu-Yi; Yan, Tao; Zhang, Shang-Yong

    2017-09-01

    This article is based on the structure of three-dimensional angle-interlock longitudinal.The 3-layer, 5-layer, 7-layer and 9-layer of angle-interlock 3D fabrics are woven on sample weaving machine respectively with the 1500D Kevlar fiber twist filament produced by United States DuPont. At the same time, Kevlar plain weave fabric is woven, and three, five, seven and nine layers’ fabric are to be compared. In the process of VARTM composite technology, epoxy resin is matrix material, acetone is diluent, triethylene tetramine is curing agent and the five different fabrics are the reinforced materials respectively. Finally, eight different three-dimensional woven fabric composites were prepared. In this paper, the tensile properties of eight kinds of three-dimensional woven fabric composites were tested respectively.Finally, it is concluded that the five-layer angle-interlock woven fabric prepared by Kevlar fiber shows the best tensile property.

  6. 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

  7. 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.

  8. 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.

  9. Study on drilling induced delamination of woven kenaf fiber reinforced epoxy composite using carbide drills

    Science.gov (United States)

    Suhaily, M.; Hassan, C. H. Che; Jaharah, A. G.; Azmi, H.; Afifah, M. A.; Khairusshima, M. K. Nor

    2018-04-01

    In this research study, it presents the influences of drilling parameters on the delamination factor during the drilling of woven kenaf fiber reinforced epoxy composite laminates when using the carbide drill bits. The purpose of this study is to investigate the influence of drilling parameters such as cutting speed, feed rate and drill sizes on the delamination produced when drilling woven kenaf reinforced epoxy composite using the non-coated carbide drill bits. The damage generated on the woven kenaf reinforced epoxy composite laminates were observed both at the entrance and exit surface during the drilling operation. The experiments were conducted according to the Box Behnken experimental designs. The results indicated that the drill diameter has a significant influence on the delamination when drilling the woven kenaf fiber reinforced epoxy composites.

  10. 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.

  11. Effect of young’s modulus on springback for low, medium and high carbon steels during cold drawing of seamless tubes

    Science.gov (United States)

    Karanjule, D. B.; Bhamare, S. S.; Rao, T. H.

    2018-04-01

    Cold drawing is widely used deformation process for seamless tube manufacturing. Springback is one of the major problem faced in tube drawing. Springback is due to the elastic energy stored in the tubes during forming process. It is found that this springback depends upon Young’s modulus of the material. This paper reports mechanical testing of three grades of steels viz. low carbon steel, medium carbon steel and high carbon steel to measure their Young’s modulus and corresponding springback. The results shows that there is 10-20 % variation in the Young’s modulus and inverse proportion between the springback and Young’s modulus. More the percentage of carbon, more the strength, less the value of Young’s modulus and more will springback. The study further leads to identify optimum die semi angle of 15 degree, land width of 10 mm and drawing speed of 8, 6 and 4 m/min for least springback in all the three grades respectively and die semi angle as a most dominant factor causing springback.

  12. Woven fabric composites: Can we peel it?

    NARCIS (Netherlands)

    Sacchetti, Francisco; Grouve, Wouter Johannes Bernardus; Warnet, Laurent; Villegas, I. Fernandez

    2016-01-01

    The present work focuses on the applicability of the mandrel peel test to quantify the fracture toughness of woven fabric Carbon/PEEK composites. For this purpose, the mandrel peel test was compared to the standardized DCB test. Unstable crack propagation (stick-slip) was observed in both testing

  13. 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.

  14. 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

  15. Vertically aligned TiO2 nanorods-woven carbon fiber for reinforcement of both mechanical and anti-wear properties in resin composite

    Science.gov (United States)

    Fei, Jie; Zhang, Chao; Luo, Dan; Cui, Yali; Li, Hejun; Lu, Zhaoqing; Huang, Jianfeng

    2018-03-01

    A series of TiO2 nanorods were successfully grown on woven carbon fiber by hydrothermal method to reinforce the resin composite. The TiO2 nanorods improved the mechanical interlocking among woven carbon fibers and resin matrix, resulting in better fibers/resin interfacial bonding. Compared with desized-woven carbon fiber, the uniform TiO2 nanorods array resulted in an improvement of 84.3% and 73.9% in the tensile and flexural strength of the composite. However, the disorderly TiO2 nanorods on woven carbon fiber leaded to an insignificant promotion of the mechanical strength. The enhanced performance of well-proportioned TiO2 nanorods-woven carbon fiber was also reflected in the nearly 56% decrease of wear rate, comparing to traditional woven carbon fiber reinforced composite.

  16. The study of stiffness modulus values for AC-WC pavement

    Science.gov (United States)

    Lubis, AS; Muis, Z. A.; Iskandar, T. D.

    2018-02-01

    One of the parameters of the asphalt mixture in order for the strength and durability to be achieved as required is the stress-and-strain showing the stiffness of a material. Stiffness modulus is a very necessary factor that will affect the performance of asphalt pavements. If the stiffness modulus value decreases there will be a cause of aging asphalt pavement crack easily when receiving a heavy load. The high stiffness modulus asphalt concrete causes more stiff and resistant to bending. The stiffness modulus value of an asphalt mixture material can be obtained from the theoretical (indirect methods) and laboratory test results (direct methods). For the indirect methods used Brown & Brunton method, and Shell Bitumen method; while for the direct methods used the UMATTA tool. This study aims to determine stiffness modulus values for AC-WC pavement. The tests were conducted in laboratory that used 3 methods, i.e. Brown & Brunton Method, Shell Bitumen Method and Marshall Test as a substitute tool for the UMATTA tool. Hotmix asphalt made from type AC-WC with pen 60/70 using a mixture of optimum bitumen content was 5.84% with a standard temperature variation was 60°C and several variations of temperature that were 30, 40, 50, 70 and 80°C. The stiffness modulus value results obtained from Brown & Brunton Method, Shell Bitumen Method and Marshall Test which were 1374,93 Mpa, 235,45 Mpa dan 254,96 Mpa. The stiffness modulus value decreases with increasing temperature of the concrete asphalt. The stiffness modulus value from the Bitumen Shell method and the Marshall Test has a relatively similar value.The stiffness modulus value from the Brown & Brunton method is greater than the Bitumen Shell method and the Marshall Test, but can not measure the stiffness modulus value at temperature above 80°C.

  17. 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.

  18. 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

  19. Evaluation on mechanical properties of woven aloevera and sisal ...

    Indian Academy of Sciences (India)

    Administrator

    behaviour of this composite is observed to be more effec- tive.5 The fibre .... been made to study the mechanical properties of woven aloevera and ... In each case, minimum of ... tions in automotive components, structures and consumer goods.

  20. 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.

  1. Relationship between low-temperature boson heat capacity peak and high-temperature shear modulus relaxation in a metallic glass

    International Nuclear Information System (INIS)

    Vasiliev, A. N.; Voloshok, T. N.; Granato, A. V.; Joncich, D. M.; Mitrofanov, Yu. P.; Khonik, V. A.

    2009-01-01

    Low-temperature (2 K≤T≤350 K) heat capacity and room-temperature shear modulus measurements (ν=1.4 MHz) have been performed on bulk Pd 41.25 Cu 41.25 P 17.5 in the initial glassy, relaxed glassy, and crystallized states. It has been found that the height of the low-temperature Boson heat capacity peak strongly correlates with the changes in the shear modulus upon high-temperature annealing. It is this behavior that was earlier predicted by the interstitialcy theory, according to which dumbbell interstitialcy defects are responsible for a number of thermodynamic and kinetic properties of crystalline, (supercooled) liquid, and solid glassy states.

  2. Process for preparing polyolefin gel articles as well as for preparing herefrom articles having a high tensile strength and modulus

    NARCIS (Netherlands)

    1990-01-01

    A process is described for the preparation of highly stretchable high-molecular weight polyolefin gel articles and polyolefin gel articles prepared therefrom having combined high tensile strength and high modulus, wherein an initial shaped article of the polyolefin is exposed to or contacted with a

  3. Effects of Weave Styles and Crimp Gradients on Damage Tolerance and Energy-Absorption Capacities of Woven Kevlar/Epoxy Composites

    Science.gov (United States)

    2015-09-01

    Capacities of Woven Kevlar /Epoxy Composites Paul V. Cavallaro Ranges, Engineering, and Analysis Department NEWPORT Naval Undersea Warfare Center Division...the Kevlar woven fabrics and technical data and to Core Composites Inc. for fabricating the composite laminates. Reviewed and Approved: 1...Effects of Weave Styles and Crimp Gradients on Damage Tolerance and Energy-Absorption Capacities of Woven Kevlar /Epoxy Composites 5a. CONTRACT NUMBER 5b

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

    KAUST Repository

    Oh, Jae Eun; Clark, Simon M.; Wenk, Hans-Rudolf; Monteiro, Paulo J.M.

    2012-01-01

    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.

  5. 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.

  6. An enhanced method to determine the Young’s modulus of technical single fibres by means of high resolution digital image correlation

    Science.gov (United States)

    Huether, Jonas; Rupp, Peter; Kohlschreiber, Ina; André Weidenmann, Kay

    2018-04-01

    To obtain mechanical tensile properties of materials it is customary to equip the specimen directly with a device to measure strain and Young’s modulus correctly and only within the measuring length defined by the standards. Whereas a variety of tools such as extensometers, strain gauges and optical systems are available for specimens on coupon level, no market-ready tools to measure strains of single fibres during single fibre tensile tests are available. Although there is a standard for single fibre testing, the procedures described there are only capable of measuring strains of the whole testing setup rather than the strain of the fibre. Without a direct strain measurement on the specimen, the compliance of the test rig itself influences the determination of the Young’s modulus. This work aims to fill this gap by establishing an enhanced method to measure strains directly on the tested fibre and thus provide accurate values for Young’s modulus. It is demonstrated that by applying and then optically tracking fluorescing polymeric beads on single glass fibres, Young’s modulus is determined directly and with high repeatability, without a need to measure at different measuring lengths or compensating for the system compliance. Employing this method to glass fibres, a Young’s modulus of approximately 82.5 GPa was determined, which is in the range of values obtained by applying a conventional procedure. This enhanced measuring technology achieves high accuracy and repeatability while reducing scatter of the data. It was demonstrated that the fluorescing beads do not affect the fibre properties.

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

    International Nuclear Information System (INIS)

    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.

    2013-01-01

    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

  8. 75 FR 46911 - Certain Woven Electric Blankets from the People's Republic of China: Amended Final Determination...

    Science.gov (United States)

    2010-08-04

    ... Blankets from the People's Republic of China: Amended Final Determination of Sales at Less Than Fair Value... than fair value (``LTFV'') in the antidumping investigation of certain woven electric blankets (``woven... From the People's Republic of China: Final Determination of Sales at Less Than Fair Value, 75 FR 38459...

  9. Elastic modulus and internal friction of SOFC electrolytes at high temperatures under controlled atmospheres

    Science.gov (United States)

    Kushi, Takuto; Sato, Kazuhisa; Unemoto, Atsushi; Hashimoto, Shinichi; Amezawa, Koji; Kawada, Tatsuya

    2011-10-01

    Mechanical properties such as Young's modulus, shear modulus, Poisson's ratio and internal friction of conventional electrolyte materials for solid oxide fuel cells, Zr0.85Y0.15 O1.93 (YSZ), Zr0.82Sc0.18O1.91 (ScSZ), Zr0.81Sc0.18Ce0.01O2-δ (ScCeSZ), Ce0.9Gd0.1O2-δ (GDC), La0.8Sr0.2Ga0.8Mg0.15Co0.05O3-δ (LSGMC), La0.8Sr0.2Ga0.8Mg0.2O3-δ (LSGM), were evaluated by a resonance method at temperatures from room temperature to 1273 K in various oxygen partial pressures. The Young's modulus of GDC gradually decreased with increasing temperature in oxidizing conditions. The Young's moduli of the series of zirconia and lanthanum gallate based materials drastically decreased in an intermediate temperature range and increased slightly with increasing temperature at higher temperatures. The Young's modulus of GDC considerably decreased above 823 K in reducing atmospheres in response to the change of oxygen nonstoichiometry. However, temperature dependences of the Young's moduli of ScCeSZ and LSGMC in reducing atmospheres did not show any significant differences with those in oxidizing atmospheres.

  10. 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 re...

  11. 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...

  12. The Young's modulus of high-aspect-ratio carbon/carbon nanotube composite microcantilevers by experimental and modeling validation

    International Nuclear Information System (INIS)

    Zhou, Peng; Yang, Xiao; He, Liang; Hao, Zhimeng; Luo, Wen; Xiong, Biao; Xu, Xu; Niu, Chaojiang; Yan, Mengyu; Mai, Liqiang

    2015-01-01

    This paper reports the Young's modulus of a carbon nanotube (CNT)-reinforced carbon/CNT (C/CNT) composite microcantilevers measured by laser Doppler vibrometer and validated by finite element method. Also, the microfabrication process of the high-aspect-ratio C/CNT microcantilever arrays based on silicon micromolding and pyrolysis is presented in detail. With the in-plane natural resonant frequencies of the microcantilevers measured by a laser Doppler vibrometer, a single degree of freedom (SDoF) model based on Euler-Bernoulli (E-B) beam theory is used to calculate the Young's modulus of this composite. To figure out whether this SDoF model can be applied to these composite microcantilevers, the finite element (FE) simulation of these microcantilevers was performed. The Young's modulus of C/CNT composite microcantilevers fabricated by the pyrolysis process at 600 °C is 9391 MPa, and a good agreement between the results from experiments and FE simulation is obtained

  13. 77 FR 31182 - Final Withdrawal of Regulations Pertaining to Imports of Cotton Woven Fabric and Short Supply...

    Science.gov (United States)

    2012-05-25

    ... Woven Fabric and Short Supply Procedures AGENCY: Import Administration, International Trade... final rule withdrawing regulations pertaining to imports of cotton woven fabric and short supply..., and the short supply voluntary restraints have not affected U.S. trade for over 19 years. The removal...

  14. Ballistic Impact Resistance of Plain Woven Kenaf/Aramid Reinforced Polyvinyl Butyral Laminated Hybrid Composite

    Directory of Open Access Journals (Sweden)

    Suhad D. Salman

    2016-07-01

    Full Text Available Traditionally, the helmet shell has been used to provide protection against head injuries and fatalities caused by ballistic threats. In this study, because of the high cost of aramid fibres and the necessity for environmentally friendly alternatives, a portion of aramid was replaced with plain woven kenaf fibre, with different arrangements and thicknesses, without jeopardising the requirements demanded by U.S. Army helmet specifications. Furthermore, novel helmets were produced and tested to reduce the dependency on the ballistic resistance components. Their use could lead to helmets that are less costly and more easily available than conventional helmet armour. The hybrid materials subjected to ballistic tests were composed of 19 layers and were fabricated by the hot press technique using different numbers and configurations of plain woven kenaf and aramid layers. In the case of ballistic performance tests, a positive effect was found for the hybridisation of kenaf and aramid laminated composites.

  15. 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.

  16. 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.

  17. Resilient modulus of black cotton soil

    Directory of Open Access Journals (Sweden)

    K.H. Mamatha

    2017-03-01

    Full Text Available Resilient modulus (MR values of pavement layers are the basic input parameters for the design of pavements with multiple layers in the current mechanistic empirical pavement design guidelines. As the laboratory determination of resilient modulus is costly, time consuming and cumbersome, several empirical models are developed for the prediction of resilient modulus for different regions of the world based on the database of resilient modulus values of local soils. For use of these relationships there is a need to verify the suitability of these models for local conditions. Expansive clay called black cotton soil (BC soil is found in several parts of India and is characterized by low strength and high compressibility. This soil shows swell – shrink behaviour upon wetting and drying and are problematic. The BC soil shows collapse behaviour on soaking and therefore the strength of the soil needs to be improved. Additive stabilization is found to be very effective in stabilizing black cotton soils and generally lime is used to improve the strength and durability of the black cotton soil. In this paper, the results of repeated load tests on black cotton soil samples for the determination of MR under soaked and unsoaked conditions at a relative compaction levels of 100% and 95% of both standard and modified proctor conditions are reported. The results indicate that the black cotton soil fails to meet the density requirement of the subgrade soil and shows collapse behaviour under soaked condition. To overcome this, lime is added as an additive to improve the strength of black cotton soil and repeated load tests were performed as per AASHTO T 307 - 99 for MR determination. The results have shown that the samples are stable under modified proctor condition with MR values ranging from 36 MPa to 388 MPa for a lime content of 2.5% and curing period ranging from 7 to 28 days. Also, it is observed that, the CBR based resilient modulus is not in agreement

  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 (p<0.001), resilience (p<0.05), work of fracture (p<0.001), strain energy release (p<0.05), critical stress intensity factor (p<0.001) and strain (p<0.001).

  19. 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....... Data for a large selection of metallic glasses are compared to three different versions of the shoving model. The original shear-modulus based version shows a slight correlation to the Poisson ratio, which is eliminated by the energy-landscape formulation of the model in which the bulk modulus plays...

  20. 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...

  1. Modulus D-term inflation

    Science.gov (United States)

    Kadota, Kenji; Kobayashi, Tatsuo; Saga, Ikumi; Sumita, Keigo

    2018-04-01

    We propose a new model of single-field D-term inflation in supergravity, where the inflation is driven by a single modulus field which transforms non-linearly under the U(1) gauge symmetry. One of the notable features of our modulus D-term inflation scenario is that the global U(1) remains unbroken in the vacuum and hence our model is not plagued by the cosmic string problem which can exclude most of the conventional D-term inflation models proposed so far due to the CMB observations.

  2. Numerical study of the heat transfer in wound woven wire matrix of a Stirling regenerator

    International Nuclear Information System (INIS)

    Costa, S.C.; Barrutia, Harritz; Esnaola, Jon Ander; Tutar, Mustafa

    2014-01-01

    Highlights: • A correlation equation to characterize regenerator heat transfer is proposed. • Proposed correlation can be used as a effective tool to optimize the heat transfer. • Thermal efficiency can be maximized by optimizing Stirling regenerator heat transfer. • The wound woven wire matrix provides lower Nusselt numbers compared to stacked. • The developed correlation can be used for Reynolds number range from 4 to 400. - Abstract: Nusselt number correlation equations are numerically derived by characterizing the heat transfer phenomena through porous medium of both stacked and wound woven wire matrices of a Stirling engine regenerator over a specified range of Reynolds number, diameter and porosity. A finite volume method (FVM) based numerical approach is proposed and validated against well known experimentally obtained empirical correlations for a random stacking woven wire matrix, the most widely used due to fabrication issues, for Reynolds number up to 400. The results show that the numerically derived correlation equation corresponds well with the experimentally obtained correlations with less than 6% deviation with the exception of low Reynolds numbers. Once the numerical approach is validated, the study is further extended to characterize the heat transfer in a wound woven wire matrix model for a diameter range from 0.08 to 0.11 mm and a porosity range from 0.60 to 0.68 within the same Reynolds number range. Thus, the new correlation equations are numerically derived for different flow configurations of the Stirling engine regenerator. It is believed that the developed correlations can be applied with confidence as a cost effective solution to characterize and hence to optimize stacked and wound woven wire Stirling regenerator in the above specified ranges

  3. The influence of FLiNaK salt impregnation on the mechanical properties of a 2D woven C/C composite

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Dongsheng, E-mail: zhangdongsheng@sinap.ac.cn; Xia, Huihao; Yang, Xinmei, E-mail: yangxinmei@sinap.ac.cn; Feng, Shanglei; Song, Jinliang; Zhou, Xingtai

    2017-03-15

    Impregnating of molten LiF-NaF-KF salt (LiF-NaF-KF: 46.5–11.5-42 mol%, FLiNaK) into a 2D woven C/C composite was performed at 650 °C under different pressure. The weight gain and mechanical properties change of the 2D woven C/C composite after FLiNaK salt impregnation were measured. The FLiNaK salt distribution into the 2D woven C/C composite was observed by X-ray computed tomography (X-ray CT) and scanning electron microscopy. The results showed that the weight gain of the 2D woven C/C composite increased with increasing impregnating pressure. In X-ray CT images, FLiNaK salt was distributed into the open pores and fissures among fiber bundles and neighboring plies. The interlaminar shear strength, compressive strength, and flexural strength of the 2D woven C/C composite increased with the increase of weight gain. The influence of FLiNaK salt impregnation on the mechanical properties was attributed to the coupling effect of re-densification of FLiNaK salt impregnation and residual stress formed in 2D woven C/C composite. - Highlights: • FLiNaK salt was distributed into the open pores and fissures among fiber bundles. • The mechanical properties of the 2D woven C/C composite increased with the increase of weight gain. • The influence of FLiNaK was attributed to the re-densification of FLiNaK salt and residual stress.

  4. Young’s modulus of multi-layer microcantilevers

    Directory of Open Access Journals (Sweden)

    Zhikang Deng

    2017-12-01

    Full Text Available A theoretical model for calculating the Young’s modulus of multi-layer microcantilevers with a coating is proposed, and validated by a three-dimensional (3D finite element (FE model using ANSYS parametric design language (APDL and atomic force microscopy (AFM characterization. Compared with typical theoretical models (Rayleigh-Ritz model, Euler-Bernoulli (E-B beam model and spring mass model, the proposed theoretical model can obtain Young’s modulus of multi-layer microcantilevers more precisely. Also, the influences of coating’s geometric dimensions on Young’s modulus and resonant frequency of microcantilevers are discussed. The thickness of coating has a great influence on Young’s modulus and resonant frequency of multi-layer microcantilevers, and the coating should be considered to calculate Young’s modulus more precisely, especially when fairly thicker coating is employed.

  5. The elastic modulus of alumina-zirconia composite using through transmission ultrasonics

    International Nuclear Information System (INIS)

    Tan, K.S.; Hing, P.

    1996-01-01

    The elastic modulus of unstabilized Al 2 O 3 -ZrO 2 composites is determined from ultrasonic velocities and density measurements. The dynamic elastic modulus and the density of the green unstabilized Al 2 O 3 -ZrO 2 follow the rule of mixture. However, the elastic modulus and density of the sintered Al 2 O 3 -ZrO 2 do not follow the rule of mixture. The elastic modulus and diametrical compressive fracture stress of the Al 2 O 3 can be enhanced by (1) a high green (before sintering) compacting pressure and (2) addition of about 3wt% unstabilized ZrO 2 at a sintering time of two hours at 1550 degC. The ZrO 2 is found to improve the bulk density of the composite by a reduction in the porosity. This improves the elastic modulus and the diametrical compressive fracture stress. The thermal expansion on cooling with > 25wt% ZrO 2 in the Al 2 O 3 matrix has also been established. (author)

  6. Determination of Young's Modulus of Graphene by Raman Spectroscopy

    Science.gov (United States)

    Lee, Jae-Ung; Yoon, Duhee; Cheong, Hyeonsik

    2012-02-01

    The mechanical properties of graphene are interesting research subjects because its Young's modulus and strength are extremely high. Values of ˜1 TPa for the Young's modulus have been reported [Lee et al. Science, 321, 385 (2008), Koenig et al. Nat. Nanotech. 6, 543 (2011)]. We made a graphene sample on a SiO2/Si substrate with closed-bottom holes by mechanical exfoliation. A pressure difference across the graphene membrane was applied by putting the sample in a vacuum chamber. This pressure difference makes the graphene membrane bulge upward like a balloon. By measuring the shifts of the Raman G and 2D bands, we estimated the amount of strain on the graphene membrane. By comparing the strain estimated from the Raman measurements with numerical simulations based on the finite element method, we obtained the Young's modulus of graphene.

  7. Experimental and Numerical Simulation Analysis of Typical Carbon Woven Fabric/Epoxy Laminates Subjected to Lightning Strike

    Science.gov (United States)

    Yin, J. J.; Chang, F.; Li, S. L.; Yao, X. L.; Sun, J. R.; Xiao, Y.

    2017-12-01

    To clarify the evolution of damage for typical carbon woven fabric/epoxy laminates exposed to lightning strike, artificial lightning testing on carbon woven fabric/epoxy laminates were conducted, damage was assessed using visual inspection and damage peeling approaches. Relationships between damage size and action integral were also elucidated. Results showed that damage appearance of carbon woven fabric/epoxy laminate presents circular distribution, and center of the circle located at the lightning attachment point approximately, there exist no damage projected area dislocations for different layers, visual damage territory represents maximum damage scope; visible damage can be categorized into five modes: resin ablation, fiber fracture and sublimation, delamination, ablation scallops and block-shaped ply-lift; delamination damage due to resin pyrolysis and internal pressure exist obvious distinguish; project area of total damage is linear with action integral for the same type specimens, that of resin ablation damage is linear with action integral, but no correlation with specimen type, for all specimens, damage depth is linear with logarithm of action integral. The coupled thermal-electrical model constructed is capable to simulate the ablation damage for carbon woven fabric/epoxy laminates exposed to simulated lightning current through experimental verification.

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

    Science.gov (United States)

    Katogi, Hideaki; Takemura, Kenichi; Akiyama, Motoki

    2016-07-14

    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.

  9. 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.

  10. On the common modulus attack into the LUC4,6 cryptosystem

    Science.gov (United States)

    Wong, Tze Jin; Said, Mohd Rushdan Md; Othman, Mohamed; Koo, Lee Feng

    2015-05-01

    The LUC4,6 cryptosystem is a system analogy with RSA cryptosystem and extended from LUC and LUC3 cryptosystems. The process of encryption and decryption are derived from the fourth order linear recurrence sequence and based on Lucas function. This paper reports an investigation into the common modulus attack on the LUC4,6 cryptosystem. In general, the common modulus attack will be succeeded if the sender sends the plaintext to two users used same RSA-modulus and both of encryption keys of them are relatively prime to each other. However, based on the characteristics of high order Lucas sequence, the LUC4,6 cryptosystem is unattackable

  11. 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.

  12. Structure and bulk modulus of Ln-doped UO{sub 2} (Ln = La, Nd) at high pressure

    Energy Technology Data Exchange (ETDEWEB)

    Rittman, Dylan R., E-mail: drittman@stanford.edu [Department of Geological Sciences, Stanford University, Stanford, CA 94305 (United States); Park, Sulgiye; Tracy, Cameron L. [Department of Geological Sciences, Stanford University, Stanford, CA 94305 (United States); Zhang, Lei [Peter A. Rock Thermochemistry Laboratory and NEAT ORU, University of California Davis, Davis, CA 95616 (United States); Department of Chemical Engineering and Materials Science, University of California Davis, Davis, CA 95616 (United States); Palomares, Raul I.; Lang, Maik [Department of Nuclear Engineering, University of Tennessee, Knoxville, TN 37996 (United States); Navrotsky, Alexandra [Peter A. Rock Thermochemistry Laboratory and NEAT ORU, University of California Davis, Davis, CA 95616 (United States); Department of Chemical Engineering and Materials Science, University of California Davis, Davis, CA 95616 (United States); Mao, Wendy L. [Department of Geological Sciences, Stanford University, Stanford, CA 94305 (United States); Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA 94025 (United States); Ewing, Rodney C. [Department of Geological Sciences, Stanford University, Stanford, CA 94305 (United States)

    2017-07-15

    The structure of lanthanide-doped uranium dioxide, Ln{sub x}U{sub 1-x}O{sub 2-0.5x+y} (Ln = La, Nd), was investigated at pressures up to ∼50–55 GPa. Samples were synthesized with different lanthanides at different concentrations (x ∼ 0.2 and 0.5), and all were slightly hyperstoichiometric (y ∼ 0.25–0.4). In situ high-pressure synchrotron X-ray diffraction was used to investigate their high-pressure phase behavior and determine their bulk moduli. All samples underwent a fluorite-to-cotunnite phase transformation with increasing pressure. The pressure of the phase transformation increased with increasing hyperstoichiometry, which is consistent with results from previous computational simulations. Bulk moduli are inversely proportional to both the ionic radius of the lanthanide and its concentration, as quantified using a weighted cationic radius ratio. This trend was found to be consistent with the behavior of other elastic properties measured for Ln-doped UO{sub 2}, such as Young's modulus. - Highlights: •Ln-doped UO{sub 2} transforms from fluorite to cotunnite at high pressure. •Transition pressure increases with increasing hyperstoichiometry. •Bulk modulus decreases with increasing Ln-dopant radius and concentration.

  13. Evaluation of the use of polymer modified bitumen in the production of high modulus asphalt for heavily-trafficked roads

    CSIR Research Space (South Africa)

    Komba, Julius J

    2015-05-01

    Full Text Available Enrobé à Module Élevé (EME) technology, a High Modulus Asphalt (HiMA), has been introduced to South Africa to provide an optimum solution for the design and construction of heavily trafficked roads. Implementation of EME technology in South Africa...

  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. Determining the complex modulus of alginate irreversible hydrocolloid dental material.

    Science.gov (United States)

    King, Shalinie; See, Howard; Thomas, Graham; Swain, Michael

    2008-11-01

    The aim of the study is to investigate the visco-elastic response of an alginate irreversible hydrocolloid dental impression material during setting. A novel squeeze film Micro-Fourier Rheometer (MFR, GBC Scientific Equipment, Australia) was used to determine the complex modulus of an alginate irreversible hydrocolloid dental impression material (Algident, ISO 1563 Class A Type 1, Dentalfarm Australia Pty. Ltd.) during setting after mixing. Data was collected every 30s for 10 min in one study and every 10 min for a total of 60 min in another study. A high level of repeatability was observed. The results indicate that the MFR is capable of recording the complex shear modulus of alginate irreversible hydrocolloid for 60 min from the start of mixing and to simultaneously report the changing visco-elastic parameters at all frequencies between 1 Hz and 100 Hz. The storage modulus shows a dramatic increase to 370% of its starting value after 6 min and then reduces to 55% after 60 min. The loss modulus increases to a maximum of 175% of its starting value after 10 min and then reduces to 94% after 60 min. The MFR enables the changes in the complex modulus through the complete setting process to be followed. It is anticipated this approach may provide a better method to compare the visco-elastic properties of impression materials and assist with identification of optimum types for different clinical requirements. The high stiffness of the instrument and the use of band-limited pseudo-random noise as the input signal are the main advantages of this technique over conventional rheometers for determining the changes in alginate visco-elasticity.

  16. 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.

  17. Long-term follow-up of aneurysms treated electively with woven stent-assisted coiling.

    Science.gov (United States)

    Cheung, Nicholas K; Chiu, Albert Hy; Cheung, Andrew K; Wenderoth, Jason D

    2017-12-15

    Preliminary short-term results for stent-assisted coil embolization (SACE) using woven/braided stents have been promising. However, evidence supporting mid- to long-term efficacy and durability is lacking. To report the long-term results for the durability of elective intracranial aneurysms treated with woven stents. Between May 2012 and May 2015, 98 consecutive patients with 103 aneurysms underwent elective woven SACE across three Australian neurovascular centres. All patients had immediate, 6- and 18-month clinical and radiological follow-up. Radiological assessment was performed with modified Raymond-Roy occlusion scores based on angiography results, while clinical assessment was based on the modified Rankin Scale. Six-month follow-up was available in 100 aneurysms, and an 18-month follow-up in 97 aneurysms. Total occlusion rates of 82% were achieved at inception, 82% at 6 months, and 90% at 18 months. Satisfactory occlusion with small neck remnants was present in 17% at inception, 16% at 6 months, and 9% at 18 months. Good neurological outcomes were achieved in 95% at 18 months. Intraprocedural thromboembolic events were recorded in 3% and delayed events in 1% (all in patients taking clopidogrel). Aneurysm recurrence occurred in one patient (1%). Technical complications occurred in 5%. The total complication rate was 10%. Woven SACE is safe, efficacious, and durable at long-term 18-month follow-up, with very low recurrence and re-treatment rates. Preliminary results appear better than those for traditional laser-cut stents. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  18. 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.

  19. Static and Dynamic Behavior of High Modulus Hybrid Boron/Glass/Aluminum Fiber Metal Laminates

    Science.gov (United States)

    Yeh, Po-Ching

    2011-12-01

    This dissertation presents the investigation of a newly developed hybrid fiber metal laminates (FMLs) which contains commingled boron fibers, glass fibers, and 2024-T3 aluminum sheets. Two types of hybrid boron/glass/aluminum FMLs are developed. The first, type I hybrid FMLs, contained a layer of boron fiber prepreg in between two layers of S2-glass fiber prepreg, sandwiched by two aluminum alloy 2024-T3 sheets. The second, type II hybrid FMLs, contained three layer of commingled hybrid boron/glass fiber prepreg layers, sandwiched by two aluminum alloy 2024-T3 sheets. The mechanical behavior and deformation characteristics including blunt notch strength, bearing strength and fatigue behavior of these two types of hybrid boron/glass/aluminum FMLs were investigated. Compared to traditional S2-glass fiber reinforced aluminum laminates (GLARE), the newly developed hybrid boron/glass/aluminum fiber metal laminates possess high modulus, high yielding stress, and good blunt notch properties. From the bearing test result, the hybrid boron/glass/aluminum fiber metal laminates showed outstanding bearing strength. The high fiber volume fraction of boron fibers in type II laminates lead to a higher bearing strength compared to both type I laminates and traditional GLARE. Both types of hybrid FMLs have improved fatigue crack initiation lives and excellent fatigue crack propagation resistance compared to traditional GLARE. The incorporation of the boron fibers improved the Young's modulus of the composite layer in FMLs, which in turn, improved the fatigue crack initiation life and crack propagation rates of the aluminum sheets. Moreover, a finite element model was established to predict and verify the properties of hybrid boron/glass/aluminum FMLs. The simulated results showed good agreement with the experimental results.

  20. Thermal expansivity and bulk modulus of ZnO with NaCl-type cubic structure at high pressures and temperatures

    International Nuclear Information System (INIS)

    Sun Xiaowei; Liu Zijiang; Chen Qifeng; Chu Yandong; Wang Chengwei

    2006-01-01

    The thermal expansivity and bulk modulus of ZnO with NaCl-type cubic structure were estimated by using the constant temperature and pressure molecular dynamics technique with effective pair potentials which consist of the Coulomb, dispersion, and repulsion interaction at high pressures and temperatures. It is shown that the calculated thermodynamic parameters including linear thermal expansion coefficient, isothermal bulk modulus and its pressure derivative are in good agreement with the available experimental data and the latest theoretical results. At an extended pressure and temperature ranges, linear thermal expansion coefficient and isothermal bulk modus have also been predicted. The thermodynamic properties of ZnO with NaCl-type cubic structure are summarized in the pressure 0-150 GPa ranges and the temperature up to 3000 K

  1. Small compression modulus of the flux line lattice and large density fluctuations at high fields may explain peak effect

    International Nuclear Information System (INIS)

    Brandt, E.H.

    1976-01-01

    The elastic properties of the flux line lattice in Type II superconductors as calculated from the Ginsburg-Landau theory are discussed. They are non-local on a length scale much larger than the flux line distance and divergent at Hsub(c2). The compression modulus may become much smaller than its long-wavelength limit, B 2 /4π, and if the deformation is not homogeneous, at Hsub(c2) the modulus vanishes as (Hsub(c2) - B) 2 . At arbitrary induction the compression modulus of strain waves with wavelengths of several flux line distances is of the order of the (small) shear modulus. (author)

  2. Thermal compression modulus of polarized neutron matter

    International Nuclear Information System (INIS)

    Abd-Alla, M.

    1990-05-01

    We applied the equation of state for pure polarized neutron matter at finite temperature, calculated previously, to calculate the compression modulus. The compression modulus of pure neutron matter at zero temperature is very large and reflects the stiffness of the equation of state. It has a little temperature dependence. Introducing the spin excess parameter in the equation of state calculations is important because it has a significant effect on the compression modulus. (author). 25 refs, 2 tabs

  3. In-situ growth of high-performance all-solid-state electrode for flexible supercapacitors based on carbon woven fabric/ polyaniline/ graphene composite

    Science.gov (United States)

    Lin, Yingxi; Zhang, Haiyan; Deng, Wentao; Zhang, Danfeng; Li, Na; Wu, Qibai; He, Chunhua

    2018-04-01

    For the development of wearable electronic devices, it is crucial to develop energy storage components combining high-capacity and flexibility. Herein, an all-solid-state supercapacitor is prepared through an in-situ "growth and wrapping" method. The electrode contains polyaniline deposited on a carbon woven fabric and wrapped with a graphene-based envelop. The hybrid electrode exhibits excellent mechanical and electrochemical performance. The optimized few layer graphene wrapping layer provides for a conductive network, which effectively enhances the cycling stability as 88.9% of the starting capacitance is maintained after 5000 charge/discharge cycles. Furthermore, the assembled device delivers a high areal capacity (of 790 F cm-2) at the current density of 1 A cm-2, a high areal energy (28.21 uWh cm-2) at the power densities of 0.12 mW cm-2 and shows no significant decrease in the performance with a bending angle of 180°. This unique flexible supercapacitor thus exhibits great potential for wearable electronics.

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

    International Nuclear Information System (INIS)

    Chen, X.; Yao, L.; Xue, J.; Zhao, D.; Lan, Y.; Qian, X.; Wang, C.X.; Qiu, Y.

    2008-01-01

    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

  5. 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.

  6. Dynamic modulus of nanosilica modified porous asphalt

    Science.gov (United States)

    Arshad, A. K.; Masri, K. A.; Ahmad, J.; Samsudin, M. S.

    2017-11-01

    Porous asphalt (PA) is a flexible pavement layer with high interconnected air void contents and constructed using open-graded aggregates. Due to high temperature environment and increased traffic volume in Malaysia, PA may have deficiencies particularly in rutting and stiffness of the mix. A possible way to improve these deficiencies is to improve the asphalt binder used. Binder is normally modified using polymer materials to improve its properties. However, nanotechnology presently is being gradually used for asphalt modification. Nanosilica (NS), a byproduct of rice husk and palm oil fuel ash is used as additive in this study. The aim of this study is to enhance the rutting resistance and stiffness performance of PA using NS. This study focused on the performance of PA in terms of dynamic modulus with the addition of NS modified binder to produce better and more durable PA. From the result of Dynamic SPT Test, it shows that the addition of NS was capable in enhancing the stiffness and rutting resistance of PA. The addition of NS also increase the dynamic modulus value of PA by 50%.

  7. Theory of thermal expansivity and bulk modulus

    International Nuclear Information System (INIS)

    Kumar, Munish

    2005-01-01

    The expression for thermal expansivity and bulk modulus, claimed by Shanker et al. to be new [Physica B 233 (1977) 78; 245 (1998) 190; J. Phys. Chem. Solids 59 (1998) 197] are compared with the theory of high pressure-high temperature reported by Kumar and coworkers. It is concluded that the Shanker formulation and the relations based on this are equal to the approach of Kumar et al. up to second order

  8. In situ determination of a rock mass modulus using a high resolution tiltmeter

    Energy Technology Data Exchange (ETDEWEB)

    Saleh, B.; Husein Malkawi, A.I. [University of Jordan, Amman (Jordan); Blum, P.A. [Universite Pierre et Marie Curie, 75 - Paris (France)

    1996-04-01

    A very sensitive, compact tiltmeter made of melted silica, developed for the measurement of small deformations of various civil engineering structures, was described. The instrument is capable of giving a continuous record and was used to establish a new approach to directly evaluating the in situ average elastic rock mass modulus. Such information is important in decision making during the design stages of large civil engineering works, such as dams, nuclear plant facilities, and underground structures. Five tiltmeters were installed on the facades of the Louvre in Paris to study the deformation induced by internal structural work and by the impact of the Paris metro traffic movement. The data was used to determine displacement using the Boussinesq equation. Results were consistent with typical elastic rock-mass modulus for the rock found in the museum`s foundations. 13 refs., 1 tab., 10 figs.

  9. A Two-Step Methodology to Study the Influence of Aggregation/Agglomeration of Nanoparticles on Young's Modulus of Polymer Nanocomposites

    Science.gov (United States)

    Ma, Xinyue; Zare, Yasser; Rhee, Kyong Yop

    2017-12-01

    A two-step technique based on micromechanical models is suggested to determine the influence of aggregated/agglomerated nanoparticles on Young's modulus of polymer nanocomposites. The nanocomposite is assumed to include nanoparticle aggregation/agglomeration and effective matrix phases. This method is examined for different samples, and the effects of important parameters on the modulus are investigated. Moreover, the highest and the lowest levels of predicted modulus are calculated based on the current methodology. The suggested technique can correctly predict Young's modulus for the samples assuming the aggregation/agglomeration of nanoparticles. Additionally, the aggregation/agglomeration of nanoparticles decreases Young's modulus of polymer nanocomposites. It is demonstrated that the high modulus of nanoparticles is not sufficient to obtain a high modulus in nanocomposites, and the surface chemistry of components should be adjusted to prevent aggregation/agglomeration and to disperse nano-sized particles in the polymer matrix.

  10. Textile electrodes woven by carbon nanotube-graphene hybrid fibers for flexible electrochemical capacitors.

    Science.gov (United States)

    Cheng, Huhu; Dong, Zelin; Hu, Chuangang; Zhao, Yang; Hu, Yue; Qu, Liangti; Chen, Nan; Dai, Liming

    2013-04-21

    Functional graphene-based fibers are promising as new types of flexible building blocks for the construction of wearable architectures and devices. Unique one-dimensional (1D) carbon nanotubes (CNTs) and 2D graphene (CNT/G) hybrid fibers with a large surface area and high electrical conductivity have been achieved by pre-intercalating graphene fibers with Fe3O4 nanoparticles for subsequent CVD growth of CNTs. The CNT/G hybrid fibers can be further woven into textile electrodes for the construction of flexible supercapacitors with a high tolerance to the repeated bending cycles. Various other applications, such as catalysis, separation, and adsorption, can be envisioned for the CNT/G hybrid fibers.

  11. 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.

  12. Study of the internal confinement of concrete reinforced (in civil engineering) with woven reinforcement

    Science.gov (United States)

    Dalal, M.; Goumairi, O.; El Malik, A.

    2017-10-01

    Concrete is generally the most used material in the field of construction. Despite its extensive use in structures, it represents some drawbacks related to its properties including its low tensile strength and low ductility. To solve this problem, the use of steel reinforcement in concrete structures is possible. Another possibility is the introduction of different types of continuous fibre / staple in the concrete, such as steel fibres or synthetic fibres, to obtain ″Concretes bundles″. Many types of fibre concrete, which have been developed and for many of them, the gain provided by the fibre was rather low and no significant improvement in tensile strength was really reaching. By cons, the ductility was higher than that of ordinary concrete. The objective of this study is to examine concrete reinforcement by inserting reinforcements woven polyester. These are either woven bidirectional (2D) or three-dimensional woven (3D). So we will report the properties of each type of reinforcement and the influence of the method of weaving on the strength reinforcements and on the strength of concrete in which they are incorporated. Such influence should contribute to improving the sustainability and enhancement of reinforcement

  13. 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 This study explores the dynamic mechanical behavior of woven sisal fabric reinforced natural rubber composites. The influence of chemical modification on the viscoelastic properties has also been determined. Moreover, the effect of frequency...

  14. High Bulk Modulus of Ionic Liquid and Effects on Performance of Hydraulic System

    Directory of Open Access Journals (Sweden)

    Milan Kambic

    2014-01-01

    Full Text Available Over recent years ionic liquids have gained in importance, causing a growing number of scientists and engineers to investigate possible applications for these liquids because of their unique physical and chemical properties. Their outstanding advantages such as nonflammable liquid within a broad liquid range, high thermal, mechanical, and chemical stabilities, low solubility for gases, attractive tribological properties (lubrication, and very low compressibility, and so forth, make them more interesting for applications in mechanical engineering, offering great potential for new innovative processes, and also as a novel hydraulic fluid. This paper focuses on the outstanding compressibility properties of ionic liquid EMIM-EtSO4, a very important physical chemically property when IL is used as a hydraulic fluid. This very low compressibility (respectively, very high Bulk modulus, compared to the classical hydraulic mineral oils or the non-flammable HFDU type of hydraulic fluids, opens up new possibilities regarding its usage within hydraulic systems with increased dynamics, respectively, systems’ dynamic responses.

  15. High bulk modulus of ionic liquid and effects on performance of hydraulic system.

    Science.gov (United States)

    Kambic, Milan; Kalb, Roland; Tasner, Tadej; Lovrec, Darko

    2014-01-01

    Over recent years ionic liquids have gained in importance, causing a growing number of scientists and engineers to investigate possible applications for these liquids because of their unique physical and chemical properties. Their outstanding advantages such as nonflammable liquid within a broad liquid range, high thermal, mechanical, and chemical stabilities, low solubility for gases, attractive tribological properties (lubrication), and very low compressibility, and so forth, make them more interesting for applications in mechanical engineering, offering great potential for new innovative processes, and also as a novel hydraulic fluid. This paper focuses on the outstanding compressibility properties of ionic liquid EMIM-EtSO4, a very important physical chemically property when IL is used as a hydraulic fluid. This very low compressibility (respectively, very high Bulk modulus), compared to the classical hydraulic mineral oils or the non-flammable HFDU type of hydraulic fluids, opens up new possibilities regarding its usage within hydraulic systems with increased dynamics, respectively, systems' dynamic responses.

  16. Analysis and modeling of delamination factor in drilling of woven kenaf fiber reinforced epoxy using Box Behnken experimental design

    Science.gov (United States)

    Suhaily, M.; Che Hassan, C. H.; Jaharah, A. G.; Afifah, M. A.; Nor Khairusshima, M. K.

    2018-01-01

    In this research study, it presents a comprehensive mathematical model for correlating the influences of drilling parameters on the delamination factor during the drilling of woven kenaf fiber reinforced epoxy composite laminates using the Box Behnken experimental design. The purpose of this study is to investigate the influence of drilling parameters such as cutting speed, feed rate and drill sizes on the delamination produced when drilling woven kenaf reinforced epoxy composite using the non-coated HSS drill bits. The damage generated on the woven kenaf reinforced epoxy composite laminates were observed both at the entrance and exit surface during the drilling operation. The experiments were conducted according to the Box Behnken experimental designs.

  17. 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.

  18. Calibration of 3D Woven Preform Design Code for CMC Materials, Phase II

    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...

  19. Influence of substrate modulus on gecko adhesion

    Science.gov (United States)

    Klittich, Mena R.; Wilson, Michael C.; Bernard, Craig; Rodrigo, Rochelle M.; Keith, Austin J.; Niewiarowski, Peter H.; Dhinojwala, Ali

    2017-03-01

    The gecko adhesion system fascinates biologists and materials scientists alike for its strong, reversible, glue-free, dry adhesion. Understanding the adhesion system’s performance on various surfaces can give clues as to gecko behaviour, as well as towards designing synthetic adhesive mimics. Geckos encounter a variety of surfaces in their natural habitats; tropical geckos, such as Gekko gecko, encounter hard, rough tree trunks as well as soft, flexible leaves. While gecko adhesion on hard surfaces has been extensively studied, little work has been done on soft surfaces. Here, we investigate for the first time the influence of macroscale and nanoscale substrate modulus on whole animal adhesion on two different substrates (cellulose acetate and polydimethylsiloxane) in air and find that across 5 orders of magnitude in macroscale modulus, there is no change in adhesion. On the nanoscale, however, gecko adhesion is shown to depend on substrate modulus. This suggests that low surface-layer modulus may inhibit the gecko adhesion system, independent of other influencing factors such as macroscale composite modulus and surface energy. Understanding the limits of gecko adhesion is vital for clarifying adhesive mechanisms and in the design of synthetic adhesives for soft substrates (including for biomedical applications and wearable electronics).

  20. Notched Strength of Woven Fabric Kenaf Composites with Different Fiber Orientations

    Directory of Open Access Journals (Sweden)

    Ahmad Hilton

    2017-01-01

    Full Text Available The awareness of implementing sustainable materials in construction industry is gaining good attention among engineers worldwide. Kenaf fibers are local renewable materials to combine with epoxy polymers matrix in producing lightweight composite materials which may replace imported synthetic fiber composites especially in developing countries. Other benefits of using kenaf fiber composites are relatively cheap, less abrasive and less hazardous during fabrication handling. Current study investigates parametric study on notched strength of woven fabric kenaf composite plates with different fiber orientations and circular hole sizes. Stress concentration occurred at the notch edge promotes to micro-damage events such as matrix cracking and fiber fracture as remote tensile loading applied. Current study showed that 0° fiber orientation gives optimum notched strength, plates with larger fiber tilting than 0° are associated with further strength reduction. Kenaf fibers give an alternative to material designers to opt woven fabric kenaf composites in low and medium load bearing applications.

  1. 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.

  2. 3D ultrasound characterization of woven composites

    Science.gov (United States)

    Tayong, Rostand B.; Mienczakowski, Martin J.; Smith, Robert A.

    2018-04-01

    Recent studies on the Non-Destructive Testing (NDT) of composites for the aerospace industry have led to an understanding of ultrasonic propagation in these materials [1]. Techniques for enhanced ultrasonic imaging of the internal structure of composite laminates containing unidirectional fibers have been proposed and tested in a laboratory environment. For the automotive industry, textile composites are often preferred and widely used. The reason for this is that these types of composites offer good mechanical performance, with resistance to delamination and reduced manufacturing costs. In this study, two models are developed and shown to be suitable to characterize the woven specimen. The first model is a 1D analytical model that makes simplified assumptions and the second is a 3D time-domain Finite Element (FE) model developed [2] for advanced understanding of the woven composite response to an ultrasonic excitation. For each of the proposed models, three parameters are defined and used to analyze the structure behavior. They are the instantaneous amplitude, instantaneous phase and instantaneous frequency. These parameters are employed to track the in-plane fiber orientation and the ply-interface location and for the sentencing of features. Three different specimens with the following weave type: 3D orthogonal, 2D plain and Multilayer stitching were considered and scanned (using a focused ultrasonic transducer) to validate the proposed models. As a preliminary study, the work only focuses on the Orthogonal weave specimen. The results obtained from experimental, analytical and FE modeling, B-scan and C-scan are compared, discussed and presented in terms of the above defined parameters.

  3. Sucrose Treated Carbon Nanotube and Graphene Yarns and Sheets

    Science.gov (United States)

    Sauti, Godfrey (Inventor); Kim, Jae-Woo (Inventor); Siochi, Emilie J. (Inventor); Wise, Kristopher E. (Inventor)

    2017-01-01

    Consolidated carbon nanotube or graphene yarns and woven sheets are consolidated through the formation of a carbon binder formed from the dehydration of sucrose. The resulting materials, on a macro-scale are lightweight and of a high specific modulus and/or strength. Sucrose is relatively inexpensive and readily available, and the process is therefore cost-effective.

  4. Carbon nanotube woven textile photodetector

    Science.gov (United States)

    Zubair, Ahmed; Wang, Xuan; Mirri, Francesca; Tsentalovich, Dmitri E.; Fujimura, Naoki; Suzuki, Daichi; Soundarapandian, Karuppasamy P.; Kawano, Yukio; Pasquali, Matteo; Kono, Junichiro

    2018-01-01

    The increasing interest in mobile and wearable technology demands the enhancement of functionality of clothing through incorporation of sophisticated architectures of multifunctional materials. Flexible electronic and photonic devices based on organic materials have made impressive progress over the past decade, but higher performance, simpler fabrication, and most importantly, compatibility with woven technology are desired. Here we report on the development of a weaved, substrateless, and polarization-sensitive photodetector based on doping-engineered fibers of highly aligned carbon nanotubes. This room-temperature-operating, self-powered detector responds to radiation in an ultrabroad spectral range, from the ultraviolet to the terahertz, through the photothermoelectric effect, with a low noise-equivalent power (a few nW/Hz 1 /2) throughout the range and with a Z T -factor value that is twice as large as that of previously reported carbon nanotube-based photothermoelectric photodetectors. Particularly, we fabricated a ˜1 -m-long device consisting of tens of p+-p- junctions and weaved it into a shirt. This device demonstrated a collective photoresponse of the series-connected junctions under global illumination. The performance of the device did not show any sign of deterioration through 200 bending tests with a bending radius smaller than 100 μ m as well as standard washing and ironing cycles. This unconventional photodetector will find applications in wearable technology that require detection of electromagnetic radiation.

  5. Dielectric and modulus studies of polycrystalline BaZrO3 ceramic

    Science.gov (United States)

    Saini, Deepash S.; Singh, Sunder; Kumar, Anil; Bhattacharya, D.

    2018-05-01

    In the present work, dielectric and modulus studies of polycrystalline BaZrO3 ceramic, prepared by modified combustion method followed by conventional sintering, are investigated over the frequency range of 100 Hz to 106 Hz at different temperatures from 250 to 500 °C in air. The high value of dielectric constant (ɛ' ˜ 103) of BaZrO3 at high temperature and low frequency can be attributed to the Maxwell-Wagner polarization mechanism as well as to the thermally activated mechanism of charge carriers. Electric modulus reveal two type relaxations in the 250 °C to 800 °C temperature region as studied at different frequencies over 100 Hz to 106 Hz in air.

  6. Numerical Simulation with Experimental Validation of the Draping Behavior of Woven Fabrics

    Energy Technology Data Exchange (ETDEWEB)

    Rodgers, William [General Motors LLC; Pasupuleti, Praveen [ESI Group NA; Zhao, Selina [General Motors LLC; Wathen, Terry [General Motors LLC; Doroudian, Mark [ESI Group NA; Aitharaju, Venkat [General Motors LLC

    2017-10-23

    Woven fabric composites are extensively used in molding complex geometrical shapes due to their high conformability compared to other fabrics. Preforming is an important step in the overall process. In this step, the two-dimensional fabric is draped to become the three-dimensional shape of the part prior to resin injection. During preforming, the orientation of the tows may change significantly compared to the initial orientations. Accurate prediction of the tow orientations after molding is important for evaluating the structural performance of the final part. This paper investigates the fiber angle changes for carbon fiber woven fabrics during draping over a truncated pyramid tool designed and fabricated at the General Motors Research Labs. This aspect of study is a subset of the broad study conducted under the purview of a Department of Energy project funded to GM in developing state of the art computational tools for integrated manufacturing and structural performance prediction of carbon fiber composites. Fabric bending, picture frame testing, and bias-extension evaluations were carried out to determine the material parameters for these fabrics. The PAM-FORM computer program was used to model the draping behavior of these fabrics. Following deformation, fiber angle changes at different locations on the truncated pyramid were measured experimentally. The predicted angles matched the experimental results well as measured along the centerline and at several different locations on the deformed fabric. Details of the test methods used as well as the numerical results with various simulation parameters will be provided.

  7. A superplastic Al-Li-Cu-Mg-Zr powder alloy with high hardness and modulus

    International Nuclear Information System (INIS)

    Phillips, V.A.

    1986-01-01

    Structure/property studies were made on an experimental Al-3.18% Li-4.29% Cu-1.17% Mg-0.18% Zr powder alloy, which is of the low density/high modulus type. Alloy powder was made by the P and W/GPD rapid solidification rate (RSR) process, canned, and extruded to bar. The density was 2.458 x 10/sup 6/ g/m/sup 3/. The material was solution-treated, and aged at 149 0 C(300 0 F), 171 0 C(340 0 F), and 193 0 C(380 0 F), using hardness tests to determine the aging curves. Testpieces solution-treated at 516 0 C(961 0 F) showed an average yield strength (0.2% offset) of 43.3 ksi (299 MPa) and ultimate tensile strength of 50.0 ksi (345 MPa), with 1% elongation, which increased to 73.0 ksi (503 MPa) and 73.1 ksi (504 MPa), respectively, with only 0.2% elongation, on peak aging at 193 0 C(380 0 F), with a modulus of elasticity of 11.4 x 10/sup 6/ psi (78.3 GPa). Hardness values reached 90-92 R/sub B/ on aging at 149-193 0 C(300-380 0 F). The as-extruded alloy showed superplastic behavior at 400-500 0 C(752-932 0 F) with elongations of 80-185% on 25.6 mm, peaking at 450 0 C(842 0 F). An RSR Al-2.53% Li-2.82% Mn-0.02% Zr extruded allow showed only 18-23% elongation at 400-500 0 C(752-932 0 F)

  8. 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.

  9. Integration of Complex Geometry, 3D Woven Preforms via Innovative Stitching Technique, Phase II

    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....

  10. Structure and Young modulus of age hardening elinvar 45NKhT

    International Nuclear Information System (INIS)

    Baraz, V.R.; Strizhak, V.A.; Tsykin, D.N.

    1996-01-01

    The influence of quenching and ageing on structural features and Young modulus of precipitation hardening elinvar alloy 45 NKhT is under study. It is shown that the quenched alloy possesses a decreased elastic modulus which value drops with a quenching temperature increase. The ally ageing results in restoration of elastic modulus. The temperature range of Young modulus stability is shown to be independent of heat treatment conditions. The anomalies of elastic modulus in quenched alloy are conditioned by structural and magnetoelastic factors. The mechanisms of continuous and discontinuous precipitation mechanism has no effect on efficiency of Young modulus restoration. 13 refs., 6 figs

  11. 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.

  12. The variation in elastic modulus throughout the compression of foam materials

    International Nuclear Information System (INIS)

    Sun, Yongle; Amirrasouli, B.; Razavi, S.B.; Li, Q.M.; Lowe, T.; Withers, P.J.

    2016-01-01

    We present a comprehensive experimental study of the variation in apparent unloading elastic modulus of polymer (largely elastic), aluminium (largely plastic) and fibre-reinforced cement (quasi-brittle) closed-cell foams throughout uniaxial compression. The results show a characteristic “zero-yield-stress” response and thereafter a rapid increase in unloading modulus during the supposedly “elastic” regime of the compressive stress–strain curve. The unloading modulus then falls with strain due to the localised cell-wall yielding or failure in the pre-collapse stage and the progressive cell crushing in the plateau stage, before rising sharply during the densification stage which is associated with global cell crushing and foam compaction. A finite element model based on the actual 3D cell structure of the aluminium foam imaged by X-ray computed tomography (CT) predicts an approximately linear fall of elastic modulus from zero strain until a band of collapsed cells forms. It shows that the subsequent gradual decrease in modulus is caused by the progressive collapse of cells. The elastic modulus rises sharply after the densification initiation strain has been reached. However, the elastic modulus is still well below that of the constituent material even when the “fully” dense state is approached. This work highlights the fact that the unloading elastic modulus varies throughout compression and challenges the idea that a constant elastic modulus can be applied in a homogenised foam model. It is suggested that the most representative value of elastic modulus may be obtained by extrapolating the measured unloading modulus to zero strain.

  13. Muscle shear elastic modulus is linearly related to muscle torque over the entire range of isometric contraction intensity.

    Science.gov (United States)

    Ateş, Filiz; Hug, François; Bouillard, Killian; Jubeau, Marc; Frappart, Thomas; Couade, Mathieu; Bercoff, Jeremy; Nordez, Antoine

    2015-08-01

    Muscle shear elastic modulus is linearly related to muscle torque during low-level contractions (torque over the entire range of isometric contraction and (ii) the influence of the size of the region of interest (ROI) used to average the shear modulus value. Ten healthy males performed two incremental isometric little finger abductions. The joint torque produced by Abductor Digiti Minimi was considered as an index of muscle torque and elastic modulus. A high coefficient of determination (R(2)) (range: 0.86-0.98) indicated that the relationship between elastic modulus and torque can be accurately modeled by a linear regression over the entire range (0% to 100% of MVC). The changes in shear elastic modulus as a function of torque were highly repeatable. Lower R(2) values (0.89±0.13 for 1/16 of ROI) and significantly increased absolute errors were observed when the shear elastic modulus was averaged over smaller ROI, half, 1/4 and 1/16 of the full ROI) than the full ROI (mean size: 1.18±0.24cm(2)). It suggests that the ROI should be as large as possible for accurate measurement of muscle shear modulus. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Young Modulus of Crystalline Polyethylene from ab Initio Molecular Dynamics

    NARCIS (Netherlands)

    Hageman, J.C.L.; Meier, Robert J.; Heinemann, M.; Groot, R.A. de

    1997-01-01

    The Young modulus for crystalline polyethylene is calculated using ab initio molecular dynamics based on density functional theory in the local density approximation (DFT-LDA). This modulus, which can be seen as the ultimate value for the Young modulus of polyethylene fibers, is found to be 334 GPa.

  15. Determination of elastic modulus of ceramics using ultrasonic testing

    Science.gov (United States)

    Sasmita, Firmansyah; Wibisono, Gatot; Judawisastra, Hermawan; Priambodo, Toni Agung

    2018-04-01

    Elastic modulus is important material property on structural ceramics application. However, bending test as a common method for determining this property require particular specimen preparation. Furthermore, elastic modulus of ceramics could vary because it depends on porosity content. For structural ceramics industry, such as ceramic tiles, this property is very important. This drives the development of new method to improve effectivity or verification method as well. In this research, ultrasonic testing was conducted to determine elastic modulus of soda lime glass and ceramic tiles. The experiment parameter was frequency of probe (1, 2, 4 MHz). Characterization of density and porosity were also done for analysis. Results from ultrasonic testing were compared with elastic modulus resulted from bending test. Elastic modulus of soda-lime glass based on ultrasonic testing showed excellent result with error 2.69% for 2 MHz probe relative to bending test result. Testing on red and white ceramic tiles were still contained error up to 41% and 158%, respectively. The results for red ceramic tile showed trend that 1 MHz probe gave better accuracy in determining elastic modulus. However, testing on white ceramic tile showed different trend. It was due to the presence of porosity and near field effect.

  16. 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.

  17. Temperature dependence of Young's modulus of silica refractories

    Czech Academy of Sciences Publication Activity Database

    Gregorová, E.; Černý, Martin; Pabst, W.; Esposito, L.; Zanelli, C.; Hamáček, J.; Kutzendorfer, J.

    2015-01-01

    Roč. 41, č. 1 (2015), s. 1129-1138 ISSN 0272-8842 Institutional support: RVO:67985891 Keywords : mechanical properties * elastic modulus (Young's modulus ) * SiO2 * Silica brick materials (cristobalite, tridymite) Subject RIV: JH - Ceramics, Fire-Resistant Materials and Glass Impact factor: 2.758, year: 2015

  18. Proposal of Design Formulae for Equivalent Elasticity of Masonry Structures Made with Bricks of Low Modulus

    Directory of Open Access Journals (Sweden)

    Muhammad Ridwan

    2017-01-01

    Full Text Available Bricks of low elastic modulus are occasionally used in some developing countries, such as Indonesia and India. Most of the previous research efforts focused on masonry structures built with bricks of considerably high elastic modulus. The objective of this study is to quantify the equivalent elastic modulus of lower-stiffness masonry structures, when the mortar has a higher modulus of elasticity than the bricks, by employing finite element (FE simulations and adopting the homogenization technique. The reported numerical simulations adopted the two-dimensional representative volume elements (RVEs using quadrilateral elements with four nodes. The equivalent elastic moduli of composite elements with various bricks and mortar were quantified. The numerically estimated equivalent elastic moduli from the FE simulations were verified using previously established test data. Hence, a new simplified formula for the calculation of the equivalent modulus of elasticity of such masonry structures is proposed in the present study.

  19. Fatigue damage mechanism and strength of woven laminates

    International Nuclear Information System (INIS)

    Xiao, J.; Bathias, C.

    1993-01-01

    The apparent secant stiffness changes with the cyclic number for both unnotched and notched woven laminated specimens (two orthotropic and one quasi-isotropic) during tensile fatigue test at a fixed ratio of maximum fatigue load to UTS were observed. The observable damage initiation and evolution as a function of the cyclic number were directly measured at the notched specimen surface with a video-camera system. The fatigue strengths of the unnotched and notched specimens were determined. The results show that the normalized apparent secant stiffness change curves as a function of cyclic numbers can be divided into three stages. For the first and the second stages in notched specimens and for total life of unnotched specimens, the damage has not been evidently observed and certainly verified with the traditional experimental methods such as radiography and microscopy although many acoustic emission signals can be obtained. The last stage for the notched specimens (N/Nf>0.4, the secant stiffness decreases fast) corresponds to the initiation and evolution of the observable damages. The fatigue strength of these woven composite laminates is dominated by the third stage during which the observable damage develops along the specimen ligament until fracture. During the third stage, a critical dimension at the specimen ligament and a life threshold can be found beyond which a final catastrophic fracture will immediately occur. The quasi-isotropic laminate is of a fatigue strength lower than the two orthotropic laminates of which the fatigue strengths are approaching to each other. The fatigue life is also influenced by the stacking sequences. (orig.)

  20. On Young's modulus of multi-walled carbon nanotubes

    Indian Academy of Sciences (India)

    WINTEC

    load transfer in nanocomposites. In the present work, CNT/Al ... calculations. The theoretical modulus of the graphene sheet is supposed to be 1060 GPa (Harris 2004). The reason why multi-walled nanotubes have a modulus > 1060 GPa (that of graphene sheet) is currently not understood. However, in the present paper, ...

  1. 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

  2. Probabilistic Modeling of High-Temperature Material Properties of a 5-Harness 0/90 Sylramic Fiber/ CVI-SiC/ MI-SiC Woven Composite

    Science.gov (United States)

    Nagpal, Vinod K.; Tong, Michael; Murthy, P. L. N.; Mital, Subodh

    1998-01-01

    An integrated probabilistic approach has been developed to assess composites for high temperature applications. This approach was used to determine thermal and mechanical properties and their probabilistic distributions of a 5-harness 0/90 Sylramic fiber/CVI-SiC/Mi-SiC woven Ceramic Matrix Composite (CMC) at high temperatures. The purpose of developing this approach was to generate quantitative probabilistic information on this CMC to help complete the evaluation for its potential application for HSCT combustor liner. This approach quantified the influences of uncertainties inherent in constituent properties called primitive variables on selected key response variables of the CMC at 2200 F. The quantitative information is presented in the form of Cumulative Density Functions (CDFs). Probability Density Functions (PDFS) and primitive variable sensitivities on response. Results indicate that the scatters in response variables were reduced by 30-50% when the uncertainties in the primitive variables, which showed the most influence, were reduced by 50%.

  3. 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.

  4. Effect of a High Density of Stacking Faults on the Young's Modulus of GaAs Nanowires.

    Science.gov (United States)

    Chen, Yujie; Burgess, Tim; An, Xianghai; Mai, Yiu-Wing; Tan, H Hoe; Zou, Jin; Ringer, Simon P; Jagadish, Chennupati; Liao, Xiaozhou

    2016-03-09

    Stacking faults (SFs) are commonly observed crystalline defects in III-V semiconductor nanowires (NWs) that affect a variety of physical properties. Understanding the effect of SFs on NW mechanical properties is critical to NW applications in nanodevices. In this study, the Young's moduli of GaAs NWs with two distinct structures, defect-free single crystalline wurtzite (WZ) and highly defective wurtzite containing a high density of SFs (WZ-SF), are investigated using combined in situ compression transmission electron microscopy and finite element analysis. The Young's moduli of both WZ and WZ-SF GaAs NWs were found to increase with decreasing diameter due to the increasing volume fraction of the native oxide shell. The presence of a high density of SFs was further found to increase the Young's modulus by 13%. This stiffening effect of SFs is attributed to the change in the interatomic bonding configuration at the SFs.

  5. The Use of Decorative Styles of Woven Songket as a Source of Learning in the Course Textile Design and Decoration

    Directory of Open Access Journals (Sweden)

    Made Budhyani I Dewa Ayu

    2018-01-01

    Full Text Available The use of learning sources in the learning process greatly contributes to the achievement of its goal. The use of learning sources greatly affects the teaching and learning process. It is necessary to use different learning sources when creating a textile design in order to produce a quality product. The decorative style of woven songket can be used as one of the learning sources. The different decorative types of the woven songket contain aesthetic values. The decorative type of woven songket is a product of the crafter’s feeling, creativity, and intention inspired by the environment. The natural objects such as plants, animals, human beings, and geometric elements are stylized into the decorative forms. The decorative style used on the woven songket can be used as the learning source in order to create the decorative style in the course Textile Design and Decoration. There are several aesthetic elements which inspire where the decorative style is placed; they are composition, rhythm, balance, the harmonious layout of the decorative style, and the variation of the decorative style on the textile design. In general, the composition of the placement of the main object of the decorative style is more dominant on the piece of fabric. Rhythm and how the decorative style is composed are shown through the composition of the decorative motive forms such as how big and small they are, how high and low they are and how long and short they are. The ways in which the decorative motives and colors are entirely shown contribute to the harmony and placement of decorative style. The symmetric balance is used to create balance and avoid the impression of being biased. The placement of what the motives contain and how they are composed are used to determine the variation of the decorative style used. The placement of objects and the marginal decoration of the fabric also determine the variation used.

  6. Asphalt mix characterization using dynamic modulus and APA testing.

    Science.gov (United States)

    2005-11-01

    final report summarizes two research efforts related to asphalt mix characterization: dynamic modulus and Asphalt Pavement Analyzer testing. One phase of the research consisted of a laboratory-based evaluation of dynamic modulus of Oregon dense-grade...

  7. The Applicability of Taylor’s Model to the Drilling of CFRP Using Uncoated WC-Co Tools: The Influence of Cutting Speed on Tool Wear

    OpenAIRE

    Merino Perez, J.L.; Merson, E.; Ayvar-Soberanis, S.; Hodzic, A.

    2014-01-01

    This work investigates the applicability of Taylor’s model on the drilling of CFRP using uncoated WC-Co tools, by assessing the influence of cutting speed (Vc) on tool wear. Two different resins, possessing low and high glass transition temperatures (Tg), and two different reinforcements, high strength and high modulus woven fabrics, were combined into three different systems. Flank wear rate gradient exhibited to be more reinforcement dependent, while the actual flank wear rate showed to be ...

  8. 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.

  9. 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.

  10. Frequency-dependent complex modulus of the uterus: preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Kiss, Miklos Z [Department of Medical Physics, University of Wisconsin, Madison, WI 53706 (United States); Hobson, Maritza A [Department of Medical Physics, University of Wisconsin, Madison, WI 53706 (United States); Varghese, Tomy [Department of Medical Physics, University of Wisconsin, Madison, WI 53706 (United States); Harter, Josephine [Department of Surgical Pathology, University of Wisconsin, Madison, WI 53706 (United States); Kliewer, Mark A [Department of Radiology, University of Wisconsin, Madison, WI 53706 (United States); Hartenbach, Ellen M [Department of Obstetrics and Gynecology, University of Wisconsin, Madison, WI 53706 (United States); Zagzebski, James A [Department of Medical Physics, University of Wisconsin, Madison, WI 53706 (United States)

    2006-08-07

    The frequency-dependent complex moduli of human uterine tissue have been characterized. Quantification of the modulus is required for developing uterine ultrasound elastography as a viable imaging modality for diagnosing and monitoring causes for abnormal uterine bleeding and enlargement, as well assessing the integrity of uterine and cervical tissue. The complex modulus was measured in samples from hysterectomies of 24 patients ranging in age from 31 to 79 years. Measurements were done under small compressions of either 1 or 2%, at low pre-compression values (either 1 or 2%), and over a frequency range of 0.1-100 Hz. Modulus values of cervical tissue monotonically increased from approximately 30-90 kPa over the frequency range. Normal uterine tissue possessed modulus values over the same range, while leiomyomas, or uterine fibroids, exhibited values ranging from approximately 60-220 kPa.

  11. Frequency-dependent complex modulus of the uterus: preliminary results

    International Nuclear Information System (INIS)

    Kiss, Miklos Z; Hobson, Maritza A; Varghese, Tomy; Harter, Josephine; Kliewer, Mark A; Hartenbach, Ellen M; Zagzebski, James A

    2006-01-01

    The frequency-dependent complex moduli of human uterine tissue have been characterized. Quantification of the modulus is required for developing uterine ultrasound elastography as a viable imaging modality for diagnosing and monitoring causes for abnormal uterine bleeding and enlargement, as well assessing the integrity of uterine and cervical tissue. The complex modulus was measured in samples from hysterectomies of 24 patients ranging in age from 31 to 79 years. Measurements were done under small compressions of either 1 or 2%, at low pre-compression values (either 1 or 2%), and over a frequency range of 0.1-100 Hz. Modulus values of cervical tissue monotonically increased from approximately 30-90 kPa over the frequency range. Normal uterine tissue possessed modulus values over the same range, while leiomyomas, or uterine fibroids, exhibited values ranging from approximately 60-220 kPa

  12. The effect of z-binding yarns on the electrical properties of 3D woven composites

    KAUST Repository

    Saleh, Mohamed Nasr

    2017-09-28

    Electrical resistance monitoring (ERM) has been used to study the effect of the z-binding yarns on the initial electrical resistance (ER) and its change of three architectures of 3D woven carbon fibre composites namely (orthogonal “ORT”, layer-to-layer “LTL” and angle interlock “AI”) when tested in tension. Specimens are loaded in on-axis “warp” and off-axis “45°” directions. In-situ ERM is achieved using the four-probe technique. Monotonic and cyclic “load/unload” tests are performed to investigate the effect of piezo-resistivity and residual plasticity on resistance variation. The resistance increase for the off-axis loaded specimens (∼90%) is found to be higher than that of their on-axis counterparts (∼20%). In the case of cyclic testing, the resistance increase upon unloading is irreversible which suggests permanent damage presence not piezo-resistive effect. At the moment, it is difficult to obtain a direct correlation between resistance variation and damage in 3D woven composites due to the complexity of the conduction path along the three orthogonal directions, however this study demonstrates the potential of using ERM for damage detection in 3D woven carbon fibre-based composites and highlights the challenges that need to be overcome to establish ERM as a Structural Health Monitoring (SHM) technique for such material systems.

  13. Investigating the Potential of Using Off-Axis 3D Woven Composites in Composite Joints’ Applications

    KAUST Repository

    Saleh, Mohamed Nasr; Wang, Ying; Yudhanto, Arief; Joesbury, Adam; Potluri, Prasad; Lubineau, Gilles; Soutis, Constantinos

    2016-01-01

    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. © 2016 The Author(s)

  14. 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)

  15. 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

  16. 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.

  17. Effect of stacking angles on mechanical properties and damage propagation of plain woven carbon fiber laminates

    Science.gov (United States)

    Zhuang, Weimin; Ao, Wenhong

    2018-03-01

    Damage propagation induced failure is a predominant damage mechanism. This study is aimed at assessing the damage state and damage propagation induced failure with different stacking angles, of woven carbon fiber/epoxy laminates subjected to quasi-static tensile and bending load. Different stages of damage processing and damage behavior under the bending load are investigated by Scanning Electron Microscopy (SEM). The woven carbon fiber/epoxy laminates which are stacked at six different angles (0°, 15°, 30°, 45°, 60°, 75°) with eight plies have been analyzed: [0]8, [15]8, [30]8, [45]8, [60]8, [75]8. Three-point bending test and quasi-static tensile test are used in validating the woven carbon fiber/epoxy laminates’ mechanical properties. Furthermore, the damage propagation and failure modes observed under flexural loading is correlated with flexural force and load-displacement behaviour respectively for the laminates. The experimental results have indicated that [45]8 laminate exhibits the best flexural performance in terms of energy absorption duo to its pseudo-ductile behaviour but the tensile strength and flexural strength drastically decreased compared to [0]8 laminate. Finally, SEM micrographs of specimens and fracture surfaces are used to reveal the different types of damage of the laminates with different stacking angles.

  18. 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.

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

    OpenAIRE

    A.E. Ismail; M.A. Che Abdul Aziz

    2015-01-01

    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...

  20. 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 subnanometer thickness resolution on SU-8 MC arrays by means of atomic layer deposition. The resonant frequencies of the MCs were measured before and after coating and the elastic moduli of the films were determined by a theoretical model developed for this purpose. The Young's modulus of thicker TiO2 films...... (>75 nm) was estimated to be about 110 GPa, this value being consistent with the value of amorphous TiO2. On the other hand we observed a marked decrease of the Young's modulus for TiO2 films with a thickness below 50 nm. This behavior was found not to be related to a decrease of the film mass density...

  1. CEMCAN Software Enhanced for Predicting the Properties of Woven Ceramic Matrix Composites

    Science.gov (United States)

    Murthy, Pappu L. N.; Mital, Subodh K.; DiCarlo, James A.

    2000-01-01

    Major advancements are needed in current high-temperature materials to meet the requirements of future space and aeropropulsion structural components. Ceramic matrix composites (CMC's) are one class of materials that are being evaluated as candidate materials for many high-temperature applications. Past efforts to improve the performance of CMC's focused primarily on improving the properties of the fiber, interfacial coatings, and matrix constituents as individual phases. Design and analysis tools must take into consideration the complex geometries, microstructures, and fabrication processes involved in these composites and must allow the composite properties to be tailored for optimum performance. Major accomplishments during the past year include the development and inclusion of woven CMC micromechanics methodology into the CEMCAN (Ceramic Matrix Composites Analyzer) computer code. The code enables one to calibrate a consistent set of constituent properties as a function of temperature with the aid of experimentally measured data.

  2. Investigation of statistical relationship between dynamic modulus and thermal strength of asphalt concrete

    International Nuclear Information System (INIS)

    Qadir, A.; Gular, M.

    2011-01-01

    Dynamic modulus is a performance indicator for asphalt concrete and is used to qualify asphalt mixtures based on stress-strain characteristics under repeated loading. Moreover, the low temperature cracking of asphalt concrete mixes are measured in terms of fracture strength and fracture temperature. Dynamic modulus test was selected as one of the simple performance tests in the AASHTO 2002 guidelines to rate mixtures according to permanent deformation performance. However, AASHTO 2002 guidelines is silent in relating dynamic modulus values to low temperature cracking, probably because of weak correlations reported between these two properties. The present study investigates the relation between these two properties under the influence of aggregate type and mix gradation. Mixtures were prepared with two types of aggregate and gradations, while maintaining the binder type and air voids constant. The mixtures were later tested for dynamic modulus and fracture strength using thermal stress restrained specimen test (TSRST). Results indicate that there exists a fair correlation between the thermal fracture strength and stiffness at a selected test temperature and frequency level. These correlations are highly dependent upon the type of aggregate and mix gradation. (author)

  3. Young's modulus of individual ZnO nanowires

    International Nuclear Information System (INIS)

    Jiang, Dayong; Tian, Chunguang; Liu, Qingfei; Zhao, Man; Qin, Jieming; Hou, Jianhua; Gao, Shang; Liang, Qingcheng; Zhao, Jianxun

    2014-01-01

    We used a contact-mode atomic force microscopy (AFM) to study the mechanical properties of an individual ZnO nanowire in the open air. It is noteworthy that the Young's modulus can be determined by an AFM tip compressing a single nanowire on a rigid substrate, which can bring more repeatability and accuracy for the measurements. In particular, the calculated radial Young's modulus of ZnO nanowires is consistent with the data of ZnO bulks and thin films. We also present the Young's modulus with different diameters, and all these are discussed deeply

  4. Potential application of microporous structured poly(vinylidene fluoride-hexafluoropropylene)/poly(ethylene terephthalate) composite nonwoven separators to high-voltage and high-power lithium-ion batteries

    International Nuclear Information System (INIS)

    Jeong, Hyun-Seok; Choi, Eun-Sun; Kim, Jong Hun; Lee, Sang-Young

    2011-01-01

    Highlights: → Microporous-structured PVdF-HFP/PET composite nonwoven separators for Li-batteries. → Well-developed microporous structure and liquid electrolyte wettability. → Provision of facile ion transport and suppressed growth of cell impedance. → Superior cell performance at high-voltages/high-current densities. - Abstract: We demonstrate potential application of a new composite non-woven separator, which is comprised of a phase inversion-controlled, microporous polyvinylidene fluoride-hexafluoropropylene (PVdF-HFP) gel polymer electrolyte and a polyethylene terephthalate (PET) non-woven support, to high-voltage and high-power lithium-ion batteries. In comparison to a commercialized polyethylene (PE) separator, the composite non-woven separator exhibits distinct improvements in microporous structure and liquid electrolyte wettability. Based on the understanding of the composite non-woven separator, cell performances of the separator at challenging charge/discharge conditions are investigated and discussed in terms of ion transport of the separator and AC impedance of the cell. The aforementioned advantageous features of the composite non-woven separator play a key role in providing facile ion transport and suppressing growth of cell impedance during cycling, which in turn contribute to superior cell performances at harsh charge/discharge conditions such as high voltages and high current densities.

  5. A note on the applied tearing modulus (Tsub(J)sup(app)) in ductile instability testing and analysis

    International Nuclear Information System (INIS)

    Saka, Masumi; Takahashi, Hideaki; Abe, Hiroyuki; Ando, Kotoji.

    1984-01-01

    In the evaluation of the soundness of the structures made of high toughness materials, it is a very important problem to clarify by what dynamic condition the transition from the stable propagation of ductile cracks to ductile unstable breaking is controlled. As a criterion for ductile unstable breaking, Paris et al. proposed that an applied tearing modulus is not smaller than a material tearing modulus, based on J-integral. In order to make highly reliable forecast on the starting point of ductile unstable breaking, it is necessary to sufficiently examine the features of an applied tearing modulus. In this study, referring to the test results of the ductile unstable breaking of ITCT test pieces of A508 steel for reactor pressure vessels, the features of the changing tendency of an applied tearing modulus accompanying crack development and the cause of these features were examined in detail. Moreover, the errors in the theoretical forecast of J-integral and the amount of crack development at the start of ductile unstable breaking in relation to the above features were examined. The test pieces and the experimental method, the method of analysis, the experimental results, the features of an applied tearing modulus and the accuracy of forecast are reported. (Kako, I.)

  6. 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...

  7. 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.

  8. Determination of elastic modulus in nickel alloy from ultrasonic ...

    Indian Academy of Sciences (India)

    als scientists, and solid-state theorists; they connect to tech- nological, structural economics and safety, to various mate- rials phenomena and to their fundamental interatomic forces. (Ledbetter 1983). In any material which is a multiphase alloy, the elastic modulus is determined by the modulus of the indi- vidual phases and ...

  9. Evaluation of linear polymerization shrinkage, flexural strength and modulus of elasticity of dental composites

    Directory of Open Access Journals (Sweden)

    Gabriela Queiroz de Melo Monteiro

    2010-03-01

    Full Text Available Linear polymerization shrinkage (LPS, flexural strength (FS and modulus of elasticity (ME of 7 dental composites (Filtek Z350™, Filtek Z250™/3M ESPE; Grandio™, Polofil Supra™/VOCO; TPH Spectrum™, TPH3™, Esthet-X™/Denstply were measured. For the measurement of LPS, composites were applied to a cylindrical metallic mold and polymerized (n = 8. The gap formed at the resin/mold interface was observed using scanning electron microscopy (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. TPH Spectrum presented significantly higher LPS values (29.45 µm. Grandio had significantly higher mean values for FS (141.07 MPa and ME (13.91 GPa. The relationship between modulus of elasticity and polymerization shrinkage is the main challenge for maintenance of the adhesive interface, thus composites presenting high shrinkage values, associated with a high modulus of elasticity tend to disrupt the adhesive interface under polymerization.

  10. The thermal non-equilibrium porous media modelling for CFD study of woven wire matrix of a Stirling regenerator

    International Nuclear Information System (INIS)

    Costa, S.C.; Barreno, I.; Tutar, M.; Esnaola, J.A.; Barrutia, H.

    2015-01-01

    Highlights: • A numerical procedure to derive porous media’s coefficients is proposed. • The local thermal non-equilibrium porous media model is more suitable for regenerators. • The regenerator temperature profiles can be better fitted to a logarithmic curve. • The wound woven wire matrix provides lower performance compared to stacked. • The numerical characterization methodology is useful for the multi-D Stirling engine models. - Abstract: Different numerical methods can be applied to the analysis of the flow through the Stirling engine regenerator. One growing approach is to model the regenerator as porous medium to simulate and design the full Stirling engine in three-dimensional (3-D) manner. In general, the friction resistance coefficients and heat transfer coefficient are experimentally obtained to describe the flow and thermal non-equilibrium through a porous medium. A finite volume method (FVM) based non-thermal equilibrium porous media modelling approach characterizing the fluid flow and heat transfer in a representative small detailed flow domain of the woven wire matrix is proposed here to obtain the porous media coefficients without further requirement of experimental studies. The results are considered to be equivalent to those obtained from the detailed woven wire matrix for the pressure drop and heat transfer. Once the equivalence between the models is verified, this approach is extended to model oscillating regeneration cycles through a full size regenerator porous media for two different woven wire matrix configurations of stacked and wound types. The results suggest that the numerical modelling approach proposed here can be applied with confidence to model the regenerator as a porous media in the multi-dimensional (multi-D) simulations of Stirling engines

  11. 2 filler on the dielectric permittivity and electrical modulus of PMMA

    Indian Academy of Sciences (India)

    The real and imaginary part of the dielectric permittivity decreased with the increase in frequency but increased with temperature. The electrical conductivity measurement showed a plateau-like behaviour in the low-frequency region and dispersion in the high-frequency region. The frequency-dependent electrical modulus ...

  12. 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.

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

    Science.gov (United States)

    2007-02-01

    08 Aug 2006. Paper contains color . 14. ABSTRACT Monazite coatings were deposited on woven cloths and tows of NextelTM 610 fibers by heterogeneous...by dissolving concentrated phosphoric acid ( Fish - er Scientific Co., Pittsburgh, PA) or a combination of lantha- num nitrate (Aldrich Chemical Co...Boccaccini, P. Karapappas, J. M. Marijuan, and C. Kaya, ‘‘ TiO2 Coat- ings on Silicon Carbide Fiber Substrates by Electrophoretic Deposition,’’ J.Mater. Sci

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

    KAUST Repository

    Saleh, Mohamed Nasr; Yudhanto, Arief; Potluri, Prasad; Lubineau, Gilles; Soutis, Constantinos

    2016-01-01

    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

  15. 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...

  16. 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.

  17. Modeling and characterization of through-the-thickness properties of 3D woven composites

    Science.gov (United States)

    Hartranft, Dru; Pravizi-Majidi, Azar; Chou, Tsu-Wei

    1995-01-01

    The through-the-thickness properties of three-dimensionally (3D) woven carbon/epoxy composites have been studied. The investigation aimed at the evaluation and development of test methodologies for the property characterization in the thickness direction, and the establishment of fiber architectures were studied: layer-to-layer Angle Interlock, through-the-thickness Orthogonal woven preform with surface pile was also designed and manufactured for the fabrication of tensile test coupons with integrated grips. All the preforms were infiltrated by the resin transfer molding technique. The microstructures of the composites were characterized along the warp and fill (weft) directions to determine the degree of yarn undulations, yarn cross-sectional shapes, and microstructural dimensions. These parameters were correlated to the fiber architecture. Specimens were designed and tested for the direct measurement of the through-the-thickness tensile, compressive and shear properties of the composites. Design optimization was conducted through the analysis of the stress fields within the specimen coupled with experimental verification. The experimentally-derived elastic properties in the thickness direction compared well with analytical predictions obtained from a volume averaging model.

  18. The effect of z-binding yarns on the electrical properties of 3D woven composites

    KAUST Repository

    Saleh, Mohamed Nasr; Yudhanto, Arief; Lubineau, Gilles; Soutis, Constantinos

    2017-01-01

    Electrical resistance monitoring (ERM) has been used to study the effect of the z-binding yarns on the initial electrical resistance (ER) and its change of three architectures of 3D woven carbon fibre composites namely (orthogonal “ORT”, layer

  19. The temperature dependence of the isothermal bulk modulus at 1 bar pressure

    International Nuclear Information System (INIS)

    Garai, J.; Laugier, A.

    2007-01-01

    It is well established that the product of the volume coefficient of thermal expansion and the bulk modulus is nearly constant at temperatures higher than the Debye temperature. Using this approximation allows predicting the values of the bulk modulus. The derived analytical solution for the temperature dependence of the isothermal bulk modulus has been applied to ten substances. The good correlations to the experiments indicate that the expression may be useful for substances for which bulk modulus data are lacking

  20. Phenomenology of mixed modulus-anomaly mediation in fluxed string compactifications and brane models

    International Nuclear Information System (INIS)

    Choi, Kiwoon; Jeong, Kwang-Sik; Okumura, Ken-ichi

    2005-01-01

    In some string compactifications, for instance the recently proposed KKLT set-up, light moduli are stabilized by nonperturbative effects at supersymmetric AdS vacuum which is lifted to a dS vacuum by supersymmetry breaking uplifting potential. In such models, soft supersymmetry breaking terms are determined by a specific mixed modulus-anomaly mediation in which the two mediations typically give comparable contributions to soft parameters. Similar pattern of soft terms can arise also in brane models to stabilize the radion by nonperturbative effects. We examine some phenomenological consequences of this mixed modulus-anomaly mediation, including the pattern of low energy sparticle spectrum and the possibility of electroweak symmetry breaking. It is noted that adding the anomaly-mediated contributions at M GUT amounts to replacing the messenger scale of the modulus mediation by a mirage messenger scale (m 3/2 /M Pl ) α/2 M GUT where α = m 3/2 /[M 0 ln (M Pl /m 3/2 )] for M 0 denoting the modulus-mediated contribution to the gaugino mass at M GUT . The minimal KKLT set-up predicts α = 1. As a consequence, for α = O(1), the model can lead to a highly distinctive pattern of sparticle masses at TeV scale, particularly when α = 2

  1. Design of a 5.8 GHz Multi-Modulus Prescaler

    OpenAIRE

    Myklebust, Vidar

    2006-01-01

    A 64-modulus prescaler operating at 5.8 GHz has been designed in a 0.18 μm CMOS process. The prescaler uses a four-phase high-speed ÷4 circuit at the input, composed of two identical cascaded ÷2 circuits implemented in pseudo-NMOS. The high-speed divider is followed by a two-bits phase switching stage, which together with the input divider forms a ÷4/5/6/7 circuit. The phase switching stage is mostly implemented in complementary CMOS. After this follows four identical ÷2/3 cells with local fe...

  2. 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

  3. Determination of young's modulus of PZT-influence of cantilever orientation

    NARCIS (Netherlands)

    Nazeer, H.; Woldering, L.A.; Abelmann, Leon; Elwenspoek, Michael Curt

    Calculation of the resonance frequency of cantilevers fabricated from an elastically anisotropic material requires the use of an effective Young’s modulus. In this paper a technique to determine the appropriate effective Young’s modulus for arbitrary cantilever geometries is introduced. This

  4. Young's Modulus of Wurtzite and Zinc Blende InP Nanowires.

    Science.gov (United States)

    Dunaevskiy, Mikhail; Geydt, Pavel; Lähderanta, Erkki; Alekseev, Prokhor; Haggrén, Tuomas; Kakko, Joona-Pekko; Jiang, Hua; Lipsanen, Harri

    2017-06-14

    The Young's modulus of thin conical InP nanowires with either wurtzite or mixed "zinc blende/wurtzite" structures was measured. It has been shown that the value of Young's modulus obtained for wurtzite InP nanowires (E [0001] = 130 ± 30 GPa) was similar to the theoretically predicted value for the wurtzite InP material (E [0001] = 120 ± 10 GPa). The Young's modulus of mixed "zinc blende/wurtzite" InP nanowires (E [111] = 65 ± 10 GPa) appeared to be 40% less than the theoretically predicted value for the zinc blende InP material (E [111] = 110 GPa). An advanced method for measuring the Young's modulus of thin and flexible nanostructures is proposed. It consists of measuring the flexibility (the inverse of stiffness) profiles 1/k(x) by the scanning probe microscopy with precise control of loading force in nanonewton range followed by simulations.

  5. Elastic modulus of tree frog adhesive toe pads.

    Science.gov (United States)

    Barnes, W Jon P; Goodwyn, Pablo J Perez; Nokhbatolfoghahai, Mohsen; Gorb, Stanislav N

    2011-10-01

    Previous work using an atomic force microscope in nanoindenter mode indicated that the outer, 10- to 15-μm thick, keratinised layer of tree frog toe pads has a modulus of elasticity equivalent to silicone rubber (5-15 MPa) (Scholz et al. 2009), but gave no information on the physical properties of deeper structures. In this study, micro-indentation is used to measure the stiffness of whole toe pads of the tree frog, Litoria caerulea. We show here that tree frog toe pads are amongst the softest of biological structures (effective elastic modulus 4-25 kPa), and that they exhibit a gradient of stiffness, being stiffest on the outside. This stiffness gradient results from the presence of a dense network of capillaries lying beneath the pad epidermis, which probably has a shock absorbing function. Additionally, we compare the physical properties (elastic modulus, work of adhesion, pull-off force) of the toe pads of immature and adult frogs.

  6. 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.

  7. A meso-scale model to study the compressive strength of woven carbon fiber reinforced plastics

    NARCIS (Netherlands)

    Schormans, J.M.J.; Remmers, J.J.C.; Wilson, W.; Deshpande, V.S.

    2016-01-01

    Modeling kink-band formation in woven composites using a detailed micro-model is numerically expensive. In order to reduce the computational resources, a method to homogenize fiber-tows is proposed which uses a rules of mixture approach. The method is tested by comparing the stiffness and

  8. Effect of storage conditions on graft of polypropylene non-woven fabric induced by electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jin Young; Jeun, Joon Pyo; Kang, Phil Hyun [Radiation Research Dvision for Industry and Environment, Korea Atomic Energy Research Institute, Jeongeup(Korea, Republic of)

    2015-05-15

    In this study, we fabricated effect of storage conditions on graft of polypropylene (PP) non-woven fabric induced by electron beam. The electron beam irradiations on PP non-woven fabric were carried out over a range of irradiation doses from 25 to 100 kGy to make free radicals on fabric surface. The radical measurement was established by electron spin resonance (ESR) for confirming the changes of the alkyl radical and peroxy radical according to effect of storage time, storage temperature and atmosphere. It was observed that the free radicals were increased with irradiation dose and decreased with storage time due to the continuous oxidation. However, the radical extinction was significantly delayed due to reduced mobility of radicals at extremely low temperature. The degree of graft based on the analysis of ESR was investigated. The conditions of graft reaction were set at a temperature: 60 degrees Celcius, reaction time: 6 hours and styrene monomer concentration: 20 wt%.

  9. Standardizing lightweight deflectometer modulus measurements for compaction quality assurance : research summary.

    Science.gov (United States)

    2017-09-01

    The mechanistic-empirical pavement design method requires the elastic resilient modulus as the key input for characterization of geomaterials. Current density-based QA procedures do not measure resilient modulus. Additionally, the density-based metho...

  10. 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.

  11. 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.

  12. Determination of resilient modulus values for typical plastic soils in Wisconsin.

    Science.gov (United States)

    2011-09-01

    "The objectives of this research are to establish a resilient modulus test results database and to develop : correlations for estimating the resilient modulus of Wisconsin fine-grained soils from basic soil properties. A : laboratory testing program ...

  13. Advances in Computational High-Resolution Mechanical Spectroscopy HRMS Part II: Resonant Frequency – Young's Modulus

    International Nuclear Information System (INIS)

    Majewski, M; Magalas, L B

    2012-01-01

    In this paper, we compare the values of the resonant frequency f 0 of free decaying oscillations computed according to the parametric OMI method (Optimization in Multiple Intervals) and nonparametric DFT-based (discrete Fourier transform) methods as a function of the sampling frequency. The analysis is carried out for free decaying signals embedded in an experimental noise recorded for metallic samples in a low-frequency resonant mechanical spectrometer. The Yoshida method (Y), the Agrez' method (A), and new interpolated discrete Fourier transform (IpDFT) methods, that is, the Yoshida-Magalas (YM) and (YM C ) methods developed by the authors are carefully compared for the resonant frequency f 0 = 1.12345 Hz and the logarithmic decrement, δ = 0.0005. Precise estimation of the resonant frequency (Youngs' modulus ∼ f 0 2 ) for real experimental conditions, i.e., for exponentially damped harmonic signals embedded in an experimental noise, is a complex task. In this work, various computing methods are analyzed as a function of the sampling frequency used to digitize free decaying oscillations. The importance of computing techniques to obtain reliable and precise values of the resonant frequency (i.e. Young's modulus) in materials science is emphasized.

  14. Strengthening the Fabric of Government: A Description of WOVEN (Women's Ohio Volunteer Employment Network).

    Science.gov (United States)

    Miller, Mary E.

    WOVEN (Women's Ohio Volunteer Employment Network), is directed at changing the low representation of women in decision making positions in public service. Women comprise more than a third of the work force in the State of Ohio; yet they have typically held the low level, low paying jobs. A 1973 status report on women in State government revealed…

  15. 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...

  16. Fatigue Life Prediction of High Modulus Asphalt Concrete Based on the Local Stress-Strain Method

    Directory of Open Access Journals (Sweden)

    Mulian Zheng

    2017-03-01

    Full Text Available Previously published studies have proposed fatigue life prediction models for dense graded asphalt pavement based on flexural fatigue test. This study focused on the fatigue life prediction of High Modulus Asphalt Concrete (HMAC pavement using the local strain-stress method and direct tension fatigue test. First, the direct tension fatigue test at various strain levels was conducted on HMAC prism samples cut from plate specimens. Afterwards, their true stress-strain loop curves were obtained and modified to develop the strain-fatigue life equation. Then the nominal strain of HMAC course determined using finite element method was converted into local strain using the Neuber method. Finally, based on the established fatigue equation and converted local strain, a method to predict the pavement fatigue crack initiation life was proposed and the fatigue life of a typical HMAC overlay pavement which runs a risk of bottom-up cracking was predicted and validated. Results show that the proposed method was able to produce satisfactory crack initiation life.

  17. Functionalisation of polypropylene non-woven fabrics (NWFs): Functionalisation by oxyfluorination as a first step for graft polymerisation

    CSIR Research Space (South Africa)

    Vargha, V

    2011-10-01

    Full Text Available Surface oxyfluorination had been carried out on polypropylene non-woven fabric (PP NWF) samples of different morphologies and pore sizes. The modified surfaces were characterised by Attenuated Total Reflectance Fourier Transform InfraRed (ATR...

  18. The Effect of Annealing on the Elastic Modulus of Orthodontic Wires

    Science.gov (United States)

    Higginbottom, Kyle

    Introduction: Nickel Titanium orthodontic wires are currently used in orthodontic treatment due to their heat activated properties and their delivery of constant force. The objective of this study was to determine the effect of annealing on the elastic modulus of Nickel Titanium, Stainless Steel and Beta-titanium (TMA) wires. Different points along the wire were tested in order to determine how far from the annealed ends the elastic modulus of the wires was affected. Methods: Eighty (80) orthodontic wires consisting of 4 equal groups (SS/TMA/Classic NitinolRTM/Super Elastic NitinolRTM) were used as the specimens for this study. All wires were measured and marked at 5mm measurements, and cut into 33.00mm sections. The wires were heated with a butane torch until the first 13.00mm of the wires were red hot. Load deflection tests using an InstronRTM universal testing machine were run at 5mm distances from the end of the wire that had been annealed. The change in elastic modulus was then determined. Results: There was a significant difference (F = 533.001, p = 0.0005) in the change in elastic modulus for the four distances. There was also a significant difference (F = 57.571, p = 0.0005) in the change in elastic modulus for the four wire types. There was a significant interaction (F = 19.601, p = 0.005) between wire type and distance, however this interaction negated the differences between the wires. Conclusion: 1) There are significant differences in the changes in elastic modulus between the areas of the wires within the annealed section and those areas 5mm and 10mm away from the annealed section. The change in elastic modulus within the annealed section was significantly greater at 8 mm than it was at 13mm, and this was significantly greater than 18mm and 23mm (5mm and 10mm beyond the annealed section). However, there was no statistical difference in the change in elastic modulus between 5mm and 10mm away from the annealed section (18mm and 23mm respectively). 2

  19. Effects of creep and oxidation on reduced modulus in high-temperature nanoindentation

    International Nuclear Information System (INIS)

    Li, Yan; Fang, Xufei; Lu, Siyuan; Yu, Qingmin; Hou, Guohui; Feng, Xue

    2016-01-01

    Nanoindentation tests were performed on single crystal Ni-based superalloy at temperatures ranging from 20 °C to 800 °C in inert environment. Load-displacement curves at temperatures higher than 500 °C exhibit obvious creep inferred by increasing displacements at load-holding segments. Load-displacement curves obtained at 800 °C also display negative unloading stiffness. Examination of the microstructure beneath the indented area using Transmission Electron Microscope (TEM) reveals abundant dislocation piling up as well as oxide formation on the substrate. A method considering the creep effect is proposed to calculate the reduced modulus. In addition, a dimensionless ratio relating indentation depth and oxide film thickness is introduced to explain the oxidation effect on the mechanical properties derived from the load-displacement curves.

  20. High frequency acoustic microscopy for the determination of porosity and Young's modulus in high burnup uranium dioxide nuclear fuel

    International Nuclear Information System (INIS)

    Marchetti, M.; Laux, D.; Cappia, F.; Laurie, M.; Van Uffelen, P.; Rondinella, V.V.; Despaux, G.

    2015-01-01

    During irradiation UO 2 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 the porosity and of elastic properties in high burnup UO 2 pellet can be investigated via high frequency acoustic microscopy. 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 67 MWd/kgU UO 2 pellet was characterized using the acoustic microscope installed in the hot cells of the Institute of Transuranium Elements: 90 MHz frequency was applied, methanol was used as coupling liquid and VR was measured at different radial positions. By comparing the porosity values obtained via acoustic microscopy with those determined using ceramographic image analysis a good agreement was found, 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. (authors)

  1. Geometrical modulus of a casting and its influence on solidification process

    Directory of Open Access Journals (Sweden)

    F. Havlicek

    2011-10-01

    Full Text Available Object: The work analyses the importance of the known criterion for evaluating the controlled solidification of castings, so called geometrical modulus defined by N. Chvorinov as the first one. Geometrical modulus influences the solidification process. The modulus has such specificity that during the process of casting formation it is not a constant but its initial value decreases with the solidification progress because the remaining melt volume can decrease faster than its cooling surface.Methodology: The modulus is determined by a simple calculation from the ratio of the casting volume after pouring the metal in the mould to the cooled mould surface. The solidified metal volume and the cooled surface too are changed during solidification. That calculation is much more complicated. Results were checked up experimentally by measuring the temperatures in the cross-section of heavy steel castings during cooling them.Results: The given experimental results have completed the original theoretical calculations by Chvorinov and recent researches done with use of numerical calculations. The contribution explains how the geometrical modulus together with the thermal process in the casting causes the higher solidification rate in the axial part of the casting cross-section and shortening of solidification time. Practical implications: Change of the geometrical modulus negatively affects the casting internal quality. Melt feeding by capillary filtration in the dendritic network in the casting central part decreases and in such a way the shrinkage porosity volume increases. State of stress character in the casting is changed too and it increases.

  2. 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.

  3. Ultrasound estimation and FE analysis of elastic modulus of Kelvin foam

    International Nuclear Information System (INIS)

    Kim, Nohyu; Yang, Seung Yong

    2016-01-01

    The elastic modulus of a 3D-printed Kelvin foam plate is investigated by measuring the acoustic wave velocity of 1 MHz ultrasound. An isotropic tetrakaidecahedron foam with 3 mm unit cell is designed and printed layer upon layer to fabricate a Kelvin foam plate of 14 mm thickness with a 3D CAD/printer using ABS plastic. The Kelvin foam plate is completely filled with paraffin wax for impedance matching, so that the 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 and is used to calculate the elastic modulus of the Kelvin foam plate based on acousto-elasticity. Finite element method (FEM) and micromechanics is applied to the Kelvin foam plate to calculate the theoretical elastic modulus using a non-isotropic tetrakaidecahedron model. The predicted elastic modulus of the Kelvin foam plate from FEM and micromechanics model is similar, which is only 3-4% of the bulk material. The experimental value of the elastic modulus from the ultrasonic method is approximately twice as that of the numerical and theoretical methods because of the flexural deformation of the cell edges neglected in the ultrasonic method

  4. Ultrasound estimation and FE analysis of elastic modulus of Kelvin foam

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Nohyu; Yang, Seung Yong [School of Mechatronics Engineering, Korea University of Technology and Education, Cheonan (Korea, Republic of)

    2016-02-15

    The elastic modulus of a 3D-printed Kelvin foam plate is investigated by measuring the acoustic wave velocity of 1 MHz ultrasound. An isotropic tetrakaidecahedron foam with 3 mm unit cell is designed and printed layer upon layer to fabricate a Kelvin foam plate of 14 mm thickness with a 3D CAD/printer using ABS plastic. The Kelvin foam plate is completely filled with paraffin wax for impedance matching, so that the 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 and is used to calculate the elastic modulus of the Kelvin foam plate based on acousto-elasticity. Finite element method (FEM) and micromechanics is applied to the Kelvin foam plate to calculate the theoretical elastic modulus using a non-isotropic tetrakaidecahedron model. The predicted elastic modulus of the Kelvin foam plate from FEM and micromechanics model is similar, which is only 3-4% of the bulk material. The experimental value of the elastic modulus from the ultrasonic method is approximately twice as that of the numerical and theoretical methods because of the flexural deformation of the cell edges neglected in the ultrasonic method.

  5. Permeability measurements and modeling of topology-optimized metallic 3-D woven lattices

    International Nuclear Information System (INIS)

    Zhao, Longyu; Ha, Seunghyun; Sharp, Keith W.; Geltmacher, Andrew B.; Fonda, Richard W.; Kinsey, Alex H.; Zhang, Yong; Ryan, Stephen M.; Erdeniz, Dinc; Dunand, David C.; Hemker, Kevin J.; Guest, James K.; Weihs, Timothy P.

    2014-01-01

    Topology optimization was combined with a 3-D weaving technique to design and fabricate structures with optimized combinations of fluid permeability and mechanical stiffness. Two different microarchitected structures are considered: one is a “standard” weave in which all wires were included, while the other is termed an “optimized” weave as specific wires were removed to maximize the permeability of the resulting porous materials with only a limited reduction in stiffness. Permeability was measured and predicted for both structures that were 3-D woven with either Cu or Ni–20Cr wires. The as-woven wires in the Cu lattices were bonded at contact points using solder or braze while the Ni–20Cr wires were bonded at contact points using pack aluminization. Permeability was measured under laminar flow conditions in all three normal directions for unbonded and bonded samples and in the optimized structure it was found to increase between 200% and 600%, depending on direction, over the standard structures. Permeability was also predicted using finite-element modeling with as-fabricated wires positions that were identified with optical microscopy or X-ray tomography; the measurements and predictions show good agreement. Lastly, the normalized permeability values significantly exceed those found for stochastic, metallic foams and other periodic structures with a material volume fraction of over 30%

  6. 78 FR 6069 - Laminated Woven Sacks From the People's Republic of China: Preliminary Results of Antidumping...

    Science.gov (United States)

    2013-01-29

    ... the People's Republic of China: Preliminary Results of Antidumping Duty Administrative Review; 2011... antidumping duty order on laminated woven sacks (``sacks'') from the People's Republic of China (``PRC''). The period of review (``POR'') is August 1, 2011, through July 31, 2012. The review covers one exporter of...

  7. Mechanical characterization of glass fiber (woven roving/chopped strand mat E-glass fiber) reinforced polyester composites

    Science.gov (United States)

    Bhaskar, V. Vijaya; Srinivas, Kolla

    2017-07-01

    Polymer reinforced composites have been replacing most of the engineering material and their applications become more and more day by day. Polymer composites have been analyzing from past thirty five years for their betterment for adapting more applications. This paper aims at the mechanical properties of polyester reinforced with glass fiber composites. The glass fiber is reinforced with polyester in two forms viz Woven Rovings (WRG) and Chopped Strand Mat (CSMG) E-glass fibers. The composites are fabricated by hand lay-up technique and the composites are cut as per ASTM Standard sizes for corresponding tests like flexural, compression and impact tests, so that flexural strength, compression strength, impact strength and inter laminar shear stress(ILSS) of polymer matrix composites are analyzed. From the tests and further calculations, the polyester composites reinforced with Chopped Strand Mat glass fiber have shown better performance against flexural load, compression load and impact load than that of Woven Roving glass fiber.

  8. Examining Young's modulus for wood

    International Nuclear Information System (INIS)

    Perkalskis, Benjamin S; Freeman, J Reuben; Suhov, Alexander

    2004-01-01

    Symmetry considerations, dimensional analysis and simple approximations are used to derive a formula for Young's modulus of a simple anisotropic system, a straight-layer wood bar whose fibre axis makes an angle with respect to the bar's longitudinal axis. Agreement between the derived formula and experiment (carried out in far from ideal conditions) is within 10%. Improvements and extensions are suggested for this undergraduate physics experiment

  9. 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.

  10. High-capacity optical long data memory based on enhanced Young's modulus in nanoplasmonic hybrid glass composites.

    Science.gov (United States)

    Zhang, Qiming; Xia, Zhilin; Cheng, Yi-Bing; Gu, Min

    2018-03-22

    Emerging as an inevitable outcome of the big data era, long data are the massive amount of data that captures changes in the real world over a long period of time. In this context, recording and reading the data of a few terabytes in a single storage device repeatedly with a century-long unchanged baseline is in high demand. Here, we demonstrate the concept of optical long data memory with nanoplasmonic hybrid glass composites. Through the sintering-free incorporation of nanorods into the earth abundant hybrid glass composite, Young's modulus is enhanced by one to two orders of magnitude. This discovery, enabling reshaping control of plasmonic nanoparticles of multiple-length allows for continuous multi-level recording and reading with a capacity over 10 terabytes with no appreciable change of the baseline over 600 years, which opens new opportunities for long data memory that affects the past and future.

  11. Resilient modulus for unbound granular materials and subgrade soils in Egypt

    Directory of Open Access Journals (Sweden)

    Mousa Rabah

    2017-01-01

    Full Text Available Mechanistic Empirical (ME pavement design methods started to gain attention especially the last couple of years in Egypt and the Middle East. One of the challenges facing the spread of these methods in Egypt is lack of advanced properties of local soil and asphalt, which are needed as input data in ME design. Resilient modulus (Mr for example is an important engineering property that expresses the elastic behavior of soil/unbound granular materials (UGMs under cyclic traffic loading for ME design. In order to overcome the scarcity of the resilient modulus data for soil/UGMs in Egypt, a comprehensive laboratory testing program was conducted to measure resilient modulus of typical UGMs and subgrade soils typically used in pavement construction in Egypt. The factors that affect the resilient modulus of soil/UGMs were reviewed, studied and discussed. Finally, the prediction accuracy of the most well-known Mr Prediction models for the locally investigated materials was investigated.

  12. Influence of dynamic dislocation drag on amplitude dependences of damping decrement and modulus defect in lead

    International Nuclear Information System (INIS)

    Soifer, Y.M.; Golosovskii, M.A.; Kobelev, N.P.

    1981-01-01

    A study was made of the amplitude dependences of the damping decrement and the modulus defect in lead at low temperatures at frequencies of 100 kHz and 5 MHz. It was shown that in pure lead at high frequencies a change in the amplitude dependences of the damping decrement and the modulus defect under the superconducting transition is due mainly to the change in the losses caused by the dynamic drag of dislocations whereas in measurements at low frequencies the influence of the superconducting transition is due to the change in the conditions of dislocation unpinning from point defects. The influence of the dynamic dislocation drag on the amplitude dependences of the damping decrement and the modulus defect is calculated and a method is presented for experimental estimation of the contribution of dynamic effects to the amplitude-dependent internal friction

  13. Estimation of Elastic Modulus of Intact Rocks by Artificial Neural Network

    Science.gov (United States)

    Ocak, Ibrahim; Seker, Sadi Evren

    2012-11-01

    The modulus of elasticity of intact rock ( E i) is an important rock property that is used as an input parameter in the design stage of engineering projects such as dams, slopes, foundations, tunnel constructions and mining excavations. However, it is sometimes difficult to determine the modulus of elasticity in laboratory tests because high-quality cores are required. For this reason, various methods for predicting E i have been popular research topics in recently published literature. In this study, the relationships between the uniaxial compressive strength, unit weight ( γ) and E i for different types of rocks were analyzed, employing an artificial neural network and 195 data obtained from laboratory tests carried out on cores obtained from drilling holes within the area of three metro lines in Istanbul, Turkey. Software was developed in Java language using Weka class libraries for the study. To determine the prediction capacity of the proposed technique, the root-mean-square error and the root relative squared error indices were calculated as 0.191 and 92.587, respectively. Both coefficients indicate that the prediction capacity of the study is high for practical use.

  14. Thickness dependence of nanofilm elastic modulus

    Czech Academy of Sciences Publication Activity Database

    Fedorchenko, Alexander I.; Wang, A. B.; Cheng, H.H.

    2009-01-01

    Roč. 94, č. 15 (2009), s. 152111-152113 ISSN 0003-6951 Institutional research plan: CEZ:AV0Z20760514 Keywords : nanofilm * elastic modulus * thickness dependence Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.554, year: 2009 http://link.aip.org/link/?APPLAB/94/152111/1

  15. The Pathology of Weaving and Production of the Hand-woven Carpets: Heriz Region Case Study

    Directory of Open Access Journals (Sweden)

    Sepideh Taravati Mahjoubi

    2017-04-01

    Full Text Available The carpet, as one of the most precious achievement of people, is a culture. The world’s recognition of Iranian carpet and its glorification originates from endeavor of people who have integrated artistic verve with mysterious attractions of national culture and arts. This study is descriptive-analytic. The data were collected through field research method and direct communication with people and workshops of drawing, weaving, and dyeing. In fact, the assessment tools were taken to the field, and data collection was completed by questioning, interview, observation, and shooting. Then, they were used for derivation, classification, and analysis. SPSS software also used to analyze collected data. . According to the result of this study, regarding the latest forecasts for Iranian hand-woven carpet industry, carpet exports will increase in the future. Therefore, it is better to consider the weaving and marketing of the carpet as a luxury product in order to achieve the profits maintaining the incentive of production in all units involved in the hand-woven carpet’s production and also to reduce poor quality carpets available in the market.

  16. Estimation of Bulk modulus and microhardness of tetrahedral semiconductors

    International Nuclear Information System (INIS)

    Gorai, Sanjay Kumar

    2012-01-01

    A general empirical formula was found for calculating of bulk modulus (B) and microhardness (H) from electronegativity and principal quantum number of II-VI, III-V semiconductors. Constant C1, appearing the in the expression of bulk modulus and constants C2 and C3, appearing in the expression of microhardness and the exponent M have following values respectively The numerical values of C1,C2, C3 and M are respectively 206.6, 8.234, 1.291, -1.10 for II-VI 72.4, 31.87, 7.592, -0.95 for III-V semiconductors. Both electro-negativity and principal quantum number can effectively reflect on the chemical bonding behaviour of constituent atoms in these semiconductors. The calculated values of bulk modulus and microhardness are in good agreement with the reported values in the literature. Present study helps in designing novel semiconductor materials, and to further explore the mechanical properties of these semiconductors.

  17. A two-crown finite element technique for the determination of tearing modulus

    International Nuclear Information System (INIS)

    Suo, X.Z.; Combescure, A.

    1989-01-01

    The importance of approach to the subject of crack instability for the design of structures containing cracks has increased considerably over the last few years. The tearing modulus theory recently enunciated by Paris and co-workers has emerged as one of the leading criterions for stable crack growth and for instability, and the estimation of T termed Tearing modulus in the theory has since been extensively investigated theoretically as well as experimentally. Analytical methods exist for calculating the tearing modulus of various crack configurations in simple-shaped structures under certain loading conditions. However, for arbitrary structures under general loading, more sophisticated calculation techniques are required. Extending the virtual crack extension method introduced independently by Hellen and Parks, a new numerical approach for calculating the tearing modulus is presented hereafter and put in a form suitable for the instability analysis of structures containing one single crack or several interacting cracks. As it is well-known that the calculation of the energy release rate in elasticity by the virtual crack extension method is related to a stiffness derivative to which only a small region around the crack tip has a contribution, the technique described in the paper shows that it would be reasonable to evaluate the tearing modulus, or rather, the second derivative of potential energy with respect to the crack length, by means of two stiffness derivative calculations in two crowns around the crack tip. In particular, when one crown is strictly included in another one, computation is largely curtailed at this point with some saving of computer time, but a very accurate value of tearing modulus is obtained. As an interesting consequence, an another expression of the tearing modulus is carried out. In Section 4: the classical tearing modulus is proved to be precisely equivalent to a line integral which is independent of integration path. Numerical example

  18. Influence of flock coating on bending rigidity of woven fabrics

    Science.gov (United States)

    Ozdemir, O.; Kesimci, M. O.

    2017-10-01

    This work presents the preliminary results of our efforts that focused on the effect of the flock coating on the bending rigidity of woven fabrics. For this objective, a laboratory scale flocking unit is designed and flocked samples of controlled flock density are produced. Bending rigidity of the samples with different flock densities are measured on both flocked and unflocked sides. It is shown that the bending rigidity depends on both flock density and whether the side to be measured is flocked or not. Adhesive layer thickness on the bending rigidity is shown to be dramatic. And at higher basis weights, flock density gets less effective on bending rigidity.

  19. 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.

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

    International Nuclear Information System (INIS)

    You, J.H.; Hoeschen, 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

  1. 78 FR 12716 - Laminated Woven Sacks From the People's Republic of China: Negative Final Determination of...

    Science.gov (United States)

    2013-02-25

    ... visible, although, they are produced using only two inks and a screen. Petitioners contend that such graphics would normally be printed using three inks printed in register at three different print stations...-circumvention inquiry is laminated woven sacks produced with two ink colors printed in register and a screening...

  2. Young's modulus of defective graphene sheet from intrinsic thermal vibrations

    International Nuclear Information System (INIS)

    Thomas, Siby; Mrudul, M S; Ajith, K M; Valsakumar, M C

    2016-01-01

    Classical molecular dynamics simulations have been performed to establish a relation between thermally excited ripples and Young's modulus of defective graphene sheet within a range of temperatures. The presence of the out-of-plane intrinsic ripples stabilizes the graphene membranes and the mechanical stability is analyzed by means of thermal mean square vibration amplitude in the long wavelength regime. We observed that the presence of vacancy and Stone-Wales (SW) defects reduces the Young's modulus of graphene sheets. Graphene sheet with vacancy defects possess superior Young's modulus to that of a sheet with Stone-Wales defects. The obtained room temperature Young's modulus of pristine and defective graphene sheet is ∼ 1 TPa, which is comparable to the results of earlier experimental and atomistic simulation studies. (paper)

  3. Developing the elastic modulus measurement of asphalt concrete using the compressive strength test

    Science.gov (United States)

    Setiawan, Arief; Suparma, Latif Budi; Mulyono, Agus Taufik

    2017-11-01

    Elastic modulus is a fundamental property of an asphalt mixture. An analytical method of the elastic modulus is needed to determine the thickness of flexible pavement. It has a role as one of the input values on a stress-strain analysis in the finite element method. The aim of this study was to develop the measurement of the elastic modulus by using compressive strength testing. This research used a set of specimen mold tool and Delta Dimensi software to record strain changes occurring in the proving ring of compression machine and the specimens. The elastic modulus of the five types of aggregate gradation and 2 types of asphalt were measured at optimum asphalt content. Asphalt Cement 60/70 and Elastomer Modified Asphalt (EMA) were used as a binder. Manufacturing success indicators of the specimens used void-in-the-mix (VIM) 3-5 % criteria. The success rate of the specimen manufacturing was more than 76%. Thus, the procedure and the compressive strength test equipment could be used for the measurement of the elastic modulus. The aggregate gradation and asphalt types significantly affected the elastic modulus of the asphalt concrete.

  4. Young's Modulus of Single-Crystal Fullerene C Nanotubes

    Directory of Open Access Journals (Sweden)

    Tokushi Kizuka

    2012-01-01

    Full Text Available We performed bending tests on single-crystal nanotubes composed of fullerene C70 molecules by in situ transmission electron microscopy with measurements of loading forces by an optical deflection method. The nanotubes with the outer diameters of 270–470 nm were bent using simple-beam and cantilever-beam loading by the piezomanipulation of silicon nanotips. Young's modulus of the nanotubes increased from 61 GPa to 110 GPa as the outer diameter decreased from 470 nm to 270 nm. Young's modulus was estimated to be 66% of that of single-crystal C60 nanotubes of the same outer diameter.

  5. 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.

  6. Short cellulosic fiber/starch acetate composites — micromechanical modeling of Young’s modulus

    DEFF Research Database (Denmark)

    Madsen, Bo; Joffe, Roberts; Peltola, Heidi

    2011-01-01

    This study is presented to predict the Young’s modulus of injection-molded short cellulosic fiber/plasticized starch acetate composites with variable fiber and plasticizer content. A modified rule of mixtures model is applied where the effect of porosity is included, and where the fiber weight...... (density and Young’s modulus). The measured Young’s modulus of the composites varies in the range 1.1—8.3 GPa, and this is well predicted by the model calculations. A property diagram is presented to be used for the tailor-making of composites with Young’s modulus in the range 0.2—10 GPa....

  7. Modular correction method of bending elastic modulus based on sliding behavior of contact point

    International Nuclear Information System (INIS)

    Ma, Zhichao; Zhao, Hongwei; Zhang, Qixun; Liu, Changyi

    2015-01-01

    During the three-point bending test, the sliding behavior of the contact point between the specimen and supports was observed, the sliding behavior was verified to affect the measurements of both deflection and span length, which directly affect the calculation of the bending elastic modulus. Based on the Hertz formula to calculate the elastic contact deformation and the theoretical calculation of the sliding behavior of the contact point, a theoretical model to precisely describe the deflection and span length as a function of bending load was established. Moreover, a modular correction method of bending elastic modulus was proposed, via the comparison between the corrected elastic modulus of three materials (H63 copper–zinc alloy, AZ31B magnesium alloy and 2026 aluminum alloy) and the standard modulus obtained from standard uniaxial tensile tests, the universal feasibility of the proposed correction method was verified. Also, the ratio of corrected to raw elastic modulus presented a monotonically decreasing tendency as the raw elastic modulus of materials increased. (technical note)

  8. Bisphosphonate treatment affects trabecular bone apparent modulus through micro-architecture rather than matrix properties

    DEFF Research Database (Denmark)

    Ding, Ming

    2004-01-01

    and trabecular architecture independently. Conventional histomorphometry and microdamage data were obtained from the second and third lumbar vertebrae of the same dogs [Bone 28 (2001) 524]. Bisphosphonate treatment resulted in an increased apparent Young's modulus, decreased bone turnover, increased calcified...... matrix density, and increased microdamage. We could not detect any change in the effective Young's modulus of the calcified matrix in the bisphosphonate treated groups. The observed increase in apparent Young's modulus was due to increased bone mass and altered trabecular architecture rather than changes...... in the calcified matrix modulus. We hypothesize that the expected increase in the Young's modulus of the calcified matrix due to the increased calcified matrix density was counteracted by the accumulation of microdamage. Udgivelsesdato: 2004 May...

  9. Characterization of multilayer nitride coatings by electron microscopy and modulus mapping

    International Nuclear Information System (INIS)

    Pemmasani, Sai Pramod; Rajulapati, Koteswararao V.; Ramakrishna, M.; Valleti, Krishna; Gundakaram, Ravi C.; Joshi, Shrikant V.

    2013-01-01

    This paper discusses multi-scale characterization of physical vapour deposited multilayer nitride coatings using a combination of electron microscopy and modulus mapping. Multilayer coatings with a triple layer structure based on TiAlN and nanocomposite nitrides with a nano-multilayered architecture were deposited by Cathodic arc deposition and detailed microstructural studies were carried out employing Energy Dispersive Spectroscopy, Electron Backscattered Diffraction, Focused Ion Beam and Cross sectional Transmission Electron Microscopy in order to identify the different phases and to study microstructural features of the various layers formed as a result of the deposition process. Modulus mapping was also performed to study the effect of varying composition on the moduli of the nano-multilayers within the triple layer coating by using a Scanning Probe Microscopy based technique. To the best of our knowledge, this is the first attempt on modulus mapping of cathodic arc deposited nitride multilayer coatings. This work demonstrates the application of Scanning Probe Microscopy based modulus mapping and electron microscopy for the study of coating properties and their relation to composition and microstructure. - Highlights: • Microstructure of a triple layer nitride coating studied at multiple length scales. • Phases identified by EDS, EBSD and SAED (TEM). • Nanolayered, nanocomposite structure of the coating studied using FIB and TEM. • Modulus mapping identified moduli variation even in a nani-multilayer architecture

  10. Computational experiences with variable modulus, elastic-plastic, and viscoelastic concrete models

    International Nuclear Information System (INIS)

    Anderson, C.A.

    1981-01-01

    Six years ago the Reactor Safety Research Division of the Nuclear Regulatory Commission (NRC) approached the Los Alamos National Laboratory to develop a comprehensive concrete structural analysis code to predict the static and dynamic behavior of Prestressed Concrete Reactor Vessels (PCRVs) that serve as the containment structure of a High-Temperature Gas-Cooled Reactor. The PCRV is a complex concrete structure that must be modeled in three dimensions and posseses other complicating features such as a steel liner for the reactor cavity and woven cables embedded vertically in the PCRV and wound circumferentially on the outside of the PCRV. The cables, or tendons, are used for prestressing the reactor vessel. In addition to developing the computational capability to predict inelastic three dimensional concrete structural behavior, the code response was verified against documented experiments on concrete structural behavior. This code development/verification effort is described

  11. Influence of various factors on the Young modulus of metals

    International Nuclear Information System (INIS)

    Drapkin, B.M.

    1980-01-01

    The equivalence of temperature and pressure effects in the elastic area on the Young modulus of different metals (Ni, Mo, W, Na, Fe and ets.) is established on the basis of the analysis of literature and calculated data. It is shown that the value of the change in the Young modulus of the alloy is connected with mutual arrangement of alloy components in the periodic system of elements

  12. 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

    ... the People's Republic of China: Preliminary Results of the Second Administrative Review AGENCY: Import... laminated woven sacks (``LWS'') from the People's Republic of China (``PRC'') covering the period August 1, 2009, through July 31, 2010. This review covers imports of subject merchandise from one manufacturer...

  13. Effect of single-particle magnetostriction on the shear modulus of compliant magnetoactive elastomers

    Science.gov (United States)

    Kalita, Viktor M.; Snarskii, Andrei A.; Shamonin, Mikhail; Zorinets, Denis

    2017-03-01

    The influence of an external magnetic field on the static shear strain and the effective shear modulus of a magnetoactive elastomer (MAE) is studied theoretically in the framework of a recently introduced approach to the single-particle magnetostriction mechanism [V. M. Kalita et al., Phys. Rev. E 93, 062503 (2016), 10.1103/PhysRevE.93.062503]. The planar problem of magnetostriction in an MAE with magnetically soft inclusions in the form of a thin disk (platelet) having the magnetic anisotropy in the plane of this disk is solved analytically. An external magnetic field acts with torques on magnetic filler particles, creates mechanical stresses in the vicinity of inclusions, induces shear strain, and increases the effective shear modulus of these composite materials. It is shown that the largest effect of the magnetic field on the effective shear modulus should be expected in MAEs with soft elastomer matrices, where the shear modulus of the matrix is less than the magnetic anisotropy constant of inclusions. It is derived that the effective shear modulus is nonlinearly dependent on the external magnetic field and approaches the saturation value in magnetic fields exceeding the field of particle anisotropy. It is shown that model calculations of the effective shear modulus correspond to a phenomenological definition of effective elastic moduli and magnetoelastic coupling constants. The obtained theoretical results compare well with known experimental data. Determination of effective elastic coefficients in MAEs and their dependence on magnetic field is discussed. The concentration dependence of the effective shear modulus at higher filler concentrations has been estimated using the method of Padé approximants, which predicts that both the absolute and relative changes of the magnetic-field-dependent effective shear modulus will significantly increase with the growing concentration of filler particles.

  14. 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.

  15. Determination of correlation between backflow volume and mitral valve leaflet young modulus from two dimensional echocardiogram images

    Science.gov (United States)

    Jong, Rudiyanto P.; Osman, Kahar; Adib, M. Azrul Hisham M.

    2012-06-01

    Mitral valve prolapse without proper monitoring might lead to a severe mitral valve failure which eventually leads to a sudden death. Additional information on the mitral valve leaflet condition against the backflow volume would be an added advantage to the medical practitioner for their decision on the patients' treatment. A study on two dimensional echocardiography images has been conducted and the correlations between the backflow volume of the mitral regurgitation and mitral valve leaflet Young modulus have been obtained. Echocardiogram images were analyzed on the aspect of backflow volume percentage and mitral valve leaflet dimensions on different rates of backflow volume. Young modulus values for the mitral valve leaflet were obtained by using the principle of elastic deflection and deformation on the mitral valve leaflet. The results show that the backflow volume increased with the decrease of the mitral valve leaflet Young modulus which also indicate the condition of the mitral valve leaflet approaching failure at high backflow volumes. Mitral valve leaflet Young modulus values obtained in this study agreed with the healthy mitral valve leaflet Young modulus from the literature. This is an initial overview of the trend on the prediction of the behaviour between the fluid and the structure of the blood and the mitral valve which is extendable to a larger system of prediction on the mitral valve leaflet condition based on the available echocardiogram images.

  16. An Integrated Computational Materials Engineering Method for Woven Carbon Fiber Composites Preforming Process

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-10-19

    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.

  17. The effect of magnetic stress and stiffness modulus on resonant characteristics of Ni-Mn-Ga ferromagnetic shape memory alloy actuators

    International Nuclear Information System (INIS)

    Techapiesancharoenkij, Ratchatee; Kostamo, Jari; Allen, Samuel M.; O'Handley, Robert C.

    2011-01-01

    The prospect of using ferromagnetic shape memory alloys (FSMAs) is promising for a resonant actuator that requires large strain output and a drive frequency below 1 kHz. In this investigation, three FSMA actuators, equipped with tetragonal off-stoichiometric Ni 2 MnGa single crystals, were developed to study their frequency response and resonant characteristics. The first actuator, labeled as A1, was constructed with low-k bias springs and one Ni-Mn-Ga single crystal. The second actuator, labeled as A2, was constructed with high-k bias springs and one Ni-Mn-Ga crystal. The third actuator, labeled as A3, was constructed with high-k bias springs and two Ni-Mn-Ga crystals connected in parallel. The three actuators were magnetically driven over the frequency range of 10 Hz-1 kHz under 2 and 3.5 kOe magnetic-field amplitudes. The field amplitude of 2 kOe is insufficient to generate significant strain output from all three actuators; the maximum magnetic-field-induced strain (MFIS) at resonance is 2%. The resonant MFIS output improves to 5% under 3.5-kOe amplitude. The frequency responses of all three actuators show a strong effect of the spring k constant and the Ni-Mn-Ga modulus stiffness on the resonant frequencies. The resonant frequency of the Ni-Mn-Ga actuator was raised from 450 to 650 Hz by increasing bias spring k constant and/or the number of Ni-Mn-Ga crystals. The higher number of the Ni-Mn-Ga crystals not only increases the magnetic force output but also raises the total stiffness of the actuator resulting in a higher resonant frequency. The effective modulus of the Ni-Mn-Ga is calculated from the measured resonant frequencies using the mass-spring equation; the calculated modulus values for the three actuators fall in the range of 50-60 MPa. The calculated effective modulus appears to be close to the average modulus value between the low twinning modulus and high elastic modulus of the untwined Ni-Mn-Ga crystal. - Highlights: → Dynamic FSMA actuation shows

  18. Diagnostic procedure on brake pad assembly based on Young's modulus estimation

    International Nuclear Information System (INIS)

    Chiariotti, P; Santolini, C; Tomasini, E P; Martarelli, M

    2013-01-01

    Quality control of brake pads is an important issue, since the pad is a key component of the braking system. Typical damage of a brake pad assembly is the pad–backing plate detachment that affects and modifies the mechanical properties of the whole system. The most sensitive parameter to the damage is the effective Young's modulus, since the damage induces a decrease of the pad assembly stiffness and therefore of its effective Young's modulus: indeed its variation could be used for diagnostic purposes. The effective Young's modulus can be estimated from the first bending resonance frequency identified from the frequency response function measured on the pad assembly. Two kinds of excitation methods, i.e. conventional impulse excitation and magnetic actuation, will be presented and two different measurement sensors, e.g. laser Doppler vibrometer and microphone, analyzed. The robustness of the effective Young's modulus as a diagnostic feature will be demonstrated in comparison to the first bending resonance frequency, which is more sensitive to geometrical dimensions. Variability in the sample dimension, in fact, will induce a variation of the resonance frequency which could be mistaken for damage. The diagnostic approach has been applied to a set of undamaged and damaged pad assemblies showing good performance in terms of damage identification. The environmental temperature can be an important interfering input for the diagnostic procedure, since it influences the effective Young's modulus of the assembly. For that reason, a test at different temperatures in the range between 15 °C and 30 °C has been performed, evidencing that damage identification technique is efficient at any temperature. The robustness of the Young's modulus as a diagnostic feature with respect to damping is also presented. (paper)

  19. Young's modulus of a copper-stabilized niobium-titanium superconductive wire

    International Nuclear Information System (INIS)

    Ledbetter, H.M.; Moulder, J.C.; Austin, M.W.

    1980-01-01

    Young's modulus was determined for a 0.6-mm-dia niobium-titanium superconductive wire. Two methods were used: continuous-wave-resonance and laser-pulse-excitation. Young's moduli were also determined for the components - copper and Nb-Ti - in both wire and bulk forms. Some mechanical-deformation effects on Young's modulus were also measured. From the component' elastic moduli, that of the composite was predicted accurately by a simple rule-of-mixtures relationship

  20. High frequency acoustic microscopy for the determination of porosity and Young's modulus in high burnup uranium dioxide nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    Marchetti, M. [European Commission, Joint Research Centre, Institute for Transuranium Elements P.O. Box 2340 76125 Karlsruhe (Germany); University of Montpellier, IES, UMR 5214, F-34000, Montpellier (France); Laux, D. [University of Montpellier, IES, UMR 5214, F-34000, Montpellier (France); CNRS, IES, UMR 5214, F-34000, Montpellier (France); Cappia, F. [European Commission, Joint Research Centre, Institute for Transuranium Elements P.O. Box 2340 76125 Karlsruhe (Germany); Technische Universitaet Muenchen, Department of Nuclear Engineering, Boltzmannstrasse 15, 85747 Garching bei Munchen (Germany); Laurie, M.; Van Uffelen, P.; Rondinella, V.V. [European Commission, Joint Research Centre, Institute for Transuranium Elements P.O. Box 2340 76125 Karlsruhe (Germany); Despaux, G. [University of Montpellier, IES, UMR 5214, F-34000, Montpellier (France); CNRS, IES, UMR 5214, F-34000, Montpellier (France)

    2015-07-01

    During irradiation UO{sub 2} 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 the porosity and of elastic properties in high burnup UO{sub 2} pellet can be investigated via high frequency acoustic microscopy. 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 67 MWd/kgU UO{sub 2} pellet was characterized using the acoustic microscope installed in the hot cells of the Institute of Transuranium Elements: 90 MHz frequency was applied, methanol was used as coupling liquid and VR was measured at different radial positions. By comparing the porosity values obtained via acoustic microscopy with those determined using ceramographic image analysis a good agreement was found, 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. (authors)

  1. The effects of the modulus of the lens material on intraocular pressure measurement through soft contact lenses.

    Science.gov (United States)

    Boyraz, S; Güngör, I

    2013-09-01

    To investigate the effects of the modulus of the lens material on the intraocular pressure measurement using the Tono-Pen XL applanation tonometer through soft contact lenses. Thirty eyes of 15 patients with myopia were evaluated. Intraocular pressure (IOP) measurements were performed using Tono-Pen XL directly over cornea, and subsequently through three soft contact lenses made up of different lens materials. All were -3.00 diopter soft contact lenses: lotrafilcon A with a low water content (24%) and high modulus (1.4 MPa) (CL-I), balafilcon A with a moderate water content (36%) and moderate modulus (1.1 MPa) (CL-II), and vifilcon A with a moderate water content (55%) and low modulus (0.79 MPa) (CL-III). IOP measurements through contact lenses were compared with each other, and with direct corneal measurements. The mean age of the patients (11 males and 4 females) was 26.86±5.62 years. All measurements obtained through CLs were significantly higher than the direct corneal measurements. The measurements through CLs differed by 4.61±0.54 mmHg (P=0,001), 2.9±0.46 mmHg (P=0.001), and 1.94±0.51 mmHg (P=0,003) for CL-I, CL-II and CL-III, respectively. In the paired comparisons of measurements through CLs, all comparisons were significant except the comparison of measurements through CL-II and CL-III (P=0.128). IOP measurements through silicone-hydrogel contact lenses with a high modulus and low water content were higher compared to the other contact lenses. While measuring IOP through CLs, the clinicians should consider the effect of the lens material and the features of the device used.

  2. Structural relaxation monitored by instantaneous shear modulus

    DEFF Research Database (Denmark)

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

    1998-01-01

    time definition based on a recently proposed expression for the relaxation time, where G [infinity] reflects the fictive temperature. All parameters entering the reduced time were determined from independent measurements of the frequency-dependent shear modulus of the equilibrium liquid....

  3. Effects of Crimped Fiber Paths on Mixed Mode Delamination Behaviors in Woven Fabric Composites

    Science.gov (United States)

    2016-09-01

    of several fabric weave styles and crimp gradients on the damage tolerance and energy absorption capacities in 20-ply Kevlar / epoxy composite...Styles and Crimp Gradients on Woven Kevlar Epoxy Composites,” Experimental Mechanics, vol. 56, no. 4, pp. 617–635, 2016. 12. ABAQUS, Ver. 6.10...mismatched element sizes between interface surfaces. Benzeggagh and Kenane3 conducted experimental tests and fractography on 6-mm-thick E-glass/ epoxy

  4. Hardness and Elastic Modulus of Titanium Nitride Coatings Prepared by Pirac Method

    Science.gov (United States)

    Wu, Siyuan; Wu, Shoujun; Zhang, Guoyun; Zhang, Weiguo

    In the present work, hardness and elastic modulus of a titanium nitride coatings prepared on Ti6Al4V by powder immersion reaction-assisted coating (PIRAC) are tested and comparatively studied with a physical vapor deposition (PVD) TiN coating. Surface hardness of the PIRAC coatings is about 11GPa, much lower than that of PVD coating of 22GPa. The hardness distribution profile from surface to substrate of the PVD coatings is steeply decreased from ˜22GPa to ˜4.5GPa of the Ti6Al4V substrate. The PIRAC coatings show a gradually decreasing hardness distribution profile. Elastic modulus of the PVD coating is about 426GPa. The PIRAC coatings show adjustable elastic modulus. Elastic modulus of the PIRAC coatings prepared at 750∘C for 24h and that at 800∘C for 8h is about 234 and 293GPa, respectively.

  5. Investigation of modulus hardening of various co-clusters in aged Al-Cu-Mg-Ag alloy by atom probe tomography

    Energy Technology Data Exchange (ETDEWEB)

    Bai, Song [Key Laboratory of Nonferrous Metal Materials Science and Engineering, Ministry of Education, Central South University, Changsha 410083 (China); School of Material Science and Engineering, Central South University, Changsha 410083 (China); Liu, Zhiyi, E-mail: liuzhiyi@csu.edu.cn [Key Laboratory of Nonferrous Metal Materials Science and Engineering, Ministry of Education, Central South University, Changsha 410083 (China); School of Material Science and Engineering, Central South University, Changsha 410083 (China); Ying, Puyou; Wang, Jian; Li, Junlin [Key Laboratory of Nonferrous Metal Materials Science and Engineering, Ministry of Education, Central South University, Changsha 410083 (China); School of Material Science and Engineering, Central South University, Changsha 410083 (China)

    2016-06-21

    The modulus hardening capability of various co-clusters in a low Cu/Mg ratio Al-Cu-Mg-Ag alloy aged at 165 °C is investigated by quantitative atom probe tomography analysis. Prolonged aging from 5 min to 2 h leads to the simultaneous increase in the critical shear stress of both Mg-Ag and Cu-Mg co-clusters. Regardless of the higher shear modulus of Cu-Mg co-clusters, calculation results show that Mg-Ag co-clusters possess a greater modulus hardening capability than Cu-Mg co-clusters, suggesting its primary contribution to the rapid hardening at the early aging stage. As aging extends from 30 min to 2 h, the increment in the critical shear stress of Mg-Ag co-clusters is lower than that of Cu-Mg co-clusters due to the precipitation of high density Ω phase. In addition, the shear modulus of Mg-Ag co-clusters is generally independent on its size at each investigated condition.

  6. Investigation of modulus hardening of various co-clusters in aged Al-Cu-Mg-Ag alloy by atom probe tomography

    International Nuclear Information System (INIS)

    Bai, Song; Liu, Zhiyi; Ying, Puyou; Wang, Jian; Li, Junlin

    2016-01-01

    The modulus hardening capability of various co-clusters in a low Cu/Mg ratio Al-Cu-Mg-Ag alloy aged at 165 °C is investigated by quantitative atom probe tomography analysis. Prolonged aging from 5 min to 2 h leads to the simultaneous increase in the critical shear stress of both Mg-Ag and Cu-Mg co-clusters. Regardless of the higher shear modulus of Cu-Mg co-clusters, calculation results show that Mg-Ag co-clusters possess a greater modulus hardening capability than Cu-Mg co-clusters, suggesting its primary contribution to the rapid hardening at the early aging stage. As aging extends from 30 min to 2 h, the increment in the critical shear stress of Mg-Ag co-clusters is lower than that of Cu-Mg co-clusters due to the precipitation of high density Ω phase. In addition, the shear modulus of Mg-Ag co-clusters is generally independent on its size at each investigated condition.

  7. Quick analytical separation of glucose and fructose with impregnated woven glass fiber

    International Nuclear Information System (INIS)

    Jones, S.C.

    1978-01-01

    (1) A wide separation of glucose and fructose was obtained in 30 min with simple, inexpensive equipment using polysilicic impregnated woven glass fiber and the solvent acetone-n-butanol-1 M H 3 BO 3 (50:40:10). (2) A calibration of a radiochromatogram scanner was performed for 11 C. (3) Three Rsub(F) values could be compared to provide positive chemical identification of [ 11 C]glucose and [ 11 C]fructose. (4) Radiochemical composition and approximate specific activity were determined from a small aliquot (1-4 μl). (Auth.)

  8. Room temperature Young's modulus, shear modulus, Poisson's ratio and hardness of PbTe-PbS thermoelectric materials

    Energy Technology Data Exchange (ETDEWEB)

    Ni, Jennifer E [Chemical Engineering and Materials Science Department, Michigan State University, East Lansing, MI 48824 (United States); Case, Eldon D., E-mail: casee@egr.msu.edu [Chemical Engineering and Materials Science Department, Michigan State University, East Lansing, MI 48824 (United States); Khabir, Kristen N; Stewart, Ryan C [Chemical Engineering and Materials Science Department, Michigan State University, East Lansing, MI 48824 (United States); Wu, Chun-I; Hogan, Timothy P [Electrical and Computer Engineering Department, Michigan State University, East Lansing, MI 48824 (United States); Timm, Edward J [Mechanical Engineering Department, Michigan State University, East Lansing, MI 48824 (United States); Girard, Steven N; Kanatzidis, Mercouri G [Department of Chemistry, Northwestern University, Evanston, IL (United States)

    2010-06-15

    Two-phase PbTe-PbS materials, in which PbS is a nanostructured phase, are promising thermoelectric materials for the direct conversion of heat energy into electricity. In this study, a Vickers indentation mean hardness of 1.18 {+-} 0.09 GPa was measured for hot pressed specimens Pb{sub 0.95}Sn{sub 0.05}Te-PbS 8% while the mean hardness of cast specimens was 0.68 {+-} 0.07 GPa. The mean fracture toughness of the not pressed specimens was estimated as 0.35 {+-} 0.04 MPa m{sup 1/2} via Vickers indentation. Resonant Ultrasound Spectroscopy (RUS) measurements on hot pressed specimens gave mean values of Young's modulus, shear modulus and Poisson's ratio of 53.1 GPa, 21.4 GPa and 0.245, respectively while for the cast specimens the Young's and shear moduli were about 10% lower than for the hot pressed, with a mean value of Poisson's ratio of 0.245. The differences between the hardness and elastic moduli values for the cast and hot pressed specimens are discussed.

  9. Young modulus and internal friction of a fiber-reinforced composite

    International Nuclear Information System (INIS)

    Ledbetter, H.M.; Lei, M.; Austin, M.W.

    1986-01-01

    By a kilohertz-frequency resonance method we determined the Young modulus and internal friction of a uniaxially fiber-reinforced composite. The composite comprised glass fibers in an epoxy-resin matrix. We studied three fiber contents: 0, 41, and 49 vol %. The Young modulus fit a linear rule of mixture. The internal friction fit a classical free-damped-oscillator model where one assumes a linear rule of mixture for three quantities: mass, force constant, and mechanical-resistance constant

  10. Nonlinear Multiscale Modeling of 3D Woven Fiber Composites under Ballistic Loading

    Science.gov (United States)

    2013-07-11

    estimates (Nemat-Nasser 1993). We denote the fiber and matrix Young’s modulus, shear modulus and Poisson ratio is denoted as Ef ,ν f ,µ f and Em,νm...2008) which need tracking of cracks explicitly with restrictions on periodicity are impractical for complex, dynamic loading of fiber reinforced ...and Rotem 1973) is often used to initiate the damage modes in fiber reinforced composite. According to the criteria damage accumulation starts when

  11. Modelling the Effect of Weave Structure and Fabric Thread Density on Mechanical and Comfort Properties of Woven Fabrics

    Directory of Open Access Journals (Sweden)

    Maqsood Muhammad

    2016-09-01

    Full Text Available The paper investigates the effects of weave structure and fabric thread density on the comfort and mechanical properties of various test fabrics woven from polyester/cotton yarns. Three different weave structures, that is, 1/1 plain, 2/1 twill and 3/1 twill, and three different fabric densities were taken as input variables whereas air permeability, overall moisture management capacity, tensile strength and tear strength of fabrics were taken as response variables and a comparison is made of the effect of weave structure and fabric density on the response variables. The results of fabric samples were analysed in Minitab statistical software. The coefficients of determinations (R-sq values of the regression equations show a good predictive ability of the developed statistical models. The findings of the study may be helpful in deciding appropriate manufacturing specifications of woven fabrics to attain specific comfort and mechanical properties.

  12. Variation of the Young's modulus with plastic strain applying to elastoplastic software

    International Nuclear Information System (INIS)

    Morestin, F.; Boivin, M.

    1993-01-01

    Work hardening of steel involves modifications of the elastic properties of the material, for instance, an increase of its yield stress. It may be also the cause of an appreciable decrease of the Young's modulus. This property decreases as plastic strain increases. Experiments with a microcomputer controlled tensile test machine indicated that diminution could reach more than 10% of the initial value, after only 5% of plastic strain. In spite of this fact, lots of elastoplastic softwares don't combine the decrease of the Young's modulus with plastification though it may involve obvious differences among results. As an application we have developed a software which computes the deformation of steel sheet in press forming, after springback. This software takes into account the decrease of the Young's modulus and its results are very close to experimental values. Quite arbitrarily, we noticed a recovery of the Young's modulus of plastified specimens after few days but not for all steels tested. (author)

  13. 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.

  14. Mechanical Researches on Young's Modulus of SCS Nanostructures

    Directory of Open Access Journals (Sweden)

    Qinhua Jin

    2009-01-01

    Full Text Available Nanostructures of SingleCrystalSilicon (SCS with superior electrical, mechanical, thermal, and optical properties are emerging in the development of novel nanodevices. Mechanical properties especially Young's modulus are essential in developing and utilizing such nanodevices. In this paper, experimental researches including bending tests, resonance tests, and tensile tests on Young' s modulus of nanoscaled SCS are reviewed, and their results are compared. It was found that the values of E measured by different testing methods cannot match to each other. As the differences cannot be explained as experimental errors, it should be understood by taking surface effect into account. With a simplified model, we qualitatively explained the difference in E value measured by tensile test and by resonance test for Si nanobeams.

  15. Temperature dependence of bulk modulus and second-order elastic constants

    International Nuclear Information System (INIS)

    Singh, P.P.; Kumar, Munish

    2004-01-01

    A simple theoretical model is developed to investigate the temperature dependence of the bulk modulus and second order elastic constants. The method is based on the two different approaches viz. (i) the theory of thermal expansivity formulated by Suzuki, based on the Mie-Gruneisen equation of state, (ii) the theory of high-pressure-high-temperature equation of state formulated by Kumar, based on thermodynamic analysis. The results obtained for a number of crystals viz. NaCl, KCl, MgO and (Mg, Fe) 2 SiO 4 are discussed and compared with the experimental data. It is concluded that the Kumar formulation is far better that the Suzuki theory of thermal expansivity

  16. E-modulus evolution and its relation to solids formation of pastes from commercial cements

    International Nuclear Information System (INIS)

    Maia, Lino; Azenha, Miguel; Geiker, Mette; Figueiras, Joaquim

    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 recently developed methodology allowed continuous monitoring of E-modulus from the time of casting. The methodology is a variant of classic resonant frequency methods, which are based on determination of the first resonant frequency of a composite beam containing the material. The hydration kinetics — and thus the rate of formation of solids — was determined using chemical shrinkage measurements. For the cements studied similar relationships between E-modulus and chemical shrinkage were observed for comparable water-to-binder ratio. For commercial cements it is suggested to model the E-modulus evolution based on the amount of binder reacted, instead of the degree of hydration.

  17. 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

    ... the People's Republic of China: Final Results of Expedited First Sunset Review of the Antidumping Duty...'') initiated the first five-year (``sunset'') review of the antidumping duty order on laminated woven sacks from the People's Republic of China (``PRC'') pursuant to section 751(c) of the Tariff Act of 1930, as...

  18. 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.

  19. Nano-fillers to tune Young’s modulus of silicone matrix

    International Nuclear Information System (INIS)

    Xia Lijin; Xu Zhonghua; Sun Leming; Caveney, Patrick M.; Zhang Mingjun

    2013-01-01

    In this study, we investigated nanoparticles, nanofibers, and nanoclays for their filler effects on tuning the Young’s modulus of silicone matrix, a material with broad in vivo applications. Nano-fillers with different shapes, sizes, and surface properties were added into silicone matrix, and then their filler effects were evaluated through experimental studies. It was found that spherical nanoparticles could clearly improve Young’s modulus of the silicone matrix, while nanoclays and carbon nanofibers had limited effects. Smaller spherical nanoparticles were better in performance compared to larger nanoparticles. In addition, enhanced distribution of the nanoparticles in the matrix has been observed to improve the filler effect. In order to minimize toxicity of the nanoparticles for in vivo applications, spherical nanoparticles coated with amine, acid, or hydroxide groups were also investigated, but they were found only to diminish the filler effect of nanoparticles. This study demonstrated that spherical nanoparticles could serve as fillers to tune Young’s modulus of silicone matrix for potential applications in medicine.

  20. A Regev-Type Fully Homomorphic Encryption Scheme Using Modulus Switching

    Science.gov (United States)

    Chen, Zhigang; Wang, Jian; Song, Xinxia

    2014-01-01

    A critical challenge in a fully homomorphic encryption (FHE) scheme is to manage noise. Modulus switching technique is currently the most efficient noise management technique. When using the modulus switching technique to design and implement a FHE scheme, how to choose concrete parameters is an important step, but to our best knowledge, this step has drawn very little attention to the existing FHE researches in the literature. The contributions of this paper are twofold. On one hand, we propose a function of the lower bound of dimension value in the switching techniques depending on the LWE specific security levels. On the other hand, as a case study, we modify the Brakerski FHE scheme (in Crypto 2012) by using the modulus switching technique. We recommend concrete parameter values of our proposed scheme and provide security analysis. Our result shows that the modified FHE scheme is more efficient than the original Brakerski scheme in the same security level. PMID:25093212

  1. A simple model for calculating the bulk modulus of the mixed ionic ...

    Indian Academy of Sciences (India)

    thermophysical properties, viz., bulk modulus, molecular force constant, reststrahlen fre- quency and Debye temperature using the three-body potential model. The calculated bulk modulus, from the TBPM model, for the pure end members (NH4Cl and NH4Br) are in agreement with the experimental values, as shown in ...

  2. Change and anisotropy of elastic modulus in sheet metals due to plastic deformation

    Science.gov (United States)

    Ishitsuka, Yuki; Arikawa, Shuichi; Yoneyama, Satoru

    2015-03-01

    In this study, the effect of the plastic deformation on the microscopic structure and the anisotropy of the elastic modulus in the cold-rolled steel sheet (SPCC) is investigated. Various uniaxial plastic strains (0%, 2.5%, 5%, 7.5%, and 10%) are applied to the annealed SPCC plates, then, the specimens for the tensile tests are cut out from them. The elastic moduli in the longitudinal direction and the transverse direction to the direction that are pre-strained are measured by the tensile tests. Cyclic tests are performed to investigate the effects of the internal friction caused by the movable dislocations in the elastic deformation. Also, the movable dislocations are quantified by the boundary tracking for TEM micrographs. In addition, the behaviors of the change of the elastic modulus in the solutionized and thermal aged aluminum alloy (A5052) are measured to investigate the effect on the movable dislocations with the amount of the depositions. As a result in SPCC, the elastic moduli of the 0° and 90° directions decrease more than 10% as 10% prestrain applied. On the other hand, the elastic modulus shows the recovery behavior after the strain aging and the annealing. The movable dislocation and the internal friction show a tendency to increase as the plastic strain increases. The marked anisotropy is not observed in the elastic modulus and the internal friction. The elastic modulus in A5052 with many and few depositions decreases similarly by the plastic deformation. From the above, the movable dislocations affect the elastic modulus strongly without depending on the deposition amount. Moreover, the elastic modulus recovers after the plastic deformation by reducing the effects of them with the strain aging and the heat treatment.

  3. 76 FR 21333 - Laminated Woven Sacks From the People's Republic of China: Final Results of Second Antidumping...

    Science.gov (United States)

    2011-04-15

    ..., 75 FR 60076 (September 29, 2010). The review was initiated with respect to Zibo Aifudi Plastic... one or both sides of the fabric; laminated by any method either to an exterior ply of plastic film... weight. Laminated woven sacks are typically used for retail packaging of consumer goods such as pet foods...

  4. Experimental methods to characterize the woven composite prepreg behavior during the preforming process

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Weizhao; Ren, Huaqing; Lu, Jie; Zhang, Zixuan; Su, Lingxuan; Wang, Q Jane; Zeng, Danielle; Su, Xuming; Cao, Jian

    2016-09-19

    This paper reports several characterization methods of the properties of the uncured woven prepreg during the preforming process. The uniaxial tension, bias-extension, and bending tests are conducted to measure the in-plane properties of the material. The friction tests utilized to reveal the prepreg-prepreg and prepreg-forming tool interactions. All these tests are performed within the temperature range of the real manufacturing process. The results serve as the inputs to the numerical simulation for the product prediction and preforming process parameter optimization.

  5. Linear analysis using secants for materials with temperature dependent nonlinear elastic modulus and thermal expansion properties

    Science.gov (United States)

    Pepi, John W.

    2017-08-01

    Thermally induced stress is readily calculated for linear elastic material properties using Hooke's law in which, for situations where expansion is constrained, stress is proportional to the product of the material elastic modulus and its thermal strain. When material behavior is nonlinear, one needs to make use of nonlinear theory. However, we can avoid that complexity in some situations. For situations in which both elastic modulus and coefficient of thermal expansion vary with temperature, solutions can be formulated using secant properties. A theoretical approach is thus presented to calculate stresses for nonlinear, neo-Hookean, materials. This is important for high acuity optical systems undergoing large temperature extremes.

  6. Damage development in woven fabric composites during tension-tension fatigue

    DEFF Research Database (Denmark)

    Hansen, U.

    1999-01-01

    of the operating fatigue damage mechanism(s). Fatigue leads to a degradation of material properties. Consequently, in connection with impact induced local stress raisers, fatigue produces continuously changing non-uniform stress fields because of stress redistribution effects. Other models addressing evolution...... of fatigue damage in composite materials have not been able to simulate evolving nonuniform stress fields. Therefore. in the second part of this paper, an analytical/numerical approach capable of addressing these issues is also proposed.......Impacted woven fabric composites were tested in tension-tension fatigue. In contrast to results from static testing, the effects of low energy impact damage in a fatigue environment were found to be the critical element leading to failure of the specimen. This difference emphasizes the need...

  7. Effective Elastic Modulus of Structured Adhesives: From Biology to Biomimetics

    Directory of Open Access Journals (Sweden)

    Xin Wang

    2017-06-01

    Full Text Available Micro- and nano-hierarchical structures (lamellae, setae, branches, and spatulae on the toe pads of many animals play key roles for generating strong but reversible adhesion for locomotion. The hierarchical structure possesses significantly reduced, effective elastic modulus (Eeff, as compared to the inherent elastic modulus (Einh of the corresponding biological material (and therefore contributes to a better compliance with the counterpart surface. Learning from nature, three types of hierarchical structures (namely self-similar pillar structure, lamella–pillar hybrid structure, and porous structure have been developed and investigated.

  8. Evaluating elastic modulus and strength of hard coatings by relative method

    International Nuclear Information System (INIS)

    Bao, Y.W.; Zhou, Y.C.; Bu, X.X.; Qiu, Y.

    2007-01-01

    A simple approach named relative method is developed for determining the elastic modulus and strength of hard coatings. Analytical relationship among the moduli of the film, the substrate, and the film/substrate system was derived based on bending model, from which the elastic modulus of the coating can be determined uniquely via the measured moduli of the samples before and after coating. Furthermore, the relationship between the strength of the films and the bending strength of the coated sample is derived, thus both the modulus and the strength of coating can be evaluated via traditional tests on coated samples. Mathematic expressions of those calculations were derived, respectively for rectangular beam samples with three types of coating configurations: single face coating, sandwich coating and around coating. Experimental results using various brittle coatings demonstrated the validity and convenience of this method

  9. Chromium effect on the Young modulus and thermoelastic coefficient of elinvars

    International Nuclear Information System (INIS)

    Sazykina, A.V.; Khomenko, O.A.

    1976-01-01

    The effect was studied of thermal and thermal-mechanical treatment upon the elastic modules and its temperature coefficient in iron-nickel Elinvars with different chromium contents (from 0 to 6.7%). It has been shown that doping with chromium results in an increase in the modulus of elasticity of Elinvars after hardening. The elastic modulus of alloys containing no chromium increases after a cold plastic deformation (drawing), whereas that of chromous Elinvars decreases upon such a treatment. It has been established that the elastic modulus of hardened and cold drawn after hardening Elinvars increases upon ageing. An increase in chromium content in iron-nickel Elinvars reduces the effect of the temperature of ageing upon the thermoelastic coefficient during the usual heat treatment and the thermalmechanical treatment and lowers its sensitivity to the influence of an external magnetic field [ru

  10. Evaluating elastic modulus and strength of hard coatings by relative method

    Energy Technology Data Exchange (ETDEWEB)

    Bao, Y.W. [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China); China Building Materials Academy, Beijing 100024 (China)], E-mail: ywbao@imr.ac.cn; Zhou, Y.C. [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China); Bu, X.X. [China Building Materials Academy, Beijing 100024 (China); Qiu, Y. [China Building Materials Academy, Beijing 100024 (China)

    2007-06-15

    A simple approach named relative method is developed for determining the elastic modulus and strength of hard coatings. Analytical relationship among the moduli of the film, the substrate, and the film/substrate system was derived based on bending model, from which the elastic modulus of the coating can be determined uniquely via the measured moduli of the samples before and after coating. Furthermore, the relationship between the strength of the films and the bending strength of the coated sample is derived, thus both the modulus and the strength of coating can be evaluated via traditional tests on coated samples. Mathematic expressions of those calculations were derived, respectively for rectangular beam samples with three types of coating configurations: single face coating, sandwich coating and around coating. Experimental results using various brittle coatings demonstrated the validity and convenience of this method.

  11. 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.

    2013-01-01

    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. PMID:24309375

  12. Resilient Modulus Characterization of Alaskan Granular Base Materials

    Science.gov (United States)

    2010-08-01

    Resilient modulus (MR) of base course material is an important material input for : pavement design. In Alaska, due to distinctiveness of local climate, material source, : fines content and groundwater level, resilient properties of D-1 granular base...

  13. The effect of compressive stress on the Young's modulus of unirradiated and irradiated nuclear graphites

    International Nuclear Information System (INIS)

    Oku, T.; Usui, T.; Ero, M.; Fukuda, Y.

    1977-01-01

    The Young's moduli of unirradiated and high temperature (800 to 1000 0 C) irradiated graphites for HTGR were measured by the ultrasonic method in the direction of applied compressive stress during and after stressing. The Young's moduli of all the tested graphites decreased with increasing compressive stress both during and after stressing. In order to investigate the reason for the decrease in Young's modulus by applying compressive stress, the mercury pore diameter distributions of a part of the unirradiated and irradiated specimens were measured. The change in pore distribution is believed to be associated with structural changes produced by irradiation and compressive stressing. The residual strain, after removing the compressive stress, showed a good correlation with the decrease in Young's modulus caused by the compressive stress. The decrease in Young's modulus by applying compressive stress was considered to be due to the increase in the mobile dislocation density and the growth or formation of cracks. The results suggest, however, that the mechanism giving the larger contribution depends on the brand of graphite, and in anisotropic graphite it depends on the direction of applied stress and the irradiation conditions. (author)

  14. Arithmetic convergent sequence space defined by modulus function

    Directory of Open Access Journals (Sweden)

    Taja Yaying

    2019-10-01

    Full Text Available The aim of this article is to introduce the sequence spaces $AC(f$ and $AS(f$ using arithmetic convergence and modulus function, and study algebraic and topological properties of this space, and certain inclusion results.

  15. Minimization of complementary energy to predict shear modulus of laminates with intralaminar cracks

    International Nuclear Information System (INIS)

    Giannadakis, K; Varna, J

    2012-01-01

    The most common damage mode and the one examined in this work is the formation of intralaminar cracks in layers of laminates. These cracks can occur when the composite structure is subjected to mechanical and/or thermal loading and eventually lead to degradation of thermo-elastic properties. In the present work, the shear modulus reduction due to cracking is studied. Mathematical models exist in literature for the simple case of cross-ply laminates. The in-plane shear modulus of a damaged laminate is only considered in a few studies. In the current work, the shear modulus reduction in cross-plies will be analysed based on the principle of minimization of complementary energy. Hashin investigated the in-plane shear modulus reduction of cross-ply laminates with cracks in inside 90-layer using this variational approach and assuming that the in-plane shear stress in layers does not depend on the thickness coordinate. In the present study, a more detailed and accurate approach for stress estimation is followed using shape functions for this dependence with parameters obtained by minimization. The results for complementary energy are then compared with the respective from literature and finally an expression for shear modulus degradation is derived.

  16. Advanced soft coverpad made of non-woven fabric; Soft fushokufu coverpad no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Hayakawa, t; Kamezaki, K; Tokita, T [Takashimaya Nippatsu Kogyo, Aichi (Japan); Yamada, Y; Ono, H; Araki, O [Toyota Motor Corp., Aichi (Japan)

    1997-10-01

    At the present expected to enhance the product-value of automobile, it can be considered that advancement of touching and fitting feeling of seat would be important factors. For the purpose of materializing of these factors, We have noted softening of seat cover and carried out development of cover pad made of non-woven fablic. As a result of pursuing compatibility of soft feeling and durability of the cover pad, we could achieve to ensure the quality required for the material as the seat cover pad. 3 refs., 15 figs., 4 tabs.

  17. Comparative Analysis of Soft Computing Models in Prediction of Bending Rigidity of Cotton Woven Fabrics

    Science.gov (United States)

    Guruprasad, R.; Behera, B. K.

    2015-10-01

    Quantitative prediction of fabric mechanical properties is an essential requirement for design engineering of textile and apparel products. In this work, the possibility of prediction of bending rigidity of cotton woven fabrics has been explored with the application of Artificial Neural Network (ANN) and two hybrid methodologies, namely Neuro-genetic modeling and Adaptive Neuro-Fuzzy Inference System (ANFIS) modeling. For this purpose, a set of cotton woven grey fabrics was desized, scoured and relaxed. The fabrics were then conditioned and tested for bending properties. With the database thus created, a neural network model was first developed using back propagation as the learning algorithm. The second model was developed by applying a hybrid learning strategy, in which genetic algorithm was first used as a learning algorithm to optimize the number of neurons and connection weights of the neural network. The Genetic algorithm optimized network structure was further allowed to learn using back propagation algorithm. In the third model, an ANFIS modeling approach was attempted to map the input-output data. The prediction performances of the models were compared and a sensitivity analysis was reported. The results show that the prediction by neuro-genetic and ANFIS models were better in comparison with that of back propagation neural network model.

  18. Drop Weight Impact Studies of Woven Fibers Reinforced Modified Polyester Composites

    Directory of Open Access Journals (Sweden)

    Muhammed Tijani ISA

    2014-02-01

    Full Text Available Low velocity impact tests were conducted on modified unsaturated polyester reinforced with four different woven fabrics using hand-layup method to investigate the effect of fiber type and fiber combinations. The time-load curves were analysed and scanning electron microscopy was used to observe the surface of the impacted composite laminates. The results indicated that all the composites had ductility index (DI of above two for the test conducted at impact energy of 27J with the monolithic composite of Kevlar having the highest DI. The damage modes observed were mainly matrix cracks and fiber breakages. Hybridization of the fibers in the matrix was observed to minimize these damages.

  19. Assessment of Characteristic Function Modulus of Vibroacoustic Signal Given a Limit State Parameter of Diagnosed Equipment

    Science.gov (United States)

    Kostyukov, V. N.; Naumenko, A. P.; Kudryavtseva, I. S.

    2018-01-01

    Improvement of distinguishing criteria, determining defects of machinery and mechanisms, by vibroacoustic signals is a recent problem for technical diagnostics. The work objective is assessment of instantaneous values by methods of statistical decision making theory and risk of regulatory values of characteristic function modulus. The modulus of the characteristic function is determined given a fixed parameter of the characteristic function. It is possible to determine the limits of the modulus, which correspond to different machine’s condition. The data of the modulus values are used as diagnostic features in the vibration diagnostics and monitoring systems. Using such static decision-making methods as: minimum number of wrong decisions, maximum likelihood, minimax, Neumann-Pearson characteristic function modulus limits are determined, separating conditions of a diagnosed object.

  20. Consequence of reduced necrotic bone elastic modulus in a Perthes' hip

    DEFF Research Database (Denmark)

    Salmingo, Remel A.; Skytte, Tina Lercke; Mikkelsen, Lars Pilgaard

    Introduction Perthes is a destructive hip joint disorder characterized as a malformation of the femoral head which affects young children. Several studies have shown the change of mechanical properties of the femoral head in Perthes’ disease. However, the consequence of the changes in bone...... mechanical properties in a Perthes’ hip is not well established. Due to the material differences, changes in bone mechanical properties might lead to localization of stress and deformation. Thus, the objective of this study was to investigate the effects of reduced elastic modulus of necrotic bone...... weight) was applied on the top of the femoral head. The distal part of the femur was fixed. The same Poisson’s ratio 0.3 was set for the femoral and necrotic bone. The elastic modulus (E) of femoral bone was 500 MPa. To investigate the effects of reduced elastic modulus, the necrotic bone E was reduced...

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

    OpenAIRE

    VÎLCU Adrian; HRISTIAN Liliana; BORDEIANU Demetra L.; VÎLCU Catalin

    2014-01-01

    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 ...

  2. CFD Simulation and Experimental Analyses of a Copper Wire Woven Heat Exchanger Design to Improve Heat Transfer and Reduce the Size of Adsorption Beds

    Directory of Open Access Journals (Sweden)

    John White

    2016-02-01

    Full Text Available The chief objective of this study is the proposal design and CFD simulation of a new compacted copper wire woven fin heat exchanger and silica gel adsorbent bed used as part of an adsorption refrigeration system. This type of heat exchanger design has a large surface area because of the wire woven fin design. It is estimated that this will help improve the coefficient of performance (COP of the adsorption phase and increase the heat transfer in this system arrangement. To study the heat transfer between the fins and porous adsorbent reactor bed, two experiments were carried out and matched to computational fluid dynamics (CFD results.

  3. Particle size dependence of the Young's modulus of filled polymers: 1. Preliminary experiments

    NARCIS (Netherlands)

    Vollenberg, P.H.T.; Heikens, D.

    1989-01-01

    Experimental results are reported from which it appears that in the case of polymer filled with silane-treated glass beads the Young's modulus is, in accordance with present theory, independent of the particle size of the filler. However, if pure glass beads are used as filler, the Young's modulus

  4. 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.

  5. Elastic Modulus Measurement of ORNL ATF FeCrAl Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, Zachary T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Terrani, Kurt A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Yamamoto, Yukinori [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-10-01

    Elastic modulus and Poisson’s ratio for a number of wrought FeCrAl alloys, intended for accident tolerant fuel cladding application, are determined via resonant ultrasonic spectroscopy. The results are reported as a function of temperature from room temperature to 850°C. The wrought alloys were in the fully annealed and unirradiated state. The elastic modulus for the wrought FeCrAl alloys is at least twice that of Zr-based alloys over the temperature range of this study. The Poisson’s ratio of the alloys was 0.28 on average and increased very slightly with increasing temperature.

  6. Floating liquid bridge tensile behavior: Electric-field-induced Young's modulus measurements

    Science.gov (United States)

    Teschke, Omar; Mendez Soares, David; Valente Filho, Juracyr Ferraz

    2013-12-01

    A floating bridge is formed spontaneously when high voltage is applied to polar fluids in two capillary tubes that were in contact and then separated. This bridge bends under its own weight, and its bending profile was used to calculate its Young's modulus. For electric field intensities of ˜106 V/m, water bridges exhibit viscoelastic behavior, with Young's moduli of ˜24 MPa; dimethylsulfoxide (DMSO) bridges exhibited Young's moduli of ˜60 kPa. The scheme devised to measure the voltage drop across the water bridge for high voltages applied between the electrodes shows that the bulk water resistance decreases with increasing voltage.

  7. 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.

  8. Performance of Plain Woven Jute Fabric-Reinforced Polyester Matrix Composite in Multilayered Ballistic System

    Directory of Open Access Journals (Sweden)

    Sergio Neves Monteiro

    2018-02-01

    Full Text Available The ballistic performance of plain woven jute fabric-reinforced polyester matrix composites was investigated as the second layer in a multilayered armor system (MAS. Volume fractions of jute fabric, up to 30 vol %, were mixed with orthophthalic polyester to fabricate laminate composites. Ballistic tests were conducted using high velocity 7.62 mm ammunition. The depth of penetration caused by the bullet in a block of clay witness, simulating a human body, was used to evaluate the MAS ballistic performance according to the international standard. The fractured materials after tests were analyzed by scanning electron microscopy (SEM. The results indicated that jute fabric composites present a performance similar to that of the much stronger Kevlar™, which is an aramid fabric laminate, as MAS second layer with the same thickness. The mechanism of this similar ballistic behavior as well as the comparative advantages of the jute fabric composites over the Kevlar™ are discussed.

  9. 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.

  10. A biomimetic multilayer nanofiber fabric fabricated by electrospinning and textile technology from polylactic acid and Tussah silk fibroin as a scaffold for bone tissue engineering

    International Nuclear Information System (INIS)

    Shao, Weili; He, Jianxin; Han, Qiming; Sang, Feng; Wang, Qian; Chen, Li; Cui, Shizhong

    2016-01-01

    To engineer bone tissue, a scaffold with good biological properties should be provided to approximate the hierarchical structure of collagen fibrils in natural bone. In this study, we fabricated a novel scaffold consisting of multilayer nanofiber fabrics (MLNFFs) by weaving nanofiber yarns of polylactic acid (PLA) and Tussah silk fibroin (TSF). The yarns were fabricated by electrospinning, and we found that spinnability, as well as the mechanical properties of the resulting scaffold, was determined by the ratio between polylactic acid and Tussah silk fibroin. In particular, a 9:1 mixture can be spun continuously into nanofiber yarns with narrow diameter distribution and good mechanical properties. Accordingly, woven scaffolds based on this mixture had excellent mechanical properties, with Young's modulus 417.65 MPa and tensile strength 180.36 MPa. For nonwoven scaffolds fabricated from the same materials, the Young's modulus and tensile strength were 2- and 4-fold lower, respectively. Woven scaffolds also supported adhesion and proliferation of mouse mesenchymal stem cells, and promoted biomineralization via alkaline phosphatase and mineral deposition. Finally, the scaffolds significantly enhanced the formation of new bone in damaged femoral condyle in rabbits. Thus, the scaffolds are potentially suitable for bone tissue engineering because of biomimetic architecture, excellent mechanical properties, and good biocompatibility. - Highlights: • A novel strategy to mimic the hierarchical collagen fibril in bone is proposed by electrospinning and conventional textile technology. • The tensile strength of the woven scaffold was nearly 4-fold larger than that of nonwoven mats. • The nanofiber woven scaffolds show excellent cytocompatibility and accelerate osteoblast differentiation. • The composite scaffold significantly enhanced formation of new bone in damaged condyles in rabbit femur.

  11. A biomimetic multilayer nanofiber fabric fabricated by electrospinning and textile technology from polylactic acid and Tussah silk fibroin as a scaffold for bone tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Shao, Weili [Key Laboratory of Advanced Textile Composites, Ministry of Education, Institute of Textile Composites, Tianjin Polytechnic University, Tianjin 300387 (China); Henan provincial key laboratory of functional textile materials, Zhongyuan University of Technology, Zhengzhou 450007 (China); Collaborative Innovation Center of Textile and Garment Industry, Henan Province, Zhengzhou 450007 (China); He, Jianxin, E-mail: hejianxin771117@163.com [Henan provincial key laboratory of functional textile materials, Zhongyuan University of Technology, Zhengzhou 450007 (China); Collaborative Innovation Center of Textile and Garment Industry, Henan Province, Zhengzhou 450007 (China); Han, Qiming [Henan provincial key laboratory of functional textile materials, Zhongyuan University of Technology, Zhengzhou 450007 (China); Collaborative Innovation Center of Textile and Garment Industry, Henan Province, Zhengzhou 450007 (China); Sang, Feng [Department of Acquired Immune Deficiency Syndrome Treatment and Research Center, The First Affiliated Hospital of Henan University of Traditional Chinese Medicine, Zhengzhou 450000 (China); Wang, Qian [Henan provincial key laboratory of functional textile materials, Zhongyuan University of Technology, Zhengzhou 450007 (China); Collaborative Innovation Center of Textile and Garment Industry, Henan Province, Zhengzhou 450007 (China); Chen, Li [Key Laboratory of Advanced Textile Composites, Ministry of Education, Institute of Textile Composites, Tianjin Polytechnic University, Tianjin 300387 (China); Cui, Shizhong [Key Laboratory of Advanced Textile Composites, Ministry of Education, Institute of Textile Composites, Tianjin Polytechnic University, Tianjin 300387 (China); Henan provincial key laboratory of functional textile materials, Zhongyuan University of Technology, Zhengzhou 450007 (China); Collaborative Innovation Center of Textile and Garment Industry, Henan Province, Zhengzhou 450007 (China); and others

    2016-10-01

    To engineer bone tissue, a scaffold with good biological properties should be provided to approximate the hierarchical structure of collagen fibrils in natural bone. In this study, we fabricated a novel scaffold consisting of multilayer nanofiber fabrics (MLNFFs) by weaving nanofiber yarns of polylactic acid (PLA) and Tussah silk fibroin (TSF). The yarns were fabricated by electrospinning, and we found that spinnability, as well as the mechanical properties of the resulting scaffold, was determined by the ratio between polylactic acid and Tussah silk fibroin. In particular, a 9:1 mixture can be spun continuously into nanofiber yarns with narrow diameter distribution and good mechanical properties. Accordingly, woven scaffolds based on this mixture had excellent mechanical properties, with Young's modulus 417.65 MPa and tensile strength 180.36 MPa. For nonwoven scaffolds fabricated from the same materials, the Young's modulus and tensile strength were 2- and 4-fold lower, respectively. Woven scaffolds also supported adhesion and proliferation of mouse mesenchymal stem cells, and promoted biomineralization via alkaline phosphatase and mineral deposition. Finally, the scaffolds significantly enhanced the formation of new bone in damaged femoral condyle in rabbits. Thus, the scaffolds are potentially suitable for bone tissue engineering because of biomimetic architecture, excellent mechanical properties, and good biocompatibility. - Highlights: • A novel strategy to mimic the hierarchical collagen fibril in bone is proposed by electrospinning and conventional textile technology. • The tensile strength of the woven scaffold was nearly 4-fold larger than that of nonwoven mats. • The nanofiber woven scaffolds show excellent cytocompatibility and accelerate osteoblast differentiation. • The composite scaffold significantly enhanced formation of new bone in damaged condyles in rabbit femur.

  12. 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

  13. Young`s modulus of ceramic matrix composites with polysiloxane based matrix at elevated temperatures

    Czech Academy of Sciences Publication Activity Database

    Černý, Martin; Glogar, Petr

    2004-01-01

    Roč. 39, č. 6 (2004), s. 2239-2242 ISSN 0022-2461 R&D Projects: GA ČR GA106/02/0177; GA ČR GP106/02/P025 Institutional research plan: CEZ:AV0Z3046908 Keywords : composite material * Young `s modulus * high temperature Subject RIV: JI - Composite Materials Impact factor: 0.864, year: 2004

  14. Effect of bulk modulus on deformation of the brain under rotational accelerations

    Science.gov (United States)

    Ganpule, S.; Daphalapurkar, N. P.; Cetingul, M. P.; Ramesh, K. T.

    2018-01-01

    Traumatic brain injury such as that developed as a consequence of blast is a complex injury with a broad range of symptoms and disabilities. Computational models of brain biomechanics hold promise for illuminating the mechanics of traumatic brain injury and for developing preventive devices. However, reliable material parameters are needed for models to be predictive. Unfortunately, the properties of human brain tissue are difficult to measure, and the bulk modulus of brain tissue in particular is not well characterized. Thus, a wide range of bulk modulus values are used in computational models of brain biomechanics, spanning up to three orders of magnitude in the differences between values. However, the sensitivity of these variations on computational predictions is not known. In this work, we study the sensitivity of a 3D computational human head model to various bulk modulus values. A subject-specific human head model was constructed from T1-weighted MRI images at 2-mm3 voxel resolution. Diffusion tensor imaging provided data on spatial distribution and orientation of axonal fiber bundles for modeling white matter anisotropy. Non-injurious, full-field brain deformations in a human volunteer were used to assess the simulated predictions. The comparison suggests that a bulk modulus value on the order of GPa gives the best agreement with experimentally measured in vivo deformations in the human brain. Further, simulations of injurious loading suggest that bulk modulus values on the order of GPa provide the closest match with the clinical findings in terms of predicated injured regions and extent of injury.

  15. Shear elastic modulus of magnetic gels with random distribution of magnetizable particles

    Science.gov (United States)

    Iskakova, L. Yu; Zubarev, A. Yu

    2017-04-01

    Magnetic gels present new type of composite materials with rich set of uniquie physical properties, which find active applications in many industrial and bio-medical technologies. We present results of mathematically strict theoretical study of elastic modulus of these systems with randomly distributed magnetizable particles in an elastic medium. The results show that an external magnetic field can pronouncedly increase the shear modulus of these composites.

  16. Shear modulus and damping ratio of natural rubber containing carbon nanotubes

    Science.gov (United States)

    Ismail, R.; Ibrahim, A.; Rusop, M.; Adnan, A.

    2018-05-01

    This paper presents the results of an investigation into the potential application of Natural rubber (NR) containing Carbon Nanotubes (CNTs) by measuring its shear modulus and damping ratio. Four different types of rubber specimens which fabricated with different MWCNT loadings: 0 wt% (pure natural rubber), 1 wt%, 3 wt%, and 5 wt%. It is observed that the shear modulus and damping ratio of CNTs filled rubber composites are remarkably higher than that of raw rubber indicating the inherent reinforcing potential of CNTs.

  17. A Mesoscopic Analytical Model to Predict the Onset of Wrinkling in Plain Woven Preforms under Bias Extension Shear Deformation

    Directory of Open Access Journals (Sweden)

    Abbas Hosseini

    2017-10-01

    Full Text Available A mesoscopic analytical model of wrinkling of Plain-Woven Composite Preforms (PWCPs under the bias extension test is presented, based on a new instability analysis. The analysis is aimed to facilitate a better understanding of the nature of wrinkle formation in woven fabrics caused by large in-plane shear, while it accounts for the effect of fabric and process parameters on the onset of wrinkling. To this end, the mechanism of wrinkle formation in PWCPs in mesoscale is simplified and an equivalent structure composed of bars and different types of springs is proposed, mimicking the behavior of a representative PWCP element at the post-locking state. The parameters of this equivalent structure are derived based on geometric and mechanical characteristics of the PWCP. The principle of minimum total potential energy is employed to formluate the model, and experimental validation is carried out to reveal the effectiveness of the derived wrinkling prediction equation.

  18. Elastic modulus and fracture of boron carbide

    International Nuclear Information System (INIS)

    Hollenberg, G.W.; Walther, G.

    1978-12-01

    The elastic modulus of hot-pressed boron carbide with 1 to 15% porosity was measured at room temperature. K/sub IC/ values were determined for the same porosity range at 500 0 C by the double torsion technique. The critical stress intensity factor of boron carbide with 8% porosity was evaluated from 25 to 1200 0 C

  19. 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.

  20. Resilient modulus prediction of soft low-plasticity Piedmont residual soil using dynamic cone penetrometer

    Directory of Open Access Journals (Sweden)

    S. Hamed Mousavi

    2018-04-01

    Full Text Available Dynamic cone penetrometer (DCP has been used for decades to estimate the shear strength and stiffness properties of the subgrade soils. There are several empirical correlations in the literature to predict the resilient modulus values at only a specific stress state from DCP data, corresponding to the predefined thicknesses of pavement layers (a 50 mm asphalt wearing course, a 100 mm asphalt binder course and a 200 mm aggregate base course. In this study, field-measured DCP data were utilized to estimate the resilient modulus of low-plasticity subgrade Piedmont residual soil. Piedmont residual soils are in-place weathered soils from igneous and metamorphic rocks, as opposed to transported or compacted soils. Hence the existing empirical correlations might not be applicable for these soils. An experimental program was conducted incorporating field DCP and laboratory resilient modulus tests on “undisturbed” soil specimens. The DCP tests were carried out at various locations in four test sections to evaluate subgrade stiffness variation laterally and with depth. Laboratory resilient modulus test results were analyzed in the context of the mechanistic-empirical pavement design guide (MEPDG recommended universal constitutive model. A new approach for predicting the resilient modulus from DCP by estimating MEPDG constitutive model coefficients (k1, k2 and k3 was developed through statistical analyses. The new model is capable of not only taking into account the in situ soil condition on the basis of field measurements, but also representing the resilient modulus at any stress state which addresses a limitation with existing empirical DCP models and its applicability for a specific case. Validation of the model is demonstrated by using data that were not used for model development, as well as data reported in the literature. Keywords: Dynamic cone penetrometer (DCP, Resilient modulus, Mechanistic-empirical pavement design guide (MEPDG, Residual

  1. Determining a membrane's shear modulus, independent of its area-dilatation modulus, via capsule flow in a converging micro-capillary.

    Science.gov (United States)

    Dimitrakopoulos, P; Kuriakose, S

    2015-04-14

    Determination of the elastic properties of the membrane of artificial capsules is essential for the better design of the various devices that are utilized in their engineering and biomedical applications. However this task is complicated owing to the combined effects of the shear and area-dilatation moduli on the capsule deformation. Based on computational investigation, we propose a new methodology to determine a membrane's shear modulus, independent of its area-dilatation modulus, by flowing strain-hardening capsules in a converging micro-capillary of comparable size under Stokes flow conditions, and comparing the experimental measurements of the capsule elongation overshooting with computational data. The capsule prestress, if any, can also be determined with the same methodology. The elongation overshooting is practically independent of the viscosity ratio for low and moderate viscosity ratios, and thus a wide range of capsule fluids can be employed. Our proposed experimental device can be readily produced via glass fabrication while owing to the continuous flow in the micro-capillary, the characterization of a large number of artificial capsules is possible.

  2. Effect of time of sintering of a castable with andalusite aggregates in the rupture modulus and elastic modulus

    International Nuclear Information System (INIS)

    Oliveira, M.R.; Garcia, G.C.R.; Claudinei, S.; Ribeiro, S.

    2011-01-01

    The studied castable contain andalusite aggregates, and when sintered in temperatures above 1280 deg C, transformed into mullite improving the properties of concrete due to its low expansion and thermal conductivity, creep resistance and thermal shock. The refractory was homogenized in a mixer with 5.5% m/m of water and poured into a metal mold resulting in prismatic bars. After curing for 48 hours, were sintered at 1450 ° C for 0 h, 1 h, 2.5 h and 10 h with heating and cooling rates of 2 ° C / min. The results of elastic modules were, respectively, in GPa: 25.75±1.75, 37.79±0.36, 39.03±1.97 and 54.47±4.01, and rupture, MPa: 8.40±0.78, 11.94±0.68, 10.91±0.91 and 11,34±1.16, showing the increase in elastic modulus for longer times and for times exceeding one hour, no significant changes in results of the modulus of rupture , stabilizing the change of this refractory's properties after the first hour of sintering. (author)

  3. Evaluation report on the study on the application of 3D woven C/C composite materials; Sanjigenori C/C composite zairyo no kikai buhin eno oyo ni kansuru kenkyu hyoka hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    The paper described a study made during 1995 through 1998 on the application of 3D woven C/C composite materials to machine parts. The materials are large in rigidity, small in specific gravity, excellent in specific rigidity, and suitable for high speed rotation. They are excellent in heat resistance/dynamic reformation and expected as materials which can exceed limits of the existing steel for machine parts. However, to use them as machine parts, a possibility of high precision cutting is required. Therefore, a study was made on metal multi-layer membrane coating to C/C composites. Pitch-system high-elastic carbon fibers were made a 4-directional material by orienting horizontally in 3 directions at 120 degrees per plane and also orienting vertically. Various materials such as W, Mo and WC were coated by the laser assisted plasma hybrid spraying method. High adhesion coats with little pore were obtained. Multi-directionally woven C/C composites used to be poor in surface precision workability, but the problem was able to be solved by coating surfaces with metal layers and metal multi-layer membranes. The application is expanded not only to polygonal mirrors (for laser printing machine) and milling spindles, but largely to machine parts. 11 figs., 1 tab.

  4. Mechanical properties of concrete with SAP. Part II: Modulus of elasticity

    DEFF Research Database (Denmark)

    Hasholt, Marianne Tange; Jespersen, Morten H. Seneka; Jensen, Ole Mejlhede

    2010-01-01

    In this study, focus is on the modulus of elasticity for concrete with superabsorbent polymers (SAP). The results show that based on composite theory it is possible to establish a model, which predicts overall concrete elasticity. The model assumes a three phase material of aggregate, cement paste......, and air with volume fractions of the three phases as well as elastic properties of paste and aggregates as input parameters. Addition of SAP changes the E-modulus, because it both has an influence on properties of the cement paste and on the volume of air voids. Here, the E-modulus is an example...... a more or less empirical relation. The results show that when introducing SAP, models of a more empirical nature can be misleading (and e.g. relations stated in codes are often of this empirical nature). The reason is twofold: First, the empirical models often have a general problem with the effect...

  5. Influence of grain size distribution on dynamic shear modulus of sands

    Directory of Open Access Journals (Sweden)

    Dyka Ireneusz

    2017-11-01

    Full Text Available The paper presents the results of laboratory tests, that verify the correlation between the grain-size characteristics of non-cohesive soils and the value of the dynamic shear modulus. The problem is a continuation of the research performed at the Institute of Soil Mechanics and Rock Mechanics in Karlsruhe, by T. Wichtmann and T. Triantafyllidis, who derived the extension of the applicability of the Hardin’s equation describing the explicite dependence between the grain size distribution of sands and the values of dynamic shear modulus. For this purpose, piezo-ceramic bender elements generating elastic waves were used to investigate the mechanical properties of the specimens with artificially generated particle distribution. The obtained results confirmed the hypothesis that grain size distribution of non-cohesive soils has a significant influence on the dynamic shear modulus, but at the same time they have shown that obtaining unambiguous results from bender element tests is a difficult task in practical applications.

  6. Use of the laboratory tests of soil modulus in modelling pile behaviour

    Science.gov (United States)

    Dyka, Ireneusz

    2012-10-01

    This article deals with the question of theoretical description of behaviour of a single pile rested in a layered soil medium. Particular attention is paid to soil modulus which is used in calculation method for pile load-settlement curve. A brief analysis of the results obtained by laboratory tests to assess soil modulus and its nonlinear variability has been presented. The results of tests have been used in triaxial apparatus and resonant column/torsional shear device. There have also been presented the results of load-settlement calculation for a single pile under axial load with implementation of different models of soil modulus degradation. On this basis, possibilities of using particular kinds of laboratory tests in calculation procedure of foundation settlement have been presented as well as further developments of them.

  7. Effective elastic modulus of isolated gecko setal arrays.

    Science.gov (United States)

    Autumn, K; Majidi, C; Groff, R E; Dittmore, A; Fearing, R

    2006-09-01

    Conventional pressure sensitive adhesives (PSAs) are fabricated from soft viscoelastic materials that satisfy Dahlquist's criterion for tack with a Young's modulus (E) of 100 kPa or less at room temperature and 1 Hz. In contrast, the adhesive on the toes of geckos is made of beta-keratin, a stiff material with E at least four orders of magnitude greater than the upper limit of Dahlquist's criterion. Therefore, one would not expect a beta-keratin structure to function as a PSA by deforming readily to make intimate molecular contact with a variety of surface profiles. However, since the gecko adhesive is a microstructure in the form of an array of millions of high aspect ratio shafts (setae), the effective elastic modulus (E(eff)) is much lower than E of bulk beta-keratin. In the first test of the E(eff) of a gecko setal adhesive, we measured the forces resulting from deformation of isolated arrays of tokay gecko (Gekko gecko) setae during vertical compression, and during tangential compression at angles of +45 degrees and -45 degrees . We tested the hypothesis that E(eff) of gecko setae falls within Dahlquist's criterion for tack, and evaluated the validity of a model of setae as cantilever beams. Highly linear forces of deformation under all compression conditions support the cantilever model. E(eff) of setal arrays during vertical and +45 degrees compression (along the natural path of drag of the setae) were 83+/-4.0 kPa and 86+/-4.4 kPa (means +/- s.e.m.), respectively. Consistent with the predictions of the cantilever model, setae became significantly stiffer when compressed against the natural path of drag: E(eff) during -45 degrees compression was 110+/-4.7 kPa. Unlike synthetic PSAs, setal arrays act as Hookean elastic solids; setal arrays function as a bed of springs with a directional stiffness, assisting alignment of the adhesive spatular tips with the contact surface during shear loading.

  8. The Near-IR TRGB Magnitude and Distance Modulus to NGC 185

    Directory of Open Access Journals (Sweden)

    Y.-J. Sohn

    2008-09-01

    Full Text Available We determined values of distance modulus to nearby dwarf galaxy NGC 185 from the Tip of Red-Giant Branch (TRGB method. Apparent magnitudes of the TRGB are estimated from the near-infrared JHK luminosity functions (LFs of the resolved giant branch stars. Theoretical absolute magnitudes of the TRGB in near-infrared bands have been extracted from the Yonsei-Yale isochrones. The observed apparent and theoretical absolute magnitudes of the TRGB provide values of distance modulus to NGC 185 as (m - M.

  9. Influence of locational states of submicron fibers added into matrix on mechanical properties of plain-woven Carbon Fiber Composite

    Directory of Open Access Journals (Sweden)

    Kumamoto Soichiro

    2016-01-01

    Full Text Available The aim of this study was to show the influence of locational states of submicron fibers added into epoxy matrix on mechanical properties of modified plane-woven carbon fiber reinforced plastic (CFRP. To change the locational states of submicron fibers, two kinds of fabrication processes were applied in preparing specimen by hand lay-up method. Submicron fibers were simply added into epoxy resin with ethanol after they were stirred by a dispersion process using homogenizer to be located far from the interface between reinforcement and matrix. In contrast, submicron fibers were attached onto the carbon fibers by injecting from a spray nozzle accompanying with ethanol to be located near the interface, after they were tentatively contained in ethanol. The plain-woven CFRP plates were fabricated by hand lay-up method and cured at 80 degree-C for 1 hour and then at 150 degree-C for 3 hours. After curing, the plain-woven CFRP plates were cut into the dimension of specimen. Tensile shear strength and Mode-II fracture toughness of CFRP were determined by tensile lap-shear test and End-notched flexure(ENF test, respectively. When submicron fibers were located far from the interface between carbon fibers and epoxy resin, tensile shear strength and Mode-II fracture toughness of CFRP were improved 30% and 18% compared with those of unmodified case. The improvement ratio in modified case was rather low (about few percentages in the case where submicron fibers were located near the interface. The result suggested that crack propagation should be prevented when submicron fibers were existed far from the interface due to the effective stress state around the crack tip.

  10. Thermo-responsive wound dressings by grafting chitosan and poly(N-isopropylacrylamide) to plasma-induced graft polymerization modified non-woven fabrics

    International Nuclear Information System (INIS)

    Chen, Jyh-Ping; Kuo, Chang-Yi; Lee, Wen-Li

    2012-01-01

    Highlights: ► Poly(N-isopropylacrylamide) and chitosan were grafted to polypropylene non-wovens. ► An easily stripped off thermo-responsive wound dressing was developed. ► The wound dressing is biocompatible, has antibacterial and wound healing abilities. ► The bigraft non-woven will be a potential wound dressing for biomedical use. - Abstract: To obtain a chitosan wound dressings with temperature-responsive characteristics, polypropylene (PP) non-woven fabric (NWF) was modified by direct current pulsed oxygen plasma-induced grafting polymerization of acrylic acid (AAc) to improve hydrophilicity and to introduce carboxylic acid groups. Conjugation of chitosan and poly(N-isopropylacrylamide) (PNIPAAm) followed by using water-soluble carbodiimide as a coupling agent to form a novel bigraft PP-g-chitosan-g-PNIPAAm wound dressing. The amount of chitosan and PNIPAAm grafted to PP-g-chitosan-g-PNIPAAm were 83.0 ± 4.6 μg/cm 2 and 189.5 ± 8.2 μg/cm 2 , respectively. The surface chemical composition and microstructure of the NWF were studied by electron spectroscopy for chemical analysis (ESCA) and scanning electron microscopy (SEM). The linkages between AAc, chitosan, and PNIPAAm were confirmed with the formation of amide bonds. Physical properties of the NWF were characterized and potentials of these NWFs as wound dressings were evaluated using SD rat as the animal model. NWFs contained PNIPAAm were better than those contained only chitosan in wound healing rates and the wound areas covered by PP-g-chitosan-g-PNIPAAm wound dressings healed completely in 17 days.

  11. 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. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Temperature Effects on Mechanical Properties of Woven Thermoplastic Composites for Secondary Aircraft Structure Applications

    Directory of Open Access Journals (Sweden)

    Wang Yue

    2017-01-01

    Full Text Available The effect of temperature on the mechanical behavior of 8-H satin woven glass fabric/polyethylene sulfide (GF/PPS was investigated in this paper. Static-tensile tests were both conducted on notched and unnotched specimens at typical temperatures (ambient, 95°C and 125°C based on the glass transition temperatures (Tg of the neat resin and composite, their strength and moduli were obtained and compared. The damage patterns of failed specimens of notched and unnotched were examined with the aid of high-definition camera and stereomicroscope. The results of stress-strain relationships showed that the slight nonlinearity of the curves were observed for these two specimens, which was associated with the plastic deformation of localized resin. The damage patterns of notched and unnotched specimens at different temperatures proved that damage and plastic deformation were two simultaneous mechanisms and it was prominent in the notched. It was the overstress accommodation mechanism that led to a relative high strength rentention for the notched and a reduction of the hole sensitivity. The results obtained in this paper indicated that GF/PPS can be used as secondary aircraft structures at elevated temperatures higher than its Tg.

  13. Young's modulus of elasticity of Schlemm's canal endothelial cells.

    Science.gov (United States)

    Zeng, Dehong; Juzkiw, Taras; Read, A Thomas; Chan, Darren W-H; Glucksberg, Matthew R; Ethier, C Ross; Johnson, Mark

    2010-02-01

    Schlemm's canal (SC) endothelial cells are likely important in the physiology and pathophysiology of the aqueous drainage system of the eye, particularly in glaucoma. The mechanical stiffness of these cells determines, in part, the extent to which they can support a pressure gradient and thus can be used to place limits on the flow resistance that this layer can generate in the eye. However, little is known about the biomechanical properties of SC endothelial cells. Our goal in this study was to estimate the effective Young's modulus of elasticity of normal SC cells. To do so, we combined magnetic pulling cytometry of isolated cultured human SC cells with finite element modeling of the mechanical response of the cell to traction forces applied by adherent beads. Preliminary work showed that the immersion angles of beads attached to the SC cells had a major influence on bead response; therefore, we also measured bead immersion angle by confocal microscopy, using an empirical technique to correct for axial distortion of the confocal images. Our results showed that the upper bound for the effective Young's modulus of elasticity of the cultured SC cells examined in this study, in central, non-nuclear regions, ranged between 1,007 and 3,053 Pa, which is similar to, although somewhat larger than values that have been measured for other endothelial cell types. We compared these values to estimates of the modulus of primate SC cells in vivo, based on images of these cells under pressure loading, and found good agreement at low intraocular pressure (8-15 mm Hg). However, increasing intraocular pressure (22-30 mm Hg) appeared to cause a significant increase in the modulus of these cells. These moduli can be used to estimate the extent to which SC cells deform in response to the pressure drop across the inner wall endothelium and thereby estimate the extent to which they can generate outflow resistance.

  14. Fabrication and Synthesis of Highly Ordered Nickel Cobalt Sulfide Nanowire-Grown Woven Kevlar Fiber/Reduced Graphene Oxide/Polyester Composites.

    Science.gov (United States)

    Hazarika, Ankita; Deka, Biplab K; Kim, DoYoung; Roh, Hyung Doh; Park, Young-Bin; Park, Hyung Wook

    2017-10-18

    Well-aligned NiCo 2 S 4 nanowires, synthesized hydrothermally on the surface of woven Kevlar fiber (WKF), were used to fabricate composites with reduced graphene oxide (rGO) dispersed in polyester resin (PES) by means of vacuum-assisted resin transfer molding. The NiCo 2 S 4 nanowires were synthesized with three precursor concentrations. Nanowire growth was characterized using scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. Hierarchical and high growth density of the nanowires led to exceptional mechanical properties of the composites. Compared with bare WKF/PES, the tensile strength and absorbed impact energy were enhanced by 96.2% and 92.3%, respectively, for WKF/NiCo 2 S 4 /rGO (1.5%)/PES. The synergistic effect of NiCo 2 S 4 nanowires and rGO in the fabricated composites improved the electrical conductivity of insulating WKF/PES composites, reducing the resistance to ∼10 3 Ω. Joule heating performance depended strongly on the precursor concentration of the nanowires and the presence of rGO in the composite. A maximum surface temperature of 163 °C was obtained under low-voltage (5 V) application. The Joule heating performance of the composites was demonstrated in a surface deicing experiment; we observed that 17 g of ice melted from the surface of the composite in 14 min under an applied voltage of 5 V at -28 °C. The excellent performance of WKF/NiCo 2 S 4 /rGO/PES composites shows great potential for aerospace structural applications requiring outstanding mechanical properties and Joule heating capability for deicing of surfaces.

  15. Elastic modulus, thermal expansion, and specific heat at a phase transition

    International Nuclear Information System (INIS)

    Testardi, L.R.

    1975-01-01

    The interrelation of the elastic modulus, thermal-expansion coefficient, and specific heat of a transformed phase relative to the untransformed phase is calculated assuming a particular but useful form of the thermodynamic potential. For second-order phase transitions where this potential applies, measurements of modulus, expansion, and specific heat can yield the general (longitudinal as well as shear) first- and second-order stress (or strain) dependences of the transition temperature and of the order parameter at absolute zero. An exemplary application to one type of phase transition is given

  16. 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.

  17. Powder metallurgical low-modulus Ti-Mg alloys for biomedical applications.

    Science.gov (United States)

    Liu, Yong; Li, Kaiyang; Luo, Tao; Song, Min; Wu, Hong; Xiao, Jian; Tan, Yanni; Cheng, Ming; Chen, Bing; Niu, Xinrui; Hu, Rong; Li, Xiaohui; Tang, Huiping

    2015-11-01

    In this work, powder metallurgical (PM) Ti-Mg alloys were prepared using combined techniques of mechanical alloying and spark plasma sintering. The alloys mainly consist of super saturations of Mg in Ti matrix, and some laminar structured Ti- and Mg-rich phases. The PM Ti-Mg alloys contain a homogeneous mixtures of nanocrystalline Mg and Ti phases. The novel microstructures result in unconventional mechanical and biological properties. It has been shown that the PM Ti-Mg alloys have a much lower compression modulus (36-50GPa) compared to other Ti alloys, but still remain a very high compressive strength (1500-1800MPa). In addition, the PM Ti-Mg alloys show good biocompatibility and bioactivity. Mg can dissolve in the simulated body fluids, and induce the formation of the calcium phosphate layer. The compression modulus of PM Ti-Mg alloys decreases with the amount of Mg, while the bioactivity increases. Although the corrosion resistance of Ti-Mg alloys decreases with the content of Mg, the alloys still show good stability in simulated body fluid under electrochemical conditions. The indirect and direct cytotoxicity results show that PM Ti-Mg alloys have a good biocompatibility to NIH-3T3 cells. Therefore, the PM Ti-Mg alloys are promising candidates in biomedical applications. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Multiphase composites with extremal bulk modulus

    DEFF Research Database (Denmark)

    Gibiansky, L. V.; Sigmund, Ole

    2000-01-01

    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...... isotropic three-dimensional three-phase composites with cylindrical inclusions of arbitrary cross-sections (plane strain problem) or transversely isotropic thin plates (plane stress or bending of plates problems). (C) 2000 Elsevier Science Ltd. All rights reserved....

  19. 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 recently...

  20. Standardizing lightweight deflectometer modulus measurements for compaction quality assurance

    Science.gov (United States)

    2017-09-01

    To evaluate the compaction of unbound geomaterials under unsaturated conditions and replace the conventional methods with a practical modulus-based specification using LWD, this study examined three different LWDs, the Zorn ZFG 3000 LWD, Dynatest 303...

  1. Variations in local elastic modulus along the length of the aorta as observed by use of a scanning haptic microscope (SHM).

    Science.gov (United States)

    Moriwaki, Takeshi; Oie, Tomonori; Takamizawa, Keiichi; Murayama, Yoshinobu; Fukuda, Toru; Omata, Sadao; Kanda, Keiichi; Nakayama, Yasuhide

    2011-12-01

    Variations in microscopic elastic structures along the entire length of canine aorta were evaluated by use of a scanning haptic microscope (SHM). The total aorta from the aortic arch to the abdominal aorta was divided into 6 approximately equal segments. After embedding the aorta in agar, it was cut into horizontal circumferential segments to obtain disk-like agar portions containing ring-like samples of aorta with flat surfaces (thickness, approximately 1 mm). The elastic modulus and topography of the samples under no-load conditions were simultaneously measured along the entire thickness of the wall by SHM by using a probe with a diameter of 5 μm and a spatial resolution of 2 μm at a rate of 0.3 s/point. The elastic modulus of the wall was the highest on the side of the luminal surface and decreased gradually toward the adventitial side. This tendency was similar to that of the change in the elastin fiber content. During the evaluation of the mid-portion of each tunica media segment, the highest elastic modulus (40.8 ± 3.5 kPa) was identified at the thoracic section of the aorta that had the highest density of elastic fibers. Under no-load conditions, portions of the aorta with high elastin density have a high elastic modulus.

  2. The effect of gamma ray irradiation on PAN-based intermediate modulus carbon fibers

    International Nuclear Information System (INIS)

    Li, Bin; Feng, Yi; Qian, Gang; Zhang, Jingcheng; Zhuang, Zhong; Wang, Xianping

    2013-01-01

    Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) were conducted on PAN-based intermediate modulus carbon fibers to investigate the structure and surface hydrophilicity of the carbon fibers before and after gamma irradiation. Two methods were used to determine Young’s modulus of the carbon fibers. The results show that gamma ray irradiation improved the degree of graphitization and introduced compressive stress into carbon fiber surface. Gamma ray also improved the carbon fiber surface hydrophilicity through increasing the value of O/C and enhancing the quantity of oxygen functional groups on carbon fibers. No distinct morphology change was observed after gamma ray irradiation. The Young’s modulus of the fibers increased with increasing irradiation dose

  3. Maximisation of the ratio of microhardness to the Young's modulus of Ti-12Mo-13Nb alloy through microstructure changes.

    Science.gov (United States)

    Gabriel, Sinara B; de Almeida, Luiz H; Nunes, Carlos A; Dille, Jean; Soares, Glória A

    2013-08-01

    Alloys for orthopaedic and dentistry applications require high mechanical strength and a low Young's modulus to avoid stress shielding. Metastable β titanium alloys appear to fulfil these requirements. This study investigated the correlation of phases precipitated in a Ti-12Mo-13Nb alloy with changes in hardness and the Young's modulus. The alloy was produced by arc melting under an argon atmosphere, after which, it was heat treated and cold forged. Two different routes of heat treatment were employed. Phase transformations were studied by employing X-ray diffraction and transmission electron microscopy. Property characterisation was based on Vickers microhardness tests and Young's modulus measurements. The highest ratio of microhardness to the Young's modulus was obtained using thermomechanical treatment, which consists of heating at 1000°C for 24h, water quenching, cold forging to reduce 80% of the area, and ageing at 500°C for 24h, where the final microstructure consisted of an α phase dispersed in a β matrix. The α phase appeared in two different forms: as fine lamellas (with 240±100 nm length) and massive particles of 200-500 nm size. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. Estimate of K-functionals and modulus of smoothness constructed ...

    Indian Academy of Sciences (India)

    2016-08-26

    functional and a modulus of smoothness for the Dunkl transform on Rd. Author Affiliations. M El Hamma1 R Daher1. Department of Mathematics, Faculty of Sciences Aïn Chock, University of Hassan II, Casablanca, Morocco. Dates.

  5. Effect of Li level, artificial aging, and TiB2 reinforcement on the modulus of Weldalite (tm) 049

    Science.gov (United States)

    1991-01-01

    The dynamic Young's Modulus (E) was determined for (1) alloys 049(1.3)(heat 072), (2) 049(1.9), and (3) 049(1.3) TiB2 in the T3 temper and after aging at 160 C were made on a single 0.953 cm (0.375 in) cube to reduce scatter from microstructural inhomogeneities. Both shear and transverse wave velocities were measured for the L, LT, and ST directions by a pulse echo technique. These velocities were then used to calculate modulus. The change is shown in E with aging time at 160 C (320 F) for the three alloys. It is clear from the plots that aging has a minor, but measurable, influence on the E of alloys 049(1.3) and 049(1.9): E decreases by -2.5 pct. for 2 and 3 during the initial stages of artificial aging. This decrease in E generally follows the strength reversion. On further aging beyond the reversion well, E increases and then decreases again as the alloy overage. The slightly higher modulus in the T8 than in the T3 temper is consistent with the presence of the high modulus T sub 1 phase in the T8 temper. A similar change in E was observed on aging for the TiB2 reinforced variant that also follows the aging curve.

  6. Reliable measurement of elastic modulus of cells by nanoindentation in an atomic force microscope

    KAUST Repository

    Zhou, Zhoulong; Ngan, Alfonso H W; Tang, Bin; Wang, Anxun

    2012-01-01

    The elastic modulus of an oral cancer cell line UM1 is investigated by nanoindentation in an atomic force microscope with a flat-ended tip. The commonly used Hertzian method gives apparent elastic modulus which increases with the loading rate, indicating strong effects of viscoelasticity. On the contrary, a rate-jump method developed for viscoelastic materials gives elastic modulus values which are independent of the rate-jump magnitude. The results show that the rate-jump method can be used as a standard protocol for measuring elastic stiffness of living cells, since the measured values are intrinsic properties of the cells. © 2011 Elsevier Ltd.

  7. Reliable measurement of elastic modulus of cells by nanoindentation in an atomic force microscope

    KAUST Repository

    Zhou, Zhoulong

    2012-04-01

    The elastic modulus of an oral cancer cell line UM1 is investigated by nanoindentation in an atomic force microscope with a flat-ended tip. The commonly used Hertzian method gives apparent elastic modulus which increases with the loading rate, indicating strong effects of viscoelasticity. On the contrary, a rate-jump method developed for viscoelastic materials gives elastic modulus values which are independent of the rate-jump magnitude. The results show that the rate-jump method can be used as a standard protocol for measuring elastic stiffness of living cells, since the measured values are intrinsic properties of the cells. © 2011 Elsevier Ltd.

  8. 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.)

  9. Connecting Jacobi elliptic functions with different modulus parameters

    Indian Academy of Sciences (India)

    found in the literature do not involve any change in the modulus parameter m. For ... Here, the right-hand side contains the sum of two terms with arguments separated ...... able thing is that, it is precisely these sums for which Landen formulas, mentioned above ... ematical sciences (Springer-Verlag, New York, 1989) vol. 80.

  10. High frequency characterization of conductive inks embedded within a structural composite

    Science.gov (United States)

    Pa, Peter; McCauley, Raymond; Larimore, Zachary; Mills, Matthew; Yarlaggada, Shridhar; Mirotznik, Mark S.

    2015-06-01

    Woven fabric composites provide an attractive platform for integrating electromagnetic functionality—such as conformal load-bearing antennas and frequency selective surfaces—into a structural platform. One practical fabrication method for integrating conductive elements within a woven fabric composite system involves using additive manufacturing systems such as screen printing. While screen printing is an inherently scalable, flexible and cost effective method, little is known about the high frequency electrical properties of its conductive inks when they are embedded within the woven fabric composite. Thus, we have completed numerical and experimental studies to determine the electrical conductivity of screen printable conductive inks that are embedded within this composite. We have also performed mechanical studies to evaluate how printing affects the structural performance of the composite.

  11. Increasing Accuracy of Tissue Shear Modulus Reconstruction Using Ultrasonic Strain Tensor Measurement

    Science.gov (United States)

    Sumi, C.

    Previously, we developed three displacement vector measurement methods, i.e., the multidimensional cross-spectrum phase gradient method (MCSPGM), the multidimensional autocorrelation method (MAM), and the multidimensional Doppler method (MDM). To increase the accuracies and stabilities of lateral and elevational displacement measurements, we also developed spatially variant, displacement component-dependent regularization. In particular, the regularization of only the lateral/elevational displacements is advantageous for the lateral unmodulated case. The demonstrated measurements of the displacement vector distributions in experiments using an inhomogeneous shear modulus agar phantom confirm that displacement-component-dependent regularization enables more stable shear modulus reconstruction. In this report, we also review our developed lateral modulation methods that use Parabolic functions, Hanning windows, and Gaussian functions in the apodization function and the optimized apodization function that realizes the designed point spread function (PSF). The modulations significantly increase the accuracy of the strain tensor measurement and shear modulus reconstruction (demonstrated using an agar phantom).

  12. Low modulus and bioactive Ti/α-TCP/Ti-mesh composite prepared by spark plasma sintering.

    Science.gov (United States)

    Guo, Yu; Tan, Yanni; Liu, Yong; Liu, Shifeng; Zhou, Rui; Tang, Hanchun

    2017-11-01

    A titanium mesh scaffold composite filled with Ti/α-TCP particles was prepared by spark plasma sintering (SPS). The microstructures and interfacial reactions of the composites were investigated by scanning electron microscopy (SEM), Energy Dispersive Spectroscopy (EDS) and X-ray diffraction (XRD) analyses. The compressive strength and elastic modulus were also measured. In vitro bioactivity and biocompatibility was evaluated by using simulated body fluid and cells culture, respectively. After high temperature sintering, Ti oxides, Ti x P y and CaTiO 3 were formed. The formation of Ti oxides and Ti x P y were resulted from the diffusion of O and P elements from α-TCP to Ti. CaTiO 3 was the reaction product of Ti and α-TCP. The composite of 70Ti/α-TCP incorporated with Ti mesh showed a high compressive strength of 589MPa and a low compressive modulus of 30GPa. The bioactivity test showed the formation of a thick apatite layer on the composite and well-spread cells attachment. A good combination of mechanical properties and bioactivity indicated a high potential application of Ti/α-TCP/Ti-mesh composite for orthopedic implants. Copyright © 2017. Published by Elsevier B.V.

  13. Study on Size-Dependent Young’s Modulus of a Silicon Nano beam by Molecular Dynamics Simulation

    International Nuclear Information System (INIS)

    Yu, H.; Sun, C.; Zhang, W.W.; Lei, S.Y.; Huang, K.A.

    2013-01-01

    Young’s modulus of a silicon nano beam with a rectangular cross-section is studied by molecular dynamics method. Dynamic simulations are performed for doubly clamped silicon nano beams with lengths ranging from 4.888 to 12.491 nm and cross-sections ranging from 1.22 nm ×1.22 nm to 3.39 nm × 3.39 nm. The results show that Young’s moduli of such small silicon nano beams are much higher than the value of Young’s modulus for bulk silicon. Moreover, the resonant frequency and Young’s modulus of the Si nano beam are strongly dependent not only on the size of the nano beam but also on surface effects. Young’s modulus increases significantly with the decreasing of the thickness of the silicon nano beam. This result qualitatively agrees with one of the conclusions based on a semi continuum model, in which the surface relaxation and the surface tension were taken into consideration. The impacts of the surface reconstruction with (2 ×1) dimmers on the resonant frequency and Young’s modulus are studied in this paper too. It is shown that the surface reconstruction makes the silicon nano beam stiffer than the one without the surface reconstruction, resulting in a higher resonant frequency and a larger Young’s modulus

  14. Mechanical performance of carbon-epoxy laminates. Part I: quasi-static and impact bending properties

    Directory of Open Access Journals (Sweden)

    José Ricardo Tarpani

    2006-06-01

    Full Text Available In Part I of this study, quasi-static and impact bending properties of four aeronautical grade carbon-epoxy laminates have been determined and compared. Materials tested were unidirectional cross-ply (tape and bidirectional woven textile (fabric carbon fiber lay-up architectures, impregnated with standard and rubber-toughened resins, respectively, giving rise to 1.5 mm-thick laminates. Quasi-static mechanical properties assessed in transversal mode loading were modulus of elasticity, flexural strength and tenacity at the maximum load, whereas the net absorbed energy was determined under translaminar impact conditions. Two-dimensional woven carbon fiber reinforcements embedded in a rubber-toughened matrix presented the best mechanical performance under static loading. Under dynamic loading conditions, woven fiber fabric pre-forms were favorably sensitive to increasing impact energies regardless the nature of the employed epoxy resin. However, it was concluded that great care should be taken with this material within the low energy impact regimen.

  15. 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...

  16. Noninvasive Vascular Displacement Estimation for Relative Elastic Modulus Reconstruction in Transversal Imaging Planes

    Directory of Open Access Journals (Sweden)

    Chris L. de Korte

    2013-03-01

    Full Text Available Atherosclerotic plaque rupture can initiate stroke or myocardial infarction. Lipid-rich plaques with thin fibrous caps have a higher risk to rupture than fibrotic plaques. Elastic moduli differ for lipid-rich and fibrous tissue and can be reconstructed using tissue displacements estimated from intravascular ultrasound radiofrequency (RF data acquisitions. This study investigated if modulus reconstruction is possible for noninvasive RF acquisitions of vessels in transverse imaging planes using an iterative 2D cross-correlation based displacement estimation algorithm. Furthermore, since it is known that displacements can be improved by compounding of displacements estimated at various beam steering angles, we compared the performance of the modulus reconstruction with and without compounding. For the comparison, simulated and experimental RF data were generated of various vessel-mimicking phantoms. Reconstruction errors were less than 10%, which seems adequate for distinguishing lipid-rich from fibrous tissue. Compounding outperformed single-angle reconstruction: the interquartile range of the reconstructed moduli for the various homogeneous phantom layers was approximately two times smaller. Additionally, the estimated lateral displacements were a factor of 2–3 better matched to the displacements corresponding to the reconstructed modulus distribution. Thus, noninvasive elastic modulus reconstruction is possible for transverse vessel cross sections using this cross-correlation method and is more accurate with compounding.

  17. Use of an ultrasonic device for the determination of elastic modulus of dentin.

    Science.gov (United States)

    Miyazaki, Masashi; Inage, Hirohiko; Onose, Hideo

    2002-03-01

    The mechanical properties of dentin substrate are one of the important factors in determining bond strength of dentin bonding systems. The purpose of this study was to determine the elastic modulus of dentin substrate with the use of an ultrasonic device. The dentin disks of about 1 mm thickness were obtaining from freshly extracted human third molars, and the dentin disk was shaped in a rectangular form with a line diamond point. The size and weight of each specimen was measured to calculate the density of the specimen. The ultrasonic equipment employed in this study was composed of a Pulser-Receiver (Model 5900PR, Panametrics), transducers (V155, V156, Panametrics) and an oscilloscope. The measured two-way transit time through the dentin disk was divided by two to account for the down-and-back travel path, and then multiplied by the velocity of sound in the test material. Measuring the longitudinal and share wave sound velocity determine elastic modulus. The mean elastic modulus of horizontally sectioned specimens was 21.8 GPa and 18.5 GPa for the vertically sectioned specimens, and a significant difference was found between the two groups. The ultrasonic method used in this study shows considerable promise for determination of the elastic modulus of the tooth substrate.

  18. Modelling of the Elasticity Modulus for Rock Using Genetic Expression Programming

    Directory of Open Access Journals (Sweden)

    Umit Atici

    2016-01-01

    Full Text Available In rock engineering projects, statically determined parameters are more reflective of actual load conditions than dynamic parameters. This study reports a new and efficient approach to the formulation of the static modulus of elasticity Es applying gene expression programming (GEP with nondestructive testing (NDT methods. The results obtained using GEP are compared with the results of multivariable linear regression analysis (MRA, univariate nonlinear regression analysis (URA, and the dynamic elasticity modulus (Ed. The GEP model was found to produce the most accurate calculation of Es. The proposed approach is a simple, nondestructive, and practical way to determine Es for anisotropic and heterogeneous rocks.

  19. Anticoagulant and antimicrobial finishing of non-woven polypropylene textiles

    International Nuclear Information System (INIS)

    Degoutin, S; Jimenez, M; Casetta, M; Bellayer, S; Chai, F; Blanchemain, N; Neut, C; Kacem, I; Traisnel, M; Martel, B

    2012-01-01

    The aim of this work is to prepare non-woven polypropylene (PP) textile functionalized with bioactive molecules in order to improve its anticoagulation and antibacterial properties. This paper describes the optimization of the grafting process of acrylic acid (AA) on low-pressure cold-plasma pre-activated PP, the characterization of the modified substrates and the effect of these modifications on the in vitro biological response towards cells. Then, the immobilization of gentamicin (aminoglycoside antibiotic) and heparin (anticoagulation agent) has been carried out on the grafted samples by either ionic interactions or covalent linkages. Their bioactivity has been investigated and related to the nature of their interactions with the substrate. For gentamicin-immobilized AA-grafted samples, an inhibition radius and a reduction of 99% of the adhesion of Escherichia coli have been observed when gentamicin was linked by ionic interactions, allowing the release of the antibiotic. By contrast, for heparin-immobilized AA-grafted PP samples, a strong increase of the anticoagulant effect up to 35 min has been highlighted when heparin was covalently bonded on the substrate, by contact with the blood drop. (paper)

  20. Influence of the cementitious paste composition on the E-modulus and heat of hydration evolutions

    International Nuclear Information System (INIS)

    Maia, Lino; Azenha, Miguel; Faria, Rui; Figueiras, Joaquim

    2011-01-01

    E-modulus and heat of hydration are features of cement-based materials that follow a rapid rate of change at early ages. This paper analyses the influence of the composition of cementitious pastes on these features by using two methods: (i) a novel technique for continuously monitoring the E-modulus of cement-based materials, based on evaluating the first resonant frequency of a composite beam containing the material under testing, and (ii) an isothermal calorimeter to determine the released heat of hydration. Seventeen mixes are tested, encompassing pastes with five w/c ratios, as well as different contents of limestone filler, fly ash, silica fume and metakaolin. The results permit the comparison of the E-modulus and heat of hydration sensitivities to mix composition changes, and to check possible relations between these features. This work also helps to establish the technique (i) as a non-destructive method for monitoring the E-modulus evolution in cement-based materials since casting.

  1. Design of the Elastic Modulus of Nanoparticles-Containing PVA/PVAc Films by the Response Surface Method

    Science.gov (United States)

    Jelinska, N.; Kalnins, M.; Kovalovs, A.; Chate, A.

    2015-11-01

    By the surface response method, a regression equation is constructed, and the tensile elastic modulus of films made from polyvinyl alcohol/polyvinyl acetate (PVA/PVAc) blends filled with montmorillonite clay and microcrystalline cellulose nanoparticles is investigated. It is established that the introduction of the nanoparticles improves the mechanical properties of the blends in tension considerably: their strength and elastic modulus increase with content of the particles. Using the regression equation, the optimum composition of nanoparticlefilled PVA/PVAc blends with the highest value of elastic modulus is found.

  2. Young’s Modulus and Poisson’s Ratio of Monolayer Graphyne

    Directory of Open Access Journals (Sweden)

    H. Rouhi

    2013-09-01

    Full Text Available Despite its numerous potential applications, two-dimensional monolayer graphyne, a novel form of carbon allotropes with sp and sp2 carbon atoms, has received little attention so far, perhaps as a result of its unknown properties. Especially, determination of the exact values of its elastic properties can pave the way for future studies on this nanostructure. Hence, this article describes a density functional theory (DFT investigation into elastic properties of graphyne including surface Young’s modulus and Poisson’s ratio. The DFT analyses are performed within the framework of generalized gradient approximation (GGA, and the Perdew–Burke–Ernzerhof (PBE exchange correlation is adopted. This study indicates that the elastic modulus of graphyne is approximately half of that of graphene due to its lower number of bonds.

  3. 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\

  4. 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.

  5. Determining the Gaussian Modulus and Edge Properties of 2D Materials: From Graphene to Lipid Bilayers

    Science.gov (United States)

    Zelisko, Matthew; Ahmadpoor, Fatemeh; Gao, Huajian; Sharma, Pradeep

    2017-08-01

    The dominant deformation behavior of two-dimensional materials (bending) is primarily governed by just two parameters: bending rigidity and the Gaussian modulus. These properties also set the energy scale for various important physical and biological processes such as pore formation, cell fission and generally, any event accompanied by a topological change. Unlike the bending rigidity, the Gaussian modulus is, however, notoriously difficult to evaluate via either experiments or atomistic simulations. In this Letter, recognizing that the Gaussian modulus and edge tension play a nontrivial role in the fluctuations of a 2D material edge, we derive closed-form expressions for edge fluctuations. Combined with atomistic simulations, we use the developed approach to extract the Gaussian modulus and edge tension at finite temperatures for both graphene and various types of lipid bilayers. Our results possibly provide the first reliable estimate of this elusive property at finite temperatures and appear to suggest that earlier estimates must be revised. In particular, we show that, if previously estimated properties are employed, the graphene-free edge will exhibit unstable behavior at room temperature. Remarkably, in the case of graphene, we show that the Gaussian modulus and edge tension even change sign at finite temperatures.

  6. Elastic modulus of muscle and tendon with shear wave ultrasound elastography: variations with different technical settings.

    Directory of Open Access Journals (Sweden)

    Brian Chin Wing Kot

    Full Text Available Standardization on Shear wave ultrasound elastography (SWUE technical settings will not only ensure that the results are accurate, but also detect any differences over time that may be attributed to true physiological changes. The present study evaluated the variations of elastic modulus of muscle and tendon using SWUE when different technical aspects were altered. The results of this study indicated that variations of elastic modulus of muscle and tendon were found when different transducer's pressure and region of interest (ROI's size were applied. No significant differences in elastic modulus of the rectus femoris muscle and patellar tendon were found with different acquisition times of the SWUE sonogram. The SWUE on the muscle and tendon should be performed with the lightest transducer's pressure, a shorter acquisition time for the SWUE sonogram, while measuring the mean elastic modulus regardless the ROI's size.

  7. 3-D FDTD simulation of shear waves for evaluation of complex modulus imaging.

    Science.gov (United States)

    Orescanin, Marko; Wang, Yue; Insana, Michael

    2011-02-01

    The Navier equation describing shear wave propagation in 3-D viscoelastic media is solved numerically with a finite differences time domain (FDTD) method. Solutions are formed in terms of transverse scatterer velocity waves and then verified via comparison to measured wave fields in heterogeneous hydrogel phantoms. The numerical algorithm is used as a tool to study the effects on complex shear modulus estimation from wave propagation in heterogeneous viscoelastic media. We used an algebraic Helmholtz inversion (AHI) technique to solve for the complex shear modulus from simulated and experimental velocity data acquired in 2-D and 3-D. Although 3-D velocity estimates are required in general, there are object geometries for which 2-D inversions provide accurate estimations of the material properties. Through simulations and experiments, we explored artifacts generated in elastic and dynamic-viscous shear modulus images related to the shear wavelength and average viscosity.

  8. Estimating Young’s Modulus of Single-Walled Zirconia Nanotubes Using Nonlinear Finite Element Modeling

    Directory of Open Access Journals (Sweden)

    Ibrahim Dauda Muhammad

    2015-01-01

    Full Text Available The single-walled zirconia nanotube is structurally modeled and its Young’s modulus is valued by using the finite element approach. The nanotube was assumed to be a frame-like structure with bonds between atoms regarded as beam elements. The properties of the beam required for input into the finite element analysis were computed by connecting energy equivalence between molecular and continuum mechanics. Simulation was conducted by applying axial tensile strain on one end of the nanotube while the other end was fixed and the corresponding reaction force recorded to compute Young’s modulus. It was found out that Young’s modulus of zirconia nanotubes is significantly affected by some geometrical parameters such as chirality, diameter, thickness, and length. The obtained values of Young’s modulus for a certain range of diameters are in agreement with what was obtained in the few experiments that have been conducted so far. This study was conducted on the cubic phase of zirconia having armchair and zigzag configuration. The optimal diameter and thickness were obtained, which will assist in designing and fabricating bulk nanostructured components containing zirconia nanotubes for various applications.

  9. Aluminum oxide from trimethylaluminum and water by atomic layer deposition: The temperature dependence of residual stress, elastic modulus, hardness and adhesion

    International Nuclear Information System (INIS)

    Ylivaara, Oili M.E.; Liu, Xuwen; Kilpi, Lauri; Lyytinen, Jussi; Schneider, Dieter; Laitinen, Mikko; Julin, Jaakko; Ali, Saima; Sintonen, Sakari; Berdova, Maria; Haimi, Eero; Sajavaara, Timo; Ronkainen, Helena; Lipsanen, Harri

    2014-01-01

    Use of atomic layer deposition (ALD) in microelectromechanical systems (MEMS) has increased as ALD enables conformal growth on 3-dimensional structures at relatively low temperatures. For MEMS device design and fabrication, the understanding of stress and mechanical properties such as elastic modulus, hardness and adhesion of thin film is crucial. In this work a comprehensive characterization of the stress, elastic modulus, hardness and adhesion of ALD aluminum oxide (Al 2 O 3 ) films grown at 110–300 °C from trimethylaluminum and water is presented. Film stress was analyzed by wafer curvature measurements, elastic modulus by nanoindentation and surface-acoustic wave measurements, hardness by nanoindentation and adhesion by microscratch test and scanning nanowear. The films were also analyzed by ellipsometry, optical reflectometry, X-ray reflectivity and time-of-flight elastic recoil detection for refractive index, thickness, density and impurities. The ALD Al 2 O 3 films were under tensile stress in the scale of hundreds of MPa. The magnitude of the stress decreased strongly with increasing ALD temperature. The stress was stable during storage in air. Elastic modulus and hardness of ALD Al 2 O 3 saturated to a fairly constant value for growth at 150 to 300 °C, while ALD at 110 °C gave softer films with lower modulus. ALD Al 2 O 3 films adhered strongly on cleaned silicon with SiO x termination. - Highlights: • The residual stress of Al 2 O 3 was tensile and stable during the storage in air. • Elastic modulus of Al 2 O 3 saturated to at 170 GPa for films grown at 150 to 300 °C. • At 110 °C Al 2 O 3 films were softer with high residual hydrogen and lower density. • The Al 2 O 3 adhered strongly on the SiO x -terminated silicon

  10. 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

  11. Vacuum Characterization of a Woven Carbon Fiber Cryosorber in Presence of $H_2$

    CERN Document Server

    Baglin, V; Garcin, T

    2004-01-01

    Some of the cold bores of the Large Hadron Collider (LHC) will operate at 4.5K. In these elements, the desorbed H2 pressure will rapidly reach the saturated vapour pressure, 3 orders of magnitude larger than the design pressure. Therefore, the use of cryosorbers is mandatory to provide the required pumping capacity and pumping speed. The behaviour of a woven carbon fiber to be potentially used as a cryosorber has been studied under H2 injection. The pumping speed and capacity measured in the range 6 to 30 K are described. Observations made with an electron microscope are shown. A proposed pumping mechanism and the implications for the LHC are discussed.

  12. Effect of the Young modulus variability on the mechanical behaviour of a nuclear containment vessel

    Energy Technology Data Exchange (ETDEWEB)

    Larrard, T. de, E-mail: delarrard@lmt.ens-cachan.f [LMT-ENS Cachan, CNRS/UPMC/PRES UniverSud Paris (France); Colliat, J.B.; Benboudjema, F. [LMT-ENS Cachan, CNRS/UPMC/PRES UniverSud Paris (France); Torrenti, J.M. [Universite Paris-Est, LCPC (France); Nahas, G. [IRSN/DSR/SAMS/BAGS, Fontenay-aux-Roses (France)

    2010-12-15

    This study aims at investigating the influence of the Young modulus variability on the mechanical behaviour of a nuclear containment vessel in case of a loss of cooling agent accident and under the assumption of an elastic behaviour. To achieve this investigation, the Monte-Carlo Method is carried out thanks to a middleware which encapsulates the different components (random field generation, FE simulations) and enables calculations parallelisation. The main goal is to quantify the uncertainty propagation by comparing the maximal values of outputs of interest (orthoradial stress and Mazars equivalent strain) for each realisation of the considered random field with the ones obtained from a reference calculation taking into account uniform field (equal to the expected value of the random field). The Young modulus is supposed to be accurately represented by a weakly homogeneous random field and realisations are provided through its truncated Karhunen-Loeve expansion. This study reveals that the expected value for the maximal equivalent strain in the structure is more important when considering the Young modulus spatial variability than the value obtained from a deterministic approach with a uniform Young modulus field. The influence of the correlation length is investigated too. Finally it is shown that there is no correlation between the maximal values location of equivalent strain and the ones where the Young modulus extreme values are observed for each realisation.

  13. Binding Energy and Compression Modulus of Infinite Nuclear Matter ...

    African Journals Online (AJOL)

    ... MeV at the normal nuclear matter saturation density consistent with the best available density-dependent potentials derived from the G-matrix approach. The results of the incompressibility modulus, k∞ is in excellent agreement with the results of other workers. Journal of the Nigerian Association of Mathematical Physics, ...

  14. Poisson's ratio and Young's modulus of lipid bilayers in different phases

    Directory of Open Access Journals (Sweden)

    Tayebeh eJadidi

    2014-04-01

    Full Text Available A general computational method is introduced to estimate the Poisson's ratio for membranes with small thickness.In this method, the Poisson's ratio is calculated by utilizing a rescaling of inter-particle distancesin one lateral direction under periodic boundary conditions. As an example for the coarse grained lipid model introduced by Lenz and Schmid, we calculate the Poisson's ratio in the gel, fluid, and interdigitated phases. Having the Poisson's ratio, enable us to obtain the Young's modulus for the membranes in different phases. The approach may be applied to other membranes such as graphene and tethered membranes in orderto predict the temperature dependence of its Poisson's ratio and Young's modulus.

  15. Effect of fabric texture and material on perceived discomfort at high humidity

    DEFF Research Database (Denmark)

    Toftum, Jørn; Rasmussen, Leif W.; Mackeprang, Jørgen

    1999-01-01

    This study investigated the effect of material (cotton/polyester) and texture (woven/knitted) of the inner layer of a clothing ensemble on human discomfort at high skin humidity. No clear effect on discomfort of material and texture could be detected. However, acceptability of skin humidity de......-crea-sed with increasing relative skin humidity. A model was developed that predicts the percentage of persons dissatisfied due to humid skin as a function of relative skin humidity. The model applies for woven and knitted cot-ton and polyester materials and for activity levels typical for office work. Even at very high...

  16. MODULUS OF ELASTICITY AND HARDNESS OF COMPRESSION AND OPPOSITE WOOD CELL WALLS OF MASSON PINE

    Directory of Open Access Journals (Sweden)

    Yanhui Huang,

    2012-05-01

    Full Text Available Compression wood is commonly found in Masson pine. To evaluate the mechanical properties of the cell wall of Masson pine compression and opposite wood, nanoindentation was used. The results showed that the average values of hardness and cell wall modulus of elasticity of opposite wood were slightly higher than those of compression wood. With increasing age of the annual ring, the modulus of elasticity showed a negative correlation with microfibril angle, but a weak correlation was observed for hardness. In opposite and compression wood from the same annual ring, the differences in average values of modulus of elasticity and hardness were small. These slight differences were explained by the change of microfibril angle (MFA, the press-in mode of nanoindentation, and the special structure of compression wood. The mechanical properties were almost the same for early, transition, and late wood in a mature annual ring of opposite wood. It can therefore be inferred that the average modulus of elasticity (MOE and hardness of the cell walls in a mature annual ring were not being affected by cell wall thickness.

  17. A computer simulation approach to quantify the true area and true area compressibility modulus of biological membranes

    International Nuclear Information System (INIS)

    Chacón, Enrique; Tarazona, Pedro; Bresme, Fernando

    2015-01-01

    We present a new computational approach to quantify the area per lipid and the area compressibility modulus of biological membranes. Our method relies on the analysis of the membrane fluctuations using our recently introduced coupled undulatory (CU) mode [Tarazona et al., J. Chem. Phys. 139, 094902 (2013)], which provides excellent estimates of the bending modulus of model membranes. Unlike the projected area, widely used in computer simulations of membranes, the CU area is thermodynamically consistent. This new area definition makes it possible to accurately estimate the area of the undulating bilayer, and the area per lipid, by excluding any contributions related to the phospholipid protrusions. We find that the area per phospholipid and the area compressibility modulus features a negligible dependence with system size, making possible their computation using truly small bilayers, involving a few hundred lipids. The area compressibility modulus obtained from the analysis of the CU area fluctuations is fully consistent with the Hooke’s law route. Unlike existing methods, our approach relies on a single simulation, and no a priori knowledge of the bending modulus is required. We illustrate our method by analyzing 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine bilayers using the coarse grained MARTINI force-field. The area per lipid and area compressibility modulus obtained with our method and the MARTINI forcefield are consistent with previous studies of these bilayers

  18. Influence of cold-working and subsequent heat-treatment on young's modulus and strength of Co-Ni-Cr-Mo alloy

    International Nuclear Information System (INIS)

    Otomo, Takuma; Matsumoto, Hiroaki; Chiba, Akihiko; Nomura, Naoyuki

    2009-01-01

    Changes in Young's modulus of the Co-31 mass%Ni-19 mass%Cr-10 mass%Mo alloy (Co-Ni based alloy) with cold-swaging, combined with heat-treatment at temperatures from 673 to 1323 K, was investigated to enhance the Young's modulus of Co-Ni based alloy. After cold-swaging, the Co-Ni based alloy, forming fiber deformation texture, shows the Young's modulus of 220 GPa. Furthermore, after ageing the cold-swaged alloy at temperature from 673 to 1323 K, the Young's modulus increased to 230 GPa, accompanied by a decrease in the internal fiction and an increase in the tensile strength. This suggests that the increment in Young's modulus is caused by a moving of the vacancies to the dislocation cores and a continuous locking of the dislocations along their entire length with solute atoms (trough model). By annealing at 1323 K after cold swaging, Young's modulus slightly increased to 236 GPa. On the other hand, the tensile strength decreases to almost the same value as that before cold swaging due to recrystallization. These results suggest that the Young's modulus and the strength in the present alloy are simultaneously enhanced by the continuous dislocation locking during aging as well as the formation of fiber deformation texture. (author)

  19. Damage in woven CFRP laminates under impact loading

    Science.gov (United States)

    Ullah, H.; Harland, A. R.; Silberschmidt, V. V.

    2012-08-01

    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.

  20. 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

  1. 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.

  2. Mechanical properties of banana/kenaf fiber-reinforced hybrid polyester composites: Effect of woven fabric and random orientation

    International Nuclear Information System (INIS)

    Alavudeen, A.; Rajini, N.; Karthikeyan, S.; Thiruchitrambalam, M.; Venkateshwaren, N.

    2015-01-01

    Highlights: • This paper is presents the fabrications of kenaf/banana fiber hybrid composites. • Effect of weaving pattern and random orientation on mechanical properties was studied. • Role of interfacial adhesion due to chemical modifications were analyzed with the aid of SEM. • Hybridization of kenaf and banana fibers in plain woven composites exhibits maximum mechanical strength. - Abstract: The present work deals with the effect of weaving patterns and random orientatation on the mechanical properties of banana, kenaf and banana/kenaf fiber-reinforced hybrid polyester composites. Composites were prepared using the hand lay-up method with two different weaving patterns, namely, plain and twill type. Of the two weaving patterns, the plain type showed improved tensile properties compared to the twill type in all the fabricated composites. Furthermore, the maximum increase in mechanical strength was observed in the plain woven hybrid composites rather than in randomly oriented composites. This indicates minimum stress development at the interface of composites due to the distribution of load transfer along the fiber direction. Moreover, alkali (NaOH) and sodium lauryl sulfate (SLS) treatments appear to provide an additional improvement in mechanical strength through enhanced interfacial bonding. Morphological studies of fractured mechanical testing samples were performed by scanning electron microscopy (SEM) to understand the de-bonding of fiber/matrix adhesion

  3. Effect of bulk modulus on performance of a hydrostatic transmission ...

    Indian Academy of Sciences (India)

    an induction motor, a fixed or variable displacement motor, and all required ... oped a linear relation between oil bulk modulus and pressure for a HST system. ..... Piotrowska A 2003 The control of the rotational speed of hydraulic engine in ...

  4. Tension-Compression Fatigue Behavior of Plain Woven Kenaf/Kevlar Hybrid Composites

    Directory of Open Access Journals (Sweden)

    Suhad D. Salman

    2016-02-01

    Full Text Available The applications of hybrid natural/synthetic reinforced polymer composites have been rapidly gaining market share in structural applications due to their remarkable characteristics and the fact that most of the components made of these materials are subjected to cyclic loading. Their fatigue properties have received a lot of attention because predicting their behavior is a challenge due to the effects of the synergies between the fibers. The purpose of this work is to characterize the tension, compression, and tensile-compression fatigue behavior of six layers of Kevlar hybridized with one layer of woven kenaf reinforced epoxy, at a 35% weight fraction. Fatigue tests were carried out and loaded cyclically at 60%, 70%, 80%, and 90% of their ultimate compressive stress. The results give a complete description for tensile and compression properties and could be used to predict fatigue-induced failure mechanisms.

  5. The construction phase’s influence to the moving ability of cross-sections of woven structure

    Science.gov (United States)

    Inogamdjanov, D.; Daminov, A.; Kasimov, O.

    2017-10-01

    The purpose of this study is to work out bases to predict properties for single layer flat woven fabrics depending on changes of construction phases. A structural model of cross-section of single layered fabric is described based on the Pierce’s model. Form transformation of the yarn like straight, semi-arch and arch yarn is considered according to the alteration of yarn tension under the theory of Novikov. The value contributions to movement index of warp and weft yarn and their total moving ability in cross-sections at all structure phases of fabric are summarized.

  6. Pseudo-variables method to calculate HMA relaxation modulus through low-temperature induced stress and strain

    International Nuclear Information System (INIS)

    Canestrari, Francesco; Stimilli, Arianna; Bahia, Hussain U.; Virgili, Amedeo

    2015-01-01

    Highlights: • Proposal of a new method to analyze low-temperature cracking of bituminous mixtures. • Reliability of the relaxation modulus master curve modeling through Prony series. • Suitability of the pseudo-variables approach for a close form solution. - Abstract: Thermal cracking is a critical failure mode for asphalt pavements. Relaxation modulus is the major viscoelastic property that controls the development of thermally induced tensile stresses. Therefore, accurate determination of the relaxation modulus is fundamental for designing long lasting pavements. This paper proposes a reliable analytical solution for constructing the relaxation modulus master curve by measuring stress and strain thermally induced in asphalt mixtures. The solution, based on Boltzmann’s Superposition Principle and pseudo-variables concepts, accounts for time and temperature dependency of bituminous materials modulus, avoiding complex integral transformations. The applicability of the solution is demonstrated by testing a reference mixture using the Asphalt Thermal Cracking Analyzer (ATCA) device. By applying thermal loadings on restrained and unrestrained asphalt beams, ATCA allows the determination of several parameters, but is still unable to provide reliable estimations of relaxation properties. Without them the measurements from ATCA cannot be used in modeling of pavement behavior. Thus, the proposed solution successfully integrates ATCA experimental data. The same methodology can be applied to all test methods that concurrently measure stress and strain. The statistical parameters used to evaluate the goodness of fit show optimum correlation between theoretical and experimental results, demonstrating the accuracy of this mathematical approach

  7. Preparation of a non-woven poly(ε-caprolactone) fabric with partially embedded apatite surface for bone tissue engineering applications by partial surface melting of poly(ε-caprolactone) fibers.

    Science.gov (United States)

    Kim, In Ae; Rhee, Sang-Hoon

    2017-07-01

    This article describes a novel method for the preparation of a biodegradable non-woven poly(ε-caprolactone) fabric with a partially embedded apatite surface designed for application as a scaffold material for bone tissue engineering. The non-woven poly(ε-caprolactone) fabric was generated by the electro-spinning technique and then apatite was coated in simulated body fluid after coating the PVA solution containing CaCl 2 ·2H 2 O. The apatite crystals were partially embedded or fully embedded into the thermoplastic poly(ε-caprolactone) fibers by controlling the degree of poly(ε-caprolactone) fiber surface melting in a convection oven. Identical apatite-coated poly(ε-caprolactone) fabric that did not undergo heat-treatment was used as a control. The features of the embedded apatite crystals were evaluated by FE-SEM, AFM, EDS, and XRD. The adhesion strengths of the coated apatite layers and the tensile strengths of the apatite coated fabrics with and without heat-treatment were assessed by the tape-test and a universal testing machine, respectively. The degree of water absorbance was assessed by adding a DMEM droplet onto the fabrics. Moreover, cell penetrability was assessed by seeding preosteoblastic MC3T3-E1 cells onto the fabrics and observing the degrees of cell penetration after 1 and 4 weeks by staining nuclei with DAPI. The non-woven poly(ε-caprolactone) fabric with a partially embedded apatite surface showed good water absorbance, cell penetrability, higher apatite adhesion strength, and higher tensile strength compared with the control fabric. These results show that the non-woven poly(ε-caprolactone) fabric with a partially embedded apatite surface is a potential candidate scaffold for bone tissue engineering due to its strong apatite adhesion strength and excellent cell penetrability. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1973-1983, 2017. © 2017 Wiley Periodicals, Inc.

  8. A maximum modulus theorem for the Oseen problem

    Czech Academy of Sciences Publication Activity Database

    Kračmar, S.; Medková, Dagmar; Nečasová, Šárka; Varnhorn, W.

    2013-01-01

    Roč. 192, č. 6 (2013), s. 1059-1076 ISSN 0373-3114 R&D Projects: GA ČR(CZ) GAP201/11/1304; GA MŠk LC06052 Institutional research plan: CEZ:AV0Z10190503 Keywords : Oseen problem * maximum modulus theorem * Oseen potentials Subject RIV: BA - General Mathematics Impact factor: 0.909, year: 2013 http://link.springer.com/article/10.1007%2Fs10231-012-0258-x

  9. Estimate of K-functionals and modulus of smoothness constructed ...

    Indian Academy of Sciences (India)

    ... and -functionals. The main result of the paper is the proof of the equivalence theorem for a -functional and a modulus of smoothness for the Dunkl transform on R d . Author Affiliations. M El Hamma1 R Daher1. Department of Mathematics, Faculty of Sciences Aïn Chock, University of Hassan II, Casablanca, Morocco ...

  10. Calculation of wear (f.i. wear modulus) in the plastic cup of a hip joint prosthesis

    NARCIS (Netherlands)

    Ligterink, D.J.

    1975-01-01

    The wear equation is applied to the wear process in a hip joint prosthesis and a wear modulus is defined. The sliding distance, wear modulus, wear volume, wear area, contact angle and the maximum normal stress were calculated and the theoretical calculations applied to test results. During the wear

  11. Antibacterial properties of modified biodegradable PHB non-woven fabric.

    Science.gov (United States)

    Slepička, P; Malá, Z; Rimpelová, S; Švorčík, V

    2016-08-01

    The antibacterial properties of poly(hydroxybutyrate) (PHB) non-woven fabric were explored in this study. The PHB was activated by plasma modification and subsequently processed with either immersion into a solution of nanoparticles or direct metallization. The wettability and surface chemistry of the PHB surface was determined. The thickness of the sputtered nanolayer on PHB fabric was characterized. It was found that plasma modification led to a formation of strongly hydrophilic surface, while the subsequent metallization by silver or gold resulted in a significantly increased water contact angle. Further, it was found that antibacterial activity may be controlled by the type of a metal and deposition method used. The immersion of plasma modified fabric into Ag nanoparticle solution led to enhanced antibacterial efficiency of PHB against Escherichia coli (E. coli). Direct silver sputtering on PHB fabric was proved to be a simple method for construction of a surface with strong antibacterial potency against both Escherichia coli (E. coli) and Staphylococcus epidermidis (S. epidermidis). We demonstrated the antibacterial activity of PHB fabric modified by plasma activation and consecutive selection of a treatment method for an effective antibacterial surface construction. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Determination of Reliability Index and Weibull Modulus as a Measure of Hypereutectic Silumins Survival

    OpenAIRE

    J. Szymszal; J. Piątkowski; J. Przondziono

    2007-01-01

    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 moul...

  13. Influence of Selected Factors on the Relationship between the Dynamic Elastic Modulus and Compressive Strength of Concrete.

    Science.gov (United States)

    Jurowski, Krystian; Grzeszczyk, Stefania

    2018-03-22

    In this paper, the relationship between the static and dynamic elastic modulus of concrete and the relationship between the static elastic modulus and compressive strength of concrete have been formulated. These relationships are based on investigations of different types of concrete and take into account the type and amount of aggregate and binder used. The dynamic elastic modulus of concrete was tested using impulse excitation of vibration and the modal analysis method. This method could be used as a non-destructive way of estimating the compressive strength of concrete.

  14. Influence of Selected Factors on the Relationship between the Dynamic Elastic Modulus and Compressive Strength of Concrete

    Science.gov (United States)

    Jurowski, Krystian; Grzeszczyk, Stefania

    2018-01-01

    In this paper, the relationship between the static and dynamic elastic modulus of concrete and the relationship between the static elastic modulus and compressive strength of concrete have been formulated. These relationships are based on investigations of different types of concrete and take into account the type and amount of aggregate and binder used. The dynamic elastic modulus of concrete was tested using impulse excitation of vibration and the modal analysis method. This method could be used as a non-destructive way of estimating the compressive strength of concrete. PMID:29565830

  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. Effects of Bone Young’s Modulus on Finite Element Analysis in the Lateral Ankle Biomechanics

    Directory of Open Access Journals (Sweden)

    W. X. Niu

    2013-01-01

    Full Text Available Finite element analysis (FEA is a powerful tool in biomechanics. The mechanical properties of biological tissue used in FEA modeling are mainly from experimental data, which vary greatly and are sometimes uncertain. The purpose of this study was to research how Young’s modulus affects the computations of a foot-ankle FEA model. A computer simulation and an in-vitro experiment were carried out to investigate the effects of incremental Young’s modulus of bone on the stress and strain outcomes in the computational simulation. A precise 3-dimensional finite element model was constructed based on an in-vitro specimen of human foot and ankle. Young’s moduli were assigned as four levels of 7.3, 14.6, 21.9 and 29.2 GPa respectively. The proximal tibia and fibula were completely limited to six degrees of freedom, and the ankle was loaded to inversion 10° and 20° through the calcaneus. Six cadaveric foot-ankle specimens were loaded as same as the finite element model, and strain was measured at two positions of the distal fibula. The bone stress was less affected by assignment of Young’s modulus. With increasing of Young’s modulus, the bone strain decreased linearly. Young’s modulus of 29.2 GPa was advisable to get the satisfactory surface strain results. In the future study, more ideal model should be constructed to represent the nonlinearity, anisotropy and inhomogeneity, as the same time to provide reasonable outputs of the interested parameters.

  17. Flexural strength and modulus of elasticity of different types of resin-based composites.

    Science.gov (United States)

    Rodrigues Junior, Sinval Adalberto; Zanchi, Cesar Henrique; Carvalho, Rodrigo Varella de; Demarco, Flávio Fernando

    2007-01-01

    The aim of the study was to test whether the filler composition of resin composites influences their flexural strength and modulus of elasticity. Flexural strength and modulus of elasticity were obtained through a three-point bending test. Twelve bar shaped specimens of 5 commercially available composites--Supreme (3M/ESPE), a universal nanofilled composite; Esthet-X (Dentsply), Z-250 (3M/ESPE), Charisma (Heraeus Kulzer), universal hybrid composites; and Helio Fill (Vigodent), a microfine composite--were confectioned according to the ISO 4049/2000 specifications. The test was performed after a 7-days storage time using a universal test machine with a crosshead speed of 1 mm/min. The filler weight content was determined by the ashing technique. The data obtained on the mechanical properties were submitted to ANOVA and Tukey test (p elasticity results were observed among the universal hybrid composites. The nanofilled composite presented intermediary results. Within the limitations of this in vitro study, it could be concluded that the filler content significantly interfered in the flexural strength and modulus of elasticity of the composites tested.

  18. Using data logging to measure Young’s modulus

    Science.gov (United States)

    Richardson, David

    2018-03-01

    Historically the Young’s modulus of a material is measured by increasing the applied force to a wire and measuring the extension. The cross sectional area and original length allow this to be plotted as a graph of stress versus strain. This article describes how data logging sensors can be used to measure how the force changes with extension, allowing a strain versus stress graph to be plotted into the region of plastic deformation.

  19. Vacuum infusion method for woven carbon/Kevlar reinforced hybrid composite

    Science.gov (United States)

    Hashim, N.; Majid, D. L.; Uda, N.; Zahari, R.; Yidris, N.

    2017-12-01

    The vacuum assisted resin transfer moulding (VaRTM) or Vacuum Infusion (VI) is one of the fabrication methods used for composite materials. Compared to other methods, this process costs lower than using prepregs because it does not need to use the autoclave to cure. Moreover, composites fabricated using this VI method exhibit superior mechanical properties than those made through hand layup process. In this study, the VI method is used in fabricating woven carbon/Kevlar fibre cloth with epoxy matrix. This paper reports the detailed methods on fabricating the hybrid composite using VI process and several precautions that need to be taken to avoid any damage to the properties of the composite material. The result highlights that the successfully fabricated composite has approximately 60% of fibres weight fraction. Since the composites produced by the VI process have a higher fibre percentage, this process should be considered for composites used in applications that are susceptible to the conditions where the fibres need to be the dominant element such as in tension loading.

  20. Crack arrest within teeth at the dentinoenamel junction caused by elastic modulus mismatch.

    Science.gov (United States)

    Bechtle, Sabine; Fett, Theo; Rizzi, Gabriele; Habelitz, Stefan; Klocke, Arndt; Schneider, Gerold A

    2010-05-01

    Enamel and dentin compose the crowns of human teeth. They are joined at the dentinoenamel junction (DEJ) which is a very strong and well-bonded interface unlikely to fail within healthy teeth despite the formation of multiple cracks within enamel during a lifetime of exposure to masticatory forces. These cracks commonly are arrested when reaching the DEJ. The phenomenon of crack arrest at the DEJ is described in many publications but there is little consensus on the underlying cause and mechanism. Explanations range from the DEJ having a larger toughness than both enamel and dentin up to the assumption that not the DEJ itself causes crack arrest but the so-called mantle dentin, a thin material layer close to the DEJ that is somewhat softer than the bulk dentin. In this study we conducted 3-point bending experiments with bending bars consisting of the DEJ and surrounding enamel and dentin to investigate crack propagation and arrest within the DEJ region. Calculated stress intensities around crack tips were found to be highly influenced by the elastic modulus mismatch between enamel and dentin and hence, the phenomenon of crack arrest at the DEJ could be explained accordingly via this elastic modulus mismatch. Copyright 2010 Elsevier Ltd. All rights reserved.

  1. Strain Sharing Assessment in Woven Fiber Reinforced Concrete Beams Using Fiber Bragg Grating Sensors.

    Science.gov (United States)

    Montanini, Roberto; Recupero, Antonino; De Domenico, Fabrizio; Freni, Fabrizio

    2016-09-22

    Embedded fiber Bragg grating sensors have been extensively used worldwide for health monitoring of smart structures. In civil engineering, they provide a powerful method for monitoring the performance of composite reinforcements used for concrete structure rehabilitation and retrofitting. This paper discusses the problem of investigating the strain transfer mechanism in composite strengthened concrete beams subjected to three-point bending tests. Fiber Bragg grating sensors were embedded both in the concrete tensioned surface and in the woven fiber reinforcement. It has been shown that, if interface decoupling occurs, strain in the concrete can be up to 3.8 times higher than that developed in the reinforcement. A zero friction slipping model was developed which fitted very well the experimental data.

  2. 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.

  3. Mechanics of fiber reinforced materials

    Science.gov (United States)

    Sun, Huiyu

    This dissertation is dedicated to mechanics of fiber reinforced materials and the woven reinforcement and composed of four parts of research: analytical characterization of the interfaces in laminated composites; micromechanics of braided composites; shear deformation, and Poisson's ratios of woven fabric reinforcements. A new approach to evaluate the mechanical characteristics of interfaces between composite laminae based on a modified laminate theory is proposed. By including an interface as a special lamina termed the "bonding-layer" in the analysis, the mechanical properties of the interfaces are obtained. A numerical illustration is given. For micro-mechanical properties of three-dimensionally braided composite materials, a new method via homogenization theory and incompatible multivariable FEM is developed. Results from the hybrid stress element approach compare more favorably with the experimental data than other existing numerical methods widely used. To evaluate the shearing properties for woven fabrics, a new mechanical model is proposed during the initial slip region. Analytical results show that this model provides better agreement with the experiments for both the initial shear modulus and the slipping angle than the existing models. Finally, another mechanical model for a woven fabric made of extensible yarns is employed to calculate the fabric Poisson's ratios. Theoretical results are compared with the available experimental data. A thorough examination on the influences of various mechanical properties of yarns and structural parameters of fabrics on the Poisson's ratios of a woven fabric is given at the end.

  4. Using the ultrasound and instrumented indentation techniques to measure the elastic modulus of engineering materials

    International Nuclear Information System (INIS)

    Meza, J. M.; Franco, E. E.; Farias, M. C. M.; Buiochi, F.; Souza, R. M.; Cruz, J.

    2008-01-01

    Currently, the acoustic and nano indentation techniques are two of the most used techniques for materials elastic modulus measurement. In this article fundamental principles and limitations of both techniques are shown and discussed. Last advances in nano indentation technique are also reviewed. an experimental study in ceramic, metallic, composite and single crystals was also done. Results shown that ultrasonic technique is capable to provide results in agreement with those reported in literature. However, ultrasonic technique does not allow measuring the elastic modulus of some small samples and single crystals. On the other hand, the nano indentation technique estimates the elastic modulus values in reasonable agreement with those measured by acoustic methods, particularly in amorphous materials, while in some policristaline materials some deviation from expected values was obtained. (Author) 29 refs

  5. Fatigue testing of wood composites for aerogenerator blades. Pt. 11: Assessment of fatigue damage accumulation using a fatigue modulus approach

    Energy Technology Data Exchange (ETDEWEB)

    Hacker, C L; Ansell, M P [Bath Univ. (United Kingdom)

    1996-12-31

    Stress-strain hysteresis loops have been captured during fatigue tests performed at R=10 (compression-compression) and R=0.1 (tension-tension) on Khaya epoxy wood composites. A fatigue modulus approach, proposed by Hwang and Han in 1989, has been applied to the data and a relationship established between the initial change in fatigue modulus and fatigue life. By following changes in fatigue modulus during the first 100 test cycles it is possible to predict the life of the sample allowing rapid evaluation of the fatigue performance of wood composites. Fatigue modulus values have also been calculated for hysteresis loops captured during complex load - time history tests. Similar trends in change in fatigue modulus suggest that this approach could be used in complex loading conditions to evaluate fatigue damage accumulation and predict fatigue life. (Author)

  6. Effect of uncertainty parameters on graphene sheets Young's modulus prediction

    International Nuclear Information System (INIS)

    Sahlaoui, Habib; Sidhom Habib; Guedri, Mohamed

    2013-01-01

    Software based on molecular structural mechanics approach (MSMA) and using finite element method (FEM) has been developed to predict the Young's modulus of graphene sheets. Obtained results have been compared to results available in the literature and good agreement has been shown when the same values of uncertainty parameters are used. A sensibility of the models to their uncertainty parameters has been investigated using a stochastic finite element method (SFEM). The different values of the used uncertainty parameters, such as molecular mechanics force field constants k_r and k_θ, thickness (t) of a graphene sheet and length ( L_B) of a carbon carbon bonds, have been collected from the literature. Strong sensibilities of 91% to the thickness and of 21% to the stretching force (k_r) have been shown. The results justify the great difference between Young's modulus predicted values of the graphene sheets and their large disagreement with experimental results.

  7. Improving UV Resistance of High Performance Fibers

    Science.gov (United States)

    Hassanin, Ahmed

    % rutile TiO2 nanoparticles showed excellent protection of braid from PBO. Only 7.5% strength loss was observed. To optimize the degree of protection of the sheath loaded with UV blocker particles, computational models were developed to optimize the protective layer thickness/weight and the amount of UV particles that provide the maximum protection with lightest weight of the protective layer and minimum amount of UV particles. The simulated results were found to be higher that the experimental results due to the tendency of nanoparticles to be agglomerated in real experiments. The third approach to achieve a maximum protection with the minimum weight added is constructing a sleeve from SpectraRTM (Ultra High Molecular Weight Polyethylene (UHMWPE) high performance fiber), which is known to resist UV, woven fabric. Covering the braid from PBO fiber with Spectra RTM woven fabric provide hybrid structure with two compatible components that can share the load and thus maintain the high strength to weight ratio. Although the SpectraRTM fabric had maximum cover factor, 20 % of visible light and about 15 % of UV were able to penetrate the fabric. This transmittance of UV-VIS light negatively affected the protection performance of the SpectraRTM woven fabric layer. It is thought that SpectraRTM fabric be coated with a thin layer (mentioned earlier) containing UV blocker for additional protection while maintain strength contribution to the hybrid structure. To maximize the strength to weight ratio of the hybrid structure (with core from PBO braid and sheath from SpectraRTM woven fabric) an established finite element model was utilized. The theoretical results using the finite element theory indicated that by controlling the bending rigidity of the filling yarn of the SpectraRTM fabric, the extension at peak load of woven fabric in warp direction (loading direction) could be controlled to match the braid extension at peak load. The match in the extension at peak load of the two

  8. The woven fiber organic electrochemical transistors based on polypyrrole nanowires/reduced graphene oxide composites for glucose sensing.

    Science.gov (United States)

    Wang, Yuedan; Qing, Xing; Zhou, Quan; Zhang, Yang; Liu, Qiongzhen; Liu, Ke; Wang, Wenwen; Li, Mufang; Lu, Zhentan; Chen, Yuanli; Wang, Dong

    2017-09-15

    Novel woven fiber organic electrochemical transistors based on polypyrrole (PPy) nanowires and reduced graphene oxide (rGO) have been prepared. SEM revealed that the introduction of rGO nanosheets could induce the growth and increase the amount of PPy nanowires. Moreover, it could enhance the electrical performance of fiber transistors. The hybrid transistors showed high on/off ratio of 10 2 , fast switch speed, and long cycling stability. The glucose sensors based on the fiber organic electrochemical transistors have also been investigated, which exhibited outstanding sensitivity, as high as 0.773 NCR/decade, with a response time as fast as 0.5s, a linear range of 1nM to 5μM, a low detection concentration as well as good repeatability. In addition, the glucose could be selectively detected in the presence of ascorbic acid and uric acid interferences. The reliability of the proposed glucose sensor was evaluated in real samples of rabbit blood. All the results indicate that the novel fiber transistors pave the way for portable and wearable electronics devices, which have a promising future for healthcare and biological applications. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Determining the Young's modulus of a cellular titanium implant by FEM simulation

    Science.gov (United States)

    Loginov, Yu. N.; Golodnov, A. I.; Stepanov, S. I.; Kovalev, E. Yu.

    2017-12-01

    The role of additive manufacturing is noted for the construction of titanium medical implants. The purpose of the study is to determine the Young's modulus of cellular titanium implants, which is based on calculations performed by finite element analysis. A honeycomb structure from intersecting cylinder surfaces is offered for the implant made of the Ti-6Al-4V alloy. Boundary conditions are stated for the loading of the implant structure. It is demonstrated that the Young's modulus can be reduced more than three times comparing to a solid titanium alloy. Zones of strain and stress localization located near the abutment of the cylindrical surfaces. Recommendations for the further improvement of the implant architecture are generated.

  10. Recycling high-performance carbon fiber reinforced polymer composites using sub-critical and supercritical water

    Science.gov (United States)

    Knight, Chase C.

    of the polymer matrix. To date, very few studies have been reported in this area and the studies thus far have only focused on small scale feasibility and have only shown the recovery of random fibers. The goal of this research is to advance the knowledge in the field of sub-critical and supercritical fluid recycling by providing fundamental information that will be necessary to move this process forward to an industrial scale. This dissertation work consists of several phases of studies. In the first phase of this research, the feasibility of recycling woven CFRP was established on a scale approximately 30 times larger than previously reported. The industrial relevance was also conveyed, as the process was shown to remove up 99% of a highly cross-linked resin from an aerospace grade composite system with 100% retention of the single filament tensile strength and modulus whilst also retaining the highly valuable woven fiber structure. The second phase of research demonstrated the power of this technology to recycle multi-layer composites and provide the ability to reuse the highly valuable materials. Up to 99% resin elimination was achieved for a woven 12-layer aerospace grade composite. The recycled woven fabric layers, with excellent retention of the fiber architecture, were directly reused to fabricate reclaimed fiber composites (RFC). Manufacturing issues associated with the use of the recycled fiber were investigated. Several fabrication technologies were used to fabricate the composite, and the composites show moderate short beam shear strength and may be suitable for certain industrial applications. Moreover, fresh composites were also recycled, recovered, and reused to investigate the retention of flexural properties of the fibers after recycling. Up to 95% of the flexural strength and 98% of the flexural modulus was retained in the reclaimed fiber composites. The recycled resin residual can be incorporated into fresh resin and cured, demonstrating a near

  11. Measurement of the elastic modulus of Kapton perpendicular to the plane of the film at room and cryogenic temperatures

    International Nuclear Information System (INIS)

    Davidson, M.; Bastian, S.; Markley, F.

    1992-04-01

    Understanding the short term elastic properties, (i.e. the instantaneous modulus) of Kapton is essential in determining the loss of prestress during storage and operation of SSC dipole magnets. The magnet prestress contributes directly to the coil response to the Lorentz forces during ramping. The instantaneous modulus is important in extrapolating short term stress relaxation data to longer times. Most theoretical fits assume a time independent component and a time dependent component. The former may be represented by the Kapton modulus near zero K where all relaxation processes have been ''frozen'' out. Modulus measurements at 77K and 4.2K may point to a correct value for the near zero K modulus. Three companion papers presented at this conference will be: ''Stress Relaxation in SSC 50 mm Dipole Coils'' ''Temperature Dependence of the Viscoelastic Properties of SSC Coil Insulation (Kapton)'' ''Theoretical Methods for Creep and Stress Relaxation Studies of SSC Coil.''

  12. Design values of resilient modulus of stabilized and non-stabilized base.

    Science.gov (United States)

    2010-10-01

    The primary objective of this research study is to determine design value ranges for typical base materials, as allowed by LADOTD specifications, through laboratory tests with respect to resilient modulus and other parameters used by pavement design ...

  13. Size-dependent effective Young’s modulus of silicon nitride cantilevers

    NARCIS (Netherlands)

    Babaei Gavan, K.; Westra, H.J.R.; Van der Drift, E.W.J.M.; Venstra, W.J.; Van der Zant, H.S.J.

    2009-01-01

    The effective Young’s modulus of silicon nitride cantilevers is determined for thicknesses in the range of 20–684 nm by measuring resonance frequencies from thermal noise spectra. A significant deviation from the bulk value is observed for cantilevers thinner than 150 nm. To explain the observations

  14. Effect of Cooling Rate on the Longitudinal Modulus of Cu3Sn Phase of Ag-Sn-Cu Amalgam Alloy (Part II

    Directory of Open Access Journals (Sweden)

    R. H. Rusli

    2015-10-01

    Full Text Available Effects of cooling rate (at the time of solidification on the elastic constants of Cu3Sn phase of Ag-Sn-Cu dental amalgam alloy were studied. In this study, three types of alloys were made, with the composition Cu-38-37 wt% Sn by means of casting, where each alloy was subjected to different cooling rate, such as cooling on the air (AC, air blown (AB, and quenched in the water (WQ. X-ray diffraction, metallography, and Scanning Electron Microscopy with Energy Dispersive Spectroscopy studies of three alloys indicated the existence of Cu3Sn phase. Determination of the modulus of elasticity of Cu3Sn (ε phase was carried out by the measurement of longitudinal and transversal waves velocity using ultrasonic technique. The result shows that Cu3Sn (ε phase on AC gives higher modulus of elasticity values than those of Cu3Sn (ε on AB and WQ. The high modulus of elasticity value will produce a strong Ag-Sn-Cu dental amalagam alloy.

  15. Elastic Metamaterials with Simultaneously Negative Effective Shear Modulus and Mass Density

    KAUST Repository

    Wu, Ying; Lai, Yun; Zhang, Zhao-Qing

    2011-01-01

    We propose a type of elastic metamaterial comprising fluid-solid composite inclusions which can possess a negative shear modulus and negative mass density over a large frequency region. Such a material has the unique property that only transverse

  16. 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.

  17. In vivo performance of a reduced-modulus bone cement

    Science.gov (United States)

    Forehand, Brett Ramsey

    Total joint replacement has become one of the most common procedures in the area of orthopedics and is often the solution in patients with diseased or injured hip joints. Component loosening is a significant problem and is primarily caused by bone resorption at the bone-cement interface in cemented implants. It is our hypothesis that localized shear stresses are responsible for the resorption. It was previously shown analytically that local stresses at the interface could be reduced by using a cement of lower modulus. A new reduced modulus cement, polybutyl methylmethacrylate (PBMMA), was developed to test the hypothesis. PBMMA was formulated to exist as polybutyl methacrylate filler in a polymethyl methacrylate matrix. The success of PBMMA cement is based largely on the fact that the polybutyl component of the cement will be in the rubbery state at body temperature. In vitro characterization of the cement was undertaken previously and demonstrated a modulus of approximately one-eighth that of conventional bone cement, polymethyl methacrylate (PMMA) and increased fracture toughness. The purpose of this experiment was to perform an in vivo comparison of the two cements. A sheep model was selected. Total hip arthroplasty was performed on 50 ewes using either PBMMA or PMMA. Radiographs were taken at 6 month intervals. At one year, the contralateral femur of each sheep was implanted so that each animal served as its own control, and the animals were sacrificed. The stiffness of the bone-cement interface of the femoral component within the femur was assessed by applying a torque to the femoral component and demonstrated a significant difference in loosening between the cements when the specimens were tested in external rotation (p sheep had a greater amount of loosening for each subject, 59% versus 4% for standard PMMA. A radiographic analysis demonstrated more signs of loosening in the PMMA series of subjects. A brief histological examination showed similar bony

  18. Back-analysing rock mass modulus from monitoring data of two tunnels in Sydney, Australia

    Directory of Open Access Journals (Sweden)

    Robert Bertuzzi

    2017-10-01

    Full Text Available This paper presents two case studies where the rock mass modulus and in situ stress are estimated from the monitoring data obtained during the construction of underground excavations in Sydney, Australia. The case studies comprise the widening of existing twin road tunnels within Hawkesbury sandstone and the excavation of a large cavern within Ashfield shale. While back-analysis from detailed systematic monitoring has been previously published, this paper presents a relatively simple methodology to derive rock mass modulus and in situ stress from the relatively simple displacement data routinely recorded during tunnelling.

  19. A Fiber-Coupled Self-Mixing Laser Diode for the Measurement of Young’s Modulus

    Directory of Open Access Journals (Sweden)

    Ke Lin

    2016-06-01

    Full Text Available This paper presents the design of a fiber-coupled self-mixing laser diode (SMLD for non-contact and non-destructive measurement of Young’s modulus. By the presented measuring system, the Young’s modulus of aluminum 6061 and brass are measured as 70.0 GPa and 116.7 GPa, respectively, showing a good agreement within the standards in the literature and yielding a much smaller deviation and a higher repeatability compared with traditional tensile testing. Its fiber-coupled characteristics make the system quite easy to be installed in many application cases.

  20. 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.

  1. Phase I/II Trial of Autologous Bone Marrow Stem Cell Transplantation with a Three-Dimensional Woven-Fabric Scaffold for Periodontitis

    Directory of Open Access Journals (Sweden)

    Shunsuke Baba

    2016-01-01

    Full Text Available Regenerative medicine is emerging as a promising option, but the potential of autologous stem cells has not been investigated well in clinical settings of periodontal treatment. In this clinical study, we evaluated the safety and efficacy of a new regenerative therapy based on the surgical implantation of autologous mesenchymal stem cells (MSCs with a biodegradable three-dimensional (3D woven-fabric composite scaffold and platelet-rich plasma (PRP. Ten patients with periodontitis, who required a surgical procedure for intrabony defects, were enrolled in phase I/II trial. Once MSCs were implanted in each periodontal intrabony defect, the patients were monitored during 36 months for a medical exam including laboratory tests of blood and urine samples, changes in clinical attachment level, pocket depth, and linear bone growth (LBG. All three parameters improved significantly during the entire follow-up period (p<0.0001, leading to an average LBG of 4.7 mm after 36 months. Clinical mobility measured by Periotest showed a decreasing trend after the surgery. No clinical safety problems attributable to the investigational MSCs were identified. This clinical trial suggests that the stem cell therapy using MSCs-PRP/3D woven-fabric composite scaffold may constitute a novel safe and effective regenerative treatment option for periodontitis.

  2. Comparison of Elastic Modulus and Compressive Strength of Ariadent and Harvard Polycarboxylate Cement and Vitremer Resin Modified Glass Ionomer

    Directory of Open Access Journals (Sweden)

    Ahmadian Khoshemehr Leila

    2009-09-01

    Full Text Available Background: Luting agents are used to attach indirect restoration into or on the tooth. Poor mechanical properties of cement may be a cause of fracture of this layer and lead to caries and restoration removal. The purpose of this study was to compare the elastic modulus and compressive strength of Ariadent (A Poly and Harvard polycarboxylate (H Poly cements and Vitremer resin modified glass ionomer (RGl.Materials & Methods: In this experimental study 15 specimens were prepared form each experimental cement in Laboratory of Tehran Oil Refining Company. The cylindrical specimens were compressed in Instron machine after 24 hours. Elastic modulus and compressive strength were calculated from stress/strain curve of each specimen. One way ANOVA and Tukey tests were used for statistical analysis and P values<0.05 were considered to be statistically significant.Results: The mean elastic modulus and mean compressive strength were 2.2 GPa and 87.8MPa in H poly, 2.4 GPa and 56.5 MPa in A Poly, and 0.8GPa and 105.6 MPa in RGI, respectively. Statistical analysis showed that compressive strength and elastic modulus of both polycarboxylate cements were significantly different from hybrid ionomer (P<0.05, but the difference between elastic modulus of two types of polycarboxilate cements was not statistically significant. Compressive strength of two polycarboxilate cements were significantly different (P<0.05. Conclusion: An ideal lutting agent must have the best mechanical properties. Between the tested luttins RGl cement had the lowest elastic modulus and the highest compressive strength, but the A poly cement had the highest elastic modulus and the lowest compressive strength. Therefore none of them was the best.

  3. Ultrahigh-Energy Density Lithium-Ion Cable Battery Based on the Carbon-Nanotube Woven Macrofilms.

    Science.gov (United States)

    Wu, Ziping; Liu, Kaixi; Lv, Chao; Zhong, Shengwen; Wang, Qinghui; Liu, Ting; Liu, Xianbin; Yin, Yanhong; Hu, Yingyan; Wei, Di; Liu, Zhongfan

    2018-05-01

    Moore's law predicts the performance of integrated circuit doubles every two years, lasting for more than five decades. However, the improvements of the performance of energy density in batteries lag far behind that. In addition, the poor flexibility, insufficient-energy density, and complexity of incorporation into wearable electronics remain considerable challenges for current battery technology. Herein, a lithium-ion cable battery is invented, which is insensitive to deformation due to its use of carbon nanotube (CNT) woven macrofilms as the charge collectors. An ultrahigh-tap density of 10 mg cm -2 of the electrodes can be obtained, which leads to an extremely high-energy density of 215 mWh cm -3 . The value is approximately seven times than that of the highest performance reported previously. In addition, the battery displays very stable rate performance and lower internal resistance than conventional lithium-ion batteries using metal charge collectors. Moreover, it demonstrates excellent convenience for connecting electronics as a new strategy is applied, in which both electrodes can be integrated into one end by a CNT macrorope. Such an ultrahigh-energy density lithium-ion cable battery provides a feasible way to power wearable electronics with commercial viability. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Determination of elastic modulus for hollow spherical shells via resonant ultrasound spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Xiaojun [Institute of Modern Physics, Fudan University, Shanghai 200433 (China); Research Center of Laser Fusion, CAEP, Mianyang 621900 (China); Tang, Xing; Wang, Zongwei [Research Center of Laser Fusion, CAEP, Mianyang 621900 (China); Chen, Qian; Qian, Menglu [Institute of Acoustic, Tongji University, Shanghai 200092 (China); Meng, Jie [Research Center of Laser Fusion, CAEP, Mianyang 621900 (China); Tang, Yongjian [Institute of Modern Physics, Fudan University, Shanghai 200433 (China); Research Center of Laser Fusion, CAEP, Mianyang 621900 (China); Shen, Hao [Institute of Modern Physics, Fudan University, Shanghai 200433 (China); Gao, Dangzhong, E-mail: dgaocn@163.com [Research Center of Laser Fusion, CAEP, Mianyang 621900 (China)

    2017-04-15

    Highlights: • The axisymmetric frequency equation of an isotropic hollow two-layer sphere is deduced by three dimension elasticity theory and global matrix method. • The simulated results demonstrate that the natural frequencies of a hollow sphere are more strongly dependent on Young’s modulus than Poisson's ratio. • The Young’s moduli of polymer capsules with an sub-millimeter inner radius are measured accurately with an uncertainty of ∼10%. - Abstract: The elastic property of a capsule is one of the essential parameters both in engineering applications and scientific understanding of material nature in inertial confinement fusion (ICF) experiments. The axisymmetric frequency equation of an isotropic hollow two-layer sphere is deduced by three dimension elasticity theory and global matrix method, and a combined resonant ultrasound spectroscopy(RUS), which consists of a piezoelectric-based resonant ultrasound spectroscopy(PZT-RUS) and a laser-based resonant ultrasound spectroscopy(LRUS), is developed for determining the elastic modulus of capsule. To understand the behavior of natural frequencies varying with elastic properties, the dependence of natural frequencies on Young’s modulus and Poisson’s ratio are calculated numerically. Some representative polymer capsules are measured using PZT-RUS and LRUS. Based on the theoretical and experimental results, the Young’s moduli of these capsules are measured accurately with an uncertainty of ∼10%.

  5. Microstructure and mechanical properties of a newly developed low Young's modulus Ti-15Zr-5Cr-2Al biomedical alloy.

    Science.gov (United States)

    Wang, Pan; Wu, Lihong; Feng, Yan; Bai, Jiaming; Zhang, Baicheng; Song, Jie; Guan, Shaokang

    2017-03-01

    The Ti-15Zr-5Cr-2Al alloy has been developed and various heat treatments have been investigated to develop new biomedical materials. It is found that the heat treatment conditions strongly affect the phase constitutions and mechanical properties. The as-cast specimen is comprised of β phase and a small fraction of α phase, which is attributed to the suppression of ω phase caused by adding Al. A high yield strength of 1148±36MPa and moderate Young's modulus of 96±3GPa are obtained in the as-cast specimen. Besides the β phase and α phase, ω phase is also detected in the air cooled and liquid nitrogen quenched specimens, which increases the Young's modulus and lowers the ductility. In contrast, only β phase is detected after ice water quenching. The ice water quenched specimen exhibits a good combination of mechanical properties with a high microhardness of 302±10HV, a large plastic strain of 23±2%, a low Young's modulus of 58±4GPa, a moderate yield strength of 625±32MPa and a high compressive strength of 1880±59MPa. Moreover, the elastic energies of the ice water quenched specimen (3.22MJ/m 3 ) and as-cast specimen (6.86MJ/m 3 ) are higher than that of c.p. Ti (1.25MJ/m 3 ). These results demonstrate that as-cast and ice water quenched Ti-15Zr-5Cr-2Al alloys with a superior combination of mechanical properties are potential materials for biomedical applications. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Multi-beam laser heterodyne measurement with ultra-precision for Young modulus based on oscillating mirror modulation

    Science.gov (United States)

    Li, Y. Chao; Ding, Q.; Gao, Y.; Ran, L. Ling; Yang, J. Ru; Liu, C. Yu; Wang, C. Hui; Sun, J. Feng

    2014-07-01

    This paper proposes a novel method of multi-beam laser heterodyne measurement for Young modulus. Based on Doppler effect and heterodyne technology, loaded the information of length variation to the frequency difference of the multi-beam laser heterodyne signal by the frequency modulation of the oscillating mirror, this method can obtain many values of length variation caused by mass variation after the multi-beam laser heterodyne signal demodulation simultaneously. Processing these values by weighted-average, it can obtain length variation accurately, and eventually obtain value of Young modulus of the sample by the calculation. This novel method is used to simulate measurement for Young modulus of wire under different mass by MATLAB, the obtained result shows that the relative measurement error of this method is just 0.3%.

  7. Can reliable values of Young's modulus be deduced from Fisher's (1971) spinning lens measurements?

    Science.gov (United States)

    Burd, H J; Wilde, G S; Judge, S J

    2006-04-01

    The current textbook view of the causes of presbyopia rests very largely on a series of experiments reported by R.F. Fisher some three decades ago, and in particular on the values of lens Young's modulus inferred from the deformation caused by spinning excised lenses about their optical axis (Fisher 1971) We studied the extent to which inferred values of Young's modulus are influenced by assumptions inherent in the mathematical procedures used by Fisher to interpret the test and we investigated several alternative interpretation methods. The results suggest that modelling assumptions inherent in Fisher's original method may have led to systematic errors in the determination of the Young's modulus of the cortex and nucleus. Fisher's conclusion that the cortex is stiffer than the nucleus, particularly in middle age, may be an artefact associated with these systematic errors. Moreover, none of the models we explored are able to account for Fisher's claim that the removal of the capsule has only a modest effect on the deformations induced in the spinning lens.

  8. Determination of dynamic Young’s modulus of vulnerable speleothems

    Czech Academy of Sciences Publication Activity Database

    Konečný, Pavel; Lednická, Markéta; Souček, Kamil; Staš, Lubomír; Kubina, Lukáš; Gribovszki, K.

    2015-01-01

    Roč. 20, č. 2 (2015), s. 156-163 ISSN 1335-1788 R&D Projects: GA MŠk ED2.1.00/03.0082; GA MŠk(CZ) LO1406 Institutional support: RVO:68145535 Keywords : dynamic Young´s modulus * speleothem * bulk density * X-Ray Computed Tomography Subject RIV: DB - Geology ; Mineralogy Impact factor: 0.390, year: 2015 http://actamont.tuke.sk/pdf/2015/n2/10Konecny.pdf

  9. Polypropylene non-woven fabric membrane via surface modification with biomimetic phosphorylcholine in Ce(IV)/HNO{sub 3} redox system

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Jie; Shi Qiang; Luan Shifang; Song Lingjie; Yang Huawei [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Stagnaro, Paola [Istituto per Io Studio delle Macromolecole, Consiglio Nazionale delle Ricerche, Via de Marini 6, 16149 Genova (Italy); Yin Jinghua, E-mail: yinjh@ciac.jl.cn [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China)

    2012-10-01

    Surface modification of polypropylene non-woven fabric membrane (NWF) for improving its hemocompatibility was developed by grafting a biomimic monomer, 2-methacryloyloxyethyl phosphorycholine (MPC). The NWF membrane surface was first activated by potassium peroxydisulfate to form hydroxyl groups, and then grafted with MPC using ceric (IV) ammonium nitrate as the redox initiator. The surface chemical changes before and after modification were confirmed by Fourier transform infrared spectroscopy with an ATR unit (FTIR-ATR) and X-ray photoelectron spectroscopy (XPS); the water contact angle results showed the gradual changes in wettability from hydrophobic to hydrophilic surface. Meanwhile, the hemocompatibility of these samples was also evaluated by protein adsorption and platelet adhesion. These experimental results exhibited that the introduction of poly(MPC) onto the NWF membrane surfaces substantially improved their hemocompatibility. The feasibility and simplicity of this procedure may lead to potential applications of NWF membranes in biomedical separation and blood purification. - Graphical abstract: 2-methacryloyloxyethyl phosphorycholine (MPC), was grafted onto non-woven fabric (NWF) membrane surface by Ce(IV)/HNO{sub 3} redox system. The protein adsorption and platelet adhesion were substantially suppressed by the introduction of poly(MPC). Highlights: Black-Right-Pointing-Pointer MPC was successfully grafted onto NWF PP membrane surface. Black-Right-Pointing-Pointer Obviously enhanced hemocompatibility was acquired by the modified samples. Black-Right-Pointing-Pointer A facile redox grafting was adopted in the whole process.

  10. Finite element determination of tearing modulus for application to industrial cases

    International Nuclear Information System (INIS)

    Charras, T.; Combescure, A.

    1984-12-01

    The Tearing modulus, coming from a derivative of J with respect to crack-length is difficult to compute, specially in 3D, where computation costs are important. This paper presents a method to determine this value without doing two complete computations with two cracks lengths

  11. Wind Stress, METOP ASCAT, 0.25 degrees, Global, Near Real Time, Modulus

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA CoastWatch distributes near real time wind stress data in zonal, meridional, modulus, and wind stress curl sets. This data begins with wind velocity...

  12. 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.

  13. An autonomic self-healing organogel with a photo-mediated modulus

    KAUST Repository

    Xiong, Yubing

    2016-11-15

    A new method is described for fabricating autonomic, self-healing, deformable organogels. We combined imidazolium-based poly(ionic liquid) (PIL) and azobenzene-grafted poly(carboxylic acid) (PAA-Azo) in N,N-dimethyl formamide. Further, complexing PIL with unirradiated (trans) or irradiated (cis) PAA-Azo tuned the elastic modulus of the organogel. © 2016 The Royal Society of Chemistry.

  14. An autonomic self-healing organogel with a photo-mediated modulus

    KAUST Repository

    Xiong, Yubing; Chen, Zhijun; Wang, Hong; Ackermann, Lisa Maria; Klapper, Markus; Butt, Hans Jü rgen; Wu, Si

    2016-01-01

    A new method is described for fabricating autonomic, self-healing, deformable organogels. We combined imidazolium-based poly(ionic liquid) (PIL) and azobenzene-grafted poly(carboxylic acid) (PAA-Azo) in N,N-dimethyl formamide. Further, complexing PIL with unirradiated (trans) or irradiated (cis) PAA-Azo tuned the elastic modulus of the organogel. © 2016 The Royal Society of Chemistry.

  15. Insufficiency of the Young’s modulus for illustrating the mechanical behavior of GaN nanowires

    Science.gov (United States)

    Zamani Kouhpanji, Mohammad Reza; Behzadirad, Mahmoud; Feezell, Daniel; Busani, Tito

    2018-05-01

    We use a non-classical modified couple stress theory including the acceleration gradients (MCST-AG), to precisely demonstrate the size dependency of the mechanical properties of gallium nitride (GaN) nanowires (NWs). The fundamental elastic constants, Young’s modulus and length scales of the GaN NWs were estimated both experimentally, using a novel experimental technique applied to atomic force microscopy, and theoretically, using atomic simulations. The Young’s modulus, static and the dynamic length scales, calculated with the MCST-AG, were found to be 323 GPa, 13 and 14.5 nm, respectively, for GaN NWs from a few nanometers radii to bulk radii. Analyzing the experimental data using the classical continuum theory shows an improvement in the experimental results by introducing smaller error. Using the length scales determined in MCST-AG, we explain the inconsistency of the Young’s moduli reported in recent literature, and we prove the insufficiency of the Young’s modulus for predicting the mechanical behavior of GaN NWs.

  16. A Research on Low Modulus Distributed Fiber Optical Sensor for Pavement Material Strain Monitoring.

    Science.gov (United States)

    Meng, Lingjian; Wang, Linbing; Hou, Yue; Yan, Guannan

    2017-10-19

    The accumulated irreversible deformation in pavement under repeated vehicle loadings will cause fatigue failure of asphalt concrete. It is necessary to monitor the mechanical response of pavement under load by using sensors. Previous studies have limitations in modulus accommodation between the sensor and asphalt pavement, and it is difficult to achieve the distributed monitoring goal. To solve these problems, a new type of low modulus distributed optical fiber sensor (DOFS) for asphalt pavement strain monitoring is fabricated. Laboratory experiments have proved the applicability and accuracy of the newly-designed sensor. This paper presents the results of the development.

  17. Influence of seed layer moduli on finite element method-based modulus backcalculation result

    CSIR Research Space (South Africa)

    Matsui, K

    2006-01-01

    Full Text Available ) Static backcalculation E1 0 200 400 600 800 1000 1200 10 50 - 11 00 11 00 - 11 50 11 50 - 12 00 12 00 - 12 50 12 50 - 13 00 13 00 - 13 50 13 50 - 14 00 Layer modulus (MPa) Fr e qu e n c y E2 0 200 400... 600 800 1000 1200 10 0 - 12 0 12 0 - 14 0 14 0 - 16 0 16 0 - 18 0 18 0 - 20 0 20 0 - 22 0 22 0 - 24 0 Layer modulus (MPa) Fr e qu e n c y E3 0 200 400 600 800 1000 1200 70 - 80 80 - 90 90 - 10 0...

  18. Evaluation of time-accelerated irradiation method of elastomer by modulus-ultimate elongation profile

    International Nuclear Information System (INIS)

    Ito, Masayuki; Oka, Toshitaka; Hama, Yosimasa

    2009-01-01

    'Generalized modulus-ultimate elongation profile' was induced from the relationship between the modulus and the ultimate elongation of an elastomer that was quantitatively added crosslinking and scission. This profile can be used to evaluate the time-accelerated irradiation methods of ethylene-propylene-diene elastomer. The irradiation under low dose rate (0.33 kGy/h) at room temperature was the reference condition. The short-time irradiation condition was 4.2 kGy/h in 0.5 MPa oxygen at room temperature and 5.0 kGy/h in air at 70 o C. The former tended to bring about the higher ratio of scission than the reference condition; the latter tended to bring about the higher ratio of crosslinking.

  19. Characterization of the Young's modulus and residual stresses for a sputtered silicon oxynitride film using micro-structures

    International Nuclear Information System (INIS)

    Dong, Jian; Du, Ping; Zhang, Xin

    2013-01-01

    Silicon oxynitride (SiON) is an important material to fabricate micro-electro-mechanical system (MEMS) devices due to its composition-dependent tunability in electronic and mechanical properties. In this work, the SiON film with 41.45% silicon, 32.77% oxygen and 25.78% nitrogen content was deposited by RF magnetron sputtering. Two types of optimized micro-structures including micro-cantilevers and micro-rotating-fingers were designed and fabricated using MEMS surface micromachining technology. The micro-cantilever bending tests were conducted using a nanoindenter to characterize the Young's modulus of the SiON film. Owing to the elimination of the residual stress effect on the micro-cantilever structure, higher accuracy in the Young's modulus was achieved from this technique. With the information of Young's modulus of the film, the residual stresses were characterized from the deflection of the micro-rotating-fingers. This structure was able to locally measure a large range of tensile or compressive residual stresses in a thin film with sufficient sensitivities. The results showed that the Young's modulus of the SiON film was 122 GPa and the residual stresses of the SiON film were 327 MPa in the crystallographic orientation of the wafer and 334 MPa in the direction perpendicular to the crystallographic orientation, both in compression. This work presents a comprehensive methodology to measure the Young's modulus and residual stresses of a thin film with improved accuracy, which is promising for applications in mechanical characterization of MEMS devices. - Highlight: • We measured the Young's modulus and residual stress of SiON film by microstructure. • Micro cantilever structure improved the Young's modulus' measurement accuracy. • We explored the reason for the deviations of residual stress value of SiON film

  20. Maximisation of the ratio of microhardness to the Young's modulus of Ti–12Mo–13Nb alloy through microstructure changes

    Energy Technology Data Exchange (ETDEWEB)

    Gabriel, Sinara B., E-mail: sinara@metalmat.ufrj.br [Universidade Federal do Rio de Janeiro, Departamento de Engenharia Metalúrgica e de Materiais, C.P. 68505, Rio de Janeiro, RJ 21945-970 (Brazil); Centro Universitário de Volta Redonda, Volta Redonda, RJ (Brazil); Almeida, Luiz H. de [Universidade Federal do Rio de Janeiro, Departamento de Engenharia Metalúrgica e de Materiais, C.P. 68505, Rio de Janeiro, RJ 21945-970 (Brazil); Nunes, Carlos A. [Universidade de São Paulo, Departamento de Engenharia de Materiais, C.P. 116, Lorena, SP 12.600-970 (Brazil); Dille, Jean [Université Libre de Bruxelles, Chemical and Materials Department, Av. F. Roosevelt 50, C. P. 194/03, Brussels (Belgium); Soares, Glória A. [Universidade Federal do Rio de Janeiro, Departamento de Engenharia Metalúrgica e de Materiais, C.P. 68505, Rio de Janeiro, RJ 21945-970 (Brazil)

    2013-08-01

    Alloys for orthopaedic and dentistry applications require high mechanical strength and a low Young's modulus to avoid stress shielding. Metastable β titanium alloys appear to fulfil these requirements. This study investigated the correlation of phases precipitated in a Ti–12Mo–13Nb alloy with changes in hardness and the Young's modulus. The alloy was produced by arc melting under an argon atmosphere, after which, it was heat treated and cold forged. Two different routes of heat treatment were employed. Phase transformations were studied by employing X-ray diffraction and transmission electron microscopy. Property characterisation was based on Vickers microhardness tests and Young's modulus measurements. The highest ratio of microhardness to the Young's modulus was obtained using thermomechanical treatment, which consists of heating at 1000 °C for 24 h, water quenching, cold forging to reduce 80% of the area, and ageing at 500 °C for 24 h, where the final microstructure consisted of an α phase dispersed in a β matrix. The α phase appeared in two different forms: as fine lamellas (with 240 ± 100 nm length) and massive particles of 200–500 nm size. - Highlights: • The work presents microstructure change and properties of Ti–12Mo–13Nb alloy. • The better condition was achieved by the α phase distributed in the β matrix. • The values obtained were higher than of the Ti–6Al–4V alloy and cp Ti.

  1. Frequency and temperature dependence behaviour of impedance, modulus and conductivity of BaBi4Ti4O15 Aurivillius ceramic

    Directory of Open Access Journals (Sweden)

    Tanmaya Badapanda

    2014-09-01

    Full Text Available In this work, we report the dielectric, impedance, modulus and conductivity study of BaBi4Ti4O15 ceramic synthesized by solid state reaction. X-ray diffraction (XRD pattern showed orthorhombic structure with space group A21am confirming it to be an m = 4 member of the Aurivillius oxide. The frequency dependence dielectric study shows that the value of dielectric constant is high at lower frequencies and decreases with increase in frequency. Impedance spectroscopy analyses reveal a non-Debye relaxation phenomenon since relaxation frequency moves towards the positive side with increase in temperature. The shift in impedance peaks towards higher frequency side indicates conduction in material and favouring of the long rangemotion of mobile charge carriers. The Nyquist plot from complex impedance spectrum shows only one semicircular arc representing the grain effect in the electrical conduction. The modulus mechanism indicates the non-Debye type of conductivity relaxation in the material, which is supported by impedance data. Relaxation times extracted using imaginary part of complex impedance (Z′′ and modulus (M′′ were also found to follow Arrhenius law. The frequency dependent AC conductivity at different temperatures indicates that the conduction process is thermally activated. The variation of DC conductivity exhibits a negative temperature coefficient of resistance behaviour.

  2. Stiffness modulus and creep properties of the coconut shell in an ...

    African Journals Online (AJOL)

    Coconut shell (CS) is an agricultural waste engineered into a road construction material. This study was conducted to evaluate the stiffness modulus and dynamic creep properties of the asphaltic concrete containing CS as an aggregate replacement. A mixture design incorporating the bitumen penetration grade 60/70 was ...

  3. Enhancement and prediction of modulus of elasticity of palm kernel shell concrete

    International Nuclear Information System (INIS)

    Alengaram, U. Johnson; Mahmud, Hilmi; Jumaat, Mohd Zamin

    2011-01-01

    Research highlights: → Micro-pores of size 16-24 μm were found on the outer surface of palm kernel shell. → Infilling of pores by mineral admixtures was evident. → Sand content influenced both modulus of elasticity and compressive strength. → Proposed equation predicts modulus of elasticity within ±1.5 kN/mm 2 of test results. -- Abstract: This paper presents results of an investigation conducted to enhance and predict the modulus of elasticity (MOE) of palm kernel shell concrete (PKSC). Scanning electron microscopic (SEM) analysis on palm kernel shell (PKS) was conducted. Further, the effect of varying sand and PKS contents and mineral admixtures (silica fume and fly ash) on compressive strength and MOE was investigated. The variables include water-to-binder (w/b) and sand-to-cement (s/c) ratios. Nine concrete mixes were prepared, and tests on static and dynamic moduli of elasticity and compressive strength were conducted. The SEM result showed presence of large number of micro-pores on PKS. The mineral admixtures uniformly filled the micro-pores on the outer surface of PKS. Further, the increase in sand content coupled with reduction in PKS content enhanced the compressive strength and static MOE: The highest MOE recorded in this investigation, 11 kN/mm 2 , was twice that previously published. Moreover, the proposed equation based on CEB/FIP code formula appears to predict the MOE close to the experimental values.

  4. Estimation of axial stiffness of plant fibres from compaction of non-woven mats

    International Nuclear Information System (INIS)

    Gamstedt, E K; Bommier, E; Madsen, B

    2014-01-01

    Plant fibres are known to show a large variability in stiffness, which makes it time-consuming to experimentally characterize this property by conventional tensile testing. In this work, an alternative method is used, where the average fibre stiffness is back-calculated from compaction tests of in-plane randomly oriented fibre mats. The model by Toll is used to relate the load–displacement curve from the test to the Young modulus of the fibre, taking into account the natural variability in fibre cross section. Several tests have been performed on hemp fibre mats and compared with results from single-fibre tensile testing. The average back-calculated Young's modulus of the fibres was 45 GPa, whereas the average value from tensile testing ranged from 30 to 60 GPa. The straightforward compaction test can be useful in ranking of fibre stiffness, provided that the mat is composed of well-separated fibres and not of twisted yarns. (paper)

  5. Size effect of the elastic modulus of rectangular nanobeams: Surface elasticity effect

    International Nuclear Information System (INIS)

    Yao Hai-Yan; Fan Wen-Liang; Yun Guo-Hong

    2013-01-01

    The size-dependent elastic property of rectangular nanobeams (nanowires or nanoplates) induced by the surface elasticity effect is investigated by using a developed modified core-shell model. The effect of surface elasticity on the elastic modulus of nanobeams can be characterized by two surface related parameters, i.e., inhomogeneous degree constant and surface layer thickness. The analytical results show that the elastic modulus of the rectangular nanobeam exhibits a distinct size effect when its characteristic size reduces below 100 nm. It is also found that the theoretical results calculated by a modified core-shell model have more obvious advantages than those by other models (core-shell model and core-surface model) by comparing them with relevant experimental measurements and computational results, especially when the dimensions of nanostructures reduce to a few tens of nanometers. (condensed matter: structural, mechanical, and thermal properties)

  6. 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

  7. A comparative study on the elastic modulus of polyvinyl alcohol sponge using different stress-strain definitions.

    Science.gov (United States)

    Karimi, Alireza; Navidbakhsh, Mahdi; Alizadeh, Mansour; Razaghi, Reza

    2014-10-01

    There have been different stress-strain definitions to measure the elastic modulus of spongy materials, especially polyvinyl alcohol (PVA) sponge. However, there is no agreement as to which stress-strain definition should be implemented. This study was aimed to show how different results are given by the various definitions of stress-strain used, and to recommend a specific definition when testing spongy materials. A fabricated PVA sponge was subjected to a series of tensile tests in order to measure its mechanical properties. Three stress definitions (second Piola-Kichhoff stress, engineering stress, and true stress) and four strain definitions (Almansi-Hamel strain, Green-St. Venant strain, engineering strain, and true strain) were used to determine the elastic modulus. The results revealed that the Almansi-Hamel strain definition exhibited the highest non-linear stress-strain relation and, as a result, may overestimate the elastic modulus at different stress definitions (second Piola-Kichhoff stress, engineering stress, and true stress). The Green-St. Venant strain definition failed to address the non-linear stress-strain relation using different definitions of stress and invoked an underestimation of the elastic modulus values. Engineering stress and strain definitions were only valid for small strains and displacements, which make them impractical when analyzing spongy materials. The results showed that the effect of varying the stress definition on the maximum stress measurements was significant but not when calculating the elastic modulus. It is important to consider which stress-strain definition is employed when characterizing the mechanical properties of spongy materials. Although the true stress-true strain definition exhibits a non-linear relation, we favor it in spongy materials mechanics as it gives more accurate measurements of the material's response using the instantaneous values.

  8. Production of a low young modulus titanium alloy by powder metallurgy

    Directory of Open Access Journals (Sweden)

    Dalcy Roberto dos Santos

    2005-12-01

    Full Text Available Titanium alloys have several advantages over ferrous and non-ferrous metallic materials, such as high strengthto-weight ratio and excellent corrosion resistance. A blended elemental titanium powder metallurgy process has been developed to offer low cost commercial products. The process employs hydride-dehydride (HDH powders as raw material. In this work, results of the Ti-35Nb alloy sintering are presented. This alloy due to its lower modulus of elasticity and high biocompatibility is a promising candidate for aerospace and medical use. Samples were produced by mixing of initial metallic powders followed by uniaxial and cold isostatic pressing with subsequent densification by isochronal sintering between 900 up to 1600 °C, in vacuum. Sintering behavior was studied by means of microscopy and density. Sintered samples were characterized for phase composition, microstructure and microhardness by X-ray diffraction, scanning electron microscopy and Vickers indentation, respectively. Samples sintered at high temperatures display a fine plate-like alpha structure and intergranular beta. A few remaining pores are still found and density above 90% for specimens sintered in temperatures over 1500 °C is reached.

  9. Covalent immobilization of lysozyme onto woven and knitted crimped polyethylene terephthalate grafts to minimize the adhesion of broad spectrum pathogens

    International Nuclear Information System (INIS)

    Al Meslmani, Bassam M.; Mahmoud, Gihan F.; Leichtweiß, Thomas; Strehlow, Boris; Sommer, Frank O.; Lohoff, Michael D.; Bakowsky, Udo

    2016-01-01

    Graft-associated infections entirely determine the short-term patency of polyethylene terephthalate PET cardiovascular graft. We attempted to enzymatically inhibit the initial bacterial adhesion to PET grafts using lysozyme. Lysozyme was covalently immobilized onto woven and knitted forms of crimped PET grafts by the end-point method. Our figures of merit revealed lysozyme immobilization yield of 15.7 μg/cm"2, as determined by the Bradford assay. The activity of immobilized lysozyme on woven and knitted PET manifested 58.4% and 55.87% using Micrococcus lysodeikticus cells, respectively. Noteworthy, the adhesion of vein catheter-isolated Staphylococcus epidermidis decreased by 6- to 8-folds and of Staphylococcus aureus by 11- to 12-folds, while the Gram-negative Escherichia coli showed only a decrease by 3- to 4-folds. The anti-adhesion efficiency was specific for bacterial cells and no significant effect was observed on adhesion and growth of L929 cells. In conclusion, immobilization of lysozyme onto PET grafts can inhibit the graft-associated infection. - Highlights: • Lysozyme was covalently immobilized on crimped polyethylene terephthalate (PET). • The activity of immobilized lysozyme was meaningfully reduced. • The maintained activity significantly declined the adhesion of Gram-positive stains. • The enzymatic anti-adhesion efficiency reported lesser extent against Gram-negative. • The anti-bacterial activity displayed no significant effect on cells compatibility.

  10. Covalent immobilization of lysozyme onto woven and knitted crimped polyethylene terephthalate grafts to minimize the adhesion of broad spectrum pathogens

    Energy Technology Data Exchange (ETDEWEB)

    Al Meslmani, Bassam M., E-mail: almeslmanib@yahoo.com [Department of Pharmaceutical Technology and Biopharmaceutics, Marburg University, Ketzerbach 63, 35037 Marburg (Germany); Mahmoud, Gihan F., E-mail: mahmoudg@staff.uni-marburg.de [Department of Pharmaceutical Technology and Biopharmaceutics, Marburg University, Ketzerbach 63, 35037 Marburg (Germany); Department of Pharmaceutics and Industrial Pharmacy, Helwan University, Ain Helwan, 11795 Cairo (Egypt); Leichtweiß, Thomas, E-mail: Thomas.Leichtweiss@phys.Chemie.uni-giessen.de [Institute of Physical Chemistry, Justus-Liebig-University Giessen, Heinrich-Buff-Ring 58, 35392 Giessen (Germany); Strehlow, Boris, E-mail: strehlo4@staff.uni-marburg.de [Department of Pharmaceutical Technology and Biopharmaceutics, Marburg University, Ketzerbach 63, 35037 Marburg (Germany); Sommer, Frank O., E-mail: sommerf@med.uni-marburg.de [Institute for Medical Microbiology and Hospital Hygiene, Marburg University, Hans Meerwein Str 2, 35032 Marburg (Germany); Lohoff, Michael D., E-mail: lohoff@med.uni-marburg.de [Institute for Medical Microbiology and Hospital Hygiene, Marburg University, Hans Meerwein Str 2, 35032 Marburg (Germany); Bakowsky, Udo, E-mail: ubakowsky@aol.com [Department of Pharmaceutical Technology and Biopharmaceutics, Marburg University, Ketzerbach 63, 35037 Marburg (Germany)

    2016-01-01

    Graft-associated infections entirely determine the short-term patency of polyethylene terephthalate PET cardiovascular graft. We attempted to enzymatically inhibit the initial bacterial adhesion to PET grafts using lysozyme. Lysozyme was covalently immobilized onto woven and knitted forms of crimped PET grafts by the end-point method. Our figures of merit revealed lysozyme immobilization yield of 15.7 μg/cm{sup 2}, as determined by the Bradford assay. The activity of immobilized lysozyme on woven and knitted PET manifested 58.4% and 55.87% using Micrococcus lysodeikticus cells, respectively. Noteworthy, the adhesion of vein catheter-isolated Staphylococcus epidermidis decreased by 6- to 8-folds and of Staphylococcus aureus by 11- to 12-folds, while the Gram-negative Escherichia coli showed only a decrease by 3- to 4-folds. The anti-adhesion efficiency was specific for bacterial cells and no significant effect was observed on adhesion and growth of L929 cells. In conclusion, immobilization of lysozyme onto PET grafts can inhibit the graft-associated infection. - Highlights: • Lysozyme was covalently immobilized on crimped polyethylene terephthalate (PET). • The activity of immobilized lysozyme was meaningfully reduced. • The maintained activity significantly declined the adhesion of Gram-positive stains. • The enzymatic anti-adhesion efficiency reported lesser extent against Gram-negative. • The anti-bacterial activity displayed no significant effect on cells compatibility.

  11. Effect of Mesoscale and Multiscale Modeling on the Performance of Kevlar Woven Fabric Subjected to Ballistic Impact: A Numerical Study

    Science.gov (United States)

    Jia, Xin; Huang, Zhengxiang; Zu, Xudong; Gu, Xiaohui; Xiao, Qiangqiang

    2013-12-01

    In this study, an optimal finite element model of Kevlar woven fabric that is more computational efficient compared with existing models was developed to simulate ballistic impact onto fabric. Kevlar woven fabric was modeled to yarn level architecture by using the hybrid elements analysis (HEA), which uses solid elements in modeling the yarns at the impact region and uses shell elements in modeling the yarns away from the impact region. Three HEA configurations were constructed, in which the solid element region was set as about one, two, and three times that of the projectile's diameter with impact velocities of 30 m/s (non-perforation case) and 200 m/s (perforation case) to determine the optimal ratio between the solid element region and the shell element region. To further reduce computational time and to maintain the necessary accuracy, three multiscale models were presented also. These multiscale models combine the local region with the yarn level architecture by using the HEA approach and the global region with homogenous level architecture. The effect of the varying ratios of the local and global area on the ballistic performance of fabric was discussed. The deformation and damage mechanisms of fabric were analyzed and compared among numerical models. Simulation results indicate that the multiscale model based on HEA accurately reproduces the baseline results and obviously decreases computational time.

  12. The Electrical and Thermal Conductivity of Woven Pristine and Intercalated Graphite Fiber-Polymer Composites

    Science.gov (United States)

    Gaier, James R.; Vandenburg, Yvonne Yoder; Berkebile, Steven; Stueben, Heather; Balagadde, Frederick

    2002-01-01

    A series of woven fabric laminar composite plates and narrow strips were fabricated from a variety of pitch-based pristine and bromine intercalated graphite fibers in an attempt to determine the influence of the weave on the electrical and thermal conduction. It was found generally that these materials can be treated as if they are homogeneous plates. The rule of mixtures describes the resistivity of the composite fairly well if it is realized that only the component of the fibers normal to the equipotential surface will conduct current. When the composite is narrow with respect to the fiber weave, however, there is a marked angular dependence of the resistance which was well modeled by assuming that the current follows only along the fibers (and not across them in a transverse direction), and that the contact resistance among the fibers in the composite is negligible. The thermal conductivity of composites made from less conductive fibers more closely followed the rule of mixtures than that of the high conductivity fibers, though this is thought to be an artifact of the measurement technique. Electrical and thermal anisotropy could be induced in a particular region of the structure by weaving together high and low conductivity fibers in different directions, though this must be done throughout all of the layers of the structure as interlaminar conduction precludes having only the top layer carry the anisotropy. The anisotropy in the thermal conductivity is considerably less than either that predicted by the rule of mixtures or the electrical resistivity.

  13. Effect of Young's modulus evolution on residual stress measurement of thermal barrier coatings by X-ray diffraction

    International Nuclear Information System (INIS)

    Chen, Q.; Mao, W.G.; Zhou, Y.C.; Lu, C.

    2010-01-01

    Subjected to thermal cycling, the apparent Young's modulus of air plasma-sprayed (APS) 8 wt.% Y 2 O 3 -stabilized ZrO 2 (8YSZ) thermal barrier coatings (TBCs) was measured by nanoindentation. Owing to the effects of sintering and porous microstructure, the apparent Young's modulus follows a Weibull distribution and changes from 50 to 93 GPa with an increase of thermal cycling. The evolution of residual stresses in the top coating of an 8YSZ TBC system was determined by X-ray diffraction (XRD). The residual stresses derived from the XRD data are well consistent with that obtained by the Vickers indention. It is shown that the evolution of Young's modulus plays an important role in improving the measurement precision of residual stresses in TBCs by XRD.

  14. Shear Modulus of Sintered 'House of Cards'-Like Assemblies of Crystals

    NARCIS (Netherlands)

    Schaink, H.M.; Malssen, van K.

    2007-01-01

    A cell model of a 'house of cards'-like assembly of crystals is used for the study of the evolution of the shear modulus during sintering. The crystals are assumed to have a lozenge shape. The cell model takes different crystal-crystal contacts into account. The force needed to separate two sintered

  15. Comparison of elastic--plastic and variable modulus-cracking constitutive models for prestressed concrete reactor vessels

    International Nuclear Information System (INIS)

    Anderson, C.A.; Smith, P.D.

    1978-01-01

    The variable modulus-cracking model is capable of predicting the behavior of reinforced concrete structures (such as the reinforced plate under transverse pressure described previously) well into the range of nonlinear behavior including the prediction of the ultimate load. For unreinforced thick-walled concrete vessels under internal pressure the use of elastic--plastic concrete models in finite element codes enhances the apparent ductility of the vessels in contrast to variable modulus-cracking models that predict nearly instantaneous rupture whenever the tensile strength at the inner wall is exceeded. For unreinforced thick-walled end slabs representative of PCRV heads, the behavior predicted by finite element codes using variable modulus-cracking models is much stiffer in the nonlinear range than that observed experimentally. Although the shear type failures and crack patterns that are observed experimentally are predicted by such concrete models, the ultimate load carrying capacity and vessel-ductility are significantly underestimated. It appears that such models do not adequately model such features as aggregate interlock that could lead to an enhanced vessel reserve strength and ductility

  16. Cell wall elasticity: I. A critique of the bulk elastic modulus approach and an analysis using polymer elastic principles

    Science.gov (United States)

    Wu, H. I.; Spence, R. D.; Sharpe, P. J.; Goeschl, J. D.

    1985-01-01

    The traditional bulk elastic modulus approach to plant cell pressure-volume relations is inconsistent with its definition. The relationship between the bulk modulus and Young's modulus that forms the basis of their usual application to cell pressure-volume properties is demonstrated to be physically meaningless. The bulk modulus describes stress/strain relations of solid, homogeneous bodies undergoing small deformations, whereas the plant cell is best described as a thin-shelled, fluid-filled structure with a polymer base. Because cell walls possess a polymer structure, an alternative method of mechanical analysis is presented using polymer elasticity principles. This initial study presents the groundwork of polymer mechanics as would be applied to cell walls and discusses how the matrix and microfibrillar network induce nonlinear stress/strain relationships in the cell wall in response to turgor pressure. In subsequent studies, these concepts will be expanded to include anisotropic expansion as regulated by the microfibrillar network.

  17. Impact of Material and Architecture Model Parameters on the Failure of Woven Ceramic Matrix Composites (CMCs) via the Multiscale Generalized Method of Cells

    Science.gov (United States)

    Liu, Kuang C.; Arnold, Steven M.

    2011-01-01

    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 effects of many of these architectural parameters and material scatter of woven ceramic composite properties at the macroscale (woven RUC) will be studied to assess their sensitivity. 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. The macroscale responses investigated illustrate the effect of architectural and material parameters on a single RUC representing a five harness satin weave fabric. Results shows that the most critical architectural parameter is weave void shape and content with other parameters being less in severity. Variation of the matrix material properties was also studied to illustrate the influence of the material variability on the overall features of the composite stress-strain response.

  18. Bendable Electro-Acoustic Transducer Fabricated Utilizing Frequency Dispersion of Elastic Modulus

    Science.gov (United States)

    Miyoshi, Tetsu; Ohga, Juro

    2013-09-01

    To realize the speaker diaphragm that can be united with a flexible display without deteriorating lightweight properties and flexibility, a novel bendable electro-acoustic transducer (BEAT) based on 0-3-type piezoelectric composites has been developed. To overcome the trade-off between flexibility and the transmission efficiency of vibration energy, a viscoelastic polymer that has local maximum points in the loss factor as well as large frequency dispersion in the storage modulus near room temperature was employed as the matrix of the piezoelectric composite layer. Against the comparatively slow (10 Hz or less) deformation from the outside, the viscoelastic matrix is viscous enough to prevent cracking and delamination. On the other hand, in the audible range (20 Hz to 20 kHz), the matrix is elastic enough to transmit piezoelectric vibration energy, maintaining a moderately large loss factor as well as a high sound velocity. For the first time, we successfully demonstrated a rollable speaker that can continue to generate a high-quality sound while being rolled and unrolled repeatedly onto a cylinder with a curvature radius of 4 mm.

  19. Experimental investigation of effects of stitching orientation on forming behaviors of 2D P-aramid multilayer woven preform

    Science.gov (United States)

    Abtew, Mulat Alubel; Boussu, François; Bruniaux, Pascal; Loghin, Carmen; Cristian, Irina; Chen, Yan; Wang, Lichuan

    2018-05-01

    In many textile applications stitching process is one of the widely used methods to join the multi-layer fabric plies not only due to its easy applicability and flexible production but also provide structural integrity throughout-the-thickness of materials. In this research, the influences of stitching pattern on various molding characteristics of multi-layer 2D para-aramid plain woven fabrics while deformation was investigated. The fabrics were made of high performance fiber with 930dtex yarn linear density and fabric areal density of 200gm/m2. First, different stitch pattern (orientation) was applied for joining the mentioned multi-layered fabrics keeping other stitching parameters such as stitch gap, stitch thread tension, stitch length, stitch type, stitch thread type etc. constant throughout the study. Then, a pneumatic based molding device with a low speed forming process specially designed for preforming of textile with a predefined hemispherical shape of punch. The result shows that stitching pattern is one of the parameter that influences the different molding behavior and should be consider while molding stitched multi-layer fabrics.

  20. Wind Stress, QuikSCAT SeaWinds, 0.25 degrees, Global, Science Quality, Modulus

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA CoastWatch distributes science quality wind stress data in zonal, meridional, modulus, and wind stress curl sets. This data begins with wind velocity...

  1. Direct measurement of elastic modulus of Nb 3Sn using extracted filaments from superconducting composite wire and resin impregnation method

    Science.gov (United States)

    Hojo, M.; Matsuoka, T.; Hashimoto, M.; Tanaka, M.; Sugano, M.; Ochiai, S.; Miyashita, K.

    2006-10-01

    Young's modulus of Nb3Sn filaments in Nb3Sn/Cu superconducting composite wire was investigated in detail. Nb3Sn filaments were first extracted from composite wire. Nitric acid and hydrofluoric acid were used to remove copper stabilizer, Nb3Sn/Nb barrier and bronze. Then, Nb3Sn filaments were impregnated with epoxy resin to form simple filament bundle composite rods. A large difference in Young's moduli of filaments and epoxy resin enhance the accuracy of the measurement of Nb3Sn filament modulus. The ratio of Nb3Sn to Nb in filaments and the number of filaments in the fiber bundle composite rods were used in the final calculation of the Young's modulus of Nb3Sn. The obtained modulus of 127 GPa was the lower bound of the already reported values.

  2. Direct measurement of elastic modulus of Nb3Sn using extracted filaments from superconducting composite wire and resin impregnation method

    International Nuclear Information System (INIS)

    Hojo, M.; Matsuoka, T.; Hashimoto, M.; Tanaka, M.; Sugano, M.; Ochiai, S.; Miyashita, K.

    2006-01-01

    Young's modulus of Nb 3 Sn filaments in Nb 3 Sn/Cu superconducting composite wire was investigated in detail. Nb 3 Sn filaments were first extracted from composite wire. Nitric acid and hydrofluoric acid were used to remove copper stabilizer, Nb 3 Sn/Nb barrier and bronze. Then, Nb 3 Sn filaments were impregnated with epoxy resin to form simple filament bundle composite rods. A large difference in Young's moduli of filaments and epoxy resin enhance the accuracy of the measurement of Nb 3 Sn filament modulus. The ratio of Nb 3 Sn to Nb in filaments and the number of filaments in the fiber bundle composite rods were used in the final calculation of the Young's modulus of Nb 3 Sn. The obtained modulus of 127 GPa was the lower bound of the already reported values

  3. Particle size dependence of the Young's modulus of filled polymers: 2. Annealing and solid-state nuclear magnetic resonance experiments

    NARCIS (Netherlands)

    Vollenberg, P.H.T.; Haan, de J.W.; Ven, van de L.J.M.; Heikens, D.

    1989-01-01

    Experimental results are reported from which it appears that in the case of polymer filled with silane-treated glass beads the Young's modulus is, in accordance with present theory, independent of the particle size of the filler. However, if pure glass beads are used as filler, the Young's modulus

  4. Compressive Strength and Modulus of Elasticity of Concrete with Cubed Waste Tire Rubbers as Coarse Aggregates

    Science.gov (United States)

    Haryanto, Y.; Hermanto, N. I. S.; Pamudji, G.; Wardana, K. P.

    2017-11-01

    One feasible solution to overcome the issue of tire disposal waste is the use of waste tire rubber to replace aggregate in concrete. We have conducted an experimental investigation on the effect of rubber tire waste aggregate in cuboid form on the compressive strength and modulus of elasticity of concrete. The test was performed on 72 cylindrical specimens with the height of 300 mm and diameter of 150 mm. We found that the workability of concrete with waste tire rubber aggregate has increased. The concrete density with waste tire rubber aggregate was decreased, and so was the compressive strength. The decrease of compressive strength is up to 64.34%. If the content of waste tire rubber aggregate is more than 40%, then the resulting concrete cannot be categorized as structural concrete. The modulus of elasticity decreased to 59.77%. The theoretical equation developed to determine the modulus of elasticity of concrete with rubber tire waste aggregate has an accuracy of 84.27%.

  5. Damage in woven CFRP laminates subjected to low velocity impacts

    International Nuclear Information System (INIS)

    Ullah, H; Abdel-Wahab, A A; Harland, A R; Silberschmidt, V V

    2012-01-01

    Carbon fabric-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 in these materials affects both their in-service properties and performance that can deteriorate with time. These processes need adequate means of analysis and investigation, the major approaches being experimental characterisation and non-destructive examination of internal damage in composite laminates. This research deals with a deformation behaviour and damage in woven composite laminates due to low-velocity dynamic out-of-plane bending. Experimental tests are carried out to characterise the behaviour of such laminates under large-deflection dynamic bending in un-notched specimens in Izod tests using a Resil Impactor. A series of low-velocity impact tests is carried out at various levels of impact energy to assess the energy absorbed and force-time response of CFRP laminates. X-ray micro computed tomography (micro-CT) is used to investigate material damage modes in the impacted specimens. X-ray tomographs revealed that through-thickness matrix cracking, inter-ply delamination and intra-ply delamination, such as tow debonding and fabric fracture, were the prominent damage modes.

  6. Estimation of axial stiffness of plant fibres from compaction of non-woven mats

    DEFF Research Database (Denmark)

    Gamstedt, E. K.; Bommier, E.; Madsen, Bo

    2014-01-01

    -plane randomly oriented fibre mats. The model by Toll is used to relate the load-displacement curve from the test to the Young modulus of the fibre, taking into account the natural variability in fibre cross section. Several tests have been performed on hemp fibre mats and compared with results from single...

  7. Wind Diffusivity Current, METOP ASCAT, 0.25 degrees, Global, Near Real Time, Modulus

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA CoastWatch distributes near real time Ekman current (in zonal, meridional, and modulus sets) and Ekman upwelling data. This data begins with wind velocity...

  8. Measurement of Electromagnetic Shielding Effectiveness of Woven Fabrics Containing Metallic Yarns by Mobile Devices

    Directory of Open Access Journals (Sweden)

    Erhan Kenan ÇEVEN

    2016-10-01

    Full Text Available In this study, we introduce an alternative method to evaluate the electromagnetic shielding effectiveness (EMSE of woven fabrics containing metal wires. For experimental measurements, hybrid silk viscose yarns containing metal wires were first produced. Conductive test fabrics were then produced using the hybrid weft yarns and polyester warp yarns. The produced fabrics were separated in two parts and laminated together after rotating one fabric by 90 degrees to create a grid structure. The laminated fabrics were then folded by several times to create multiple layers such as 2,4,8,12,16. The EMSE of the multiple layered fabrics was measured over GSM signals received by a mobile device. For EMSE evaluation, the mobile device was placed between the laminated fabrics. The EMSE values of the fabrics were then calculated in accordance with the power variations of GSM signals.

  9. Measurement of the temperature dependence of Young's modulus of cartilage by phase-sensitive optical coherence elastography

    Energy Technology Data Exchange (ETDEWEB)

    Liu, C H; Li, J; Singh, M; Larin, K V [Department of Biomedical Engineering, University of Houston, Houston, Texas (United States); Skryabina, M N [Department of Physics, M.V. Lomonosov Moscow State University (Russian Federation); Sobol, E N [Institute of Laser and Information Technologies, Russian Academy of Sciences, Troitsk, Moscow Region (Russian Federation)

    2014-08-31

    The development of an effective system to monitor the changes in the elastic properties of cartilage tissue with increasing temperature in laser reconstruction is an urgent practical task. In this paper, the use of phase-sensitive optical coherence elastography for detection of elastic waves in the sample has allowed Young's modulus of cartilage tissue to be measured directly during heating. Young's modulus was calculated from the group velocity of propagation of elastic waves excited by means of a system supplying focused air pulses. The measurement results are in agreement with the results of measurements of the modulus of elasticity under mechanical compression. The technique developed allows for noninvasive measurements; its development is promising for the use in vivo. (laser biophotonics)

  10. Prediction and optimization of process variables to maximize the Young's modulus of plasma sprayed alumina coatings on AZ31B magnesium alloy

    Directory of Open Access Journals (Sweden)

    D. Thirumalaikumarasamy

    2017-03-01

    Full Text Available Like other manufacturing techniques, plasma spraying has also a non-linear behavior because of the contribution of many coating variables. This characteristic results in finding optimal factor combination difficult. Subsequently, the issue can be solved through effective and strategic statistical procedures integrated with systematic experimental data. Plasma spray parameters such as power, stand-off distance and powder feed rate have significant influence on coating characteristics like Young's modulus. This paper presents the use of statistical techniques in specifically response surface methodology (RSM, analysis of variance, and regression analysis to develop empirical relationship to predict Young's modulus of plasma-sprayed alumina coatings. The developed empirical relationships can be effectively used to predict Young's modulus of plasma-sprayed alumina coatings at 95% confidence level. Response graphs and contour plots were constructed to identify the optimum plasma spray parameters to attain maximum Young's modulus in alumina coatings. A linear regression relationship was established between porosity and Young's modulus of the alumina coatings.

  11. Tensile and Compressive Properties of Woven Kenaf/Glass Sandwich Hybrid Composites

    Directory of Open Access Journals (Sweden)

    Mohaiman J. Sharba

    2016-01-01

    Full Text Available Monotonic (tensile and compression properties of woven kenaf/glass reinforced unsaturated polyester sandwich hybrid composites have been experimentally investigated. Five types of composites laminates were fabricated using a combination of hand lay-up and cold press techniques, postcured for two hours at 80°C and left for 48 hours at room temperature. The hybrid composites contained fixed six layers of glass as a shell, three on each side, whereas the number of core kenaf layers was changed in three stages to get S1, S2, and S3 hybrid composites. Composites specimens with pure glass and kenaf were also fabricated for comparison. It was found that one kenaf layer replaced about 20% of total fiber weight fraction of the composite; this leads to reducing the density of final hybrid composite by 13%. Besides, in mechanical properties perspective, there are less than 1% reduction in compression strength and 40% in tensile strength when compared to pure glass composite. Generally, the results revealed that the best performance was observed in S1, which showed a good balance of all mechanical properties determined in this work.

  12. Studies of LENRA-Toughened PVC non-woven membranes prepared by electro spinning technique

    International Nuclear Information System (INIS)

    Dahlan Mohd; Mahathir Mohamed; Khirul Hafiz mohd Yusof

    2010-01-01

    Lately research in use of so-called green chemicals draws strong interest from research community due to the climate change issues. Malaysia is in strong position to take this advantage because we are among the world biggest producers of natural rubber and palm oil - the two sources of important green renewable chemical feedstock in the near future. For the last couple of years we have shown how modified natural rubbers especially liquid natural rubber and its derivatives such as liquid epoxidized natural rubber acrylate (LENRA) could be used in various applications via among others sol-gel technique and radiation curing technology. This time around we will show another application on how non-woven membranes made from PVC can be prepared by electro spinning technique using radiation curable LENRA as toughener. The electro spinning technique has great potential in producing nano fiber materials to be used in various applications to ensure sustainable energy and environments for the future. (author)

  13. Bulk modulus of CeO2 and PrO2-An experimental and theoretical study

    International Nuclear Information System (INIS)

    Gerward, L.; Staun Olsen, J.; Petit, L.; Vaitheeswaran, G.; Kanchana, V.; Svane, A.

    2005-01-01

    The high-pressure structural behaviour of CeO 2 and PrO 2 has been investigated by synchrotron X-ray diffraction at pressures up to 20 and 35 GPa, respectively. The experiments are accompanied by first principles calculations using the self-interaction corrected local spin density (SIC-LSD) approximation. The experimental values for the zero-pressure bulk modulus of CeO 2 and PrO 2 are 220(9) and 187(8) GPa, respectively. Our calculations reproduce the lattice constants with good accuracy, but find identical bulk modulii for CeO 2 (176.9 GPa) and PrO 2 (176.8 GPa)

  14. Modeling of nano-reinforced polymer composites: Microstructure effect on Young’s modulus

    DEFF Research Database (Denmark)

    Peng, R.D.; Zhou, H.W.; Wang, H.W.

    2012-01-01

    ” algorithm was developed in the ABAQUS Scripting Interface. In the computational studies, it was observed that the elastic modulus increases with the increasing the aspect ratio of nanoparticles. The thickness and properties of effective interface layers and the shape and degree of particles clustering have...

  15. Effect of stress level on static young's modulus of certain structural materials

    International Nuclear Information System (INIS)

    Vojtenko, A.F.; Skripnik, Yu.D.; Solov'eva, N.G.; Nadezhdin, G.N.

    1982-01-01

    Certain steels, titanium and aluminium alloys have been studied for their dynamic and static Young moduli. It is shown that a stress rise in materials to the level of microplastic strain realization results in a significant reduction of the static modulus of elasticity in the materials studied

  16. Printing Three-Dimensional Heterogeneities in the Elastic Modulus of an Elastomeric Matrix.

    Science.gov (United States)

    Abdel Fattah, Abdel Rahman; Ghosh, Suvojit; Puri, Ishwar K

    2016-05-04

    We present a rapid and controllable method to create microscale heterogeneities in the 3D stiffness of a soft material by printing patterns with a ferrofluid ink. An ink droplet moved through a liquid polydimethylsiloxane (PDMS) volume using an externally applied magnetic field sheds clusters of magnetic nanoparticles (MNPs) in its wake. By varying the field spatiotemporally, a well-defined three-dimensional curvilinear feature is printed that contains MNP clusters. Subsequent cross-linking of the PDMS preserves the feature in place after the magnetic field is removed. Since the ferrofluid ink interferes with the cross-linking of PDMS, a 3D print containing ink density variations leads to corresponding spatial deviations in the elastic modulus of the matrix. The modulus is mapped in the experiments with atomic force microscopy. This rapid method to print 3D heterogeneities in soft matter promises the ability to mimic mechanical variations that occur in natural biomaterials.

  17. The dimensional stability and elastic modulus of cemented simulant Winfrith reactor (SGHWR) sludge

    International Nuclear Information System (INIS)

    Holland, T.R.; Lee, D.J.

    1985-12-01

    Dimensional changes and elastic modulus have been monitored on cemented simulant sludge stored in various environments. Specimens prepared using a blended cement show no serious detrimental effects during sealed storage, underwater storage or freeze/thaw cycling. (author)

  18. Effect of Treated Coconut Shell and Fiber on the Resilient Modulus of Double-layer Porous Asphalt at Different Aging

    Science.gov (United States)

    Ting, T. L.; Ramadhansyah, P. J.; Norhidayah, A. H.; Yaacob, H.; Hainin, M. R.; Ibrahim, M. H. Wan; Jayanti, D. S.; Abdullahi, A. M.

    2018-04-01

    Coconut shell (CS) and coconut fiber (CF) are new waste products that have been of growing interest recently in the highway asphalt pavement industry. This study investigated the effect of CS and CF on the resilient modulus of double-layer porous asphalt (DLPA). CS aggregate 5 mm in size was substituted for the DLPA at 5%, 10%, and 15% by weight, while CF was added to the asphalt at 0.3% and 0.5% by weight. Before mixing with other aggregates, the CS and CF were treated with 5%wt Sodium hydroxide (NaOH) to reduce their water absorption ability. The samples were prepared via the Marshall method. The result shows that DLPA with 10% CS aggregate has better resilient modulus under 25 °C for unaged and aged samples compared with the other substitution percentages. However, the sample with CF has a lower resilient modulus because the amount of CF has increased. In general, the substitution of 10% CS provided better resilient modulus among the other percentages.

  19. Analysis of Beams with Transversal Gradations of the Young's Modulus and Variable Depths by the Meshless Method

    Directory of Open Access Journals (Sweden)

    Sátor Ladislav

    2014-03-01

    Full Text Available A numerical analysis based on the meshless local Petrov- Galerkin (MLPG method is proposed for a functionally graded material FGM (FGMfunctionally graded material beam. The planar bending of the beam is considered with a transversal gradation of Young's modulus and a variable depth of the beam. The collocation formulation is constructed from the equilibrium equations for the mechanical fields. Dirac's delta function is employed as a test function in the derivation of a strong formulation. The Moving Least Squares (MLS approximation technique is applied for an approximation of the spatial variations of all the physical quantities. An investigation of the accuracy, the convergence of the accuracy, the computational efficiency and the effect of the level of the gradation of Young's modulus on the behaviour of coupled mechanical fields is presented in various boundary value problems for a rectangular beam with a functionally graded Young's modulus.

  20. Characterization of highly hydrophobic textiles by means of X-ray microtomography, wettability analysis and drop impact

    Science.gov (United States)

    Santini, M.; Guilizzoni, M.; Fest-Santini, S.; Lorenzi, M.

    2017-11-01

    Highly hydrophobic surfaces have been intensively investigated in the last years because their properties may lead to very promising technological spillovers encompassing both everyday use and high-tech fields. Focusing on textiles, hydrophobic fabrics are of major interest for applications ranging from clothes to architecture to environment protection and energy conversion. Gas diffusion media - made by a gas diffusion layer (GDL) and a microporous layer (MPL) - for fuel cells are a good benchmark to develop techniques aimed at characterizing the wetting performances of engineered textiles. An experimental investigation was carried out about carbon-based, PTFE-treated GDLs with and without MPLs. Two samples (woven and woven-non-woven) were analysed before and after coating with a MPL. Their three-dimensional structure was reconstructed and analysed by computer-aided X-ray microtomography (µCT). Static and dynamic wettability analyses were then carried out using a modified axisymmetric drop shape analysis technique. All the surfaces exhibited very high hydrophobicity, three of them near to a super-hydrophobic behavior. Water drop impacts were performed, evidencing different bouncing, sticking and fragmentation outcomes for which critical values of the Weber number were identified. Finally, a µCT scan of a drop on a GDL was performed, confirming the Cassie-Baxter wetting state on such surface.