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1

Effect of interfacial properties on tensile strength in SiC\\/Ti–15–3 composites  

Microsoft Academic Search

Effect of interfacial properties on tensile strength in unidirectional SiC\\/Ti–15–3 composites was discussed with varying consolidation time of the composites. The strength of composites and extracted fibers decreases with increasing consolidation time of the composites, while the strength of matrix is independent of it. Furthermore, the interfacial shear strength increases with increasing consolidation time of the composites, while the interfacial

Akira Fukushima; Chikara Fujiwara; Yutaka Kagawa; Chitoshi Masuda

2000-01-01

2

Hydrate adhesive and tensile strengths  

NASA Astrophysics Data System (ADS)

The physical properties of hydrate-bearing sediments depend on the interaction between hydrates and minerals. In particular, hydrates prefer to nucleate on mineral surfaces, therefore, the hydrate-mineral adhesive strength and the tensile strength of the hydrate mass itself affect the mechanical response of hydrate-bearing sediments. In this study, ice and hydrates made with various guest molecules (CO2, CH4, and THF) are formed between mica and calcite substrates. Adhesive and tensile strengths are measured by applying an external pull-out force. Results show that tensile failure occurs in CO2 and CH4 hydrates when calcite is the substrate, while ice and all hydrates exhibit adhesive failure on mica. The debonding strength is higher when calcite substrates are involved rather than mica substrates. A nominal pull-out strength of 0.15 ± 0.03 MPa can be adopted for mechanical analyses of hydrate-bearing sediments.

Jung, J. W.; Santamarina, J. Carlos

2011-08-01

3

Tensile properties of carbon nanotubes grown on ultrahigh strength polyacrylonitrile-based and ultrahigh modulus pitch-based carbon fibers  

NASA Astrophysics Data System (ADS)

The tensile properties and fracture behavior of carbon nanotubes (CNTs) grown on ultrahigh tensile strength polyacrylonitrile (PAN)-based (T1000GB) and ultrahigh modulus pitch-based (K13D) carbon fibers have been investigated. The CNTs were grown on the carbon fiber surface using chemical vapor deposition. The statistical scattering of the tensile strength was also evaluated. The results clearly show that grafting of CNTs improves the mechanical properties and the Weibull modulus of ultrahigh tensile strength PAN-based and ultrahigh modulus pitch-based carbon fibers.

Naito, Kimiyoshi; Yang, Jenn-Ming; Tanaka, Yoshihisa; Kagawa, Yutaka

2008-06-01

4

Tensile properties of carbon nanotubes grown on ultrahigh strength polyacrylonitrile-based and ultrahigh modulus pitch-based carbon fibers  

Microsoft Academic Search

The tensile properties and fracture behavior of carbon nanotubes (CNTs) grown on ultrahigh tensile strength polyacrylonitrile (PAN)-based (T1000GB) and ultrahigh modulus pitch-based (K13D) carbon fibers have been investigated. The CNTs were grown on the carbon fiber surface using chemical vapor deposition. The statistical scattering of the tensile strength was also evaluated. The results clearly show that grafting of CNTs improves

Kimiyoshi Naito; Jenn-Ming Yang; Yoshihisa Tanaka; Yutaka Kagawa

2008-01-01

5

Tensile bond strength of dental glazes.  

PubMed

Adaptic Glaze and Finite exhibited higher tensile bonds strengths than Concise Enamel Bond and Nuva-Seal. This is probably due to inherent higher viscosity and strength properties of Adaptic Glaze and Finite rather than to differences in adhesive qualities of the various resins. Consequently, the observed occasional early clinical loss of glazes should not be attributed to poor tensile bond strength. PMID:6997470

de Wet, F A; Ferreira, M R

1980-10-01

6

The dependence of bedrock erodibility on rock material properties: is tensile strength enough?  

NASA Astrophysics Data System (ADS)

Rock resistance to fluvial abrasion by bedload sediment impacts has been shown experimentally to depend on the square of rock tensile strength across the full range of rock strengths encountered in the field. This result is consistent with fracture mechanics theory which predicts that fractures propagate when the capacity of brittle materials to store impact energy by elastic deformation is exceeded. Strain energy depends on the square of tensile strength, but also on the elastic modulus. Log-log linear regression of laboratory measurements of bedrock erosion rates against tensile strength shows order-of -magnitude variability about the power-law fit, particularly for stronger rocks. In this investigation we seek to explain this variability in terms of other rock material properties. In particular we are examining elastic modulus, crystal grain size, mineralogy, degree of cementation, rock bulk density and porosity. We have access to the same rocks used in previous bedrock abrasion experiments, as well as artificial bedrock made from controlled mixtures of sand and portland cement. We measure tensile strength by the Brazilian splitting test, and estimate elastic modulus from measurements of the velocity of ultrasonic pulses through core samples. We are analyzing thin sections and photomicrographs to measure crystal grain size, and mineral and cement composition. Bulk density, as well as porosity, are measured by comparison of dry and saturated weights for known volumes of material. Preliminary results suggest that coarse-grained rocks, such as granite and some sandstones, are less erodible for a given measured tensile strength than the fine-grained rocks tested, which include greenstone, andesite and limestone. We also find, with a small subset of rock types tested to-date, that inclusion of elastic modulus in a multiple regression reduces the uncertainty in the regression slope estimate, but that substantial variability remains to be explained. This work may have broad applicability in understanding erodibility of terrestrial bedrock by fluvial as well as eolian mechanisms, as well as controls on the surface erodibility of ice ‘bedrock’ on outer solar system satellites such as Titan.

Beyeler, J. D.; Sklar, L. S.; Litwin, K.; Johnson, J. P.; Collins, G. C.; Whipple, K. X.

2009-12-01

7

CHARACTERIZATION OF TENSILE STRENGTH OF GLOVEBOX GLOVES  

Microsoft Academic Search

A task was undertaken to compare various properties of different glovebox gloves, having various compositions, for use in gloveboxes at the Savannah River Site (SRS). One aspect of this project was to determine the tensile strength (TS) of the gloves. Longitudinal tensile samples were cut from 15 different gloves and tensile tested. The stress, load, and elongation at failure were

P. Korinko; G. Chapman

2012-01-01

8

Tensile and fatigue strength properties of Kevlar 29 aramid/epoxy unidirectional composites  

SciTech Connect

Static and fatigue tensile strength properties of filament wound undirectional Kevlar 29/epoxy, typical of filament wound material used in flywheel rotors, were studied. Machining techniques were developed to minimize fiber fuzzing on edges. The static modulus, normalized to 70% fiber volume fraction is 8.87 x 10/sup 6/ psi. The major Poisson's ratio is 0.37. The static composite tensile strength, normalized to 70% fiber volume fraction is 200 x 10/sup 3/ psi, corresponding to a fiber stress at failure of 286 x 10/sup 3/ psi, which is good for materials having a very high fiber volume fraction. The S-N curve for R = 0.7 was found to be quite flat. Although the techniques used in this program had previously been employed successfully to study the fatigue behavior of Kevlar 29/epoxy and Kevlar 49/epoxy unidirectional materials, we were unable to overcome the persistent problem of cohesive material failure in the tab regions. The apparent reason for this is the very low interlaminar shear strength of the filament wound material. 16 figures.

Zweben, C.

1981-07-22

9

Effect of pulsed current and post weld aging treatment on tensile properties of argon arc welded high strength aluminium alloy  

Microsoft Academic Search

This paper reveals the effect of pulsed current and post weld aging treatment on tensile properties of argon arc welded AA7075 aluminium alloy. This alloy has gathered wide acceptance in the fabrication of light weight structures requiring high strength-to-weight ratio, such as transportable bridge girders, military vehicles, road tankers and railway transport systems. The preferred welding processes of high strength

V. Balasubramanian; V. Ravisankar; G. Madhusudhan Reddy

2007-01-01

10

CHARACTERIZATION OF TENSILE STRENGTH OF GLOVEBOX GLOVES  

SciTech Connect

A task was undertaken to compare various properties of different glovebox gloves, having various compositions, for use in gloveboxes at the Savannah River Site (SRS). One aspect of this project was to determine the tensile strength (TS) of the gloves. Longitudinal tensile samples were cut from 15 different gloves and tensile tested. The stress, load, and elongation at failure were determined. All of the gloves that are approved for glovebox use and listed in the glovebox procurement specification met the tensile and elongation requirements. The Viton{reg_sign} compound gloves are not listed in the specification, but exhibited lower tensile strengths than permissible based on the Butyl rubber requirements. Piercan Polyurethane gloves were the thinnest samples and exhibited the highest tensile strength of the materials tested.

Korinko, P.; Chapman, G.

2012-02-29

11

Multivariate analysis approach for correlations between material properties and tablet tensile strength of microcrystalline cellulose.  

PubMed

In this study we applied statistical multivariate analysis techniques to establish correlations between material properties and tablet tensile strength (TS) of microcrystalline cellulose (MCC) with different types and manufacturers. There were sixteen MCC samples included in this analysis described by 22 material parameters. For data analysis, principal component analysis (PCA) was used to model and evaluate the various relationships between the material properties and TS. Furthermore, partial least squares regression (PLS) analysis was performed to quantify the relationships between the material properties and TS and to predict the most influential MCC parameters contributing to the compactibility. The results showed that the moisture content, hygroscopicity and crystallinity did not exhibit significant impact on TS. The turgidity, maximum water uptake, degree of polymerization and molecular weight presented a strong positive influence on TS, while the density property, bulk and tap density, exhibited an obvious negative impact. The present work demonstrated that multivariate data analysis techniques (PCA and PLS) are useful for interpreting complex relations between 22 material properties and the tabletting properties of MCC. Furthermore, the method can be used for material classification. PMID:23016450

Liao, Zhenggen; Zhang, Nan; Zhao, Guowei; Zhang, Jing; Liang, Xinli; Zhong, Shaojin; Wang, Guangfa; Chen, Xulong

2012-09-01

12

Residual tensile strength of plain concrete under tensile fatigue loading  

Microsoft Academic Search

The functional relation between the residual tensile strength of plain concrete and number of cycles was determined. 99 tappered\\u000a prism specimens of plain concrete were tested under uniaxial tensile fatigue loading. Based on the probability distribution\\u000a of the residual tensile strength, the empirical expressions of the residual tensile strength corresponding to the number of\\u000a cycles were obtained. The residual tensile

Xianhong Meng; Yupu Song

2007-01-01

13

Tensile Strength Characteristics of Unsaturated Sands  

Microsoft Academic Search

Tensile strength characteristics of unsaturated sands are examined through a combined theoretical and experimental study. The characteristics of tensile strength in all three water retention regimes of pendular, funicular, and capillary are examined. A simple direct tensile strength apparatus is employed to determine tensile strength for sands with a broad range of particle sizes from silty sand to fine sand

Ning Lu; Bailin Wu

2007-01-01

14

Tensile properties of ultrahigh strength PAN-based, ultrahigh modulus pitch-based and high ductility pitch-based carbon fibers  

Microsoft Academic Search

The tensile properties and fracture behavior of ultrahigh tensile strength PAN-based (T1000GB), ultrahigh modulus pitch-based (K13D) and high ductility pitch-based (XN-05) carbon fibers have been investigated. The statistical distributions of the tensile strength were characterized. The Weibull modulus for the T1000GB, K13D and XN-05 fibers were calculated to be 5.9, 4.2 and 7.9, respectively. The results clearly show that for

Kimiyoshi Naito; Yoshihisa Tanaka; Jenn-Ming Yang; Yutaka Kagawa

2008-01-01

15

Tensile strength requirements for sutures.  

PubMed

The official requirements for sutures in Australia are those of British Pharmacopoeia (B.P.). The results of a survey conducted by this Laboratory indicate that the B.P. test and specifications for knot pull strength are no longer appropriate for sutures currently available in this country. It is suggested that tensile strength measurements on sutures should be carried out, without prior soaking, using the load cell type of constant rate of extension apparatus rather than the pendulum type tester specified in the B.P. Use of a simple knot is suitable for testing synthetic sutures, but the surgeon's knot is preferred for catgut. All products tested easily met both the B.P. and the United States Pharmacopeia (U.S.P.) requirements for tensile strength. PMID:6131988

Lee, S; Hailey, D M; Lea, A R

1983-02-01

16

Anisotropy of tensile strength of root dentin.  

PubMed

An effect of dentinal tubule orientation on mechanical properties of dentin has been difficult to demonstrate. We have tested the hypothesis that ultimate tensile strength (UTS) of dentin is affected by tubule (and hence collagen fibril) orientation. The UTS of human root dentin was investigated by direct tensile and diametral testing of specimens of known orientation prepared from extracted teeth. Dumbbell-shaped samples were machined for direct tensile testing (load parallel or perpendicular to tubule direction) and cylinders for diametral testing (load at 0 degrees, 45 degrees, 67.5 degrees, and 90 degrees). Fractured surfaces were examined by SEM. UTS was lowest when the tensile force was parallel to tubule orientation, and greatest at 90 degrees to tubule orientation (fracture parallel to tubule direction). SEM views of fractured surfaces suggested that microstructure contributes to fracture patterns. At least for properties involving disruption of the collagen matrix, root dentin shows a definite anisotropy. PMID:11332531

Lertchirakarn, V; Palamara, J E; Messer, H H

2001-02-01

17

THE TENSILE PROPERTIES OF NIOBIUM  

Microsoft Academic Search

The tensile properties of 1\\/8-in. thick annealed niobium sheet were ; measured over the temperature range 20 to 500 deg C. Strip. 0.04-in. thick, ; obtained by cold rolling 1\\/8-in. thick annealed niobium sheet, was tensile tested ; in the cold-worked and annealed conditions. Results show that niobium retains ; its strength up to 500 deg C, while the eloagation

H. G. Vaughan; R. G. Rose

1958-01-01

18

Electronic properties and ideal tensile strength of MoSe nanowires  

NASA Astrophysics Data System (ADS)

Ab initio pseudopotential total energy calculations of MoSe nanowires were performed within the local density approximation. The Li2Mo6Se6 crystal is composed of molecular chains, which can be separated from one another to form individual nanowires approximately 3 Å in diameter. In this study we consider three systems: the quasi-one-dimensional bulk crystal Li2Mo6Se6, one isolated MoSe nanowire, and one isolated MoSe nanowire with Li adsorbates. The equilibrium structures and the electronic structures of the three systems were calculated and compared to each other. The calculated density of states of an isolated MoSe wire is compared with experimental tunneling spectroscopy measurements of the local density of states. The binding energy of a Li atom to an isolated wire was calculated and the effects of Li adsorption are discussed. In addition, the calculated value for the ideal tensile strength of a single MoSe nanowire is presented and compared with estimated values for carbon nanotubes.

Ribeiro, Filipe J.; Roundy, David J.; Cohen, Marvin L.

2002-04-01

19

49 CFR 230.26 - Tensile strength of shell plates.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Tensile strength of shell plates. 230.26 Section 230...MAINTENANCE STANDARDS Boilers and Appurtenances Strength of Materials § 230.26 Tensile strength of shell plates. When the tensile...

2012-10-01

20

49 CFR 230.26 - Tensile strength of shell plates.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Tensile strength of shell plates. 230.26 Section 230...MAINTENANCE STANDARDS Boilers and Appurtenances Strength of Materials § 230.26 Tensile strength of shell plates. When the tensile...

2011-10-01

21

49 CFR 230.26 - Tensile strength of shell plates.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Tensile strength of shell plates. 230.26 Section 230...MAINTENANCE STANDARDS Boilers and Appurtenances Strength of Materials § 230.26 Tensile strength of shell plates. When the tensile...

2010-10-01

22

49 CFR 230.26 - Tensile strength of shell plates.  

Code of Federal Regulations, 2010 CFR

...2009-10-01 2009-10-01 false Tensile strength of shell plates. 230.26 Section 230...MAINTENANCE STANDARDS Boilers and Appurtenances Strength of Materials § 230.26 Tensile strength of shell plates. When the tensile...

2009-10-01

23

Enhancement of Tensile Strength in Block Copolymers Using Solution Extrusion  

NASA Astrophysics Data System (ADS)

The effects of solution extrusion on the mechanical properties of polycyclohexylethylene-b-polyethylene diblock (CE), triblock (CEC) and pentablock (CECEC) copolymers were investigated. The tensile mechanical properties of the triblock and pentablock improved significantly, relative to melt extrusion, resulting in an ultimate tensile strength of up to 140MPa for these copolymers, over three times that of melt-extruded samples. However, the diblock properties remained poor. Solution extrusion of CEC and CECEC with 25% by weight dioctyl phthalate (DOP) leads to a suppression of the C block glass transition temperature and enhances the E block extent of crystallinity and melting temperature, enabling room temperature extension of the block copolymers up to 400%. Subsequent removal of DOP by coagulation results in the high tensile strength materials. This finding will be discussed in the context of molecular and interfacial entanglements.

Lim, Lisa S.; Harada, Tamotsu; Bates, Frank S.; Hillmyer, Marc A.

2004-03-01

24

Tensile properties of nanoclay reinforced epoxy composites  

NASA Astrophysics Data System (ADS)

Kinetic epoxy resin was filled with nanoclay to increase tensile properties of the composite for civil and structural. This project manufactured samples with different percentages by weight of nanoclay in the composites in steps of 1 wt %, which were then post-cured in an oven. The samples were then subjected to tensile tests. The results showed that the composite with 3 wt % of nanoclay produced the highest yield and tensile strengths. However, the Young's modulus increased with increasing nanoparticulate loading. It is hoped that the discussion and results in this work would not only contribute towards the further development of nanoclay reinforced epoxy composites with enhanced material properties, but also provide useful information for the studies of fracture toughness, tensile properties and flexural properties of other composites.

Ku, H.; Trada, Mohan

2013-08-01

25

Relation of Tensile Strength to Brittle Temperature in Plasticized Polymers  

Microsoft Academic Search

Since both the second-order transition temperature and the tensile strength of plasticized polymers decrease linearly with plasticizer content, and frequently in inverse proportion to the molecular weight of the plasticizer, it was predicted that a linear relationship should exist between tensile strength and transition temperature for plasticized polymers, independent of the nature of the plasticizer. Tensile strength versus heat distortion

R. F. Boyer

1951-01-01

26

Tensile strength and fracture toughness of brittle materials  

NASA Astrophysics Data System (ADS)

The fracture properties of brittle materials under tension have been explained by many authors; however, questions such as the dependence of the tensile strength on the crack tip radius of curvature and the scatter of fracture toughness are still not well explained from fundamental principles. This work aims to address this question by using a force-atomistic approach: we analyze the forces that act in the solid down to the smallest dimensions in an atomistic context, verifying the satisfaction of the static equilibrium condition given by Newton's second law up to the beginning of the rupture. We take into account the forces due to the applied stress, which may be very large at crack tips, and the material cohesion forces, particularly at the point of largest local strain and stress concentration, where the local hyperelasticity of the material plays a governing role. By considering and connecting microstructure and atomicity, and using an experimentally proved maximum tensile-stress criterion for fracture, here we obtain an expression for the tensile strength of the brittle materials, where an effective local cohesive stress is defined. Thus, we explain in a unified framework from fundamental principles a set of established experimental results of brittle fracture of materials under tension, including the dependence of the tensile strength on the crack tip radius of curvature and some scatter in reported values of fracture toughness and cleavage surface energy. This work can be useful to make more realistic predictions of fracture properties of brittle materials taking into account microstructure and atomicity.

Emmerich, Francisco G.

2007-10-01

27

Role of matrix microstructure on room-temperature tensile properties and fiber-strength utilization of an orthorhombic Ti-alloy-based composite  

SciTech Connect

Microstructure-property understanding obtained for a nominally Ti-25Al-17Nb (at. pct) monolithic sheet alloy was used to heat treat a unidirectional four-ply SCS-6/Ti-25Al-17Nb metal-matrix composite (MMC) and a fiberless neat material of the same alloy for enhancing mechanical properties. The unreinforced alloy and [0]{sub 4} composite recorded significant improvements in ductility and strength, which were related to the microstructural condition. Modeling of the tensile strength based on fiber fracture statistics helped in understanding how improved matrix microstructure provided more efficient utilization, which was related to an {alpha}{sub 2} stabilized zone around the fiber. A Nb coating on the fiber was used to modify the local microstructure, and it produced a modest improvement in strength and ductility in the transverse direction. Structure-property relations of the matrix under different heat-treatment conditions are described in terms of deformation and failure mechanisms of the constituent phases; {alpha}{sub 2} (ordered hexagonal close-packed), B2 (ordered body-centered cubic), and O (ordered orthorhombic based on Ti{sub 2}AlNb).

Boehlert, C.J.; Majumdar, B.S.; Krishnamurthy, S. [UES, Inc., Dayton, OH (United States); Miracle, D.B. [Wright Lab. Materials Directorate, Wright-Patterson AFB, OH (United States)

1997-02-01

28

Determination of critical molecular weight for entangled macromolecules using the tensile strength data  

Microsoft Academic Search

The multivariable power dependence of polymer properties on molecular characteristics (Dobkowski, 1981) has been applied to molecular weight dependence of tensile strength, and the known equation of Flory (1945) has been extended taking polydispersity of polymers into account. Constant parameters of the relevant regression equations have been calculated using experimental data on tensile strength and molecular weight averagesMn andMw of

Zbigniew Dobkowski

1995-01-01

29

Discrete Analysis of Clay Layer Tensile Strength  

NASA Astrophysics Data System (ADS)

The Discrete Element Method is used to investigate the tensile behaviour and cracks mechanisms of a clay material submitted to bending loading. It is the case of compacted clay liners in landfill cap cover application. Such as the soil tested in this study is plastic clay, the distinct elements model was calibrated with previous data results by taking into account cohesive properties. Various contact and cohesion laws are tested to show that the numerical model is able to reproduce the failure mechanism. Numerical results are extending to simulate a landfill cap cover.

Lê, T. N. H.; Plé, O.; Villard, P.; Gotteland, P.; Gourc, J. P.

2009-06-01

30

Ultimate Tensile Strength of Pitch-Based Carbon Fibers.  

National Technical Information Service (NTIS)

Histograms of the average diameter, fiber breaking load and ultimate tensile strength were determined for as-received VSB-320 grade, Thornel P-type carbon fiber. The mean fiber diameter and the mean ultimate tensile strength were determined to be 10.4 mic...

R. K. Everett

1986-01-01

31

Tensile and tear properties of dental dam.  

PubMed

The tensile and tear properties of highly extensible latex are sensitive to specimen shape. Three specimen shapes (ASTM D412 Die C dumbbell tensile specimen, rectangular tensile specimen with 1.74 mm hole, and ASTM D624 Die C tear specimen) were evaluated for proposed ANSI/ADA specification #90 for dental dams. Fresh and aged dental dams from two manufacturers (Aseptico and Hygenic) in three weights (thin, medium, and heavy) and from two other manufacturers (Ivory and Ivoclar) in one weight (medium) were tested. Means and standard deviations of 10 specimens for tensile strength (MPa), elongation (%), and tear strength (kN/m) are included herein. Data were analyzed by analysis of variance. Means were compared by a Tukey-Kramer interval calculated at the 0.05 significance level. The use of the dumbbell and tear specimens for the evaluation of dental dam should be reconsidered. The rectangular specimen with a hole is recommended for use in the proposed specification because of its sensitivity to condition (fresh versus aged) and manufacturer. PMID:8632138

Svec, T A; Powers, J M; Ladd, G D; Meyer, T N

1996-05-01

32

Tensile strength of soil cores in relation to aggregate strength, soil fragmentation and pore characteristics  

Microsoft Academic Search

Tensile failure of soil is desirable in tillage. Soil tensile strength estimates most often are obtained from compression tests of dry aggregates. As tillage is performed under moist conditions, it would be highly relevant to measure tensile strength at high water contents.Plough-layer soil was sampled in a compacted soil (PAC) and in a non-compacted reference soil (REF). Tensile strength was

Lars J Munkholm; Per Schjønning; Bev D Kay

2002-01-01

33

Effect of Electron Beam Irradiation on Tensile Strength of Polypropylene  

NASA Astrophysics Data System (ADS)

In this paper, the effects of the intensity of electron beam and the variation with time after irradiation of electron beam on the tensile strength of the polypropylene (PP), which is widely used as medicine containers, were investigated. PP with and without colorants were used first and samples irradiated under various intensity of EB. A tensile test on the irradiated samples with elapsed time after the irradiation of the electron beam was carried out. The effects of those factors on the tensile strength were discussed. The following results were obtained (1) The tensile strength of PP decreased due to the influence of the electron beam irradiation, however the rate of the decrease in strength was small compared with the original one. Furthermore, the rate of the decrease in strength was very small owing to the variation with time after the EB irradiation. (2) The tensile rupture strength of PP increased and the rupture strain owing to the influence of the electron beam irradiation compared with the original one. In addition, these rupture strength increased and the rupture strain decreased along with time after the irradiation of the electron beam. (3) The tensile rupture strain energy of PP decreased owing to the influence of the electron beam irradiation compared with the original one. In addition, the strain energy decreases with time after the irradiation of the electron beam. Moreover, the strength characteristics of PP with colorants received greater influence of electron beam compared with the one without colorants.

Yamada, Hiroshi; Ikeda, Masayuki; Shimbo, Minoru; Miyano, Yasushi

34

Network structure and compositional effects on tensile mechanical properties of hydrophobic association hydrogels with high mechanical strength  

Microsoft Academic Search

Hydrophobic association hydrogels (HA-gels) were successfully prepared through micellar copolymerization of acrylamide (AM) and a small amount of octylphenol polyoxyethylene acrylate (OP-4-AC) in an aqueous solution containing sodium dodecyl sulfate (SDS). HA-gels exhibited excellent mechanical properties and transparency. Especially, HA-gels possessed the capability of re-forming, such as self-healing and molding. From Fourier transform infrared, swelling behavior and re-forming capability of

Guoqing Jiang; Chang Liu; Xiaoli Liu; Qingrui Chen; Guohui Zhang; Meng Yang; Fengqi Liu

2010-01-01

35

Experimental and theoretical assessment of the longitudinal tensile strength of unidirectional SiC-fiber\\/titanium-matrix composites  

Microsoft Academic Search

The tensile strength of unidirectional SiC-fiber\\/titanium composites (SCS-6\\/Ti-1100) of varying fiber volume fraction (0.15–0.35) was measured in the as-produced condition. Additionally, fibers were etched from the panels and tensile tested to determine their strength distribution, interface properties were measured with fiber push-out tests, and the tensile properties of the matrix (without fiber) were also determined. From the measured constituent properties,

D. B. Gundel; F. E. Wawner

1997-01-01

36

Tensile properties of austempered ductile iron under thermomechanical treatment  

NASA Astrophysics Data System (ADS)

A new processing method was investigated for improving the strength and elongation of austempered ductile iron (ADI) by grain refinement of parent austenite using thermomechanical treatment. The material was deformed at the austenitization temperature by single and multipass rolling before the austempering treatment. The effects of the amount of deformation, austenitization temperature, austempering temperatures, reaustenitization, and secondary deformation on the tensile properties were studied. The properties obtained using the method were compared with those of the ASTM standards. The effect of deformation on the graphite shape was also studied. Tensile strength/yield strength/elongation values were found to increase with increasing austenite deformation up to 40% and then to start decreasing. Tensile strength/yield strength and elongation values of 1700 MPa/1300 MPa/5% and 1350 MPa/920 MPa/15% can be achieved with this method in the ranges of variables studied.

Achary, J.

2000-02-01

37

Tensile properties of austempered ductile iron under thermomechanical treatment  

SciTech Connect

A new processing method was investigated for improving the strength and elongation of austempered ductile iron (ADI) by grain refinement of parent austenite using thermomechanical treatment. The material was deformed at the austenitization temperature by single and multipass rolling before the austempering treatment. The effects of the amount of deformation, austenitization temperature, austempering temperatures, reaustenitization, and secondary deformation on the tensile properties were studied. The properties obtained using the method were compared with those of the ASTM standards. The effect of deformation on the graphite shape was also studied. Tensile strength/yield strength/elongation values were found to increase with increasing austenite deformation up to 40% and then to start decreasing. Tensile strength/yield strength and elongation values of 1,700 MPa/1,300 MPa/5% and 1,350 MPa/920 MPa/15% can be achieved with this method in the ranges of variables studied.

Achary, J.

2000-02-01

38

Analysis of tensile bond strengths using Weibull statistics.  

PubMed

Tensile strength tests of restorative resins bonded to dentin, and the resultant strengths of interfaces between the two, exhibit wide variability. Many variables can affect test results, including specimen preparation and storage, test rig design and experimental technique. However, the more fundamental source of variability, that associated with the brittle nature of the materials, has received little attention. This paper analyzes results from micro-tensile tests on unfilled resins and adhesive bonds between restorative resin composite and dentin in terms of reliability using the Weibull probability of failure method. Results for the tensile strengths of Scotchbond Multipurpose Adhesive (3M) and Clearfil LB Bond (Kuraray) bonding resins showed Weibull moduli (m) of 6.17 (95% confidence interval, 5.25-7.19) and 5.01 (95% confidence interval, 4.23-5.8). Analysis of results for micro-tensile tests on bond strengths to dentin gave moduli between 1.81 (Clearfil Liner Bond 2V) and 4.99 (Gluma One Bond, Kulzer). Material systems with m in this range do not have a well-defined strength. The Weibull approach also enables the size dependence of the strength to be estimated. An example where the bonding area was changed from 3.1 to 1.1 mm diameter is shown. Weibull analysis provides a method for determining the reliability of strength measurements in the analysis of data from bond strength and tensile tests on dental restorative materials. PMID:15109865

Burrow, Michael F; Thomas, David; Swain, Mike V; Tyas, Martin J

2004-09-01

39

Tensile strength of surgical knots in abdominal wound closure.  

PubMed

Abdominal wound dehiscence is a surgical catastrophe that can be attributed to patients or technical factors. The technical properties of the monofilament sutures and knots that are commonly used in abdominal closure are poorly understood. The aim of this study was to compare the tensile strength of monofilament sutures tied with conventional knots. To do this, the knot-holding capacity of four types of knots (square, surgeons', Aberdeen and loop) were tested using three types of gauge 1 monofilament suture, namely nylon, polyglyconate and polydioxanone, using a tensiometer. We found that the knot-holding capacity of the loop knot was between twofold and threefold greater than all the other knots examined. In comparing suture types, polyglyconate had the highest knot-holding capacity for all the knots that were examined and there was no difference in the tensile strength of nylon and polyglyconate tied in a square, surgeons' or Aberdeen knot (P < 0.05). In conclusion, our findings suggest that closure of an abdominal wound would be best commenced with a loop knot, using gauge 1 polyglyconate and finished with either an Aberdeen square or surgeons' knot would be appropriate. PMID:18269480

Fong, Eva D M; Bartlett, Adam S R; Malak, Sharif; Anderson, Iain A

2008-03-01

40

Correlation of Yield Strength and Tensile Strength with Hardness for Steels  

NASA Astrophysics Data System (ADS)

Hardness values as well as yield and tensile strength values were compiled for over 150 nonaustenitic, hypoeutectoid steels having a wide range of compositions and a variety of microstructures. The microstructures include ferrite, pearlite, martensite, bainite, and complex multiphase structures. The yield strength of the steels ranged from approximately 300 MPa to over 1700 MPa. Tensile strength varied over the range of 450-2350 MPa. Regression analysis was used to determine the correlation of the yield strength and the tensile strength to the diamond pyramid hardness values for these steels. Both the yield strength and tensile strength of the steels exhibited a linear correlation with the hardness over the entire range of strength values. Empirical relationships are provided that enable the estimation of strength from a bulk hardness measurement. A weak effect of strain-hardening potential on the hardness-yield strength relationship was also observed.

Pavlina, E. J.; van Tyne, C. J.

2008-12-01

41

Hoop Tensile Strength Testing of Small Diameter Ceramic Particles  

SciTech Connect

A method to measure hoop tensile strength of 1-mm-diameter brittle ceramic spheres was demonstrated through the use of a "C-sphere" flexure strength specimen. This innovative specimen geometry was chosen because a simple, monotonically increasing uniaxial compressive force produces a hoop tensile stress at the C-sphere's outer surface that ultimately initiates fracture. This enables strength quantification and strength-limiting flaw identification of the sphere itself. Such strength information is relevant to design optimization and durability assessments of ceramic fuel particles and breeder/multiplier pebbles for fusion whose surfaces are subjected to tensile stresses caused by thermal gradients, thermal transients, swelling, etc., during their manufacturing or service.

Wereszczak, Andrew A [ORNL; Jadaan, Osama M. [University of Wisconsin, Platteville; Lin, Hua-Tay [ORNL; Champoux, Gregory J [ORNL; Ryan, David P [ORNL

2007-01-01

42

Tensile Bond Strength of Latex-Modified Bonded Concrete Overlays  

NASA Astrophysics Data System (ADS)

The tensile bond strength of bonded concrete overlays was tested using the in-situ pull-off method described in ASTM C 1583 with the goal of determining whether adding latex to the mix design increases bond strength. One slab of ductile concrete (f'c > 12,000 psi) was cast with one half tined, i.e. roughened, and one half steel-troweled, i.e. smooth. The slab surface was sectioned off and overlay mixtures containing different latex contents cast in each section. Partial cores were drilled perpendicular to the surface through the overlay into the substrate. A tensile loading device applied a direct tensile load to each specimen and the load was increased until failure occurred. The tensile bond strength was then calculated for comparison between the specimens.

Dubois, Cameron; Ramseyer, Chris

2010-10-01

43

Effects of diameter, chemical impregnation and hydration on the tensile strength of gingival retraction cords.  

PubMed

Gingival retraction cords are useful clinical aids but little information is available regarding desirable physical features that would preserve their integrity under tensile forces. The study aimed to establish under experimental conditions the extent to which tensile strength is affected by variation in cord diameter; impregnation with ferric sulphate (FS) or aluminium sulphate (AS); and cord hydration (wet/dry). Commercial cords and standard cotton cords were assayed in an Instron 1137 machine. Data were analysed using t-test, and one- and four-way ANOVA. Results indicated that tensile strength for 200 commercial cords was 1.4950 +/- 1.032 kg; and for 560 cotton cords was 1.2964 +/- 1.4560 kg. Cord hydration had no significant effect on tensile strength, whereas impregnation with AS or FS, a smaller diameter, and/or being a cotton cord decreased tensile strength (P < 0.001). Bivariate analyses showed that hydrated commercial cords had higher tensile strength than dry specimens; hydrated or dry cotton cords were not different. The FS-impregnated cotton cords had lower tensile strength than AS-impregnated or control cords, and the effect was greater at higher FS concentrations. This study is one of the first evaluations of the physical properties of cords, highlighting characteristics that may minimize the risk of tearing. PMID:11874507

Del Rocío Nieto-Martínez, M; Maupomé, G; Barceló-Santana, F

2001-12-01

44

Experimental and Numerical Studies on Determination of Indirect Tensile Strength of Rocks  

NASA Astrophysics Data System (ADS)

Indirect tension tests using Brisbane tuff Brazilian disc specimens under standard Brazilian jaws and various loading arcs were performed. The standard Brazilian indirect tensile tests caused catastrophic, crushing failure of the disc specimens, rather than the expected tensile splitting failure initiated by a central crack. This led to an investigation of the fracturing of Brazilian disc specimens and the existing indirect tensile Brazilian test using steel loading arcs with different angles. The results showed that the ultimate failure load increased with increasing loading arc angles. With no international standard for determining indirect tensile strength of rocks under diametral load, numerical modelling and analytical solutions were undertaken. Numerical simulations using RFPA2D software were conducted with a heterogeneous material model. The results predicted tensile stress in the discs and visually reproduced the progressive fracture process. It was concluded that standard Brazilian jaws cause catastrophic, crushing failure of the disc specimens instead of producing a central splitting crack. The experimental and numerical results showed that 20° and 30° loading arcs result in diametral splitting fractures starting at the disc centre. Moreover, intrinsic material properties (e.g. fracture toughness) may be used to propose the best loading configuration to determine the indirect tensile strength of rocks. Here, by using numerical outcomes and empirical relationships between fracture toughness and tensile strength, the best loading geometry to obtain the most accurate indirect tensile strength of rocks was the 2? = 30° loading arc.

Erarslan, Nazife; Liang, Zheng Zhao; Williams, David John

2012-09-01

45

Predicting the tensile strength of natural fibre reinforced thermoplastics  

Microsoft Academic Search

The tensile strength of short natural fibre reinforced thermoplastics (NFRT) was modeled using a modified rule of mixtures (ROM) strength equation. A clustering parameter, requiring the maximum composite fibre volume fraction, forms the basis of the modification. The clustering parameter highlights that as fibre loading increases, the available fibre stress transfer area is decreased. Consequently, at high volume fractions this

Angelo G. Facca; Mark T. Kortschot; Ning Yan

2007-01-01

46

Notched tensile strength of SP700 laser welds  

Microsoft Academic Search

Notched tensile tests were performed to evaluate the influence of post-weld heat treatments (PWHTs) on the notched tensile strength (NTS) of two ?+? titanium alloy welds. The results indicated that SP-700 laser welds were notch brittle unless a high PWHT temperature, e.g. 760 °C, was applied. The lowest NTS was associated with the peak-aged weld, which was aged at 482 °C for

L. W. Tsay; Y. S. Ding; W. C. Chung; C. Chen

2008-01-01

47

Tensile and tear strength of carrageenan film from Philippine eucheuma species.  

PubMed

The tensile and tear strength of carrageenan film from Philippines Eucheuma species were investigated using NEC tensilon universal-testing machine according to American Society for Testing Materials methods. These properties are important for assessing carrageenan film as packaging material. The kappa and iota types were used in the study. The effect of glycerine on the tensile and tear strength including elongation was also evaluated. Addition of glycerine tended to lower the tensile strength of the film and increase its elongation properties including the tear strength. Carrageenan film without glycerine was much stronger. Glycerine made the film more flexible and easy to deform. The composite film of carrageenan and konjac gum did not exhibit elongation. It also showed higher tensile strength than did the composite film of carrageenan and xanthan gum. Compared with iota-type carrageenan film, kappa-type carrageenan film without glycerine was more comparable to low-density polyethylene (LDPE) film in terms of tensile strength as was the composite film of carrageenan-konjac gum. The kappa-type carrageenan film with glycerine was more comparable to LDPE film in terms of tear strength. The elongation reading for carrageenan film was lower than that for LDPE film. Morphologic studies showed that the carrageenan film had sets of pores distributed randomly at different places as compared to LDPE film. It also showed that the carrageenan film was more fibrous than LDPE film. PMID:15085409

Briones, Annabelle V; Ambal, Wilhelmina O; Estrella, Romulo R; Pangilinan, Rolando; De Vera, Carlos J; Pacis, Raymund L; Rodriguez, Ner; Villanueva, Merle A

2004-04-19

48

Tensile properties of a thermomechanically processed ductile iron  

Microsoft Academic Search

A ductile cast iron was continuously hot-and-warm-rolled or one-step-forged from a temperature in the austenite range (900\\u000a C to 1100 C) to a temperature below the A\\u000a 1 temperature. Various amounts of reduction were used (from 60 to more than 90 pct). Tensile properties including tensile strength\\u000a and total elongation were measured along the directions parallel and transverse to the

C. K. Syn; D. R. Lesuer; O. D. Sherby

1997-01-01

49

Tensile strength of enamel-resin-metal joints.  

PubMed

This study evaluated the tensile strength of enamel-resin-metal joints formed with four adhesive systems for attaching resin-bonded FPDs. Groups of 10 cast alloy cylinders were blasted with 50 microns alumina, washed, and prepared for bonding according to the resin as follows: (1) Panavia Ex with no treatment, (2) Super-Bond oxidized for 2 minutes with potassium permanganate in sulphuric acid, (3) Conclude electrolytically etched, and (4) ABC conditioned with primer. The cylinders were bonded to etched human enamel and after 24 hours in water at 37 degrees C the tensile strengths of the joints were recorded. Joint failure was examined under a stereomicoscope and a scanning electron microscope. The results demonstrated that the adhesive system influenced the tensile strength and mode of failure of the joints. PMID:2657026

Aboush, Y E; Jenkins, C B

1989-06-01

50

Silicon nitride having a high tensile strength  

DOEpatents

A silicon nitride ceramic is disclosed comprising: (a) inclusions no greater than 25 microns in length, (b) agglomerates no greater than 20 microns in diameter, and (c) a surface finish of less than about 8 microinches, said ceramic having a four-point flexural strength of at least about 900 MPa. 4 figs.

Pujari, V.K.; Tracey, D.M.; Foley, M.R.; Paille, N.I.; Pelletier, P.J.; Sales, L.C.; Willkens, C.A.; Yeckley, R.L.

1996-11-05

51

The tensile properties of single sugar palm (Arenga pinnata) fibre  

NASA Astrophysics Data System (ADS)

This paper presents a brief description and characterization of the sugar palm fibres, still rare in the scientific community, compared to other natural fibres employed in polymeric composites. Sugar palm fibres are cellulose-based fibres extracted from the Arenga pinnata plant. The characterization consists of tensile test and the morphological examination. The average tensile properties results of fibres such as Young's modulus is equal to 3.69 GPa, tensile strength is equal to 190.29 MPa, and strain at failure is equal to 19.6%.

Bachtiar, D.; Sapuan, S. M.; Zainudin, E. S.; Khalina, A.; Dahlan, K. Z. M.

2010-05-01

52

Tensile and bending properties of double-walled carbon nanotubes  

NASA Astrophysics Data System (ADS)

Atomistic simulations are performed to investigate the mechanical properties of uniaxial tensile and bending behaviours of double-walled carbon nanotubes. The second-generation reactive empirical bond-order potential and four different van der Waals (vdW) potentials are used to describe bonding and non-bonding atomic interactions, respectively. It is found that the tensile and bending behaviours are insensitive to the choice of vdW potential. It is shown that the effect of the helicity of nanotubes on the elastic modulus and the tensile strength is significant, while the effect of the nanotube diameter is moderate. Our simulations show that the outer tube always reaches its tensile strength first, suggesting the 'sword-in-sheath' failure mechanism. For the bending deformation, a strong non-linearity between the deformation and load is observed at small deformations, while a nearly linear relation is observed at large deformations.

Liu, P.; Zhang, Y. W.; Lu, C.; Lam, K. Y.

2004-09-01

53

The ideal tensile strength of tungsten and tungsten alloys by first-principles calculations  

NASA Astrophysics Data System (ADS)

The ideal tensile strength in the [0 0 1] direction of bcc crystal tungsten and its alloys (W-Re, W-Ta and W-V) has been investigated by using first-principles total energy method based on the density functional theory. Crystalline tungsten containing a single substitutional defect (concentration of defects about 2%) has been characterized in terms of structural and mechanical properties. The maximum tensile stress required to reach elastic instability under increasing load has been further computed.

Giusepponi, Simone; Celino, Massimo

2013-04-01

54

Effects of parachute-ribbon surface treatments on tensile strength  

Microsoft Academic Search

Routine quality-assurance evaluations of nylon ribbons used on test-deployed parachutes revealed tensile-strength degradation had occurred in some of the ribbons. The degradation occurred exclusively in some of the noncritical skirt ribbons with stenciled blue-ink identification markings. Although the strength loss was excessive, the reliability of the parachute was not affected. These results motivated an accelerated-aging study of the effects on

I. Auerbach; L. D. Whinery; D. W. Johnson; K. E. Mead; D. D. Sheldon

1986-01-01

55

Measurement of the tensile strength of pulverized and powdered materials  

Microsoft Academic Search

A number of methods have been proposed for measuring the tensile strength of powders. The most convenient method is the vertical detachable cylinder method. The results of studies conducted to develop this method, a new instrument design, and metrological studies of the instrument are described in this article. The measurements were performed on a series of industrial powdered materials in

E. I. Andrianov; N. I. Mogilko

1988-01-01

56

On the Measurement of the Tensile Strength of Soft Rocks  

Microsoft Academic Search

Summary. This paper reports on a comparative study of various types of experimental tests for measuring the tensile strength of rocks and rock-like materials. A critical assessment is presented of some widely used laboratory techniques on the basis of experimental data from the literature and from the laboratory investigation performed in this study.

A. Coviello; R. Lagioia; R. Nova

2005-01-01

57

Tensile properties of a thermomechanically processed ductile iron  

SciTech Connect

A ductile cast iron was continuously hot-and-warm-rolled or one-step-forged from a temperature in the austenite range (900 C to 1,100 C) to a temperature below the A{sub 1} temperature. Various amounts of reduction were used (from 60 to more than 90 pct). Tensile properties including tensile strength and total elongation were measured along the directions parallel and transverse to the rolling direction and along the direction transverse to the forging direction. The tensile ductility and strength both increase with a decrease in the amount of hot-and-warm working (HWW). Compared with the results obtained by other investigators, the present results showed higher strengths and ductilities over the same range of reduction in thickness. The improvement in properties is related to the lower temperature of the postprocessing heat treatment given in this study (600 C) compared to other studies (900 C). The low temperature of heat treatment leads to a structure of fine graphite in a matrix of ferrite and carbides, whereas the high temperature of heat treatment leads to coarse graphite in a matrix of carbide-free ferrite. The delay in failure from the presence of the small graphite constituent results in an increase in tensile ductility with an accompanying increase in tensile strength.

Syn, C.K.; Lesuer, D.R. [Lawrence Livermore National Lab., CA (United States); Sherby, O.D. [Stanford Univ., CA (United States). Dept. of Materials Science and Engineering

1997-05-01

58

The Effect of Reprocessing on the Tensile Properties of Composites  

NASA Astrophysics Data System (ADS)

In this study, waste cotton fabric reinforced polymer matrix composite material has been manufactured by a custom made recycling extruder. Composites with different reinforcement ratios as 12,5%wt ( 12,5%wtRPE ) and 25%wt ( 25%wtRPE ) were tested for their mechanical properties such as tensile strength and young's modulus. The material was then granulated down to the size enough to be used in the extrusion process in order to observe the effects of reprocessing. Reprocessing leads to improve Tensile Strength of composite materials and slows down the reduction of tensile strength of polyethylene. It was observed that composite materials were highly affected by the fiber orientation and acts as anisotropic material under the load.

Bodur, Mehmet Safa; Bakkal, Mustafa; Berkalp, Omer Berk; Sadikoglu, Telem Gok

2011-01-01

59

High-Temperature Tensile Properties of a Molybdenum5%Rhenium0.5%Hafnium Carbide Alloy  

Microsoft Academic Search

Tensile properties of a molybdenum-5 at % rhenium-0.5 at % hafnium carbide alloy were evaluated with a strain rate of 10-3\\/sec over a temperature region of 1200 to 2400 K in vacuum. The yield strength, tensile strength, solution induced and dispersion induced strength increments, strain-hardening exponent, and tensile elongation of this alloy were determined. The effects of rhenium, hafnium carbide

Anhua Luo; John J. Park; Dean L. Jacobson; Bang H. Tsao; Mysore L. Ramalingam

1994-01-01

60

Tensile fatigue properties of fibre Bragg grating optical fibre sensors  

Microsoft Academic Search

This paper presents an experimental study into the tensile strength and fatigue properties of uncoated optical glass fibres containing Bragg grating (FBG) sensors. The protective polymer coating of the optical fibres must be removed by chemical or mechanical stripping methods to produce the Bragg gratings in the fibre core. This paper investigates the effects of chemical or mechanical stripping on

J. Ang; H. C. H. Li; I. Herszberg; M. K. Bannister; A. P. Mouritz

2010-01-01

61

Tensile Properties of Resin-infiltrated Demineralized Human Dentin  

Microsoft Academic Search

The ability of adhesive resins to restore the physical properties of demineralized dentin has not been well-documented. The unfilled resins that are used for adhesion have relatively low moduli of elasticity and limited ability to increase dentin stiffness, although they may increase the ultimate tensile strength of dentin. This study tested the hypothesis that resin infiltration of demineralized dentin can

H. Sano; T. Takatsu; B. Ciucchi; C. M. Russell; D. H. Pashley

1995-01-01

62

The effect of repeated torque on the ultimate tensile strength of slotted gold prosthetic screws  

Microsoft Academic Search

Statement of Problem. Repeated torque may alter the mechanical properties and fracture resistance of certain prosthetic retaining screws. Purpose. This study evaluated the effect of repeated torque and salivary contamination on the ultimate tensile strength of one type of slotted gold prosthetic retaining screw. Material and Methods. Forty-five slotted gold prosthetic screws from the same manufacturer (Implant Innovations) were divided

Mohammed A. Al Rafee; William W. Nagy; Raymond A. Fournelle; Virendra B. Dhuru; George K. Tzenakis; Charles E. Pechous

2002-01-01

63

The ultimate tensile strength of metal and ceramic-matrix composites  

Microsoft Academic Search

The tensile strength of ceramic and metal matrix composites is subject to an important role of the fiber\\/matrix interface. The mechanical properties of this interface dictate the stress concentration that develops in fibers that surround a failed fiber. An analysis of this phenomenon is used to illustrate interface conditions that sufficiently diminish the stress concentration that a global load sharing

M. Y. He; A. G. Evans; W. A. Curtin

1993-01-01

64

Tensile rock mass strength estimated using InSAR  

NASA Astrophysics Data System (ADS)

The large-scale strength of rock is known to be lower than the strength determined from small-scale samples in the laboratory. However, it is not well known how strength scales with sample size. I estimate kilometer-scale tensional rock mass strength by measuring offsets across new tensional fractures (joints), formed above a shallow magmatic dike intrusion in western Arabia in 2009. I use satellite radar observations to derive 3D ground displacements and by quantifying the extension accommodated by the joints and the maximum extension that did not result in a fracture, I put bounds on the joint initiation threshold of the surface rocks. The results indicate that the kilometer-scale tensile strength of the granitic rock mass is 1-3 MPa, almost an order of magnitude lower than typical laboratory values.

Jónsson, Sigurjón

2012-11-01

65

Practical Estimates of Tensile Strength and Hoek-Brown Strength Parameter m i of Brittle Rocks  

NASA Astrophysics Data System (ADS)

By applying the Griffith stress criterion of brittle failure, one can find that the uniaxial compressive strength (?c) of rocks is eight times the value of the uniaxial tensile strength (?t). The Griffith strength ratio is smaller than what is normally measured for rocks, even with the consideration of crack closure. The reason is that Griffith’s theories address only the initiation of failure. Under tensile conditions, the crack propagation is unstable so that the tensile crack propagation stress (?cd)t and the peak tensile strength ?t are almost identical to the tensile crack initiation stress (?ci)t. On the other hand, the crack growth after crack initiation is stable under a predominantly compressive condition. Additional loading is required in compression to bring the stress from the crack initiation stress ?ci to the peak strength ?c. It is proposed to estimate the tensile strength of strong brittle rocks from the strength ratio of R = {{?_{text{c}} }/{left| {?_{text{t} } right|}}} = 8{{?_{text{c}} }/{?_{text{ci} }}}. The term {{?_{text{c}} }/{?_{text{ci} }}} accounts for the difference of crack growth or propagation in tension and compression in uniaxial compression tests. {{?c }/{?_{ci }}} depends on rock heterogeneity and is larger for coarse grained rocks than for fine grained rocks. ?ci can be obtained from volumetric strain measurement or acoustic emission (AE) monitoring. With the strength ratio R determined, the tensile strength can be indirectly obtained from left| {?_{text{t}} } right| = {{?_{text{c}} }/R} = {{?_{text{ci}} }/8}. It is found that the predicted tensile strengths using this method are in good agreement with test data. Finally, a practical estimate of the Hoek-Brown strength parameter m i is presented and a bi-segmental or multi-segmental representation of the Hoek-Brown strength envelope is suggested for some brittle rocks. In this fashion, the rock strength parameters like ?t and m i, which require specialty tests such as direct tensile (or Brazilian) and triaxial compression tests for their determination, can be reasonably estimated from uniaxial compression tests.

Cai, M.

2010-03-01

66

Evaluation of micro-tensile, shear and tensile tests determining the bond strength of three adhesive systems  

Microsoft Academic Search

Objectives. The aim of this study was to determine bond strength between dentin and three adhesive systems, by means of micro-tensile, shear and tensile tests.Methods. Extracted human molars were embedded in acrylic resin and had the dentin exposed on three of their smooth surfaces. On each surface a specimen was prepared to be submitted to either micro-tensile, shear or tensile

Paulo E. C Cardoso; Roberto R Braga; Marcela R. O Carrilho

1998-01-01

67

Measurement of tensile strength of liquids by an explosion technique  

Microsoft Academic Search

A WIDE variety of methods has been used in the estimation of the static tensile strength of water1,2. Recently, a dynamic method, using an impulse-generated pressure wave, has been described which uses a measurement of the negative pressure produced by the wave reflected from a free surface3. Wilson et al. 4 had previously shown how estimates of the negative-pressure wave

D. A. Wilson; J. W. Hoyt; J. W. McKune

1975-01-01

68

Young's modulus, fracture strain, and tensile strength of sputtered titanium thin films  

Microsoft Academic Search

The internal stress of sputtered titanium thin films was optimized for Micro Electro Mechanical System (MEMS) applications and the strength properties of the films were investigated. Low internal stress was obtained for 0.5-?m thick films by controlling the argon gas flow rate and for 1.0-?m thick films using the multiple deposition process. The Young's modulus, tensile strength, and maximum elongation

Toshiyuki Tsuchiya; Masakazu Hirata; Norio Chiba

2005-01-01

69

Morphogenesis of Plasmodium zoites is uncoupled from tensile strength.  

PubMed

A shared feature of the motile stages (zoites) of malaria parasites is a cortical cytoskeletal structure termed subpellicular network (SPN), thought to define and maintain cell shape. Plasmodium alveolins comprise structural components of the SPN, and alveolin gene knockout causes morphological abnormalities that coincide with markedly reduced tensile strength of the affected zoites, indicating the alveolins are prime cell shape determinants. Here, we characterize a novel SPN protein of Plasmodium berghei ookinetes and sporozoites named G2 (glycine at position 2), which is structurally unrelated to alveolins. G2 knockout abolishes parasite transmission and causes zoite malformations and motility defects similar to those observed in alveolin null mutants. Unlike alveolins, however, G2 contributes little to tensile strength, arguing against a cause-effect relationship between tensile strength and cell shape. We also show that G2 null mutant sporozoites display an abnormal arrangement of their subpellicular microtubules. These results provide important new understanding of the factors that determine zoite morphogenesis, as well as the potential roles of the cortical cytoskeleton in gliding motility. PMID:23773015

Tremp, Annie Z; Carter, Victoria; Saeed, Sadia; Dessens, Johannes T

2013-07-05

70

Tensile and compressive properties of flax fibres for natural fibre reinforced composites  

Microsoft Academic Search

Mechanical properties of standard decorticated and hand isolated flax bast fibres were determined in tension as well as in compression. The tensile strength of technical fibre bundles was found to depend strongly on the clamping length. The tensile strength of elementary flax fibres was found to range between 1500 MPa and 1800 MPa, depending on the isolation procedure. The compressive

H. L. Bos; M. J. A. Van Den Oever; O. C. J. J. Peters

2002-01-01

71

Effect of retained austenite characteristics on fatigue behavior and tensile properties of transformation induced plasticity steel  

Microsoft Academic Search

Transformation induced plasticity steels are commonly used for automotive industry due to their high strength and high ductility. These steels achieve good balance of strength and ductility due to transformation of retained austenite to martensite during deformation. In this study, effect of retained austenite characteristics on fatigue and tensile property of conventional CMnSi steel is evaluated. Tensile and fatigue test

M. Abareshi; E. Emadoddin

2011-01-01

72

Measurement of the tensile strength of cell–biomaterial interface using the laser spallation technique  

Microsoft Academic Search

A previously developed laser spallation technique to determine the tensile strength of thin film interfaces was successfully adopted to determine the tensile strength of interfaces between three different live mammalian cells (osteoblast, chondrocyte and fibroblast) and polystyrene (untreated and fibronectin coated) and titanium surfaces. No noticeable differences in the interfacial tensile strength values were found across the three cell types

Jaewoo Shim; Elizabeth Hagerman; Ben Wu; Vijay Gupta

2008-01-01

73

Strain-rate dependency of the dynamic tensile strength of rock  

Microsoft Academic Search

Dynamic tension tests based on Hopkinson’s effect combined with the spalling phenomena were performed on Inada granite and Tage tuff to investigate the strain-rate dependency of the dynamic tensile strength of rock. The static tensile strengths were determined and compared with the dynamic tensile strengths. The fracture processes under various loading conditions were analyzed using a proposed finite element method

Sang Ho Cho; Yuji Ogata; Katsuhiko Kaneko

2003-01-01

74

Tensile and creep properties of titanium--vanadium, titanium--molybdenum, and titanium--niobium alloys  

Microsoft Academic Search

Tensile and creep properties of experimental beta-titanium alloys were ; determined. Titanium--vanadium alloys had substantially greater tensile and ; creep strength than the titanium--niobium and titanium--molybdenum alloys tested. ; Specific tensile strengths of several titanium--vanadium--aluminium--silicon ; alloys were equivalent or superior to those of commercial titanium alloys to ; temperatures of 650°C. The Ti--50V--3Al--1Si alloy had the best balance of

Gray

1975-01-01

75

Predicting the tensile modulus and strength of single and hybrid natural fibre reinforced thermoplastic composites  

NASA Astrophysics Data System (ADS)

Natural fibre reinforced thermoplastics (NFRT) are used in a variety of commercial applications, but there is little theoretical modeling of structure/property relationships in these materials. In this thesis, micromechanical models available in the short-fibre literature were adapted to predict the tensile modulus and strength of some NFRT formulations. Hemp, 20 and 40-mesh hardwood, rice hulls and E-glass fibres were blended into HDPE to produce single and hybrid composites. Changes in fibre density and moisture content that occur during composite manufacturing were included in the micromechanical models. To account for fibre densification, the Young's modulus of the natural fibres was determined on a cell wall basis. A modified hybrid rule of mixtures (HROM) equation that uses experimental data from single NFRT was developed and found to adequately predict the tensile modulus of the hybrid composites. The tensile modulus for both the single and hybrid composites was found to linearly increase with an increase in fibre loading. The failure mechanism for all composite specimens was due to fibre pullout followed by matrix failure. Consequently the tensile strength of the NFRT was predicted using a ROM strength equation, which was modified with a derived semi-empirical fibre clustering parameter. The clustering parameter correctly predicted that as fibre loading increased, the average fibre stress would decrease. By assuming no contact between different types of fibres it was possible to use a modified HROM strength equation to predict the tensile strength of the hybrid composites. As a result parameters taken from the respective single fibre systems could be applied directly to the HROM equation. The modified ROM and HROM strength equations adequately predicted the tensile strength of various single and hybrid fibre reinforced composites over a wide range of composite loading. In this study experiments were conducted to shed light on the effect of a coupling agent (maleic anhydride) on the tensile strength and stiffness of various NFRT. Coupling agents, which alter the interfacial shear strength between the fibre and matrix, were determined to have a minimal effect on composite stiffness but produced increases in composite strength.

Facca, Angelo George

76

[Determination of the tensile strength of superficial passive implant materials].  

PubMed

The crack strength of passivating surface materials or passive layers on electroconductive substrates is determined by the electronic detection of redox reactions at the electrolyte/sample interface. A sudden increase in corrosion current under mechanical tensile loading or bending moments indicates generation or propagation of macro- and micro-cracks in the passivating layer, and exposure of the substrate. A subsequent decrease in the current indicates repassivation. Titanium oxide passivating layers generated by oxygen diffusion hardening (ODH) on titanium show crack formation at a tensile load on the substrate of more than 230 MPa. Repassivating sandwich layers of tantalum and tantalum oxide on steel substrates (AISI 31 6L) generate micro-cracks at more than 300 MPa. The crack formation of the oxide surface materials correlates with the onset of plastic deformation of the substrate. PMID:12585048

Macionczyk, F; Thull, R

2002-12-01

77

Effects of conventional welding and laser welding on the tensile strength, ultimate tensile strength and surface characteristics of two cobalt-chromium alloys: a comparative study.  

PubMed

The purpose of this study was to evaluate the efficacy of laser welding and conventional welding on the tensile strength and ultimate tensile strength of the cobalt-chromium alloy. Samples were prepared with two commercially available cobalt-chromium alloys (Wironium plus and Diadur alloy). The samples were sectioned and the broken fragments were joined using Conventional and Laser welding techniques. The welded joints were subjected to tensile and ultimate tensile strength testing; and scanning electron microscope to evaluate the surface characteristics at the welded site. Both on laser welding as well as on conventional welding technique, Diadur alloy samples showed lesser values when tested for tensile and ultimate tensile strength when compared to Wironium alloy samples. Under the scanning electron microscope, the laser welded joints show uniform welding and continuous molt pool all over the surface with less porosity than the conventionally welded joints. Laser welding is an advantageous method of connecting or repairing cast metal prosthetic frameworks. PMID:23858281

Madhan Kumar, Seenivasan; Sethumadhava, Jayesh Raghavendra; Anand Kumar, Vaidyanathan; Manita, Grover

2012-04-18

78

Relationship between fractional porosity and tensile strength for high-porosity sintered ferrous powder compacts  

SciTech Connect

The current study examines the mechanical properties of pressed and sintered ferrous powder metallurgy compacts with low relative densities, between 0.6 and 0.8. Three different powder particle compositions were investigated: eutectoid steel, stainless steel, and stainless tool steel compacts. To obtain information concerning the tensile properties of these low-density compacts, simple tensile tests were performed. In addition, Vickers microhardness tests were performed on metallographic sections of the tensile bars. The results from these tests are used to compare the measured relative strength values with estimates generated by previously published models. Also, the fracture surfaces of selected compacts were examined in the scanning electron microscope to obtain information concerning the fracture process.

Baron, R.P.; Wawner, F.E.; Wert, J.A. [Univ. of Virginia, Charlottesville, VA (United States). Dept. of Materials Science and Engineering

1998-07-03

79

Tensile strength comparison of presoldered and postsoldered joints.  

PubMed

Twenty half-dumbbell shaped rods were cast in a silverless gold-palladium alloy that contained a minimum of 42% fresh alloy and the rest once-melted alloy. Each pair of half-dumbbells was assembled and either presoldered or postsoldered using a vacuum-oven and a torch-soldering technique. There was no significant difference in the ultimate tensile strength values between the presoldered and postsoldered joints within the same technique group, but the torch-soldered joints for the same solder were significantly stronger (p less than .01). It was believed that slow heating and cooling has deleterious effects on the ultimate tensile strength joints (UTS) possibly because of the microstructural changes and the highly oxidizable content of the postsolder used. Another 15 samples cast using once, twice, and three-times remelted parent alloy were presoldered and postsoldered with the torch only. In each of these groups, specimens joined by presolder showed significantly higher strength than those joined by postsolder (p less than .02). Remelting the parent alloy affected the strength differences between the presoldered and postsoldered joints. It was assumed that on remelting, the nature of the parent alloy is changed because some original elements are volatilized and newly formed oxides dissolved into it. Because it contains copper, the postsolder is more affected by this contamination than presolder. The UTS of the parent alloy, as well as that of the presolder and postsolder, were also determined. As expected, the parent alloy possessed the highest strength and the postsolder, the lowest. PMID:2868122

Monday, J J; Asgar, K

1986-01-01

80

Tensile properties of Inconel 718 after low temperature neutron irradiation  

Microsoft Academic Search

Tensile properties of Inconel 718 (IN718) have been investigated after neutron irradiation to 0.0006–1.2 dpa at 60–100 °C in the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory (ORNL). The alloy was exposed in solution-annealed (SA) and precipitation-hardened (PH) conditions. Before irradiation, the yield strength of PH IN718 was about 1170 MPa, which was 3.7 times higher than

T. S. Byun; K. Farrell

2003-01-01

81

Tensile properties and strengthening mechanisms of Mo–Si alloy  

Microsoft Academic Search

Pure Mo and Mo–Si alloys with different silicon content were fabricated by powder-metallurgical and thermo-mechanical processing. Tensile properties of the pure Mo and Mo–Si alloys were measured at room temperature and the fracture surface was analyzed after test. The results indicate that Si can effectively reduced the grain size and improve the yield strength of Mo–Si alloys. With the decrease

Zhang Guo-jun; Lin Xiao-hui; Wang Rui-hong; Liu Gang; Sun Jun

2011-01-01

82

Hemp yarn reinforced composites – II. Tensile properties  

Microsoft Academic Search

Whereas the first paper is addressing the characteristics of textile hemp yarn, this second paper is addressing the tensile properties of aligned hemp yarn composites under influence of a number of experimental variables: hemp yarn type, fibre volume fraction, thermoplastic matrix type, process temperature, conditioning humidity, and loading direction relative to the fibre direction. Altogether, the results show that aligned

Bo Madsen; Preben Hoffmeyer; Hans Lilholt

2007-01-01

83

Some investigations about the tensile strength and the desiccation process of unsaturated clay  

NASA Astrophysics Data System (ADS)

The current paper presents an investigation on the tensile strength of unsaturated clay, and a discussion about the significant differences between the behaviours of compacted soils and those of the completely remoulded soils. The adapted experimental device based on the shear box for the measurement of the tensile strength is also presented. In the tensile tests, stress-strain characteristics are measured using high precision transducers and electronic data acquisition. The equipment is capable of measuring tensile strengths of soil (about 10 MPa). Moreover, a new model to predict cracks is presented in 3D. This analytical model for the prediction of tensile strength, as a function of suction and porosity, is given.

Trabelsi, H.; Jamei, M.; Guiras, H.; Hatem, Z.; Romero, E.; Sebastia, O.

2010-06-01

84

Tensile properties of amorphous diamond films  

SciTech Connect

The strength and modulus of amorphous diamond, a new material for surface micromachined MEMS and sensors, was tested in uniaxial tension by pulling laterally with a flat tipped diamond in a nanoindenter. Several sample designs were attempted. Of those, only the single layer specimen with a 1 by 2 {micro}m gage cross section and a fixed end rigidly attached to the substrate was successful. Tensile load was calculated by resolving the measured lateral and normal forces into the applied tensile force and frictional losses. Displacement was corrected for machine compliance using the differential stiffness method. Post-mortem examination of the samples was performed to document the failure mode. The load-displacement data from those samples that failed in the gage section was converted to stress-strain curves using carefully measured gage cross section dimensions. Mean fracture strength was found to be 8.5 {+-} 1.4 GPa and the modulus was 831 {+-} 94 GPa. Tensile results are compared to hardness and modulus measurements made using a nanoindenter.

Lavan, D.A.; Hohlfelder, R.J.; Sullivan, J.P.; Friedmann, T.A.; Mitchell, M.A.; Ashby, C.I.

1999-12-02

85

Microstructure and tensile properties of thixoformed A356 alloy  

SciTech Connect

In the research work presented here, mechanical properties of a thixoformed A356 alloy were measured and compared with the mechanical properties of rheocast and gravity-cast alloy with the same composition. In the thixoforming process, a 60% solid fraction rheocast alloy was reheated to 600 deg. C or 610 deg. C, held about 10 min, and then reduced by 30% or 50% reduction of cross section. Microstructural and mechanical properties of the alloys were investigated. The results obtained show that the tensile strength, yield strength and elongation-to-failure of the alloy thixoformed at 600 deg. C was greater than that thixoformed at 610 deg. C. Moreover, the tensile strength, yield strength and elongation-to-failure of the thixoformed alloy were higher than those of the rheocast and gravity-cast samples. The improvement in the mechanical properties due to thixoforming is attributed to morphological aspects of the silicon phase, as well as to the non-dendritic structure produced.

Tahamtan, S. [Isfahan University of Technology (Iran, Islamic Republic of); Golozar, M.A. [Isfahan University of Technology (Iran, Islamic Republic of)], E-mail: golozar@cc.iut.ac.ir; Karimzadeh, F.; Niroumand, B. [Isfahan University of Technology (Iran, Islamic Republic of)

2008-03-15

86

Predicting the tensile modulus and strength of single and hybrid natural fibre reinforced thermoplastic composites  

Microsoft Academic Search

Natural fibre reinforced thermoplastics (NFRT) are used in a variety of commercial applications, but there is little theoretical modeling of structure\\/property relationships in these materials. In this thesis, micromechanical models available in the short-fibre literature were adapted to predict the tensile modulus and strength of some NFRT formulations. Hemp, 20 and 40-mesh hardwood, rice hulls and E-glass fibres were blended

Angelo George Facca

2007-01-01

87

Effect of fiber reinforcement on the tensile, fracture and thermal properties of syntactic foam  

Microsoft Academic Search

This paper examines the effect of the fiber content and fiber length on tensile, fracture and thermal properties of syntactic foam. Results showed that a hybrid structure demonstrates a significant increase in the ultimate tensile strength, ?uts, and Young's modulus, E, with increasing fiber loading. Interestingly, the fracture toughness, KIc, and energy release rate, GIc, increased by 95% and 90%,

Erwin M. Wouterson; Freddy Y. C. Boey; Xiao Hu; Shing-Chung Wong

2007-01-01

88

Casting behavior and tensile strength of cast BaTiO sub 3 tape  

SciTech Connect

The casting behavior and properties of thin, unsintered BaTiO{sub 3} tapes were studied by measuring viscosity of the slip, green density, ultimate tensile stress, and strain to failure. It was found that increasing the binder to plasticizer ratio increased slip viscosity and strength as expected but also increased strain to failure, and that increasing the poly(ethylene glycol) to benzyl butyl phthalate ratio improved tape release and tape strength, but a small amount of benzyl butyl phthalate improved strain to failure. In addition, increasing the powder to organics ratio increased slip viscosity and green density but strength passed through a maximum and strain to failure decreased. Both slip viscosity and green density were optimized at a particular dispersant concentration but strength decreased monotonically with increased dispersant addition. Finally, an optimum cyclohexanone addition led to a maximum density and strength.

Karas, A.; Kumagai, Toshiya; Cannon, W.R. (Rutgers, The State Univ. of New Jersey, Piscataway (USA))

1988-07-01

89

Predicting yield strength and tensile strength after forming for automotive integral body structural rail type parts  

SciTech Connect

Samples of cold rolled and hot dip galvanized mild steel, microalloyed high strength steel, and dual phase steel were prestrained by bending and straightening, bending and straightening with superimposed tensile strain in a die, and cold rolling (dual phase steels only). In all three cases, the strain state was approximately plane strain. Stress-strain behavior was evaluated by conventional tensile testing of as-received and prestrained samples. For the mild and the high strength microalloyed steels, it is shown that the use of effective prestrain calculated assuming isotropy coupled with simple parabolic work hardening provides reasonable engineering estimates of the yield and tensile strength after prestraining if K and n are taken from as-received tensile tests oriented coaxially to the restrain direction. It was also found that in bending and straightening, only the absolute average value of the bending strain should be used in calculating the effective prestrain. For steels with dual phase microstructures, this approach to predicting cold work strengthening does not provide useful engineering estimates.

Levy, B.S.

1984-01-01

90

Size and temperature dependence of the tensile mechanical properties of zinc blende CdSe nanowires  

NASA Astrophysics Data System (ADS)

The effect of size and temperature on the tensile mechanical properties of zinc blende CdSe nanowires is investigated by all atoms molecular dynamic simulation. We found the ultimate tensile strength and Young's modulus will decrease as the temperature and size of the nanowire increase. The size and temperature dependence are mainly attributed to surface effect and thermally elongation effect. High reversibility of tensile behavior will make zinc blende CdSe nanowires suitable for building efficient nanodevices.

Fu, Bing; Chen, Na; Xie, Yiqun; Ye, Xiang; Gu, Xiao

2013-11-01

91

Tensile Properties of Electrodeposited Nanocrystalline FCC Metals  

Microsoft Academic Search

Bulk nanocrystalline Ni and Ni-15wt%Fe alloy were fabricated via electrodeposition techniques. The nominal grain size of nickel samples was varied from 15 to 200 nm by employing different deposition parameters. The grain size was further reduced to 9 nm by alloying nickel with iron. The tensile properties were evaluated at room temperature using dog-bone shaped samples. The results of this study confirm

F. Ebrahimi; Z. Ahmed; H. Q. Li

2006-01-01

92

High-Temperature Tensile Properties of a Molybdenum5%Rhenium0.5%Hafnium Carbide Alloy  

Microsoft Academic Search

Tensile properties of a molybdenum-5 at % rhenium-0.5 at % hafnium carbide alloy were evaluated with a strain rate of 10?3\\/sec over a temperature region of 1200 to 2400 K in vacuum. The yield strength, tensile strength, solution induced and dispersion induced strength increments, strain-hardening exponent, and tensile elongation of this alloy were determined. The effects of rhenium, hafnium carbide

Anhua Luo; John J. Park; Dean L. Jacobson; Bang H. Tsao; Mysore L. Ramalingam

1994-01-01

93

Evaluation of tensile strength of surgical synthetic absorbable suture materials: an in vitro study  

PubMed Central

Purpose The purpose of this study was to evaluate the tensile strength of surgical synthetic absorbable sutures over a period of 14 days under simulated oral conditions. Methods Three suture materials (polyglycolic acid [PGA], polyglactin [PG] 910, and poly (glycolide-co-?-caprolactone) [PGC]) were used in 4-0 and 5-0 gauges. 210 suture samples (35 of each material and gauge) were used. All of the samples were tested preimmersion and 1 hour and 1, 3, 7, 10, and 14 days postimmersion. The tensile strength of each suture material and gauge was assessed. The point of breakage and the resorption pattern of the sutures were also assessed. Results During the first 24 hours of immersion, all 4-0 and 5-0 samples of PGA, PG 910, and PGC maintained their initial tensile strength. At baseline (preimmersion), there was a statistically significant (P<0.001) difference in the tensile strengths between the 4-0 and 5-0 gauge of PGA, PG 910, and PGC. PGA 4-0 showed the highest tensile strength until day 10. At 7 days, all the 4-0 sutures of the three materials had maintained their tensile strength with PGA 4-0 having significantly greater (P=0.003) tensile strength compared to PG. Conclusions 4-0 sutures are stronger and have greater tensile strength than 5-0 sutures. The PGA 4-0 suture showed the highest tensile strength at the end of day 10.

Ranganath, V.; Nichani, Ashish Sham

2013-01-01

94

Cryogenic Tensile Properties of AA 2090 Weldments.  

National Technical Information Service (NTIS)

The influence of base metal temper and filter metal additions on the cryogenic properties Al-Li 2090 weldments are studied. The results show that as the strength of the base metal increases, strength mismatch increases and the joint efficiency decreases. ...

A. J. Sunwoo J. W. Morris

1989-01-01

95

ZERODUR: bending strength data for tensile stress loaded support structures  

NASA Astrophysics Data System (ADS)

In the past ZERODUR® was mainly used for mirror and substrate applications, where mechanical loads were given by its own weight. Nowadays substrates become more sophisticated and subject to higher stresses as consequences of high operational accelerations or vibrations. The integrity of structures such as reticle and wafer stages e.g. must be guaranteed with low failure probability over their full intended life time. Their design requires statistically relevant strength data and information. The usual way determining the design strength employs statistical Weibull distributions obtained from a set of experimental data extrapolating the results to low acceptable failure probability values. However, in many cases this led to allowable stress values too low for the intended application. Moreover, the experimental basis has been found to be too small for reliable calculations. For these reasons measurement series on the strength of ZERODUR® have been performed with different surface conditions employing a standardized ring-on-ring test setup. The numbers of specimens per sample have been extended from about 20 to 100 or even much more. The results for surfaces ground with different diamond grain sizes D151, D64 and D25 as well as for etched surfaces are presented in this paper. Glass ceramics like all glassy materials exhibit some strength reduction when being exposed to loads above a tensile stress threshold over long time periods. The strength change of ZERODUR® with time will be discussed on the basis of known and newly determined stress corrosion data. The results for samples with large numbers of specimens contribute new aspects to the common practice of extrapolation to low failure probability, since they provide evidence for the existence of minimum strength values depending on the structures surface conditions. For ground surfaces the evidence for minimum strength values is quite obvious. For etched surfaces minimum values are to be expected also. However, here closer observation is still needed. The systematic deviations from Weibull distributions lie below about 5 % failure probability and thus could not be seen in small samples as they were common in the past.

Bizjak, Tanja; Hartmann, Peter; Westerhoff, Thomas

2012-03-01

96

High tensile strength cold rolled steel sheets and high tensile strength hot-dip galvanized steel sheets  

SciTech Connect

The present invention provides high tensile strength cold rolled steel sheets having excellent formability, which consist of 0.002-0.015% of C, not more than 1.2% of Si, 0.04-0.8% of Mn, 0.03-10% of P, 0.02-0.10% and not less than N%X4 of A1, C%X3-(C%X8+0.020%) of Nb and the remainder being substantially Fe, as the high tensile strength steel sheets which reduce the weight of automobiles and the like. The steel sheet is produced by hot rolling a steel slab having the above described composition to obtain a hot rolled coil, in the hot rolling the total reduction rate being at least 90%, the rolling speed in the finishing rolling being at least 40 m/min and the coiling-up temperature being at least 600/sup 0/ C.; cold rolling the above described hot rolled coil in a conventional process to obtain a cold rolled steel strip having a final gauge; subjecting the above described cold rolled steel strip to a continuous annealing at a temperature of 700/sup 0/-900/sup 0/ C. for 10 sec-5 min and then cooling the annealed strip to 500/sup 0/ C. at a rate of at least 60/sup 0/ C./min. The steel sheets having the above described composition, except that Si is not more than 0.5%, are suitable for the continuous hot-dip galvanizing.

Irie, T.; Hashimoto, O.; Sato, S.

1984-09-25

97

Relation between tensile properties and microstructure in type 316 stainless steel SA weld metal  

Microsoft Academic Search

Tensile properties of a thick, multipass, submerged-arc (SA) weld-deposited type 316 are investigated by tests at room temperature and at 400 ° C and by microstructural and compositional analyses. The as-deposited metal, which shows a lower yield strength, a comparable ultimate tensile strength and a lower total elongation compared to the (solution-annealed) parent metal, is characterized by systematic variations in

G. Piatti; M. Vedani

1990-01-01

98

Tensile testing of insulating thin films; humidity effect on tensile strength of SiO 2 films  

Microsoft Academic Search

Humidity effect on the strength of a plasma-enhanced chemical vapor deposition (CVD) SiO2 film is evaluated with new tensile testing method using an electrostatic force grip. This method can test insulating films without troublesome specimen preparation and careful handling. To measure the humidity effect, two thin film tensile testers are used. One can perform test in air, and the other

Toshiyuki Tsuchiya; Atsuko Inoue; Jiro Sakata

2000-01-01

99

Gigacycle fatigue behaviors of two SNCM439 steels with different tensile strengths  

NASA Astrophysics Data System (ADS)

Gigacycle fatigue behaviors of two SNCM439 steels with different tensile strengthes were experimentally studied by rotating bending tests, to investigate the effects of the tensile strength obtained by different heat treatment processes on very high cycle fatigue failure mechanisms. The material with higher tensile strength of 1 710MPa exhibited typical gigacycle fatigue failure characteristics, whereas one with lower tensile strength of 1 010MPa showed only traditional fatigue limit during the tests and no gigacycle failure could be found even when the specimen ran up to more than 108 cycles. Metallographic and fractographic analysis were carried out by an optical microscope (OM) and scanning electron microscope (SEM). It showed two different crack initiation mechanisms that for the specimen with lower tensile strength the crack prefers surface initiation and for that with higher strength the crack initiates from subsurface inclusions revealed by a fish-eye like microstructure.

Duan, Zheng; Ma, Xian-Feng; Shi, Hui-Ji; Murai, Ryosuke; Yanagisawa, Eiichi

2011-10-01

100

Tensile strength of fiber reinforced plastics at 77K irradiated by various radiation sources  

SciTech Connect

The influence of radiation damage on the mechanical properties of fiber reinforced plastics (FRPs), which are considered as candidate materials for the insulation of superconducting magnets for nuclear fusion reactors, has been investigated. Different types of FRPs (epoxies, bismaleimides; two- and three-dimensional reinforcement structures with E-, S-, or T-glass fibers) has been included in the test program. Three aspects of our present results will be discussed in detail. The first is related to an assessment of the tensile strength and its radiation dependence under the influence of strongly varying radiation conditions. The second aspect refers to low temperature ({approx}5 K) reactor irradiation of selected materials. In this case, identical sets of tensile test samples were transferred into the tensile testing machine, one without warming-up to room temperature and the other after an annealing cycle to room temperature. Finally, a comparison between the radiation response of different materials is made. It turns out that the three-dimensionally reinforced bismaleimide shows the smallest degradation of its tensile properties under all irradiation conditions.

Humer, K.; Weber, H.W. [Atominstitut der Oesterreichischen Universitaeten, Vienna (Austria); Tschegg, E.K. [Technische Univ., Vienna (Austria). Inst. fuer Angewandte und Technische Physik; Egusa, S. [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Birtcher, R.C. [Argonne National Lab., IL (United States); Gerstenberg, H. [Technische Univ. Muenchen, Garching (Germany). Physikdepartment

1993-08-01

101

Thermal Degradation of the Tensile Strength of Unidirectional Boron/Aluminum Composites.  

National Technical Information Service (NTIS)

The variation of ultimate tensile strength with thermal treatment of B-Al composite materials and of boron fibers chemically removed from these composites in an attempt to determine the mechanism of the resulting strength degradation was studied. Findings...

H. H. Grimes R. A. Lad J. E. Maisel

1977-01-01

102

Effects of neutron irradiation on tensile properties of oxide dispersion strengthened (ODS) steel claddings  

NASA Astrophysics Data System (ADS)

The effects of fast neutron irradiation on ring tensile properties of oxide dispersion strengthened (ODS) steel claddings for fast reactor were investigated. Specimens were irradiated in the experimental fast reactor Joyo using the material irradiation rig at temperatures between 693 and 1108 K to fast neutron doses ranging from 16 to 33 dpa. The post-irradiation ring tensile tests were carried out at irradiation temperatures. The experimental results showed that there was no significant change in tensile strengths after neutron irradiation below 923 K, but the tensile strengths at neutron irradiation above 1023 K up to 33 dpa were decreased by about 20%. On the other hand, uniform elongation after irradiation was more than 2% at all irradiation conditions. The ring tensile properties of these ODS claddings remained excellent within these irradiation conditions compared with conventional 11Cr ferritic/martensitic steel (PNC-FMS) claddings.

Yano, Y.; Ogawa, R.; Yamashita, S.; Ohtsuka, S.; Kaito, T.; Akasaka, N.; Inoue, M.; Yoshitake, T.; Tanaka, K.

2011-12-01

103

Tensile and torsional shear strength of the bone implant interface of titanium implants in the rabbit  

Microsoft Academic Search

The effect of three different titanium plasma flame spray coatings on the tensile strength and the effect of macrostructures on the torsional shear strength of the bone implant interface was studied. Titanium cylinders, of 8 mm length and 4 mm diameter, were implanted into distal rabbit femurs. For tensile testing, two porous titanium plasma flame spray coatings, Plasmapore®, fine-grain Plasmapore®,

L. Pröbster; CH Voigt; G. Fuhrmann; U. M. Gross

1994-01-01

104

Modeling and optimization of tensile shear strength of Titanium\\/Aluminum dissimilar welded component  

Microsoft Academic Search

Titanium was successfully welded to Aluminum using laser welding. Laser welding parameters ranges combinations were experimentally determined using Taguchi approach with the objective of producing welded joint with acceptable welding profile and maximizing the tensile shear strength. Tensile shear strength of dissimilar Al\\/Ti was evaluated as a response function of the selected laser welding parameters and statistical model was developed

E. M. Anawa; A. G. Olabi; F. A. Elshukri

2009-01-01

105

Strain hardening and large tensile elongation in ultrahigh-strength nano-twinned copper  

Microsoft Academic Search

A high density of growth twins in pure Cu imparts high yield strength while preserving the capacity for efficient dislocation storage, leading to high strain hardening rates at high flow stresses, especially at 77 K. Uniform tensile deformation is stabilized to large plastic strains, resulting in an ultrahigh tensile strength of ~1 GPa together with an elongation to failure of

E. Ma; Y. M. Wang; Q. H. Lu; M. L. Sui; L. Lu; K. Lu

2004-01-01

106

FE analysis strategies for structural materials with small tensile strength  

SciTech Connect

A review of the smeared crack approach to the finite element analysis of small tensile strength (STS) materials is presented. The most widely applied strategies for crack modeling, shear transfer mechanism, and the definition of the mechanical constitutive laws and failure critically discussed. The models and special options in the ANSYS, ADINA, and ABAQUS programs are considered in detail, and applied to the analysis of a square panel under boundary pressures. The three solutions were compared in terms of the final broadening of the panel cracked zones. The results of the analysis of an hemispherical dome over a cylindrical drum are also presented. The Romulus Temple in the Roman Forum was the reference structure for this FE model. The problem was analyzed by a special procedure using the ANSYS concrete element. The results were compared with those of a discrete crack solution which reproduced the real cracked configuration of the building, and then with an experimental survey carried out by the flat jack technique.

Borri, A. (Univ. of Florence (Italy)); Sorace, S. (Univ. of Perugia (Italy))

1993-05-01

107

Effect of Processing Time on the Tensile, Morphological, and Thermal Properties of Rice Husk Powder?Filled Polypropylene Composites  

Microsoft Academic Search

Brabender plasticorder internal mixer was used to incorporate rice husk powder into polypropylene. Rice husk powder (RHP)?filled polypropylene (PP) composite was prepared by varying mixing time under constant rotor speed (50 rpm) at two mixing temperatures. Brabender mixing torque, tensile properties, morphology, and thermal properties were investigated in detail. Results indicate that the tensile properties, such as Young's modulus, yield strength,

Hattotuwa G. B. Premalal; H. Ismail; A. Baharin

2003-01-01

108

The effect of bead attachment systems on casting patterns and resultant tensile bond strength of composite resin veneer cast restorations.  

PubMed

This study compared the difference in tensile bond strength between the composite resin veneer and the cast Ni-Cr disk when different bead adhesives were used to make the laboratory patterns. Visio-Gem, cyanoacrylate, and shellac were the adhesives tested. Fifty-six composite resin bonded Ni-Cr disks were prepared and tested to tensile failure with the Kemper-Kilian device. All tested samples showed a complex failure pattern. The results showed that the mean tensile bond strength of the cyanoacrylate group was significantly higher than the other two groups. No significant difference in the mean tensile bond strength was observed between the Visio-Gem and shellac groups. The higher tensile bond strength in the cyanoacrylate group is thought to be attributed to the low rheological property of the adhesive that allowed greater exposure of the bead for retention. Using different adhesives in the fabrication of composite resin veneered-castings may affect the bond strength in the composite resin-metal interface. PMID:1805000

Lee, C F; Pierpont, H P; Strickler, E R

1991-11-01

109

Determination of tensile properties of lead-free solder joints using nanoindentation  

Microsoft Academic Search

In this work, determination of tensile properties using depth-sensing technique has been demonstrated. An empirical model has been used to extract tensile properties of bulk pure Sn and lead free solder joints using nanoindentation technique. New scheme is proposed based on the non-linear curve fitting analysis of indentation load-displacement data. Elastic modulus, yield strength, perfect plastic hardness and strain hardening

B. S. S. Chandra Rao; K. Y. Zeng; V. Kripesh

2010-01-01

110

Effect of polymerization under pressure on indirect tensile mechanical properties of light-polymerized composites  

Microsoft Academic Search

Statement of Problem. Flaws developed during polymerization of restorative materials cause a decrease in mechanical properties. Purpose. The aim of this study was to determine the effect of polymerization under pressure on the indirect tensile mechanical properties (stiffness and diametral tensile strength) of several light-polymerized composites. Material and Methods. Five light-polymerized composites were tested: Brilliant, Z100, TPH Spectrum, Prodigy, and

Tamar Brosh; Nechama Ferstand; Harold Cardash; Haim Baharav

2002-01-01

111

Low dose irradiation effects on heat-to-heat variation of type 304 stainless steel creep and tensile properties  

Microsoft Academic Search

This paper reports the determination of the low dose irradiation effects on the resulting heat-to-heat variation of DIN 1.4948 stainless steel (similar to AISI Type 304) creep and tensile properties. The variation in ultimate tensile strength of six heats of plate and forgings is unaffected by irradiation. Both tensile and creep strength are reduced by irradiation due to a decrease

van der Schaaf

1982-01-01

112

TENSILE PROPERTIES OF BINARY TITANIUM-ZIRCONIUM AND TITANIUM-HAFNIUM ALLOYS  

Microsoft Academic Search

The effects on the tensile properties of alloy content and heat ; treatment for the Ti-- Zr and Ti-Hf systems were found to be approximately the ; same. Strength increased and ductility decreased with additions of up to 40 wt% ; Zr and Hf. The beta-quenched structures showed considerably higher strengths ; than the beta-furnace-cooled structures; this was attributed to

A. G. Imgram; D. N. Williams; H. R. Ogden

1962-01-01

113

Tensile Properties of Irradiated and Unirradiated Welds of A533 Steel Plate and A508 Forgings.  

National Technical Information Service (NTIS)

The tensile properties of welds of base metals ASTM A533, Grade B, Class 1 steel plate and ASTM A508, Class 1 forgings were evaluated in irradiated (3 to 21 x 10 to the 18th power n/sq cm) and unirradiated conditions. Yield strength and ultimate strength ...

J. A. Williams

1980-01-01

114

The effect of cylindrical defects on the tensile strength of glass fiber\\/vinyl-ester matrix reinforced composite pipes  

Microsoft Academic Search

The influence of cylindrical defects on the tensile strength of glass fiber\\/vinyl-ester composite pipes was evaluated. The properties were determined using the ring test. The radius and depth of the defects were varied, and the significance of their effect on the results obtained was verified using the analysis of variance between groups (ANOVA). The analysis showed that the depth of

E. N. Buarque; J. R. M. d’Almeida

2007-01-01

115

Ultimate Strength and Failure Mechanism of Resistance Spot Weld Subjected to Tensile, Shear, or Combined Tensile\\/Shear Loads  

Microsoft Academic Search

Strength tests were performed to reveal the failure mechanisms of spot weld in lap-shear and cross tension test samples. It is shown the while the lap-shear (cross tension) sample is subjected to shear (normal) load at the structural level the failure mechanism at the spot weld is tensile (shear) mode at the materials level. Based on the observed failure mechanism,

Yuh J. Chao

2003-01-01

116

Tensile strength of titanium matrix composites: direct numerical simulations and analytic models  

Microsoft Academic Search

A recently-developed model for the numerical simulation of tensile stress-strain behavior in fiber-reinforced composites is used to predict the tensile strength of a metal matrix composite consisting of a Ti-1100 matrix reinforced with SCS-6 SiC fibers. Data on the as-processed fiber strengths, interfacial strength, composite size, and fiber volume fraction from Gundel and Wawner are used as input. The predicted

G. C. Foster; M. Ibnabdeljalil; W. A. Curtin

1998-01-01

117

Improved Tensile Strength for Cement-Treated Bases and Subbases.  

National Technical Information Service (NTIS)

The report summarizes the findings of an evaluation and interpretation of the results from previous studies concerning the tensile and shrinkage characteristics of cement-treated materials. Findings of studies performed at the Center for Highway Research ...

R. F. Cauley T. W. Kennedy

1972-01-01

118

Unbinding force of chemical bonds and tensile strength in strong crystals  

NASA Astrophysics Data System (ADS)

A model of covalent and ionic bond strength is proposed in terms of the tensile unbinding force by introducing the concept of the effectively bonded valence electron (EBVE) number of a chemical bond. Bond strength proves to be exclusively dependent on two microscopic parameters: bond length and EBVE number. This model allows us to determine bond strength for a variety of crystals and accounts for the observation that a low-coordination number of binding atoms has a tendency to higher bond strength. For crystals of simple structures, we propose linking bond strength to the theoretical tensile strength of a crystal; the latter reproduces the results of first-principles calculations. The model also allows for the assessment of the theoretical tensile strength of graphene and single-walled nanotubes constructed with typical material systems.

Guo, Xiaoju; Wang, Li-Min; Xu, Bo; Liu, Zhongyuan; Yu, Dongli; He, Julong; Wang, Hui-Tian; Tian, Yongjun

2009-12-01

119

Characterization of carbon nanotube fiber compressive properties using tensile recoil measurement.  

PubMed

The tensile properties of carbon nanotube (CNT) fibers have been widely studied. However, the knowledge of their compressive properties is still lacking. In this work, the compressive properties of both pure CNT fibers and epoxy infiltrated CNT fibers were studied using the tensile recoil measurement. The compressive strengths were obtained as 416 and 573 MPa for pure CNT fibers and CNT-epoxy composite fibers, respectively. In addition, microscopic analysis of the fiber surface morphologies revealed that the principal recoil compressive failure mode of pure CNT fiber was kinking, while the CNT-epoxy composite fibers exhibited a failure mode in bending with combined tensile and compressive failure morphologies. The effect of resin infiltration on CNT fiber compressive properties, including the compressive strength and the deformation mode, is discussed. This work expands the knowledge base of the overall mechanical properties of CNT fibers, which are essential for their application in multifunctional composites. PMID:22494330

Zu, Mei; Lu, Weibang; Li, Qing-Wen; Zhu, Yuntian; Wang, Guojian; Chou, Tsu-Wei

2012-04-18

120

Tensile strength of thermomechanically processed Cu-9Ni-6Sn alloys  

SciTech Connect

The tensile properties of Cu-9Ni-6Sn alloys with different swaging amounts of 64, 77, and 95 pct, either solutionized and aged (S/A), were examined as a function of aging time. It was found that the aging response of Cu-9Ni-6Sn alloys varied greatly depending on the prior solution heat treatment before aging and/or different swaging amounts. The swaged S/A Cu-9Ni-6Sn alloys showed a multistage increase in tensile strength with respect to aging time, probably due to the sequential occurrence of spinodal decomposition, formation of metastable {gamma}{center{underscore}dot} precipitates, and recrystallization. The effect of different swaging amounts, ranging from 64 to 95 pct, was minimal on the aging response of S/A specimens. The prior cold working, however, appeared to favor the spinodal strengthening, comparing unswaged and swaged S/A Cu-9Ni-6Sn alloys. In 95 pct swaged D/A Cu-9Ni-6Sn alloys, the level of hardening was much less sensitive to aging time. A complex interaction between the reduction in dislocation density, the formation of equilibrium precipitates, and the reduction of Sn content in the Sn-rich segregates during an aging process is believed to be responsible for such a lean sensitivity. The increases in tensile strength of 64 and 77 pct swaged D/A Cu-9Ni-6Sn alloys were found to be much steeper than that in the 95 pct counterparts in the early and intermediate stages of aging, which is believed to be related to the relative contribution from work hardening and precipitation hardening to the strength level of D/A specimens.

Rhu, J.C.; Kim, S.S.; Jung, Y.C.; Han, S.Z.; Kim, C.J.

1999-10-01

121

A novel methodology for measuring the tensile strength of expansive clays  

Microsoft Academic Search

Several experimental techniques (viz., triaxial tests, direct tensile tests or suction measurements) have been developed and employed by earlier researchers to measure the tensile strength of fine-grained soils. However, these studies yield results that are soil specific and dependent on the methodology adopted. Apart from this, due to the bulk form of the sample, the sample heterogeneity (i.e., both in

Sudarshan B. Shinde; Venkata Uday Kala; Srinivas Kadali; Mahesh S. Tirumkudulu; D. N. Singh

2012-01-01

122

A novel methodology for measuring the tensile strength of expansive clays  

Microsoft Academic Search

Several experimental techniques (viz., triaxial tests, direct tensile tests or suction measurements) have been developed and employed by earlier researchers to measure the tensile strength of fine-grained soils. However, these studies yield results that are soil specific and dependent on the methodology adopted. Apart from this, due to the bulk form of the sample, the sample heterogeneity (i.e., both in

Sudarshan B. Shinde; Venkata Uday Kala; Srinivas Kadali; Mahesh S. Tirumkudulu; D. N. Singh

2011-01-01

123

Tensile strength and creep resistance in nanocrystalline Cu, Pd and Ag  

SciTech Connect

Measurements of tensile strength and creep resistance have been made on bulk samples of nanocrystalline Cu, Pd and Ag consolidated from powders by cold compaction. Samples of Cu-Cu{sub 2}O have also been tested. Yield strength for samples with mean grains sizes of 5-80 nm and bulk densities on the order of 95% of theoretical density are increased 2--5 times over that measured in pure, annealed samples of the same composition with micrometer grain sizes. Ductility in the nanocrystalline Cu has exceeded 6% true strain, however, nanocrystalline Pd samples were much less ductile. Constant load creep tests performed at room temperature at stresses of >100 MPa indicate logarithmic creep. The mechanical properties results are interpreted to be due to grain size-related strengthening and processing flaw-related weakening. 26 refs., 2 figs.

Nieman, G.W.; Weertman, J.R. (Northwestern Univ., Evanston, IL (USA). Dept. of Materials Science and Engineering); Siegel, R.W. (Argonne National Lab., IL (USA))

1990-12-01

124

Elevated-Temperature Tensile and Creep Properties of Several Ferritic Stainless Steels.  

National Technical Information Service (NTIS)

The elevated-temperature mechanical properties of several ferritic stainless steels were determined. The alloys evaluated included Armco 18SR, GE 1541, and NASA-18T-A. Tensile and creep strength properties at 1073 and 1273 K and residual room temperature ...

J. D. Whittenberger

1977-01-01

125

An Experimental Study of the Rate Dependence of Tensile Strength Softening of Longyou Sandstone  

Microsoft Academic Search

It is well-known that the strengths of sandstones measured under fully saturated conditions are smaller than those measured\\u000a under nominally dry conditions. This strength softening phenomenon has profound implications to rock engineering. In this\\u000a work we investigate the tensile strength softening of Longyou sandstone from China. Defining the strength softening factor\\u000a as the ratio of the strength under nominally dry

Sheng Huang; Kaiwen Xia; Fei Yan; Xiating Feng

2010-01-01

126

Fracture and tensile properties of irradiated zircaloy-2 pressure tubes  

Microsoft Academic Search

The mechanical properties of nuclear reactor components degrade as a result of long service exposure in high-temperature, irradiation, and corrosive environments. Fracture toughness and tensile testing are conducted on the pressure tubes of Zircaloy-2 to evaluate the effects of neutron fluence, hydrogen content, and temperature on the mechanical properties. Tensile tests are performed on the base metal, and fracture toughness

F. H. Huang; W. J. Mills

1993-01-01

127

Tensile properties of irradiated and unirradiated welds of A533 steel plate and A508 forgings  

Microsoft Academic Search

The tensile properties of welds of base metals ASTM A533, Grade B, Class 1 steel plate and ASTM A508, Class 1 forgings were evaluated in irradiated (3 to 21 x 10¹⁸ n\\/cm²) and unirradiated conditions. Yield strength and ultimate strength both increased with increasing fluence, while small ductility losses were generally independent of fluence. Yield strength was found to be

1980-01-01

128

Effect of circumferential sutures on tensile and gap strength of repaired canine flexor tendons  

Microsoft Academic Search

Sixty-four dog cadaver flexor digitorum profundus tendons in zone 2 were lacerated and repaired with a simple or a cross-stitch\\u000a peripheral circumferential suture in combination with two-, four-, or six-strand core sutures. The tensile and gap strengths\\u000a were compared. The range of tensile strengths with the cross-stitch circumferential suture in combination with various core\\u000a suture techniques (4.28–9.37 kgf) was significantly

Hideaki Kubota; Shunsuke Hotokezaka; Donald L. Pruitt; Paul R. Manske; Yoichi Sugioka

1997-01-01

129

Tensile strength of plasma-sprayed alumina and\\/or zirconia coatings on titanium  

Microsoft Academic Search

The heat treatment effect on the characteristics and tensile strength of plasma-sprayed alumina, yttria-stabilized zirconia\\u000a (YSZ), and mixtures of alumina and YSZ coatings on titanium was investigated. The as-sprayed structures of alumina and YSZ\\u000a coatings consists of a and y alumina phases, and cubic and tetragonal zirconia phases, respectively. The tensile strength\\u000a of the coatings containing a large amount of

K. Kishitake; H. Era; S. Baba

1995-01-01

130

A novel approach for predicting the tensile strength of brazed joints  

Microsoft Academic Search

A method for predicting the tensile strength of brazed joints is presented. A finite element method (FEM) of analysis is used,\\u000a taking into account the failure within the soft interlayer metal region of the joint. A modified failure criterion is derived\\u000a in consideration of void growth and incorporated into the FEM analysis. The predicted tensile strength is discussed and compared

Kunimasa Takeshita; Yuhji Terakura

1998-01-01

131

Prediction of Tensile Strength for Sandwich Injection Molded Short-Glass-Fiber Reinforced Thermoplastics  

Microsoft Academic Search

This present paper provides a modified rule-of-mixtures relationship which allows for the calculation of ultimate tensile strength (UTS) as a function of the area fraction between skin and core layers. The effects of fiber length and fiber orientation within the skin and core layers on the tensile strength of conventional and sandwich injection molded short-glass-fiber reinforced polypropylene have been studied

Somjate PATCHARAPHUN; Gunter MENNIG

2007-01-01

132

Effects of microstructure and environment on room-temperature tensile properties of B2-type polycrystalline CoTi intermetallic compound  

Microsoft Academic Search

Room-temperature tensile property and fracture mode of B2-type polycrystalline CoTi intermetallic compound was studied as functions of microstructure and environment. Using a hot-rolled CoTi sheet, various microstructures were prepared by different heat treatments and pre-straining. Tensile elongation as well as ultimate tensile strength (UTS) of specimens deformed in vacuum (i.e. intrinsic tensile elongation and strength) depended on microstructure. The hot-rolled

Yasuyuki Kaneno; Takayuki Takasugi

2003-01-01

133

Shear, torsional, and tensile bond strengths of ceramic brackets using three adhesive filler concentrations.  

PubMed

The effect of changes in adhesive filler concentration on the shear, torsional, and tensile bond strength of a chemical, a mechanical, and a chemical/mechanical retained ceramic bracket was evaluated. Two hundred ten bovine teeth were bonded with one of three ceramic brackets using a 30%, 55%, or 80% filled adhesive. The brackets were debonded with a shear, torsional, or tensile force to test the bond strength and the site of bond failure. No significant difference was found in the shear, torsional, or tensile bond strength of each ceramic bracket type in relation to changes in the adhesive filler concentration. However, there was a trend toward increased bond strength with increasing filler concentration. Combining the data according to adhesive type revealed that the 80% filled adhesive displayed a significantly greater shear bond strength than the 30% or 55% filled adhesive and a greater torsional bond strength than the 30% filled adhesive. This supports the hypothesis of increased bond strength with increased adhesive filler concentration. The mechanically retained ceramic bracket showed greater shear bond strength and maximum shear bond strength in torsion than the chemical or chemical/mechanical retained ceramic bracket. The tensile bond strength of the mechanically retained ceramic bracket was similar to that of metal brackets reported in other studies, and the failure site was at the bracket-adhesive interface. PMID:1877551

Ostertag, A J; Dhuru, V B; Ferguson, D J; Meyer, R A

1991-09-01

134

Effects of Nano-CaCO3 Content and Surface Treatment on Tensile Properties of PPS\\/GF Ternary Composites  

Microsoft Academic Search

Nanometer calcium carbonate (nano-CaCO3) filled polyphenylene sulfide (PPS\\/GF) ternary composites reinforced with glass fiber were fabricated in this paper, and the Young's modulus, tensile strength and tensile elongation at break were measured at room temperature, to identify the influence of the content and surface treatment of the nano-CaCO3 particles on the tensile mechanical properties of these ternary composites. It was

J. Z. Liang; G. S. Liu

2009-01-01

135

Modeling of statistical tensile strength tensile of short-fiber composites  

SciTech Connect

This Paper develops a statistical strength theory for three-dimensionally (3-D) oriented short-fiber reinforced composites. Short-fiber composites are usually reinforced with glass and ceramic short fibers and whiskers. These reinforcements are brittle and display a range of strength values, which can be statistically characterized by a Weibull distribution. This statistical nature of fiber strength needs to be taken into account in the prediction of composite strength. In this paper, the statistical nature of fiber strength is incorporated into the calculation of direct fiber strengthening, and a maximum-load composite failure criterion is adopted to calculate the composite strength. Other strengthening mechanisms such as residual thermal stress, matrix work hardening, and short-fiber dispersion hardening are also briefly discussed.

Zhu, Y.T.; Blumenthal, W.R.; Stout, M.G.; Lowe, T.C.

1995-10-05

136

Numerical investigations on the role of micro-cracks in determining the compressive and tensile strength of rocks  

NASA Astrophysics Data System (ADS)

Bonded particle models implemented using the Discrete Element Method (DEM [1]) have proven a useful numerical laboratory to investigate the interplay between geological structure and mechanical response of rock specimens [4]. However, it is well-known that such bonded particle models fail to reproduce the ratios of compressive:tensile strength of rocks (typically ranging between 10:1 and 50:1). Since this strength ratio is a critical geotechnical engineering design parameter, it is important to resolve this discrepancy between rock and their DEM analogues. To date, the largest compressive:tensile strength ratio achieved in DEM rock analogue models ranges between 10:1 and 12:1 [3]. In said studies, the compressive:tensile strength ratio was found to depend on the number of particle bonds removed from the specimen prior to testing; a modelling analogy for changing the micro-crack density within the specimen. These results are consistent with the popular conjecture that the compressive and tensile strengths of rock are impacted by the opening (or closure) of micro-cracks oriented parallel (or perpendicular) to the loading direction. The current research consists of a rigorous analysis of the role of micro-cracks in governing the compressive:tensile strength ratio of DEM rock specimens. Micro-cracks are geometrically represented as planar surfaces of variable size and orientation. Spherical particles are packed around each planar micro-crack forming a surface that is flat on scales larger than the particle scale. This geometrical approach permits prescription of the sizes and orientations of micro-cracks, as well as the crack density. A series of cylindrical DEM rock specimens are prepared with varying micro-crack densities and orientations. Specimens with either or both micro-cracks sub-parallel to, or sub-perpendicular to the cylinder axis are consided. Each DEM rock specimen is subjected to both a numerical uniaxial compression test and a numerical direct tension test. From these tests, four macroscopic material properties are measured for each specimen: Young's modulus, Poisson's ratio, uniaxial compressive strength and unixial tensile strength. Fracture mechanisms are also examined. Preliminary results indicate that both micro-crack density and micro-crack orientation significantly impact the macroscopic mechanical properties of DEM rock specimens. Quantitative results will be presented at the meeting. The software employed for these experiments is ESyS-Particle [2], an Open Source DEM simulation package for multi-core PCs or supercomputers.

Weatherley, D.; Ayton, T.

2012-04-01

137

Effect of abrasive wear on the tensile strength of steel wire rope  

Microsoft Academic Search

Known amounts of external abrasive wear were introduced into a new 6-strand steel wire rope and the effects of this wear on the tensile strength of the rope examined against the rope discard criteria for wear stated in ISO 4309: 1990 and other selected international standards. The variations of strength with degree of wear in the test rope were compared

A. R. T. de Silva; Long Woon Fong

2002-01-01

138

Ab initio calculation of the ideal tensile and shear strength of cubic silicon nitride  

Microsoft Academic Search

In this study, the ideal tensile and shear strength of the recently discovered cubic spinel silicon nitride polymorph was calculated using an ab initio density functional technique. The stress-strain curve of the cubic silicon nitride structure was calculated from simulations of applied ?11 and ?23 components of strain, and the ideal strengths were estimated at ˜45 and ˜49 GPa, respectively.

Cenk Kocer; Naoto Hirosaki; Shigenobu Ogata

2003-01-01

139

Temperature dependence of the tensile strength of polymers and metals at elevated temperatures  

Microsoft Academic Search

We have studied the temperature dependence of the tensile strength for polymers at temperatures above the glass transition\\u000a temperature and for metals, above about half of the melting temperature. An empirical relation is found between the strength\\u000a of these materials, the temperature, and the time to fracture.

V. I. Vettegren; V. B. Kulik; S. V. Bronnikov

2005-01-01

140

An experimental study on the tensile strength of steel fiber reinforced concrete  

Microsoft Academic Search

This paper deals with steel fiber reinforced concrete mechanical static behaviour and with its classification with respect to fibers content and mix-design variations. A number of experimental tests were conducted to investigate uniaxial compressive strength and tensile strength. Different mixtures were prepared varying both mix-design and fiber length. Fibers content in volume was of 1% and 2%. Mechanical characterization was

R. S. Olivito; F. A. Zuccarello

2010-01-01

141

Ideal tensile and shear strength of a gum metal approximant: Ab initio density functional calculations  

NASA Astrophysics Data System (ADS)

The ideal tensile and shear strengths of binary ?-phase Ti3Nb alloys have been investigated using ab initio density functional calculations. The binary alloy is considered as an approximant to the multifunctional Ti-Nb-Ta-Zr-O alloy known as “gum metal,” which displays high strength, low elastic modulus, high yield strain, and very good ductility. This alloy has been reported to deform elastically until the stress approaches the ideal tensile strength. Our calculations have been performed for an optimized chemical decoration of the body-centered cubic (bcc) structure of the ? phase. Previous work has demonstrated that this model yields elastic constants in very good agreement with those measured for gum metal specimens and leads to a reasonably accurate description of the martensitic transformations between the bcc ?, the orthorhombic ?'' and the hexagonal ? phases [Lazar , Phys. Rev. BPLRBAQ0556-280510.1103/PhysRevB.84.054202 84, 054202 (2011)]. The simulations of the response to tensile and shear loading have been performed for large supercells which account also for the different orientations of the -Nb-Nb- chains characteristic for the ?-phase structure relative to the direction of the applied load. The energy-strain and stress-strain curves are found to be very different from those reported for all bcc metals. Under uniaxial <100> loading we find an ideal tensile strength of 2.4 GPa, the upper limit to the tensile stress arising from a shear instability of the structure. Under uniaxial <110> load we calculate an ideal tensile strength of 2.2 or 2.8 GPa, depending on the orientation of the -Nb-Nb- chains relative to the loading direction. For a realistic multidomain structure the ideal strength is expected to correspond to the average of these values. An ideal strength of 2.6 GPa under <110> loading is roughly the same as under <100> load, despite a considerable anisotropy of the tensile moduli. For {211}<111> shear we calculate an ideal shear strength of 1.6 GPa, again as an average over different possible shearing directions relative to the Nb-Nb bonds. For the {110}<110> shear system we find a lower strength of 0.9 GPa. The structures reached at the stress maximum under <100> uniaxial tension and {211}<111> shear are identical, and since the maximal shear stress is much lower than the tensile stress, the alloy will fail by shear even under strictly uniaxial tension. The values of the ideal tensile and shear strengths are significantly low, even in comparison with those calculated for bcc V and Nb with very small shear moduli and approach the values reported for gum metal alloys.

Nagasako, Naoyuki; Asahi, Ryoji; Hafner, Jürgen

2012-01-01

142

[The direct tensile test of composite resins using the small specimen--effect of the preparation of specimen, the size of specimen and the testing condition on the tensile properties].  

PubMed

The direct tensile test of composite resins using the specimen with the gauge length 10 mm has been developed by authors. In this study smaller specimens with the gauge length 5 mm and 2 mm were also investigated. As the gauge length became smaller, tensile properties such as the proportional limit, the proof stress, and the tensile strength showed the tendency to become higher. The effect of strain rate on the tensile properties appeared clearly when using the specimen with the gauge length 2 mm. The small specimen was found to have many advantages for the preparation, the cost of material and the handling during the tensile test. PMID:2133362

Fujishima, A; Miyazaki, T; Kuneshita, H; Suzuki, E; Miyaji, T

1990-09-01

143

Ultimate tensile strength of composites exhibiting fiber fragmentation  

Microsoft Academic Search

An estimate of the achievable longitudinal strength of fiber-reinforced composite systems is provided by models that are based on fiber fragmentation, interface sliding and global load sharing. A simple model is shown to provide a compact expression for the longitudinal strength and to closely approximate the values obtained from more detailed comprehensive approaches.

S. Jansson; K. Kedward

1996-01-01

144

Tensile and creep properties of reduced activation ferritic-martensitic steel for fusion energy application  

NASA Astrophysics Data System (ADS)

Tensile and creep properties of a reduced activation ferritic-martensitic (RAFM) steel for Indian Test Blanket Module (TBM) to be tested in ITER have been evaluated. The tensile strength was found to decrease with temperature; the rate of decrease being slower in the intermediate temperature range of 450-650 K. Tensile ductility of the steel decreased with increase in temperature up to 650 K, followed by a rapid increase beyond 650 K. Creep studies have been carried out at 773, 823 and 873 K over a stress range of 100-300 MPa. The variation of minimum creep rate with applied stress followed a power law, &z.epsiv; = A?n. The 'n' value decreased with increase in temperature. The creep rupture life was found to relate inversely with minimum creep rate through the Monkman-Grant relation, tr · &z.epsiv; = constant. The tensile and creep properties of the steel were comparable with those of Eurofer 97.

Mathew, M. D.; Vanaja, J.; Laha, K.; Varaprasad Reddy, G.; Chandravathi, K. S.; Bhanu Sankara Rao, K.

2011-10-01

145

Relationship between Fracture Toughness and Tensile Properties of A357 Cast Aluminum Alloy  

NASA Astrophysics Data System (ADS)

The fracture-related mechanical properties of the A357 cast aluminum alloy, namely, elongation to fracture, tensile strain energy density (tensile toughness), strain-hardening exponent, and plane strain fracture toughness were investigated. Correlations between these properties have been established for 25 different artificial aging heat-treatment conditions and for five minor variations in chemical composition. Empirical relationships between the strain energy density and both the tensile elongation to fracture and the strain-hardening exponent have been developed. Analysis of the fracture surfaces indicated that the fracture mechanism of the investigated specimens varies according to the artificial aging conditions. Moreover, empirical relationships between the fracture toughness and strain energy density and between fracture toughness and strain-hardening exponent have been developed; these can be used to estimate the plane strain fracture toughness of A357 as a function of yield strength and tensile toughness.

Alexopoulos, N. D.; Tiryakio?lu, M.

2009-03-01

146

Characterization of Optical Fiber Strength Under Applied Tensile Stress and Bending Stress  

SciTech Connect

Various types of tensile testing and bend radius tests were conducted on silica core/silica cladding optical fiber of different diameters with different protective buffer coatings, fabricated by different fiber manufacturers. The tensile tests were conducted to determine not only the average fiber strengths at failure, but also the distribution in fracture strengths, as well as the influence of buffer coating on fracture strength. The times-to-failure of fiber subjected to constant applied bending stresses of various magnitudes were measured to provide a database from which failure times of 20 years or more, and the corresponding minimum bend radius, could be extrapolated in a statistically meaningful way. The overall study was done to provide an understanding of optical fiber strength in tensile loading and in applied bending stress as related to applications of optical fiber in various potential coizfgurations for weapons and enhanced surveillance campaigns.

P.E. Klingsporn

2011-08-01

147

Quantitative fracture strength and plasticity measurements of lithiated silicon nanowires by in situ TEM tensile experiments.  

PubMed

We report in situ tensile strength measurement of fully lithiated Si (Li-Si alloy) nanowires inside a transmission electron microscope. A specially designed dual probe with an atomic force microscopy cantilever and a scanning tunneling microscopy electrode was used to conduct lithiation of Si nanowires and then perform in situ tension of the lithiated nanowires. The axial tensile strength decreased from the initial value of 3.6 GPa for the pristine unlithiated Si nanowires to 0.72 GPa for the lithiated Li-Si alloy. We observed large fracture strain ranging from 8% to 16% for Li-Si alloy, 70% of which remained permanent after fracture. This indicates a certain degree of tensile plasticity in the lithiated silicon before fracture, important for constitutive modeling of the lithium-ion battery cyclability. We also compare the ab initio computed ideal strengths with our measured strengths and attribute the differences to the morphology and flaws in the lithiated nanowires. PMID:23025575

Kushima, Akihiro; Huang, Jian Yu; Li, Ju

2012-10-05

148

Generating material strength standards of aluminum alloys for research reactors I. Yield strength values S y and tensile strength values S u  

Microsoft Academic Search

Aluminum alloys are frequently used as structural materials for research reactors. The material strength standards, however, such as the yield strength values (Sy), the tensile strength values (Su) and the design fatigue curve—which are needed to use aluminum alloys as structural materials in “design by analysis”—for those materials have not been determined yet. Hence, a series of material tests was

Hirokazu Tsuji; Kenzo Miya

1995-01-01

149

The Addition of Carbon Nanotube on the Tensile Properties of Carbon Fiber-Reinforced PEEK Composites  

Microsoft Academic Search

The main objective of this paper is to develop high strength resistance carbon fiber-reinforced polyether ether ketone (PEEK) composites with the addition of multiwall carbon nanotubes (MWCNT). These compounds were well mixed in a Haake batch mixer, and compounded polymers were fabricated into sheets of known thickness by compression moulding. Samples were tested for tensile properties with respect to different

J. Li; L. Q. Zhang

2009-01-01

150

Effect of thermal treatments on tensile strength of commercially cast pure titanium and Ti6Al4V alloys  

Microsoft Academic Search

Heating titanium structures is assumed to relieve tensions induced by the casting process as well as possibly optimizing some mechanical properties. The aim of this investigation was to evaluate the effect of thermal treatments on tensile strength of commercially pure titanium (CP Ti) and Ti-6Al-4V alloy. Thirty dumbbell rods, with diameters of 3.0 mm at the central segment and lengths

Sicknan Soares da Rocha; Gelson Luis Adabo; Luis Geraldo Vaz; Guilherme Elias Pessanha Henriques

2005-01-01

151

Improvement of shrink-resistance and tensile strength of wool fabric treated with a novel microbial transglutaminase from Streptomyces hygroscopicus  

Microsoft Academic Search

In this study, a novel microbial transglutaminase (MTG) from Streptomyces hygroscopicus WSH03-13 was applied in the processing of wool fabrics. The results indicated that MTG treatment could improve felting properties and decrease tensile strength loss of wool fabrics. For the wool fabrics used in this study, MTG treatment following chemical and protease pretreatment led to a 2.32% of area shrinkage

Guocheng Du; Li Cui; Yang Zhu; Jian Chen

2007-01-01

152

Open and filled hole static tensile strength characterization of metal matrix composite SCS-9/Beta21s. Master's thesis  

SciTech Connect

SCS-9/Beta 21s has a reduced gauge thickness, in comparison with other metal matrix composites, due to a smaller diameter fiber. This reduced gauge thickness makes it an attractive candidate for the skin of hypersonic vehicles. Tensile testing of (0/90) sub 2s and (O/+ or -45/90) sub s laminates was performed at room temperature, 482 deg C, and 650 deg C. Both notched and unnotched specimens were tested. Notched specimens, open and filled hole, had a width-to-diameter ratio of six. Materials 7075-T6 and Mar-m-246 were used as pins in the filled hole tensile testing. Analytical work was completed to predict material properties, elastic and plastic stress concentration factors, residual stresses, and failure strengths. Damage was documented in the form of fiber-matrix debonding, matrix cracking, fiber failure, and plasticity.... SCS-9, Beta 21s, Open Hole, Filled Hole, Metal Matrix Composite, Notch, Static Tensile.

Roush, J.T.

1992-12-01

153

Tensile bond strength of metal bracket bonding to glazed ceramic surfaces with different surface conditionings  

PubMed Central

Objective The objective of this study was to compare the tensile bond strength of metal brackets bonding to glazed ceramic surfaces using three various surface treatments. Materials and Methods Forty two glazed ceramic disks were assigned to three groups. In the first and second groups the specimens were etched with 9.5% hydrofluoric acid (HFA). Subsequently in first group, ceramic primer and adhesive were applied, but in second group a bonding agent alone was used. In third group, specimens were treated with 35% phosphoric acid followed by ceramic primer and adhesive application. Brackets were bonded with light cure composites. The specimens were stored in distilled water in the room temperature for 24 hours and thermocycled 500 times between 5°C and 55°C. The universal testing machine was used to test the tensile bond strength and the adhesive remenant index scores between three groups was evaluated. The data were subjected to one-way ANOVA, Tukey and Kruskal-Wallis tests respectively. Results The tensile bond strength was 3.69±0.52 MPa forfirst group, 2.69±0.91 MPa for second group and 3.60±0.41 MPa for third group. Group II specimens showed tensile strength values significantly different from other groups (P<0.01). Conclusion In spite of limitations in laboratory studies it may be concluded that in application of Scotch bond multipurpose plus adhesive, phosphoric acid can be used instead of HFA for bonding brackets to the glazed ceramic restorations with enough tensile bond strength.

Akhoundi, MS. Ahmad; Kamel, M. Rahmati; Hashemi, SH. Mahmood; Imani, M.

2011-01-01

154

Effect of thermocycling on tensile strength and tear resistance of four soft denture liners.  

PubMed

This study evaluated the effect of thermocycling on the tensile strength and tear resistance of four long-term soft denture liners. One light-activated (Astron Light, AL), two chemically activated (GC Reline Soft, GC; Silagum Comfort, SC), and one heat-cured (Molloplast-B, MLP) soft liner materials were tested. Dumbbell and trouser-leg specimen geometries were used for tensile strength and tear resistance tests, respectively. A total of 120 specimens were prepared. Test specimens for each material (n=5) were subjected to thermal cycling for 1000 and 3000 cycles between 5 degrees C and 55 degrees C in a thermocycler. Before thermocycling, AL gave the lowest tensile strength, while SC exhibited the highest tear resistance value among the materials tested (p < 0.05). Thermal cycling significantly affected the tensile strength of AL as well as the tear resistance values of AL, MLP, and GC materials. This in vitro study revealed that the tensile strength and tear resistance values of the soft liner materials tested varied according to their chemical compositions. PMID:17621948

Oguz, Serra; Mutluay, Mustafa Murat; Dogan, Orhan Murat; Bek, Bulent

2007-03-01

155

Correlation Between Tensile Strength and Hardness of Electron Beam Welded TC4-DT Joints  

NASA Astrophysics Data System (ADS)

Correlation between tensile strength and hardness for damage-tolerant Ti-6Al-4V (TC4-DT) alloy and its electron beam welded joints was investigated. Yield strength (YS), ultimate tensile strength (UTS) and strain hardening coefficient of base metal and weld metal were obtained using uniaxial tensile tests. Microhardness of the base metal, heat affected zone, and weld metal was measured. Then, the linear correlations among the yield strength, tensile strength, and hardness were proposed. Moreover, correlation between strain hardening coefficient and the ratio of YS to UTS (YS/UTS) was established. The results indicate that microhardness can be used to predict the YS and UTS of the TC4-DT welded joint successfully. In addition, the strain hardening coefficient can be predicted by the YS/UTS. The prediction of strength and strain hardening coefficient is in agreement with the experiments. The correlations are applicable and valuable for the strength prediction of narrow welded fusion zone and heat affected zone based on the microhardness measurement.

Lu, Wei; Shi, Yaowu; Li, Xiaoyan; Lei, Yongping

2013-06-01

156

Measuring tensile strength of nanofibers using conductive substrates and dynamic mechanical analyzer  

Microsoft Academic Search

Though the tensile strength of nanofibers is essential to determine their application fields, few studies have been conducted\\u000a on this topic, due to the difficulties involved in the preparation of single nanofiber tensile specimens, the manipulation\\u000a of the clamping device, and the sensing of the nano- force and strain. A bundle testing method was employed in this work to\\u000a measure

Kenny Yoonki Hwang; Woong-Ryeol Yu

2009-01-01

157

A modified Johnson–Cook model for tensile behaviors of typical high-strength alloy steel  

Microsoft Academic Search

The uniaxial tensile tests were conducted with the initial strain rates range of (0.0001–0.01)s?1 and the temperature range of (1123–1373)K for typical high-strength alloy steel. Based on the experimental results, the modified Johnson–Cook model, which considers the coupled effects of strain, strain rate and deformation temperature, was proposed to describe the tensile behaviors of the studied alloy steel. Results show

Y. C. Lin; Xiao-Min Chen; Ge Liu

2010-01-01

158

High-temperature tensile properties and oxidation behavior of carbon fiber reinforced silicon carbide bolts in a simulated re-entry environment  

Microsoft Academic Search

The tensile properties and oxidation behavior of 2D C\\/SiC bolts prepared by chemical vapor infiltration were investigated in a simulated re-entry environment. The results showed that all the tensile strengths of 2D C\\/SiC bolts at test temperatures of 1300, 1600 and 1800°C decreased, respectively, retaining 85%, 92%, and 94% of the virgin properties at room temperature. The tensile strengths and

Hui Mei; Laifei Cheng; Qingqing Ke; Litong Zhang

2010-01-01

159

Observation of static strength and fatigue life of repaired graphite\\/epoxy using a tensile coupon  

Microsoft Academic Search

The static strength and fatigue life of repaired graphite\\/epoxy laminates was observed using a tensile coupon. The lay-up of investigated laminates was [0°\\/±45°\\/90°]s. Static strength was measured from the specimens prepared by various repair techniques such as cosmetic treatment, precured-single patch, precured-double patch and cure-in-place patch methods. The strength was recovered to the extent of 60-70% of unnotched case. Fatigue

J. W. Choi; W. Hwang; H. C. Park; K. S. Han

1999-01-01

160

Semicircular bend testing with split Hopkinson pressure bar for measuring dynamic tensile strength of brittle solids  

NASA Astrophysics Data System (ADS)

We propose and validate an indirect tensile testing method to measure the dynamic tensile strength of rocks and other brittle solids: semicircular bend (SCB) testing with a modified split Hopkinson pressure bar (SHPB) system. A strain gauge is mounted near the failure spot on the specimen to determine the rupture time. The momentum trap technique is utilized to ensure single pulse loading for postmortem examination. Tests without and with pulse shaping are conducted on rock specimens. The evolution of tensile stress at the failure spot is determined via dynamic and quasistatic finite element analyses with the dynamic loads measured from SHPB as inputs. Given properly shaped incident pulse, far-field dynamic force balance is achieved and the peak of the loading matches in time with the rupture onset of the specimen. In addition, the dynamic tensile stress history at the failure spot obtained from the full dynamic finite element analysis agrees with the quasistatic analysis. The opposite occurs for the test without pulse shaping. These results demonstrate that when the far-field dynamic force balance is satisfied, the inertial effects associated with stress wave loading are minimized and thus one can apply the simple quasistatic analysis to obtain the tensile strength in the SCB-SHPB testing. This method provides a useful and cost effective way to measure indirectly the dynamic tensile strength of rocks and other brittle materials.

Dai, F.; Xia, K.; Luo, S. N.

2008-12-01

161

Treatment of bleached wool with trans-glutaminases to enhance tensile strength, whiteness, and alkali resistance.  

PubMed

Trans-glutaminases is known as a cross-linking enzyme for proteins. Wool is a proteinous fiber conventionally is treated through several processes to obtain the desirable characteristics. Bleaching is also one of the most important processes usually carried out by using an oxidizing agent in a conventional method. The tensile strength of wool yarns was reduced as a consequence of oxidative bleaching. Here, with the help of microbial trans-glutaminases (m-TGases), a novel bleaching process was disclosed in a way to obtain a bleached wool yarn with no significant reduction in the tensile strength. The results confirmed that the bleached wool yarns with H(2)O(2) could be modified by m-TGases post-treatment. The m-TGases treatment on the bleached wool yarns improved the tensile strength and whiteness along with the higher alkali resistance. PMID:21638062

Montazer, Majid; Lessan, Fatemeh; Pajootan, Elmira; Dadashian, Fatemeh

2011-06-03

162

Tensile properties of unirradiated PCA from room temperature to 700/sup 0/C  

SciTech Connect

The tensile properties of Prime Candidate Alloy (PCA) austenitic stainless steel after three different thermomechanical treatments were determined from room temperature to 700/sup 0/C. The solution-annealed PCA had the lowest strength and highest ductility, while the reverse was true for the 25%-cold-worked material. The PCA containing titanium-rich MC particles fell between the other two heats. The cold-worked PCA had nearly the same tensile properties as cold-worked type 316 stainless steel. Both alloys showed ductility minima at 300/sup 0/C.

Braski, D.N.; Maziasz, P.J.

1983-01-01

163

On the Compressive and Tensile Strength of Magnesium Aluminate Spinel  

Microsoft Academic Search

Magnesium aluminate spinel is a strong polycrystalline transparent ceramic. Spinel is an attractive material for armor applications and its behavior under shock wave loading is of obvious interest. The purpose of the present study was to determine the Hugoniot elastic limit (HEL) of this material, its Hugoniot response above the HEL, and its spall strength. Planar impact experiments were performed

S. Hayun; M. P. Dariel; N. Frage; E. Zaretsky

2009-01-01

164

Gradient syntactic foams: Tensile strength, modulus and fractographic features  

Microsoft Academic Search

Syntactic foams are new age polymer composite materials. They find use not only in aerospace but also in naval applications as marine utility components. Due to their low density, lesser ingression by water and ability to withstand compressive strengths they are considered for sub-sea applications. Dispersing hollow glass microballoons in matrices like, for instance, thermosetting epoxy resins yields on curing

Kishore; Ravi Shankar; S. Sankaran

2005-01-01

165

An investigation into welding parameters affecting the tensile properties of titanium welds  

Microsoft Academic Search

Grain size and amount of martensite formation affect the tensile strength of the alloy and these two factors are in turns related to the cooling rate of the welding process. There was found a trend of decreased tensile strength with the increase of welding heat input and a trend of increased tensile strength with the increase of welding cooling rate.

Winco K. C. Yung; B. Ralph; W. B. Lee; R. Fenn

1997-01-01

166

On the Compressive and Tensile Strength of Magnesium Aluminate Spinel  

NASA Astrophysics Data System (ADS)

Magnesium aluminate spinel is a strong polycrystalline transparent ceramic. Spinel is an attractive material for armor applications and its behavior under shock wave loading is of obvious interest. The purpose of the present study was to determine the Hugoniot elastic limit (HEL) of this material, its Hugoniot response above the HEL, and its spall strength. Planar impact experiments were performed over the 2 to 40 GPa stress range using the Velocity Interferometer System for Any Reflector (VISAR) as a principal diagnostics tool. According to these tests, spinel has a HEL of about 11.3 GPa. The spall strength of the material was found to be close to zero at low, about 2 GPa, impact stress.

Paris, V.; Hayun, S.; Dariel, M. P.; Frage, N.; Zaretsky, E.

2009-12-01

167

Development of a silicon carbide fibre with high tensile strength  

Microsoft Academic Search

MUCH work has been done on preparing heat-resistant silicon carbide materials in fibrous form, since plastics or metals can be reinforced with them to obtain very heat-resistant material of great mechanical strength. SiC whiskers1 are, however, impractical because of their shortness (several mm), their non-uniform diameter and high cost of production. SiC-on-W (ref. 2) and SiC-on-C (ref. 3) filaments have

S. Yajima; J. Hayashi; M. Omori; K. Okamura

1976-01-01

168

Tensile and transient burst properties of advanced ferritic/martensitic steel claddings after neutron irradiation  

NASA Astrophysics Data System (ADS)

The effects of fast neutron irradiation on tensile and transient burst properties of advanced ferritic/martensitic steel claddings for fast breeder reactors were investigated. Specimens were irradiated in the experimental fast reactor JOYO using the material irradiation rig at temperatures between 773 and 1013 K to fast neutron doses ranging from 11 to 102 dpa. The post-irradiation tensile and temperature-transient-to-burst tests were carried out. The results of mechanical tests showed that there was no significant degradation in tensile and transient burst strengths after neutron irradiation below 873 K. This was attributed to grain boundary strengthening caused by precipitates that preferentially formed on prior-austenite grain boundaries. Both strengths at neutron irradiation above about 903 K up to 102 dpa decreased due to radiation enhanced recovery of lath martensite structures and recrystallization.

Yano, Y.; Yoshitake, T.; Yamashita, S.; Akasaka, N.; Onose, S.; Takahashi, H.

2007-08-01

169

Dynamic tensile strength of terrestrial rocks and application to impact cratering  

NASA Astrophysics Data System (ADS)

Dynamic tensile strengths and fracture strengths of 3 terrestrial rocks, San Marcos gabbro, Coconino sandstone, and Sesia eclogite were determined by carrying out flat-plate (PMMA and aluminum) impact experiments on disc-shaped samples in the 5 to 60 m/sec range. Tensile stresses of 125 to 300 MPa and 245 to 580 MPa were induced for gabbro and eclogite, respectively (with duration time of ~1 ms). For sandstone (porosity 25%), tensile stresses normal to bedding of ~13 to 55 MPa were induced (with duration times of 2.4 and ~1.4 ms). Tensile crack failure was detected by the onset of shock-induced (damage) P and S wave velocity reduction. The dynamic tensile strength of gabbro determined from P and S wave velocity deficits agrees closely with the value of previously determined values by post-impact microscopic examination (~150 MPa). Tensile strength of Coconino sandstone is 20 MPa for a 14 ms duration time and 17 MPa for a 2.4 ms duration time. For Sesia eclogite, the dynamic tensile strength is ~240 MPa. The fracture strength for gabbro is ~250 MPa, ~500 MPa for eclogite, and ~40 MPa for sandstone. Relative crack induced reduction of S wave velocities is less than that of post-impact P wave velocity reductions for both gabbro and eclogite, indicating that the cracks were predominantly spall cracks. Impacts upon planetary surfaces induce tensile failure within shock-processed rocks beneath the resulting craters. The depth of cracking beneath impact craters can be determined both by seismic refraction methods for rocks of varying water saturation and, for dry conditions (e.g., the Moon), from gravity anomalies. In principle, depth of cracking is related to the equations-of-state of projectile and target, projectile dimension, and impact velocity. We constructed a crack-depth model applicable to Meteor Crater. For the observed 850 m depth of cracking, our preferred strength scaling model yields an impact velocity of 33 km/s and impactor radius of 9 m for an iron projectile.

Ai, Huirong-Anita; Ahrens, Thomas J.

2004-02-01

170

Correlation of tensile strength with fracture modes of KAOWOOL- and SAFFIL-reinforced 339 aluminum  

SciTech Connect

The tensile strengths of composites of 339 aluminum reinforced with either SAFFIL or KAOWOOL fibers are compared over the temperature range of 20 C to 300 C. For this type of composite, in which the discontinuous fibers are randomly oriented, the fibers perpendicular to the applied stress play a critical role, which in turn creates a dependence upon the interfacial bond strength. The KAOWOOL fibers form a strong interfacial bond so that tensile failure occurs either in the matrix at 300 C or by fiber cleavage at 20 C. In the T5 condition, the SAFFIL interface is weaker than the matrix alloy so that failure occurs by delamination of the transverse fibers. Thus, although the SAFFIL fibers are 40% stronger than the KAOWOOL fibers, the T5 composites have the same ultimate tensile strengths. A T6 heat treatment promotes an interfacial reaction with magnesium. This strengthens the SAFFIL interface so that failure occurs primarily in the matrix, producing higher composite strengths. The reaction with the KAOWOOL fibers is so extensive that the matrix, and therefore the composite strength, is drastically decreased. When account is taken of the different fracture modes, together with the matrix strengths as determined by nanoindentation, the calculated values of composite strength are in good agreement with experiment.

Baxter, W.J.; Sachdev, A.K. [General Motors R and D Center, Warren, MI (United States). Metallurgy Dept.

1999-03-01

171

Bedrock resistance to fluvial erosion: the importance of rock tensile strength, crystal grain size and porosity in scaling from the laboratory to the field  

NASA Astrophysics Data System (ADS)

Tectonics, climate and rock material properties are fundamental boundary conditions that control the evolution of mountain topography. However, the relative importance of gradients in rock resistance to fluvial incision has been difficult to distinguish from other factors. At the laboratory scale, rock resistance to wear by saltating bedload has been shown to scale with the square of rock tensile strength, consistent with fracture mechanics theory, although order-of-magnitude variability among stronger rock types has limited the applicability of this finding to the field. A possible explanation for this scatter in the correlation between tensile strength and erosion resistance is a mismatch in the temporal and spatial scale at which fractures propagate through bedrock. Wear by low-velocity particle impacts typically produces silt-sized fragments suggesting erosion at the sub-grain scale in most crystalline and clastic rocks, whereas quasi-static tensile strength tests commonly produce fractures along grain boundaries. If this is correct, the scale mismatch should be greatest for rocks with large grain sizes or greater porosity. Here we investigate the role of rock grain size and porosity in controlling variability in erosion resistance for a given tensile strength, with the goal of finding a robust predictive relation between easily measured rock properties and rock resistance to fluvial incision. We have access to rocks used previously for published erosion and strength correlations, and additional rocks collected in the field, and are analyzing thin sections and photomicrographs to measure grain size distributions. Density and porosity are measured by comparison of dry and saturated rock weights and volumes. Preliminary results suggest that strength-normalized erodibility, defined as the product of erosion rate and tensile strength squared, varies systematically with both grain size and porosity; higher porosity and larger grain size are associated with greater erodibility for a given tensile strength. SEM images reveal marked contrasts in surface texture between eroded and fractured surfaces. Fine-grained rocks, which include greenstone, andesite and limestone, are distinct from the coarse-grained rocks tested, such as granite and some sandstones, which are less erodible for a given tensile strength. SEM image analysis of fluvially eroded bedrock surfaces illustrates a mismatch between the sub-grain-scale of fluvial erosion and the fractures that propagate around and through grains which are effectively measured by the Brazilian tensile strength. Predicting erosion resistance from tensile strength, grain size, and porosity may also depend on the grain size and velocity of impactors, through the effect of strain-rate on fracture length. This work may have broad applicability for interpretation of topographic gradients in actively uplifting terrain, and to numerical modeling of the evolution of real landscapes.

Beyeler, J. D.; Sklar, L. S.

2010-12-01

172

Tensile strength of five types of retention for resin-bonded prostheses.  

PubMed

The tensile bond strengths of five retention techniques for bonded cast restorations were tested. The retentive methods were the electrolytic etch, Rochette's perforations, retention beads, the recessed surface, and soldered orthodontic mesh. The electrolytic etch and recessed surface methods gave the highest values of bond strength, followed by retention beads. Rochette's perforations and the soldered orthodontic mesh failed to surpass the bond strength of the control group (no additional retention) after 1 hour and provided the lowest bond strength after 24 hours. PMID:1687153

Bastos, M T; Mondelli, J; Ishikiriama, A; Navarro, M F

1991-12-01

173

Mechanical properties of monolayer graphene under tensile and compressive loading  

NASA Astrophysics Data System (ADS)

The mechanical properties of zigzag graphene and armchair graphene nanoribbon under tensile and compressive loading are studied by the use of quantum mechanics as well as quantum molecular dynamics (MD) method based on the Roothaan-Hall equation and the Newton motion laws. The similar failure mechanisms and different mechanical properties are found in zigzag graphene and armchair graphene subjected to mechanical load. Under tensile or compressive loadings, the critical loading of the zigzag graphene is larger than that of the armchair graphene. Both zigzag graphene and armchair graphene begin to break at the outmost carbon atomic layers. Applied mechanical loading indeed changes the electronic properties of graphene.

Gao, Yuanwen; Hao, Peng

2009-08-01

174

Tensile-strength characterization of a metal-matrix composite with circular holes. Master's thesis  

Microsoft Academic Search

Static tensile testing conducted at room temperature and 650 C shows notch sensitivity for a quasi-isotropic lay-up of a titanium alloy metal matrix composite. The specific material used was SCS-6\\/Beta 21S. Some unnotched specimens were tested and then the diameter-to-width ratio was varied from 0.1 to 0.4. The room temperature unnotched strength is 840 MPa, and the strength falls to

Rattray

1991-01-01

175

Effect of refrigeration on tensile bond strength of three adhesive systems.  

PubMed

The purpose of this study was to investigate the tensile bond strengths of three adhesive systems applied to dentin at refrigerated and room temperatures. Ninety bovine incisor teeth were obtained, embedded in self-cured acrylic resin, abraded on a lathe under water spray and polished to 400 and 600 grit to form standardized dentin surfaces before randomly assigning to six groups (n = 15). The adhesive systems Scotchbond Multi-Purpose, Single Bond and Prime & Bond NT were applied to dentin according to the manufacturers' instructions at refrigerated temperature (4 degrees C) and at room temperature (23 degrees C), before bonding resin-based composite (Z 100). The specimens were stored in distilled water at 37 degrees C for 24 hours and submitted to tensile bond strength tests on a universal testing machine (EMIC DL-2000) at a crosshead speed of 0.5 mm/min. The resulting data were statistically analyzed using analysis of variance and Tukey's test. No statistical differences were found when the adhesive systems were applied at refrigerated and room temperatures. Scotchbond Multi-Purpose and Single Bond had significantly stronger tensile bond strengths than Prime & Bond NT at room and refrigerated temperatures (p < 0.01). Scotchbond Multi-Purpose and Single Bond were statistically similar. No adverse effects upon tensile bond strength were observed when adhesive systems were taken directly from refrigerated storage. PMID:11445917

Spohr, A M; Correr Sobrinho, L; Consani, S; Sinhoreti, M A; Borges, G A

2001-01-01

176

Specification for Kevlar 49 Fiber and Sampling Plan for Tensile Strength.  

National Technical Information Service (NTIS)

A specification for Kevlar 49 yarn is presented along with a sampling plan for tensile strength. The specification may be used for purchase and acceptance or for quality control of Kevlar 49 yarn (380 denier). Applied to yarn used in high-performance fila...

L. Penn N. Hetherington

1976-01-01

177

Tensile Strengths of Silicon Carbide (SiC) Under Shock Loading.  

National Technical Information Service (NTIS)

The present work was initiated to measure and compare tensile strengths (i.e., spall thresholds) of five different types/varieties of silicon carbide materials. Two of these materials were sintered, and the remaining three were hot-pressed. Three types of...

D. P. Dandekar P. T. Bartkowski

2001-01-01

178

Wood tensile strength at temperatures and moisture contents simulating fire conditions  

Microsoft Academic Search

The immediate tensile strength parameters for spruce parallel to the grain and for hardboard have been determined at equilibrium conditions at temperatures up to 250°C. Below 100°C the moisture content has been varied between 0 and 30%. Above 100°C dry samples have been studied. An increase in moisture content up to about 12% leads to a slight increase in the

B. A..-L. Östman

1985-01-01

179

Melt reaction of zein with glyoxal to improve tensile strength and reduce solubility  

Technology Transfer Automated Retrieval System (TEKTRAN)

Glyoxal, in the presence of base, has been used to crosslink zein in a melt process, involving reaction in a melt state combined with compression molding. The resulting zein articles had improved tensile strength, increasing from 34.3 to 40.6 MPa, when the amount of glyoxal was 6% by zein weight. ...

180

Deformability and tensile strength of expanded polystyrene under short-term loading  

Microsoft Academic Search

The results obtained in the experimental investigation of deformability and tensile strength of expanded polystyrene (EPS) under short-term loading are presented. The specimens were cut from EPS boards and subjected to tension acting perpendicular to their faces in compliance with the standard EN 1607+AC. A method of experimental design was used to obtain mathematical models for optimizing the thickness H

I. Y. Gnip; S. Vejelis; V. Kersulis; S. Vaitkus

2007-01-01

181

Tensile strength and stress–strain behaviour of Devon silt under frozen fringe conditions  

Microsoft Academic Search

Frost heave is attributed to the segregation of ice and ice lens formation as a soil freezes. Ice lens formation and hence frost heave starts with the cracking of the frozen fringe. In order for these cracks to initiate and open, the tensile strength of the soil has to be exceeded. Therefore, any evaluation of the ice lens initiation condition

Tezera F. Azmatch; David C. Sego; Lukas U. Arenson; Kevin W. Biggar

2011-01-01

182

Tensile properties of Pb-Sn bearing alloy containing small amount of Sb  

NASA Astrophysics Data System (ADS)

In this study, tensile tests of Pb-9.5Sn-0.5wt%Sb bearing alloy were investigated with respect to the effect of testing temperatures ranging from 393 to 473 K and strain rates ranging from 9.1 × 10-4 to 2 × 10-2 s-1. The tensile tests revealed that the solder alloy exhibits high ductility at 433 K and 5 × 10-3 s-1. Strain rate sensitivity parameter m and activation energy were determined to clarify the deformation mechanism. The effects of Sb-addition on the tensile properties of Pb-9.5Sn-0.5wt%Sb solder alloy were studied by comparing the tensile deformation behaviour of the two solders Pb-10wt%Sn and Pb-10Sn-1.5wt%Zn. Microstructural analysis confirmed that the mechanism controlling the tensile behaviour is a grain boundary sliding (GBS). This study revealed that the Pb-9.5Sn-0.5wt%Sb alloy shows a good combination of high strength and greater ductility by grain refinement. Also, the difference in the morphology and distribution of second phase particles caused by the Sb-addition resulted in better tensile properties.

El-Daly, A. A.

2004-07-01

183

Effects of tempering treatment on tensile, hardness, and charpy impact properties of modified 9 Cr-1 Mo steel. [LMFBR  

SciTech Connect

The effects of tempering temperature and time on the tensile properties and hardness of modified 9 Cr-1 Mo steel at room temperature and on its Charpy impact energy at room temperature and at 204/sup 0/C are studied. Effects of postweld heat treatment on room-temperature tensile properties were also investigated, and tensile data at elevated temperatures were obtained for selected tempering conditions. The room-temperature tensile properties (strength and ductility), hardness and Charpy impact energy were fitted to a Holloman-Jaffe (HJ) parameter with an optimized constant of 22.3. This parameter allows the trade-off of tempering temperature and time to obtain the desirable properties. The same parameter was also suitable for obtaining the effects of post-weld heat treatment on tensile properties. The effects of specimen size and full-size tubular specimens on tensile properties are presented. The yield and ultimate tensile strengths were plotted as functions of hardness. Optical and scanning electron micrographs showed similar microstructures in specimens subjected to tempering conditions producing the same value of the HJ parameter.

Sikka, V.K.; McDonald, R.E.; Bodine, G.C.; Stelzman, W.J.

1982-10-01

184

Comparative evaluation of tensile bond strength and microleakage of conventional glass ionomer cement, resin modified glass ionomer cement and compomer: An in vitro study  

PubMed Central

Aim: The purpose of this study was to evaluate and compare the tensile bond strength and microleakage of Fuji IX GP, Fuji II LC, and compoglass and to compare bond strength with degree of microleakage exhibited by the same materials. Materials and Methods: Occlusal surfaces of 96 noncarious primary teeth were ground perpendicular to long axis of the tooth. Preparations were distributed into three groups consisting of Fuji IX GP, Fuji II LC and Compoglass. Specimens were tested for tensile bond strength by mounting them on Instron Universal Testing Machine. Ninety-six primary molars were treated with Fuji IX GP, Fuji II LC, and compoglass on box-only prepared proximal surface. Samples were thermocycled, stained with dye, sectioned, and scored for microleakage under stereomicroscope. ANOVA and Bonferrani correction test were done for comparisons. Pearson Chi-square test and regression analysis were done to assess the association between the parameters. Results: Compoglass showed highest tensile strength and Fuji II LC showed least microleakage. There was a significant difference between the three groups in tensile strength and microleakage levels. The correlation between tensile strength and microleakage level in each group showed that there was a significant negative correlation only in Group 3. Conclusion: Fuji II LC and compoglass can be advocated in primary teeth because of their superior physical properties when compared with Fuji IX GP.

Rekha, C. Vishnu; Varma, Balagopal; Jayanthi

2012-01-01

185

The Measurement of the Tensile Properties of Soil-Cement.  

National Technical Information Service (NTIS)

As part of an investigation of the design of soil-cement pavements, laboratory tests were carried out using Harmondsworth brickearth to examine the tensile properties of soil-cement and their relation to its compressive properties. The Report discusses th...

H. E. Bofinger

1970-01-01

186

Tensile strengths and porosities of solar system primitive bodies  

NASA Astrophysics Data System (ADS)

Recent measurements of asteroid bulk densities suggest that rubble-pile asteroids with typical porosities of 30 to 50% may be common (Britt et al., 2006). However, the presence of such objects doesn't mean necessarily that the initial porosity had been preserved (Kerridge, 1993). In fact, the fluffy aggregates produced in laboratory experiments that we expect to be representative of the oldest protoplanetary disk materials, exhibit even higher porosities (Blum et al., 2006). Recent results confirm that primitive meteorites (like e.g. CM carbonaceous chondrites) are compacted samples of the nebula matter exhibiting different density and porosity that their precursors materials (Trigo-Rodríguez et al., 2006). Consequently, aqueous alteration, brecciation, and impact-induced metamorphism make very unlikely to find pristine bodies between the asteroidal population. However, there is clear evidence for the existence of high-porosity bodies between the C-type asteroids like e.g. Mathilde (Housen et al., 1999) or the Tagish Lake parent body (Brown et al., 2002). Although extensive post-accretionary processing of meteorite parent bodies can produce high degrees of porosity, only the most pristine ones seem to preserve more than 50% of porosity. Consequently, we should look for these low strength bodies among the C-type asteroids, or very especially in some unprocessed comets that continue being representative of the precursor materials. Recent suggestion that CI1 chondrites are originated from comets should be studied in this context (Gounelle et al., 2006). Particularly, we think that studies of the porosity and strength of primitive meteorites would provide valuable clues on the origin and nature of their parent bodies. REFERENCES Blum J., R. Schräpler, B.J.R. Davidson and J.M. Trigo-Rodríguez (2006) Astroph. J., submitted. Britt D.T., G.J. Consolmagno, and W.J. Merline (2006) Lunar Planet. Sci. Conf. Abstract #2214. Brown, P. G., D. O. Revelle, E. Tagliaferri, and A.R. Hildebrand (2002) Meteorit. & Planet. Sci. 37, 661-675. 1 Gounelle M., P. Spurny, and P. Bland (2006) Meteorit. & Planet. Sci. 41, 135-150. Housen K.R., K.A. Holsapple and M.E. Voss (1999) Nature 402, 155. Kerridge J.F. (2003) Icarus 106, 135-150. Trigo-Rodríguez J.M., Rubin A.E. and J.T. Wasson (2006) Geochim. et Cosmoch. Acta 70, 1271-1290. 2

Trigo-Rodriguez, J. M.; Llorca, J.; Blum, J.

187

Tensile properties of copper alloyed austempered ductile iron: Effect of austempering parameters  

NASA Astrophysics Data System (ADS)

A ductile iron containing 0.6% copper as the main alloying element was austenitized at 850 °C for 120 min and was subsequently austempered for 60 min at austempering temperatures of 270, 330, and 380 °C. The samples were also austempered at 330 °C for austempering times of 30 150 min. The structural parameters for the austempered alloy austenite (X ? ), average carbon content (C ? ), the product X ? C ? , and the size of the bainitic ferrite needle (d ? ) were determined using x-ray diffraction. The effect of austempering temperature and time has been studied with respect to tensile properties such as 0.2% proof stress, ultimate tensile strength (UTS), percentage of elongation, and quality index. These properties have been correlated with the structural parameters of the austempered ductile iron microstructure. Fracture studies have been carried out on the tensile fracture surfaces of the austempered ductile iron (ADI).

Batra, U.; Ray, S.; Prabhakar, S. R.

2004-10-01

188

Effect of cold working and sandblasting on the microhardness, tensile strength and corrosion resistance of AISI 316L stainless steel  

NASA Astrophysics Data System (ADS)

The aim of this work is to investigate the effect of cold working and sandblasting on the microhardness, tensile strength and corrosion rate of AISI 316L stainless steel. The specimens were deformed from 17% to 47% and sandblasted for 20 min using SiC particles with a diameter of 500-700 ?m and an air flow with 0.6-0.7 MPa pressure. The microhardness distribution and tensile test were conducted and a measurement on the corrosion current density was done to determine the corrosion rate of the specimens. The result shows that the cold working enhances the bulk microhardness, tensile and yield strength of the specimen by the degree of deformation applied in the treatment. The sandblasting treatment increases the microhardness only at the surface of the specimen without or with a low degree of deformation. In addition, the sandblasting enhances the surface roughness. The corrosion resistance is improved by cold working, especially for the highly deformed specimen. However the follow-up sandblasting treatment reduces the corrosion resistance. In conclusion, the cold working is prominent to be used for improving the mechanical properties and corrosion resistance of AISI 316L stainless steel. Meanwhile, the sandblasting subjected to the cold worked steel is only useful for surface texturing instead of improving the mechanical properties and corrosion resistance.

Suyitno; Arifvianto, Budi; Widodo, Teguh Dwi; Mahardika, Muslim; Dewo, Punto; Salim, Urip Agus

2012-12-01

189

Effects of H on Electronic Structure and Ideal Tensile Strength of W: A First-Principles Calculation  

Microsoft Academic Search

We investigate the structure, energetics, and the ideal tensile strength of tungsten (W) with hydrogen (H) using a first-principles method. Both density of states (DOS) and the electron localization function (ELF) reveal the underlying physical mechanism that the tetrahedral interstitial H is the most energetically favorable. The first-principles computational tensile test (FPCTT) shows that the ideal tensile strength is 29.1

Yue-Lin Liu; Hong-Bo Zhou; Shuo Jin; Ying Zhang; Guang-Hong Lu

2010-01-01

190

Improvement in Tensile Strength and Water Repellency of Paper after Treatment with Methyltrimethoxysilane Oligomer Using Titanium Butoxide as a Catalyst  

Microsoft Academic Search

The improvement in the tensile strength and water repellency of paper after treatment with a 2-propanol solution of a methyltrimethoxysilane (MTMS) oligomer was studied using filter paper. Titanium butoxide introduced in the solution as a catalyst effectively reacted with the MTMS oligomer, and a Si–O–Ti bond was generated inside the paper. The tensile strength of the paper was remarkably improved

Osamu Yagi; Yoko Iwamiya; Kazumi Suzuki; Rika Funane; Fujio Ohishi

2005-01-01

191

Time-dependent effects on the tensile strength of saturated granite at Three Gorges Project in China  

Microsoft Academic Search

On the basis of split tension tests carried out for the saturated granite in the high slope of ship lock at Three Gorges Project of Yangtze River, PR China, authors of the paper analyzed the rheological relation of ‘loading-displacement-time’, time duration up to rupture and time dependency of the tensile strength of granite. Empirical relations between tensile strength and time

J. Sun; Y. Y. Hu

1997-01-01

192

Tensile strength and rupture energy of hybrid poly(methylvinylsiloxane) composites reinforced with short PET fibers and wollastonite whiskers  

Microsoft Academic Search

In this paper, the tensile strength and rupture energy of hybrid poly(methylvinylsiloxane) composites reinforced with short PET fibers and wollastonite whiskers have been studied. It was observed that for a fixed fiber volume fraction, the tensile strength and rupture energy of the hybrid composites first decreased and then increased with wollastonite whisker volume fraction. Analyses of the fiber efficiency factor

Shanju Fu; Pingping Wu; Zhewen Han

2002-01-01

193

Qualitative femur bone tensile strength analysis in radiographic images using wavelets - biomed 2011.  

PubMed

In this work, the tensile strength of femur bone is qualitatively analyzed using radiographic images. The sub anatomic tensile regions were delineated from conventional planar radiographic femur images using digital image processing algorithms. The normal and abnormal images are then subjected to Daubechies5, coiflet5 and Haar wavelets decomposed at three levels to derive approximation and detail coefficients. The qualitative analyses were also performed on the delineated images to derive apparent mineralization and total area. The values of higher order energy parameter are derived for both approximation and detail coefficients in each level of decomposition and are correlated with apparent mineralization for analysis. Results show that the low values of energy correlates well with abnormalities in all levels of decomposition for all the three wavelets. Among all, the values of energy derived out of approximation coefficient using Haar wavelets show higher degrees of correlations in both primary tensile and secondary tensile regional strength. The variations between normal and abnormal were also found to be statistically significant. Poor correlation was observed in the case of detailed coefficients for all the wavelets irrespective of levels. Among all wavelets, the parameters decomposed at level one approximation coefficient of Haar wavelet appear to be a useful predictor for classifying normal and abnormal samples. This could be attributed to sensitivity of adopted wavelets to the architectural changes and discontinuities in regional distribution of trabecular pattern in tensile region. It appears that this methodology could be used for gross abnormality detection, micro-damage studies and modeling the mechanics of soft tissue in diseases. Thus wavelet extracted feature on tensile trabeculae regions of radiographic femur images could be a used as an index for automated screening of bone strength. PMID:21525609

Sangeetha, S; Sujatha, C M; Ramakrishnan, S

2011-01-01

194

Microstructure and role of outermost coating for tensile strength of SiC fiber  

SciTech Connect

The detailed microstructure of the SiC fiber surface and the outermost coating of SiC(SCS-6) fiber are observed using transmission electron microscopy (TEM) and high resolution electron microscopy (HREM). The tensile strengths of the SiC fibers: uncoated fiber (SCS-0), coated fiber (SCS-6) and extracted fiber from fatigue-loaded SiC(SCS-6) fiber-reinforced Ti-15-3 composite are determined. Fractographic analysis is done on these fibers and the mirror radius is compared with the tensile strength. Thickness of the outermost coating is {approx}3.6 {micro}m and it consists of three different layers (i.e., sublayers 1, 2 and 3). Basically, these sublayers consist of a carbon matrix in which {beta}-SiC crystallites are dispersed. The fracture toughness of the SiC fiber is {approx}3.3 MPa m{sup 1/2}. The outermost coating increases the fiber strength twofold because it reduces stress concentration at the surface of the SiC fiber. The tensile strength of the extracted fiber (SCS-6) from fatigue-loaded specimens shows a reduced strength which is attributed to the debonding of the outermost coating while the composite is loaded.

Guo, S.Q.; Kagawa, Y. [Univ. of Tokyo (Japan). Inst. of Industrial Science; Tanaka, Y. [Univ. of Tokyo (Japan). Inst. of Industrial Science]|[National Research Inst. for Metals, Tsukuba, Ibaraki (Japan); Masuda, C. [National Research Inst. for Metals, Tsukuba, Ibaraki (Japan)

1998-09-01

195

Titanium alloy tensile properties after neutron irradiation  

Microsoft Academic Search

Irradiated specimens from three duplex annealed titanium alloys were tested in uniaxial tension in air from room temperature to 550°C. The EBR-II irradiation temperature was 550°C; the maximum fluence was 5 x 10²² n\\/cm² (E > 0.1 MeV), or 37 dpa, the highest neutron exposure received by any titanium alloy. Alloy 6242S increased in strength due to reactor exposure by

D. R. Duncan; R. J. Puigh; E. K. Opperman

1981-01-01

196

Influence of Width of Specimen on Tensile Properties of NiCo Thin Film  

NASA Astrophysics Data System (ADS)

This paper represents the results of tensile test for NiCo thin films, to investigate the size effect on tensile properties. An axial loading tensile tester developed by authors was used to measure the mechanical characteristics of thin film materials. The tester has a load cell with maximum capacity of 0.5N and a non-contact position measuring system based on the principle of capacitance micrometry. The “dog-bone” type specimen was designed and fabricated by electroplating process. The 50 and 150?m width of reduced section respectively were designed on 6 in. wafer. The length of reduced section is 1,000?m and the radius of the blending fillet is 1,000?m to minimize a stress concentration of the specimen. The thickness is 10?m. The elastic moduli of NiCo thin film were about 18 ± 4.1GPa for 50?m width and about 148 ± 8.4GPa for 150?m width. The ultimate tensile strength for the width of 50 and 150?m were 2,431±87.8 and 2,348±93.3MPa, respectively. However, the difference between tensile strengths is a little, as 3.3%.

Park, Jun-Hyub; An, Joong-Hyok; Jeon, Yun-Bae; Kim, Yun-Jae; Huh, Yong-Hak

197

The tensile properties of hot-rolled (Al 2O 3) pAl composites  

Microsoft Academic Search

Hot rolling was carried out on the extruded Al alloy 6061 composite reinforced with Al2O3 particulates ((Al2O3)p-Al composite) along a direction perpendicular to the extrusion direction of the composite. Room-temperature tensile tests of the hot-rolled composites showed a significant increase in strength and fracture strain along the transverse (rolling) direction with increasing reduction in rolling. However, the same properties along

J. C. Lee; K. N. Subramanian

1995-01-01

198

Tensile properties and morphology of S 2 Cl 2 treated PVC-g-butly rubber  

Microsoft Academic Search

We have grafted butyl rubber from PVC under a variety of conditions. The physical-mechanical properties of these graft copolymers have been examined both before and after extraction with hexane of the ungrafted butyl rubber. We have found a significant increase in the tensile strength of these materials upon S2Cl2 treatment (curing) in THF solution. This increase was observed even with

Prakash D. Trivedi; Richard J. Ambrose

1979-01-01

199

Tensile properties of alumina fibers using hot grips  

SciTech Connect

Tensile testing of single-crystal Al[sub 2]O[sub 3] fibers was conducted using a hot-grip method developing during this study. Fracture strength was measured between 25 and 1,500 C and was found to decrease with increasing temperature. However, a strength minimum, observed by others between 400 and 900 C, appeared to be absent. The experimental results are in good agreement with calculated fracture strength values based on the fracture toughness of cleavage planes up to 1,200 C. Strain rate experiments carried out at 1,300 C indicate that strength is strongly time dependent. Fracture originates from both surface flaws and internal pores in the fibers.

Uenal, O.; Lagerloef, K.P.D. (Case Western Reserve Univ., Cleveland, OH (United States). Dept. of Materials Science and Engineering)

1994-10-01

200

Tensile Properties of Plasticized Pvc as a Function of Processing.  

National Technical Information Service (NTIS)

A statistical study was made of the tensile properties of plasticized PVC as a function of processing variables and environmental exposure. For this purpose, the performance of three polyester plasticizers was studied in a typical 105C. wire-coating formu...

C. D. Bias A. W. M. Coaker J. D. Hinchen

1967-01-01

201

Effects of carbon percentage, Stelmor cooling rate and laying head temperature on tensile strength gain in low carbon steels  

NASA Astrophysics Data System (ADS)

Low carbon steel wire rods are used to produce finished products such as fine wire, coat hangers, staples, and roofing nails. These products are subjected to excessively high work hardening rates during wire drawing process resulting in a variation in wire tensile strength. This research analyzes the effects of carbon percentage, StelmorRTM cooling rate and laying head temperature on the tensile strength gain in wire drawn low carbon steels using design of experiments. The probable reasons for variations in tensile strength gain are analyzed by observing the microstructural changes during experiments. Microstructural analysis was done extensively using optical microscope and Transmission Electron Microscope (TEM) and it was found that the tensile strength gain variation is mainly caused by the increase in the dislocation density in wire rod and wire due to high cooling rate and high laying head temperature, within the range considered. This research concludes that a low carbon wire rod can be produced with minimum tensile strength gain, lower dislocation density and finer ferrite grain size by maintaining a low cooling rate in the StelmorRTM cooling zone and low laying head temperature, which is the temperature at which the wire rod coils are laid on the Stelmor RTM deck. It is also concluded from the results of the present study that: (1) The lowest tensile strength gain is for NS 1006T-3 (0.07 wt.% Carbon) with low cooling rate of 14°F/s and low laying head temperature of 1500°F. (2) The highest tensile strength gain is for NS 1006T-3 with high cooling rate of 26°F/s and high laying head temperature of 1650°F. (3) The effect of StelmorRTM cooling rate and laying head temperature and their interaction are found to be the significant factors causing the variation in wire tensile strength gain. The StelmorRTM cooling rate has the most significant effect on tensile strength gain among the three factors. (4) The effect of carbon percentage on wire tensile strength gain is very minimal. (5) With an increase in the StelmorRTM cooling rate from 14°F/s to 26°F/s, there is a substantial increase in the dislocation densities in the wire rods and wires, which is the primary cause of the increase in the tensile strength gain. (6) The effect of carbon percentage on wire tensile strength gain is very minimal. North Star Steel Texas would benefit substantially from this research by being able to produce better quality wire rods, through better understanding of the factors affecting the tensile strength gain variation. This is expected to lead to a reduction in customer complaints on failure of wire products.

Gade, Surya Prakash

202

Effects of solvent drying time and water storage on ultimate tensile strength of adhesives.  

PubMed

AIM: Simplified adhesives are a blend of monomers with solvents that are expected to evaporate before light curing. The aim of the present study was to evaluate the effects of drying time and water storage on the ultimate tensile strength (UTS) of three adhesives: Adper Single Bond 2 (ASB), One-Step Plus (OSP) and Clearfil S(3) Bond (CSB). METHODS: Dumbbell-shaped samples from each adhesive were prepared in three groups: (a) air drying prior to light curing; (b) no drying equal to active air drying; and (c) 3-h drying. Each group was further divided into two subgroups of no storage or 7 days' water storage, prior to the UTS measurement (n = 10). RESULTS: Material, drying-time, and storage had a significant effect on UTS, and the interactions of the factors were also significant (P < 0.05). OSP showed a higher evaporation rate under passive air drying, and OSP and CSB showed higher UTS values compared to ASB (P < 0.05). Air drying improved UTS in OSP and CSB, but not in ASB. Likewise, water storage only affected the UTS of OSP and CSB. CONCLUSIONS: The effects of air drying and water storage period on UTS are material dependent. Whenever solvent evaporation improved the UTS of adhesive, water storage decreased it. The all-in-one self-etching adhesive can maximize its best properties when the solvent is dried for an extended period. PMID:23355434

Emamieh, Shila; Sadr, Alireza; Ghasemi, Amir; Torabzadeh, Hassan; Akhavanzanjani, Vegharedin; Tagami, Junji

2013-01-25

203

Hydrogen Embrittlement of a 1500-MPa Tensile Strength Level Steel with an Ultrafine Elongated Grain Structure  

NASA Astrophysics Data System (ADS)

A deformation of a tempered martensitic structure ( i.e., tempforming) at 773 K (500 °C) was applied to a 0.6 pct C-2 pct Si-1 pct Cr steel. The hydrogen embrittlement (HE) property of the tempformed (TF) steel was investigated by a slow strain rate test (SSRT) and an accelerated atmospheric corrosion test (AACT). Hydrogen content within the samples after SSRT and AACT was measured by thermal desorption spectrometry (TDS). The tempforming at 773 K (500 °C) using multipass caliber rolling with an accumulative are reduction of 76 pct resulted in the evolution of an ultrafine elongated grain (UFEG) structure with a strong <110>//rolling direction (RD) fiber deformation texture and a dispersion of spheroidized cementite particles. The SSRT of the pre-hydrogen-charged notched specimens and the AACT demonstrated that the TF sample had superior potential for HE resistance to the conventional quenched and tempered (QT) sample at a tensile strength of 1500 MPa. The TDS analysis also indicated that the hydrogen might be mainly trapped by reversible trapping sites such as grain boundaries and dislocations in the TF sample, and the hydrogen trapping states of the TF sample were similar to those of the QT sample. The QT sample exhibited hydrogen-induced intergranular fracture along the boundaries of coarse prior-austenite grains. In contrast, the hydrogen-induced cracking occurred in association with the UFEG structure in the TF sample, leading to the higher HE resistance of the TF sample.

Nie, Yihong; Kimura, Yuuji; Inoue, Tadanobu; Yin, Fuxing; Akiyama, Eiji; Tsuzaki, Kaneaki

2012-05-01

204

Influence of heat treatment on the tensile properties and fracture behaviour of an aluminium alloy-ceramic particle composite  

Microsoft Academic Search

The tensile deformation and fracture behaviour of aluminium alloy 2124 reinforced with different amounts of silicon carbide particulates was studied, in the as-extruded and heat-treated conditions, with the objective of investigating the influence of heat treatment and composite microstructural effects on tensile properties and quasi-static fracture behaviour. Results indicate that for a given microstructural condition, the elastic modulus and strength

T. S. Srivatsan; J. Mattingly

1993-01-01

205

Determination of impact tensile properties of structural epoxy adhesive butt joints using a hat-shaped specimen  

Microsoft Academic Search

The impact tensile properties of structural epoxy adhesive butt joints are determined with a modified version of the split Hopkinson pressure bar using a hat-shaped joint specimen. A typical two-component structural epoxy adhesive and two different adherend materials (Al alloy 7075-T6 and 99% pure titanium) are used in the adhesion tests. The impact joint tensile strength is evaluated from the

T. Yokoyama; K. Nakai

2006-01-01

206

Tensile properties of LBW welds in Ti–6Al–4V alloy at evaluated temperatures below 450 °C  

Microsoft Academic Search

The influence of temperatures below 450 °C on the tensile properties of laser beam (LB) welds in dual phase Ti–6Al–4V titanium alloy was investigated. The ultimate tensile strength of the weldment is slightly superior than that of the as-received parent materials. Conversely, the yield stress of the weldment is inferior to that of the parent metal, especially in the 150–450

S. H Wang; M. D Wei; L. W Tsay

2003-01-01

207

Microstructure, tensile properties and fracture behaviour of Al2O3 particulate-reinforced aluminium alloy metal matrix composites  

Microsoft Academic Search

The tensile deformation and fracture behaviour of aluminium alloy 2014 discontinuously-reinforced with particulates of Al2O3 was studied with the primary objective of understanding the influence of reinforcement content on composite microstructure, tensile properties and quasi-static fracture behaviour. Results reveal that elastic modulus and strength of the metal-matrix composite increased with reinforcement content in the metal matrix. With increase in test

T. S. Srivatsan

1996-01-01

208

Laser solder repair technique for nerve anastomosis: temperatures required for optimal tensile strength  

NASA Astrophysics Data System (ADS)

Laser-assisted repair of nerves is often unsatisfactory and has a high failure rate. Two disadvantages of laser assisted procedures are low initial strength of the resulting anastomosis and thermal damage of tissue by laser heating. Temporary or permanent stay sutures are used and fluid solders have been proposed to increase the strength of the repair. These techniques, however, have their own disadvantages including foreign body reaction and difficulty of application. To address these problems solid protein solder strips have been developed for use in conjunction with a diode laser for nerve anastomosis. The protein helps to supplement the bond, especially in the acute healing phase up to five days post- operative. Indocyanine green dye is added to the protein solder to absorb a laser wavelength (approximately 800 nm) that is poorly absorbed by water and other bodily tissues. This reduces the collateral thermal damage typically associated with other laser techniques. An investigation of the feasibility of the laser-solder repair technique in terms of required laser irradiance, tensile strength of the repair, and solder and tissue temperature is reported here. The tensile strength of repaired nerves rose steadily with laser irradiance reaching a maximum of 105 plus or minus 10 N.cm-2 at 12.7 W.cm-2. When higher laser irradiances were used the tensile strength of the resulting bonds dropped. Histopathological analysis of the laser- soldered nerves, conducted immediately after surgery, showed the solder to have adhered well to the perineurial membrane, with minimal damage to the inner axons of the nerve. The maximum temperature reached at the solder surface and at the solder/nerve interface, measured using a non-contact fiber optic radiometer and thermocouple respectively, also rose steadily with laser irradiance. At 12.7 W.cm-2, the temperatures reached at the surface and at the interface were 85 plus or minus 4 and 68 plus or minus 4 degrees Celsius respectively. This study demonstrates the feasibility of the laser-solder repair technique for nerve anastomosis resulting in improved tensile strength. The welding temperature required to achieve optimal tensile strength has been identified.

McNally, Karen M.; Dawes, Judith M.; Lauto, Antonio; Parker, Anthony E.; Owen, Earl R.; Piper, James A.

1998-01-01

209

Microstructure effects on tensile properties of tungsten-Nickel-Iron composites  

NASA Astrophysics Data System (ADS)

Controlled processing of heavy alloys containing 88 to 97 pct W resulted in high sintered densities and excellent bonding between the tungsten grains and matrix. For these alloys, deformation and fracture behavior were studied via slow strain rate tensile testing at room temperature. The flow stress increased and the fracture strain decreased with increasing tungsten content. The tradeoff between strength and ductility resulted in a maximum in the ultimate tensile strength at 93 pct W. Microstructure variations, notably grain size, explain sintering temperature and time effects on the properties. During tensile testing, cracks formed on the surface of the specimens at tungsten-tungsten grain boundaries. The crack density increased with plastic strain and tungsten content. The surface cracks, though initially blunted by the matrix, eventually increased in density until catastrophic failure occurred. An empirical failure criterion was developed relating fracture to a critical value of the surface crack tip separation distance. Application of the model explains the effects of microstructural variables on tensile properties.

Rabin, B. H.; German, R. M.

1988-06-01

210

Correlation between nanoindentation and tensile properties  

Microsoft Academic Search

The nanoindentation test has become one of the most broadly expanded techniques used to measure the mechanical properties in a sub-micron range. However, the interpretation of the data is very difficult due to the Indentation Size Effect (ISE). The ISE can be defined as an increase of the nanohardness by decreasing the indentation depth of the test. In the present

R. Rodr??guez; I. Gutierrez

2003-01-01

211

The tensile strength of various peripheral circumferential repair techniques in canine flexor tendons  

Microsoft Academic Search

The purpose of this study was to evaluate the tensile strength of six peripheral circumferential suture techniques, using\\u000a a variable number of suture strands. Transverse lacerations were made in 184 fresh frozen canine flexor profundus tendons\\u000a and repaired using only a 6-0 Prolene circumferential suture. The six running suture techniques were: Simple, Simple-locking,\\u000a Lembert, Halsted, Cross-stitch and Lin-locking, and 6,

Hideaki Kubota; Mitsuhiro Aoki; Donald L. Pruitt; Paul R. Manske; Yoichi Sugioka

1996-01-01

212

Effect of different surface treatments on tensile bond strength of silicone-based soft denture liner  

Microsoft Academic Search

Failure of the bond between the acrylic resin and resilient liner material is commonly encountered in clinical practice. The\\u000a purpose of this study was to investigate the effect of different surface treatments (sandblasting, Er:YAG, Nd:YAG, and KTP\\u000a lasers) on tensile bond strength of silicone-based soft denture liner. Polymethyl methacrylate test specimens were fabricated\\u000a and each received one of eight surface

Hakan Akin; Faik Tugut; Burcu Mutaf; Gulsah Akin; A. Kemal Ozdemir

213

Tensile strength of mesh fixation methods in laparoscopic incisional hernia repair  

Microsoft Academic Search

  Background: Fixation of the mesh is crucial for the successful laparoscopic repair of incisional hernias. In the present\\u000a experimental study, we used a pig model to compare the tensile strengths of mesh fixation with helical titanium coils (tackers)\\u000a and transabdominal wall sutures. Methods: Thirty-six full-thickness specimens (5 × 7 cm) of the anterior abdominal wall of\\u000a nine pig cadavers were

M. Riet; P. J. Steenwijk; G. J. Kleinrensink; E. W. Steyerberg; H. J. Bonjer

2002-01-01

214

The influence of output current on the tensile strength of laser-welded titanium joints  

Microsoft Academic Search

The objective of this study was to examine the influences of the laser output current on the tensile strength of laser-welded\\u000a titanium bar. Titanium bars of 3 mm in diameter were perpendicularly cut to 30 mm in length for the laser welding. Two bars\\u000a were fixed to each other with a jig and welded vertically with the light of a

Dae Hee Won; Tae Sung Bae; Shoji Ohkawa; Fumio Watari

2003-01-01

215

Tensile Bond Strength and SEM Evaluation of Caries-affected Dentin Using Dentin Adhesives  

Microsoft Academic Search

Tensile bond strength measurements are commonly used for the evaluation of dentin adhesive systems. Most tests are performed using extracted non-carious human or bovine dentin. However, the adhesion of resins to caries-affected dentin is still unclear. The objectives of this study were to test the hypothesis that bonding to caries-affected dentin is inferior to bonding to normal dentin, and that

M. Nakajima; H. Sano; M. F. Burrow; J. Tagami; M. Yoshiyama; S. Ebisu; B. Ciucchi; C. M. Russell; D. H. Pashley

1995-01-01

216

Dependence of fatigue limit of high-tension bolts on mean stress and ultimate tensile strength  

Microsoft Academic Search

High tension bolts in critical joints in internal combustion engines are susceptible to fatigue failure. Computeraided bolted\\u000a joint design procedures require knowledge of the dependence of bolt fatigue limit on the mean stress and ultimate tensile\\u000a strength. This dependence is investigated with staircase fatigue limit tests. The test results show that when the bolt fatigue\\u000a limit is estimated with the

S.-S. Cho; H. Chang; K. W. Lee

2009-01-01

217

Analytical modeling and experimental study of tensile strength of asphalt concrete composite at low temperatures  

Microsoft Academic Search

In this study, analytical modeling of the tensile strength of hot-mix asphalt (HMA) mixtures at low temperatures was developed. To do this, HMA mixtures were treated as a two-phase composite material with aggregates (coarse and fine) dispersed in an asphalt mastic matrix. A two-phase composite model, which was similar to Papanicolaou and Bakos's [J. Reinforced Plast. Compos. 11 (1992) 104

Baoshan Huang; Guoqiang Li; Louay N. Mohammad

2003-01-01

218

Influence of Bolting Parameters on the Ultimate Tensile Strength and Stiffness of Composite-Metal Joints  

Microsoft Academic Search

The joining of dissimilar materials poses a challenge in mechanical structures. The objective of this research was to investigate the effect of joining parameters such as bolt spacing, geometry configuration, and overlap length on ultimate failure strength and stiffness of composite-metal hybrid joints. Woven fiberglass\\/epoxy and unidirectional carbon-fiber\\/epoxy composites have been manufactured and tested under tensile loads to obtain their

William S. Slovinsky; Parsaoran Hutapea

2010-01-01

219

Tensile strength of thin resin composite layers as a function of layer thickness.  

PubMed

As a rule, cast restorations do not allow for free curing contraction of the resin composite luting cement. In a rigid situation, the resulting contraction stress is inversely proportional to the resin layer thickness. Adhesive technology has demonstrated, however, that thin joints may be considerably stronger than thicker ones. To investigate the effects of layer thickness and contraction stress on the tensile strength of resin composite joints, we cured cylindrical samples of a chemically initiated resin composite (Clearfil F2) in restrained conditions and subsequently loaded them in tension. The samples had a diameter of 5.35 mm and thicknesses of 50, 100, 200, 300, 400, 500, 600, and 700 microns, 1.4 mm, or 2.7 mm. None of the samples fractured due to contraction stress prior to tensile loading. Tensile strength decreased gradually from 62 +/- 2 MPa for the 50-microns layer to 31 +/- 4 MPa for the 2.7-mm layer. The failures were exclusively cohesive in resin for layers between 50 and 400 microns thick. Between 500 and 700 microns, the failures were cohesive or mixed adhesive/cohesive, while the 1.4- and 2.7-mm layers always failed in a mixed adhesive/cohesive mode. For the resin composite tested, the contraction stress did not endanger the cohesive strength. It was concluded that if adhesion to tooth structure were improved, thinner adhesive joints might enhance the clinical success of luted restorations. PMID:8530735

Alster, D; Feilzer, A J; De Gee, A J; Davidson, C L

1995-11-01

220

The tensile strengths of heterogeneous interfaces: A comparison of static and dynamic first-principles calculations  

NASA Astrophysics Data System (ADS)

First-principles molecular dynamics (FPMD) simulations and static quantum chemical (QC) calculations are used to evaluate the tensile strengths, ?c, of interfaces consisting of (0001) surfaces of ?-Al2O3 separated by small organic species. The evaluation of ?c with FPMD was achieved by performing simulations in which the simulation cell was extending in a direction normal to the fracture plane until rupture of the interface occurred. The static QC calculations employed an approach which treated fracture of the interface as a competition between uniform extension of the simulation cell and crack formation at the rupture site, which is analogous to that used in the construction of universal binding energy relationships. The results showed that the static QC calculations accurately reproduced the FPMD simulations with respect to tensile strength and the cell extension at which rupture occurred, provided that the rupture site employed in the static calculations matched the site at which rupture occurred during the FPMD simulations. A simple strategy for identifying the rupture site, even in complex systems containing many potential rupture sites, is proposed. Overall, the work extends the calculation of tensile strengths with static QC methods to highly heterogeneous interfaces, thus providing a computationally efficient alternative to demanding FPMD simulations for this purpose.

Zhu, Hongjuan; Mosey, Nicholas J.

2011-12-01

221

Tensile properties of neutron-irradiated Nimonic PE16  

SciTech Connect

Tension specimens of Nimonic PE16 in the solution-treated and aged condition were irradiated in the experimental breeder reactor II to a maximum fluence of approximately 7 X 10/sup 22/ neutrons/cm/sup 2/ (E>0.1 MeV) over a temperature range of 450 to 735 degree C. Tension tests were conducted at 232 degree C (fuel handling temperature), temperature to simulate transient reactor events. The alloy exhibited high strength and adequate ductility at 232 degree C. At the irradiation temperature, the strength remained high; however, a loss in ductility occurred. No significant loss in grain boundary fracture stress was observed in the tests showing low ductility values. The loss in ductility can be explained by reduced differential between ultimate tensile strength and the yield stress.

Bajaj, R.; Shogan, R.P.; DeFlitch, C.; Fish, R.L.; Paxton, M.M.; Bleiberg, M.L.

1981-01-01

222

Tensile properties and microstructure of helium implanted EUROFER ODS  

NASA Astrophysics Data System (ADS)

To study the effect of helium (He) on tensile properties and microstructure of oxide dispersion strengthened EUROFER-ODS steel, flat tensile specimens were homogeneously implanted with 30 MeV ?-particles at the NRC KI cyclotron up to 1000 appm He at 573 K and 773 K. High-resolution and energy-filtered transmission electron microscopy showed that partly coherent Y2O3 particles are strong trapping centers for diffusing He atoms (at least up to 773 K) in reduced activation ferritic/martensitic 9Cr-1WMnVTa-0.3Y2O3 steel. After 573 K and 773 K implantation the He bubbles or He filled voids have average diameters of 1.9 and 4.2 nm with concentrations about 8 × 1022 and 7 × 1022 m-3, respectively. Tensile testing after 573 K implantation revealed a uniform elongation of more than 10%, despite an irradiation induced hardening of about 250 MPa. The role that nanoscaled Y2O3 particles play in He distribution, tensile properties, and on the mitigation of He embrittlement are discussed.

Ryazanov, A. I.; Chugunov, O. K.; Ivanov, S. M.; Latushkin, S. T.; Lindau, R.; Möslang, A.; Nikitina, A. A.; Prikhodko, K. E.; Semenov, E. V.; Unezhev, V. N.; Vladimirov, P. V.

2013-11-01

223

The tensile strength of black bear (Ursus americanus) cortical bone is not compromised with aging despite annual periods of hibernation.  

PubMed

Black bears (Ursus americanus) may not develop disuse osteoporosis during long periods of disuse (i.e. hibernation) because they may be able to maintain bone formation. Previously, we found that cortical bone bending strength was not compromised with age in black bears' tibias, despite annual periods of disuse. Here we showed that cortical bone tensile strength (166-198MPa) also does not decrease with age (2-14 years) in black bear tibias. There were also no significant age-related changes in cortical bone porosity in black bear tibias. It is likely that the ability of black bears to maintain bone formation during hibernation keeps bone porosity low (2.3-8.6%) with aging, notwithstanding annual periods of disuse. This low porosity likely preserves ultimate stress with aging. Female bears give birth and nurse during hibernation; however, we found no significant differences between male and female tensile material properties, mineral content, or porosity. Our findings support the idea that black bears, which hibernate 5-7 months annually, have evolved biological mechanisms to mitigate the adverse effects of disuse on bone porosity and strength. PMID:16115638

Harvey, Kristin B; Drummer, Thomas D; Donahue, Seth W

2005-11-01

224

Tensile Properties and Deformation Characteristics of a Ni-Fe-Base Superalloy for Steam Boiler Applications  

NASA Astrophysics Data System (ADS)

Ni-Fe-base superalloys due to their good manufacturability and low cost are the proper candidates for boiler materials in advanced power plants. The major concerns with Ni-Fe-base superalloys are the insufficient mechanical properties at elevated temperatures. In this paper, tensile properties, deformation, and fracture characteristics of a Ni-Fe-base superalloy primarily strengthened by ?' precipitates have been investigated from room temperature to 1073 K (800 °C). The results showed a gradual decrease in the strength up to about 973 K (700 °C) followed by a rapid drop above this temperature and a ductility minimum at around 973 K (700 °C). The fracture surfaces were studied using scanning electron microscopy and the deformation mechanisms were determined by the observation of deformed microstructures using transmission electron microscopy. An attempt has been made to correlate the tensile properties and fracture characteristics at different temperatures with the observed deformation mechanisms.

Zhong, Zhihong; Gu, Yuefeng; Yuan, Yong; Shi, Zhan

2013-08-01

225

Effects of ? phase precipitation on crevice corrosion and tensile strength in Ti–15Mo alloy  

Microsoft Academic Search

The effects of the ? phase precipitation on the crevice corrosion at 373K and the tensile properties at ambient temperature were investigated in the Ti–15Mo alloy. Relatively coarse ? phase precipitates with the depletion of Mo formed in the alloy after aging at 873K. The aged alloy maintained high crevice corrosion resistance in the 10% NaCl water solution with a

X. H. Min; S. Emura; T. Nishimura; L. Zhang; S. Tamilselvi; K. Tsuchiya; K. Tsuzaki

2010-01-01

226

Effect of Welding and Post-weld Heat Treatment on Tensile Properties of Nimonic 263 at Room and Elevated Temperatures  

NASA Astrophysics Data System (ADS)

Nimonic 263 has been developed for the improved ductility in welded assemblies and is a candidate material for gas turbine combustor and transition pieces along with its good weldability and mechanical properties at room and elevated temperatures. In this study, the tensile behavior of an as-welded Nimonic 263 specimen at room temperature and 1053 K (780 °C) was examined in conjunction with microstructural evolution during welding and postweld heat treatment (PWHT). With the welding and the PWHT, the yield strength (YS), ultimate tensile strength (UTS), and tensile elongation of Nimonic 263 varied in a complex manner. It was observed that the PWHT of resolutionization at 1423 K (1150 °C) for 2 hours gave the highest YS and UTS values, whereas the tensile elongation was the lowest, at both testing temperatures. With increasing resolutionization time, the YS and UTS tended to decrease along with the increase in tensile ductility. The tensile behaviors of as-welded Nimonic 263 specimens was affected by several factors, including grain size, residual stress, possible microsegregation of ?' forming elements, a tendency for interdendritic or intergranular fracture and a morphological change in both M23C6 and MC type carbides, depending on the testing temperature and the PWHT. The complex changes in tensile properties of Nimonic 263 with welding and PWHT at room temperature and 1053 K (780 °C) were discussed based on the micrographic and fractographic observations.

Jeon, Minwoo; Lee, Jae-Hyun; Woo, Ta Kwan; Kim, Sangshik

2011-04-01

227

Tensile and Charpy impact properties of irradiated reduced-activation ferritic steels  

SciTech Connect

Tensile tests were conducted on 8 reduced-activation Cr-W steels after irradiation to 15-17 and 26-29 dpa, and Charpy impact tests were conducted on steels irradiated to 26-29 dpa. Irradiation was in Fast Flux Test Facility at 365 C on steels containing 2.25-12% Cr, varying amounts of W, V, and Ta, and 0.1%C. Previously, tensile specimens were irradiated to 6-8 dpa and Charpy specimens to 6-8, 15- 17, and 20-24 dpa. Tensile and Charpy specimens were also thermally aged to 20,000 h at 365 C. Thermal aging had little effect on tensile properties or ductile-brittle transition temperature (DBTT), but several steels showed a slight increase in upper-shelf energy (USE). After 7 dpa, strength increased (hardened) and then remained relatively unchanged through 26-29 dpa (ie, strength saturated with fluence). Post-irradiation Charpy impact tests after 26-29 dpa showed that the loss of impact toughness (increased DBTT, decreased USE) remained relatively unchanged from the values after 20-24 dpa, which had been relatively unchanged from the earlier irradiations. As before, the two 9Cr steels had the most irradiation resistance.

Klueh, R.L.; Alexander, D.J.

1996-10-01

228

Dynamic Tensile Strength of Crustal Rocks and Application to Impact Cratering  

NASA Astrophysics Data System (ADS)

Dynamic tensile strengths of two crustal rocks, San Marcos gabbro and Coconino sandstone (Meteor Crater, Arizona), were determined by carrying out flat plate impact experiments. Porosity of San Marcos gabbro is very low, and the reported porosity for Coconino sandstone is approx. 25%. Aluminum flyer plates were used for gabbro with impact velocities of 13 to 50 m/s, which produce tensile stresses in the range of 120 to 450 MPa. PMMA flyer plates were used for sandstone with impact velocities of 5 to 25 m/s, resulting tensile stresses in the range of approx. 13 to 55 MPa. Impact was normal to the bedding of sandstone. Tensile duration times for two cases were approx. 1 and approx. 2.3 microns, respectively. Pre-shot and post-shot ultrasonic P and S wave velocities were measured for the targets. Velocity reduction for gabbro occurred at approx. 150 MPa, very close to the earlier result determined by microscopic examination. The reduction of S wave is slightly higher than that of P wave. This indicates that the impact-induced cracks were either aligned, or there were residual fluids within cracks, or both. Data for sandstone velocity reduction was few and scattered caused by its high porosity. The range of dynamic tensile strength of Coconino sandstone is within 25 and 30 MPa. Obvious radial cracks at certain stresses indicate that deformation was not restricted to one dimensional strain as being assumed. Spall fragmentation occurred above 40 MPa. The combination of impact velocities, U (km/s), and impactor radii, a0)(m, are constrained by Meteor Crater fracture depth, approx. 850 m, and the dynamic tensile fracture strength from our experiments, 40 MPa. Volume of the crater for each impact was calculated using V = 0.009mU1.65, where V is crater volume (cu m), m is the mass of the impactor (kg). Volume of impact with U = 28 km/s, a0 = 10 m is close to the real Meteor Crater volume, 7.6e7 cu m. Impact energy for this case is 3.08 Mt., which agrees well with theoretical calculation (3.3 to 7.4 Mt.).(1 Mt. = 4.18e 15J).

Ai, H.; Ahrens, T. J.

2003-01-01

229

Immediate and delayed micro-tensile bond strength of different luting resin cements to different regional dentin.  

PubMed

We sought to evaluate immediate and delayed micro-tensile bond strength of Panavia F2.0 and Multilink Sprint resin cement to superficial, deep and cervical dentin. Thirty-six freshly extracted non-carious human molars were sectioned in the mesiodistal direction to expose three different dentin regions including superficial dentin (1 mm below the dentine-enamel junction), deep dentin (1 mm above the highest pulp horn) and cervical dentin (0.5 mm above the cemento-enamel junction and 0.5 mm below the dentine-enamel junction). Resin cements were applied on dentin surfaces and composite blocks were luted under constant seating pressure. Each group was divided into three subgroups according to time intervals. Specimens were sectioned to obtain sticks of 1 mm(2) in diameter and subjected to microtensile bond strength testing at a cross head speed of 1 mm/min. Both resin cements showed higher micro-tensile bond strength to superficial dentin than that to deep or cervical dentin (P < 0.001). Micro-tensile bond strengths of Panavia F2.0 were higher than those of Multilink Sprint at different dentin regions (P < 0.001). Immediate micro-tensile bond strengths were higher than those of delayed micro-tensile bond strengths for both resin cements (P < 0.001). It was concluded that resin cements with different chemical formulations and applications yield significantly different micro-tensile bond strengths to different dentin regions. PMID:23554806

Ali, Abdelraheem Mohamed; Hamouda, Ibrahim Mohamed; Ghazy, Mohamed Hamed; Abo-Madina, Manal Mohamed

2012-12-06

230

Reaction synthesis of Ni\\/Ni 3Al multilayer composites using Ni and Al foils: High-temperature tensile properties and deformation behaviour  

Microsoft Academic Search

The effects of temperature on the tensile properties and deformation behaviour of Ni\\/Ni3Al multilayer composites have been systematically investigated. With increasing tensile test temperature from room temperature to 600°C, the ultimate tensile strength decreased. The ‘abnormal’ strengthening of Ni3Al gave rise to a reduction in the capability for cooperative deformation between the Ni and the Ni3Al layers at elevated temperatures.

Huabin Wang; Jiecai Han; Shanyi Du; Derek O. Northwood

2008-01-01

231

Tensile properties of the in vivo human gastrocnemius tendon  

Microsoft Academic Search

In the present experiment we obtained the tensile properties of the human gastrocnemius tendon, a high-stressed tendon suitable for spring-like action during locomotion. Measurements were taken in vivo in six men. The gastrocnemius tendon elongation during tendon loading?unloading induced by muscle contraction?relaxation was measured using real-time ultrasonography. Tendon forces were calculated from the moment generated during isometric plantarflexion contraction, using

Constantinos N Maganaris; John P Paul

2002-01-01

232

Tensile properties of glass microballoon-epoxy resin syntactic foams  

Microsoft Academic Search

The effect of hollow glass particle (microballoon) volume fraction in the range of 0.3-0.6 on the tensile properties and fracture mode of syntactic foams is characterized in the present research. Sixteen types of syntactic foams have been fabricated and tested. Four types of glass microballoons, having 220, 320, 380 and 460 kg\\/m 3 density, are used with epoxy resin matrix

Nikhil Gupta; Ruslan Nagorny

2006-01-01

233

Tensile properties of extruded ZK60–RE alloys  

Microsoft Academic Search

ZK60–RE alloys were made by melting ZK60 alloy and cerium-rich rare earth (RE) metal in an electric furnace. The content of RE is 0, 0.5, 1, 1.5, 2, 3 wt.% RE, respectively. The influence of RE on microstructure and tensile mechanical properties of ZK60 magnesium alloys was studied. The results showed that cerium-rich misch metal (MM) had an obvious effect

Chunjiang Ma; Manping Liu; Guohua Wu; Wenjiang Ding; Yanping Zhu

2003-01-01

234

Finite Element Analysis and Notched Tensile Strength Evaluation of Center-Hole 2D Carbon\\/Carbon Laminates  

Microsoft Academic Search

Finite element analysis (FEA) has been carried out on 2D carbon\\/carbon (C\\/C) laminates containing a central circular hole utilizing the ANSYS software package. The stress concentration factor obtained from the existing empirical relation is comparable with the FEA result. Utilizing the stress concentration factor and the un-notched tensile strength of the 2D carbon\\/carbon laminates, the notched tensile strength estimates are

V. Kamala Kannan; Vela Murali; A. Rajadurai; B. Nageswara Rao

2011-01-01

235

Tensile strength improvement of an Mg–12Gd–3Y (wt%) alloy processed by hot extrusion and free forging  

Microsoft Academic Search

An Mg–12Gd–3Y (wt%) alloy was prepared by conventional casting method using permanent steel mold. Then this alloy was subjected\\u000a to hot processing, involving hot extrusion and free forging. Tensile strength at room temperature can be improved, with the\\u000a highest ultimate tensile strength (UTS) value of 390.2 MPa achieved by hot extrusion in comparison to that of as-cast alloy.\\u000a Temperature dependence of

Li Lin; Lijia Chen; Zheng Liu

2008-01-01

236

Effect of abnormal grain growth on tensile strength of Al–Cu–Mg alloy friction stir welded joints  

Microsoft Academic Search

An Al-4.5%Cu-1.5%Mg aluminum alloy with a T4 temper was friction stir welded, and the effect of the abnormal grain growth\\u000a on the tensile strength of joints was investigated. Abnormal grain growth usually happens during post weld heat treatment.\\u000a It is found that the tensile strength and elongation of the heat-treated joint will increase significantly if this phenomenon\\u000a completely happens in

M. A. Safarkhanian; M. Goodarzi; S. M. A. Boutorabi

2009-01-01

237

Analysis of elevated-temperature tensile and creep properties of normalized and tempered 2 1\\/4 Cr1 Mo steel  

Microsoft Academic Search

Tensile and creep data were collected for normalized and tempered 2 1\\/4 Cr-1 Mo steel from American, Japanese, British, French, and German sources. These included creep data obtained at temperatures from 427 to 600°C (800 to 1112°F) and tensile data from room temperature to 550°C (1022°F). Properties examined included yield strength, ultimate tensile strength, 10⁵-h creep-rupture strength, and 10⁻⁵%\\/h creep

M. K. Booker; B. L. P. Booker; R. W. Swindeman

1982-01-01

238

Evaluation of Tensile Deformation Properties of Friction Stir Processed Pure Copper: Effect of Processing Parameters and Pass Number  

NASA Astrophysics Data System (ADS)

In this work, the tensile behavior of pure copper including ultimate tensile stress, yield stress, and elongation in the specimens friction stir processed under different processing parameters and pass adding was investigated in detail. The effect of strain hardening, grain refinement, and heat input on the tensile properties of these specimens was explained as well. It was observed that, regarding the aforementioned factors, the processing parameters and pass number could have considerable effects on the tensile deformation properties of the pure copper such as 300 and 47% enhancements in elongation and ultimate strength, respectively. It was demonstrated that higher passes resulted in the development of ultrafine grains (up to 700-800 nm) in the specimens. The fracture surface morphology was also used to further support the elongation results.

Barmouz, Mohsen; Besharati Givi, Mohammad Kazem; Jafari, Jalal

2013-10-01

239

A new tensile stage for in situ electron microscopy examination of the mechanical properties of ``superelastic'' specimens  

NASA Astrophysics Data System (ADS)

We have developed a novel tensile stage that can be used for in situ electron microscopy examination of the mechanical properties of ``superelastic'' materials. In our stage, one of the specimen clamps is replaced by a cylindrical roller, which when driven by a motor can easily stretch (``roll on'') any specimen irrespective of its plastic properties. We have used the so-called Roll-o-meter in the study of the tensile behavior of two different film formed latex formulations, here referred to as standard and novel. We find that the values of the tensile strength and extension to break of the studied systems, measured by using the Roll-o-meter, are similar to those measured by a Hounsfield tensile testing machine outside the microscope chamber. Further, in situ environmental scanning electron microscopy examination of the deformation and failure of the lattices revealed that the standard specimens exhibit a more ductile behavior, compared to the novel ones.

Dragnevski, Kalin I.; Fairhead, Trevor W.; Balsod, Rik; Donald, Athene M.

2008-12-01

240

Improvements of the Tensile Properties of Recycled High Density Polyethylene (HDPE) by the Use of Carbonized Olive Solid Waste  

Microsoft Academic Search

Recycling of plastic poses several concerns to manufacturers. The most important concern is the unpredictable of their mechanical properties (modulus of elasticity, tensile strength and ductility). Olive solid waste, an abundant material usually thrown into land causing harms to environment was mixed with HDPE plastic and used as a filling material. The mixture was fed to a house made extruder

Shadi Sawalha; Amer El-Hamouz

2010-01-01

241

Effect of Cold Work on Tensile Properties During Annealing Process for Pure Commercial Aluminum (AA 1070 Alloy)  

Microsoft Academic Search

The behavior of non-heat-treatable aluminum alloy in annealing process depends mainly on chemical composition and amount of cold work (strain) retained in the texture. This article discusses the effect of cold work on tensile properties during annealing process. The article discusses the steepness and magnitude of the decline in yield strength and the critical temperature, which has the greatest effect

Raed M. Al Qassab

2007-01-01

242

Effect of heat treatment on mechanical and ballistic properties of a high strength armour steel  

Microsoft Academic Search

In the present study an ultra high strength armour steel was austenatised at 910°C followed by tempering at 200, 300, 400, 500 and 600°C. After heat treatment the properties of tensile strength, ductility, charpy impact strength, hardness and microstructure were evaluated from the mechanical tests and metallographic analysis respectively. The ballistic behavior of the heat-treated plates was evaluated impacting against

P. K. Jena; Bidyapati Mishra; M. RameshBabu; Arvindha Babu; A. K. Singh; K. SivaKumar; T. Balakrishna Bhat

2010-01-01

243

Tensile Properties of Under-Matched Weld Joints for 950 MPa Steel.  

NASA Astrophysics Data System (ADS)

In welding of 950 MPa-class high tensile strength steel, preheating is crucial in order to avoid cold cracks, which, however, eventually increases welding deformations. One way to decrease welding deformations is lowering preheating temperature by using under-matched weld metal. Toyota and others clarify that although breaking elongation can decrease due to plastic constraint effect under certain conditions, static tensile of under-matched weld joints is comparable to that of base metal. However, there has still been no report about joint static tensile of under-matched weld joints applied to 950 MPa-class high tensile strength steel. In this study, we aim to research tensile strength and fatigue strength of under-matched weld joints applied to 950 MPa-class high tensile steel.

Yamamoto, Kouji; Arakawa, Toshiaki; Akazawa, Nobuki; Yamamoto, Kousei; Matsuo, Hiroki; Nakagara, Kiyoyuki; Suita, Yoshikazu

244

Influence of macrostructure on tensile properties of multipass SAW C-Mn steel deposits  

NASA Astrophysics Data System (ADS)

Blocks of 'all weld' metal were prepared by a multipass submerged arc process, using a C-Mn filler wire, at different welding currents and speeds by keeping the arc voltage constant. The variation in welding parameters was found to alter the macrostructure primarily by influencing its co-axial dendrite content. The chemical composition and hardness of the dendritic and the heat affected regions were affected little by the welding parameters. A dendrite content up to 37%, had no significant effect on the tensile properties. However an increase in it beyond 37% was found to enhance the UTS and YS and reduce percent elongation. The tensile strength was found to be a maximum in the L orientation and a minimum in the S direction. The use of post-weld heat treatment (PWHT) at 873 K caused spheroidization of cementite there by somewhat reducing the hardness and strength. The treatment while not affecting the basic dendritic morphology reduced the observed difference in tensile properties along the L, T and S directions. Implications of the data vis-a-vis industrial applications have been discussed.

Yongyuth, P.; Ghosh, P. K.; Gupta, P. C.; Patwardhan, A. K.; Prakash, Satya

1993-06-01

245

Tensile properties of fibroblasts and vascular smooth muscle cells.  

PubMed

Tensile properties of fibroblasts (FBs) and vascular smooth muscle cells (VSMCs) of synthetic and contractile phenotypes were studied using a newly developed micro-tensile tester. FBs were obtained from the rabbit patellar tendon. Synthetic and contractile VSMCs were isolated from the rabbit thoracic aorta with an explant and an enzymatic digestion method, respectively. Each cell was attached to the fine tips of a pair of micropipettes with a cell adhesive and, then, stretched at the speed of 6 microm/sec. Load and length were obtained using a cantilever-type load cell and a VDA, respectively.FBs were broken at the load of 0.9 microN and the elongation to failure of 86 microm, and had the stiffness of 0.02 N/m. VSMCs were not broken even at 2.4 microN. The stiffness of synthetic and contractile VSMCs were 0.09 and 0.17 N/m, respectively. Such large different tensile properties among the three cells are attributable to the differences in components and cytoskeletal structures. PMID:12454406

Miyazaki, Hiroshi; Hayashi, Kozaburo; Hasegawa, Yoshitaka

2003-01-01

246

New enzyme-based process direction to prevent wool shrinking without substantial tensile strength loss.  

PubMed

In this paper a new enzymatic process direction is described for obtaining machine washable wool with acceptable quality. In general, application of protease enzyme technology in wool processing results in considerable loss of tensile strength by diffusion of the enzyme into the interior of wool fibers. To overcome this disadvantage enzymatic activity has been more targeted to the outer surface of the scales by improving the susceptibility of the outer surface scale protein for proteolytic degradation. This has been realized by a pretreatment of wool with hydrogen peroxide at alkaline pH in the presence of high concentrations of salt. PMID:16791725

Lenting, H B M; Schroeder, M; Guebitz, G M; Cavaco-Paulo, A; Shen, J

2006-05-23

247

Properties of aluminum alloys: Tensile, creep, and fatigue data at high and low temperatures  

SciTech Connect

Based on work by Alcoa Laboratories over several years, this book compiles more than 300 tables listing typical average properties of a wide range of aluminum alloys. Contents include: Typical Mechanical Properties of Wrought and Cast Aluminum Alloys at Various Temperatures--tensile properties at subzero temperatures at temperature after various holding times at the test temperature, and at room temperature after exposure at various temperatures for various holding times; creep rupture strengths for various times at various temperatures; stresses required to generate various amounts of creep in various lengths of time; rotating-beam fatigue strengths; modulus of elasticity as a function of temperature; Fatigue Data--fatigue strength of wrought aluminum alloys, axial stress fatigue strength of wrought aluminum alloys (at various stress ratios, smooth and notched specimens), average fatigue strength for aluminum and aluminum alloy flat sheet specimens (under complete reversed flexure), cantilever-beam fatigue test results of aluminum alloys at elevated temperatures and following stabilization at the test temperature. The properties in this book are typical values--expected average values for representative lots produced using commercial processes and that meet industry standards, whose room temperature properties correspond to published typical values for the alloys.

Kaufman, J.G. (ed.)

1999-01-01

248

Evaluation of Interfacial Tensile Strength in Glass Fiber/Epoxy Resin Interface using the Cruciform Specimen Method  

NASA Astrophysics Data System (ADS)

Glass/epoxy interfacial tensile strength is investigated by the cruciform specimen method. The conventional transverse tensile test for single fiber composite is one of methods for evaluating the interfacial tensile strength, but stress singularity at the specimen edge is a very complicated problem to be solved. A cruciform specimen which has large width only around fiber embedded in transverse direction can potentially prevent the stress singularity problem. The cruciform specimen geometry is first discussed by means of finite element analysis considering experimental conditions. Transverse tensile test is conducted and an interfacial debonding which initiates at the middle of specimen not at edge is observed using the cruciform specimens. The interfacial tensile strength can be obtained by the value of stress concentration factor at interface multiplied by specimen stress. The location which the debonding initiates from is discussed and the validity of the evaluation method in this study is verified when interfacial tensile strength is as high as or lower than interfacial shear strength.

Ogihara, Shinji; Sakamoto, Yoriaki; Koyanagi, Jun

249

Tensile, compressive, and shear properties of a 64-kg\\/m3 polyurethane foam at low temperatures  

Microsoft Academic Search

Polyurethane foam, having a density of 64-kg\\/cu m, was tested at 295, 111, 76, and 4 K. The material properties reported are Young's modulus, proportional limit, yield strength (at 0.2% offset), tensile, shear, and compressive strengths, and elongation (elastic and plastic). To perform these tests, a unique apparatus was developed. This apparatus permits tension, compression, and shear testing of materials

J. M. Arvidson; L. L. Sparks; C. Guobang

1983-01-01

250

Tensile properties of commercially pure vanadium from room temperature to 1200°C  

Microsoft Academic Search

The tensile properties of vanadium are sensitive to interstitial impurity content, on grain size and strain rate. Thus, it is problematic to use published tensile data for materials potentially varying in these quantities. This investigation was undertaken to fully characterize the tensile properties of the commercially pure vanadium used at Lawrence Livermore. Both sheet and rod stock were tested in

G. A. Henshall; S. G. Torres

1993-01-01

251

Influence of strain rate on the quasi-static tensile strength of Kevlar 29 narrow fabrics  

SciTech Connect

Increasing the strain rate from 3 x 10/sup -4/ min/sup -1/ to 1.4 min/sup -1/ resulted in a 20% increase in fabric strength. Similar changes in strength with strain rate were obtained for warp yarns removed from the fabrics. Static and sliding loop yarn tests, and tests in which yarn was interwoven through wires, were used to determine effect of abrasion, bending and lateral compression as a function of strain rate. Results eliminated yarn damage by abrasion and demonstrated that unwoven yarn strength, in presence of bending or lateral compression, was dependent on strain rate. Yarn and fiber pullout tests showed that increasing strain rate caused a transition from stick-slip to smooth curves. Results suggested a mechanism whereby strain-rate dependent frictional behavior of Kevlar influences woven fabric strength. It appears that friction restrains highly loaded fibers in a fabric from adjusting their position to relieve stress concentrations. Yarn tensile strength is influenced by strain rate when the fiber arrangement has been altered by weaving or when bending or lateral compressive forces are also present.

Ericksen, R.H.

1981-01-01

252

Ab initio calculation of the ideal tensile and shear strength of cubic silicon nitride  

NASA Astrophysics Data System (ADS)

In this study, the ideal tensile and shear strength of the recently discovered cubic spinel silicon nitride polymorph was calculated using an ab initio density functional technique. The stress-strain curve of the cubic silicon nitride structure was calculated from simulations of applied ?11 and ?23 components of strain, and the ideal strengths were estimated at ˜45 and ˜49 GPa, respectively. In addition, the elastic constants of the cubic structure were determined and a value of ˜311 and ˜349 GPa was estimated for the bulk and shear modulus, respectively. The estimates of the elastic constants were found to be in reasonable agreement with existing data. Using a previously reported empirical relation, the hardness of the cubic phase was also estimated:?˜47 GPa.

Kocer, Cenk; Hirosaki, Naoto; Ogata, Shigenobu

2003-01-01

253

Tensile Property of Al-Mg-Sc-Zr Alloy at Cryogenic Temperature  

SciTech Connect

The tensile property and fracture characteristic of Al-Mg-Sc-Zr alloy have been investigated at 77 K, 123 K, 173 K, 223 K and 300 K respectively. Both the strength and elongation improved with decreasing temperature from 300 K to 77 K, particularly between 123 K and 77 K. However, the reduction of area exhibited a maximum at around 173 K. The fractographs of tensile specimens show a completely dimple-type ductile mode of fracture at 77 K and mixed type of fracture at 300 K, and the primary Al3(Sc,Zr) and Al6(Mn,Fe) phases are responsible for void and crack initiation at their interface with the matrix at cryogenic temperature.

Zhao, W. T.; Yan, D. S.; Li, X. Y.; Rong, L. J.; Li, Y. Y. [Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China)

2006-03-31

254

Grain boundary characteristics and tensile properties of Ti14 alloy after semi-solid deformation  

NASA Astrophysics Data System (ADS)

The microstructure and room-temperature tensile properties of Ti14, a new ?+Ti2Cu alloy, were investigated after conventional forging at 950°C and semi-solid forging at 1000 and 1050°C, respectively. Results show that coarse grains and grain boundaries are obtained in the semi-solid alloys. The coarse grain boundaries are attributed to Ti2Cu phase precipitations occurred on the grain boundaries during the solidification. It is found that more Ti2Cu phase precipitates on the grain boundaries at a higher semi-solid forging temperature, which forms precipitated zones and coarsens the grain boundaries. Tensile tests exhibit high strength and low ductility for the semi-solid forged alloys, especially after forging at 1000°C. Fracture analysis reveals the evidence of ductile failure mechanisms for the conventional forged alloy and cleavage fracture mechanisms for the alloy after semi-solid forging at 1050°C.

Chen, Yong-Nan; Wei, Jian-Feng; Zhao, Yong-Qing

2011-10-01

255

Evaluation of the Hoop Tensile Properties of a Steam Generator Tube  

NASA Astrophysics Data System (ADS)

The steam generators in a pressurized water reactor (PWR) are large heat exchangers that use the heat from the primary reactor coolant to make steam on the secondary-side to drive turbine generators. Hoop stress is known to be the main cause of fracture of inner pressurized tubes such as the steam generator tube. However, because the steam generator tube is too small to be manufactured to a standard tensile specimen in the hoop direction, the axial tensile properties of the steam generator tube (or original material properties) instead of hoop tensile properties have been used to estimate the fracture properties of a steam generator tube. In this study, we have conducted not only axial tensile tests but also ring tensile tests. From these test, both the axial and hoop tensile properties of steam generator tubes were obtained, and the reliability of the hoop tensile properties were confirmed by burst test of a real steam generator tube.

Cho, Sung-Keun; Seok, Chang-Sung; Bae, Bong-Kook; Koo, Jae-Mean

256

Evaluation in vitro of the tensile strength of crimpable hooks used for stabilization in orthognathic surgery.  

PubMed

OBJECTIVE: The aim of this study was to evaluate the tensile strength of crimpable hooks used for arch stabilization in orthognatic surgery. STUDY DESIGN: Ninety stainless steel wire (0.019" × 0.026") segments, each measuring 6 cm long, were used and attached to crimpable hooks of different commercial brands. Six groups were formed (n = 10) denominated as follows: control, in which the wire segments were perpendicularly welded by spot welding machine; and the hooks groups M (Morelli), MS (Morelli with weld), TP (TP Ortho), TPS (TP with weld), TPTg (TP-tungsten), TPTgS (TP-tungsten with weld), AO (American Orthodontics), and AOS (American Orthodontics with weld). The test specimen topography was evaluated by scanning electron microscopy before and after the tensile strength tests. After obtaining the results, the analysis of variance and Kruskal-Wallis multiple-comparison tests were applied. RESULTS: Compared with the control group, the AOS ball hooks and those from TPS required a greater amount of force to be displaced along the rectangular arch. The hooks in group M were significantly easier to displace, followed by those from AO. CONCLUSIONS: The best ball hooks for clinical application are those from AOS and TPS. PMID:21664150

Andrade Gomes, Nascimento Leonard Euller; Melo, Pithon Matheus; Lacerda, Santos Rogério; D'Albuquerque, Medeiros Paulo Jose

2011-06-01

257

Effect of Interfacial Reaction on the Tensile Strength of Sn3.5Ag\\/NiP and Sn37Pb\\/NiP Solder Joints  

Microsoft Academic Search

This work investigates the effect of interfacial reaction on the mechanical strength of two types of solder joints, Sn-3.5Ag\\/Ni-P\\u000a and Sn-37Pb\\/Ni-P. The tensile strength and fracture behavior of the joints under different thermal aging conditions have been\\u000a studied. It is observed that the tensile strength decreases with increasing aging temperature and duration. Associated with\\u000a the tensile strength decrease is the

Z. Chen; M. He; A. Kumar; G. J. Qi

2007-01-01

258

CARBON COMPOSITES BASED ON MULTI-AXIAL MULTI-PLY STITCHED PREFORMS: STIFFNESS DEGRADATION AND TENSILE STRENGTH EVOLUTION DURING FATIGUE  

Microsoft Academic Search

The fatigue properties of a 0°\\/90° carbon fibre non-crimp fabric reinforced epoxy composite were studied. Tensile-tensile fatigue cycling was carried out at load levels corresponding to the onset of damage in a static tensile test. Samples were tested in machine, cross and bias direction. Specimens in machine and cross direction did not fail up to 106 cycles; specimens in bias

Katleen Vallons; Mengmeng Zong; Stepan V. Lomov; Ignaas Verpoest

259

Tensile properties and swelling of 20%-cold-worked Type 316 stainless steel irradiated in HFIR  

SciTech Connect

Immersion density and elevated-temperature tensile properties were determined on 20%-cold-worked type 316 stainless steel irradiated in the HFIR at approximately 285, 370, 470, 560, and 620/sup 0/C to fluences of 1.8 to 6.2 x 10/sup 26/ neutrons/m/sup 2/ (> 0.1 MeV), which resulted in displacement damage levels of 16 to 54 dpa and helium concentrations of 900 to 3300 at. ppM. Tensile tests were done at temperatures near the estimated irradiation temperatures. Swelling increased with increasing irradiation temperature to a maximum of 2.1% at 620/sup 0/C. Irradiation at the lowest temperature (285 and 370/sup 0/C) increased the strength. At the higher irradiation temperatures, the strength decreased during irradiation. Ductility generally reflected the strength behavior: an increase in strength resulted in a descrease in ductility. When the present data are compared with previously published data, there is good agreement with one exception. Previous experiments showed a large decrease in ductility when irradiated at 600/sup 0/C and tested at 575/sup 0/C that was not observed in the present tests. There was also good agreement between HFIR-irradiated steel and literature data for EBR-II-irradiated steel.

Klueh, R.L.; Grossbeck, M.L.

1984-01-01

260

Effects of Irradiation on the Tensile Properties of Nb-1 Zr  

NASA Astrophysics Data System (ADS)

The alloy Nb-1 wt % Zr (Nb-lZr) has been selected for several in-core applications in the SP-100 reactor. Data on the effects of fast neutron irradiation on the tensile properties of Nb-lZr at proposed SP-100 operating temperatures are required to make certain that irradiated components have adequate ductility to preclude brittle failure during reactor transients or overpower conditions. Subsize (SS-1) tensile samples of Nb-lZr with average grain sizes of 22 and 73 ?m were irradiated up to end-of-life fluence at 1290, 1350, and 1400 K in temperature-controlled lithium filled capsules in the Fast Flux Test Facility (FFTF). For tests at 300 K, irradiation resulted in small to modest increases in 0.2% yield strength, no change in ultimate strength, and modest decreases in uniform and total elongations. After irradiation, total elongations remained high at 16 to 25%. At 300 K, the magnitude of the changes due to irradiation increased with increasing fluence and irradiation temperature. For material irradiated at 1290,1350, and 1400 K and tested at the irradiation temperature, the changes in tensile properties were less than the changes observed at 300 K, and the strength and ductility properties were within the scatter band for unirradiated Nb-lZr. Total elongation remained very high at 32 to 37%. At 1290 to 1400 K, the magnitude of the changes due to irradiation decreased with increased irradiation temperature. Results were the same for both grain sizes. After irradiation at SP-100 operating temperatures, Nb-lZr exhibited more than adequate ductility to preclude brittle failure under any anticipated SP-100 loading conditions.

Horak, James A.; Grossbeck, Martin L.; Paxton, Michael M.

1994-07-01

261

A modified Weibull model for tensile strength distribution of carbon nanotube fibers with strain rate and size effects  

NASA Astrophysics Data System (ADS)

Fundamental studies on the effects of strain rate and size on the distribution of tensile strength of carbon nanotube (CNT) fibers are reported in this paper. Experimental data show that the mechanical strength of CNT fibers increases from 0.2 to 0.8 GPa as the strain rate increases from 0.00001 to 0.1 (1/s). In addition, the influence of fiber diameter at low and high strain rate conditions was investigated further with statistical analysis. A modified Weibull distribution model for characterizing the tensile strength distribution of CNT fibers taking into account the effect of strain rate and fiber diameter is proposed.

Sun, Gengzhi; Pang, John H. L.; Zhou, Jinyuan; Zhang, Yani; Zhan, Zhaoyao; Zheng, Lianxi

2012-09-01

262

Clean Cast Steel Technology: Effect of Micro-porosity on Tensile and Charpy Properties of Four Cast Steels  

SciTech Connect

The effect of these large shrink cavities on mechanical properties could be easily calculated using well established engineering formulas. Over the years, increases in computational and metallurgical resources have allowed the modeler to improve accuracy and increase the complexity of numerical predictors. An accurate prediction of micro-porosity, not observable using conventional radiographic techniques, and an engineering understanding of the effect on mechanical properties would give a designer confidence in using a more efficient casting design and a lower safety factor. This will give castings an additional design advantage. The goal of this project is to provide current and future modelers/designers with a tensile and Charpy property dataset for validation of micro-porosity predictors. The response of ultimate strength, elongation, and reduction in area to micro-porosity was very similar in all four alloys. Ultimate strength was largely unaffected by tensile fracture surface porosity until values of about 25% were reached and decreased linearly with increasing values. Elongation and reduction in area decreased sharply after less than 5% fracture surface porosity. Niyama values of about 0.7 were produced sound material and acceptable tensile properties. Ultrasonic velocities of 0.233 in/usec and higher produced acceptable tensile properties. Metallographic examination revealed a ratio of 4-6 to 1 in fracture surface porosity to metallographic porosity. Charpy impact properties were largely unaffected by the microporosity concentrations examined in this study and did not correlate to either Niyama values, fracture surface porosity, or metallographic porosity.

Griffin, John, A.; Bates, Charles, E.

2005-09-19

263

Tensile properties of low density polypropylene (LDPE)/palm kernel shell (PKS) biocomposites: The effect of acrylic acid (AA)  

NASA Astrophysics Data System (ADS)

The surface of palm kernel was modified by acrylic acid (AA). Low density polyethylene (LDPE) was filled by palm kernel shell at various 0, 10, 20, 30 and 40 php. The effect of AA as a coupling agent on LDPE/PKS biocomposites on tensile properties and morphology was investigated. The results show that the increasing of filler content decreased the tensile strength and break elongation but increased the Young's modulus. The presence of AA indicates higher tensile strength and Young's modulus but lower elongation at break compared to untreated LDPE/PKS biocomposites. The scanning electron microscope study show that the better interfacial interaction between palm kernel shell and low density polyethylene with addition of AA.

Romisuhani, A.; Salmah, H.; Akmal, H.

2010-05-01

264

A Discrete Element Model for Predicting Shear Strength and Degradation of Rock Joint by Using Compressive and Tensile Test Data  

NASA Astrophysics Data System (ADS)

A discrete element model is proposed to examine rock strength and failure. The model is implemented by UDEC, which is developed for this purpose. The material is represented as a collection of irregular-sized deformable particles interacting at their cohesive boundaries. The interface between two adjacent particles is viewed as a flexible contact whose constitutive law controls the material fracture and fragmentation properties. To reproduce rock anisotropy, an orthotropic cohesive law is developed for the contacts, which allows their shear and tensile behaviors to be different from each other. Using a combination of original closed-form expressions and statistical calibrations, a unique set of the contact microparameters are found based on the uniaxial/triaxial compression and Brazilian tension test data of a plaster. Applying the obtained microparameters, joint specimens, made of the same plaster, are simulated, where the comparison of the obtained results to laboratory data shows a reasonable agreement.

Kazerani, T.; Yang, Z. Y.; Zhao, J.

2012-09-01

265

Role of cladding in the notched tensile properties of a titanium matrix composite  

SciTech Connect

The utility of Ti cladding in alleviating the notch sensitivity of both the monotonic and cyclic tensile properties of Ti matrix composites (TMC) has been examined. Experiments have been conducted on panels with two different clad thicknesses as well as on the TMC alone. Crack bridging models have been used to describe the composite behavior, incorporating explicitly the effects of the cladding. It is demonstrated that the notched strength can be raised up to the level corresponding to the unnotched TMC alone, with a critical clad thickness that depends on the fracture properties of the TMC and the notch size. The fatigue threshold can be elevated also, though it cannot reach the threshold of the un-notched TMC. The bridging models have been used to calculate the trends in the strength and the fatigue threshold with the clad thickness.

Ramamurty, U.; Zok, F.W.; Leckie, F.A. [Univ. of California, Santa Barbara, CA (United States)

1997-12-01

266

Addition of zinc methacrylate in dental polymers: MMP-2 inhibition and ultimate tensile strength evaluation.  

PubMed

This study evaluated the effect of zinc methacrylate (ZM) on the inhibition of matrix metalloproteinase 2 (MMP-2) and the ultimate tensile strength (UTS) of an experimental polymer. Enzymes secreted from mouse gingival tissues were analyzed by gelatin zymography in buffers containing 5 mM CaCl(2) (Tris-CaCl(2)) in 50 mM Tris-HCl buffer with various concentrations of ZM (0.5, 1, 2, 4, 8, and 16 mM). The matrix metalloproteinases present in the conditioned media were characterized by immunoprecipitation. The polymer UTS evaluation was performed in eight groups with various concentrations of ZM (0, 0.5, 1, 2.5, 5, 10, 20, and 30 wt.%), in a mechanical testing machine. MMP-2 (62 kDa) was detected in the zymographic assays and inhibited by ZM in all tested concentrations. UTS data were submitted to one-way ANOVA and Tukey's test (??=?0.05), and no significant differences were observed among groups, except in the polymer containing 30% ZM, presenting a significantly lower value when compared with the control group (p?tensile strength of the polymer. Zinc methacrylate is a metalloproteinase inhibitor that can be copolymerized with other methacrylate monomers. Yet, the addition of ZM did not affect the resin bond strength. Thus, in vivo tests should be performed to evaluate the performance of this material. PMID:21448634

Henn, Sandrina; de Carvalho, Rodrigo Varella; Ogliari, Fabrício Aulo; de Souza, Ana Paula; Line, Sergio Roberto Peres; da Silva, Adriana Fernandes; Demarco, Flávio Fernando; Etges, Adriana; Piva, Evandro

2011-03-30

267

Morphologies and tensile properties of Block-Double-Graft Copolymers  

NASA Astrophysics Data System (ADS)

Morphological characteristics and tensile properties of a series of block-double-graft (BDG) copolymers and terpolymers poly[styrene-b-(1,2-butadiene-g-R2)] (where R= 1,2-butadiene, isoprene, styrene, styrene-isoprene) were studied using transmission electron microscopy (TEM), small angle X-ray scattering (SAXS), and tensile testing. All materials contain monodisperse polystyrene-b-poly(1,2-butadiene) (PS-1,2-PBD) diblock copolymer backbones. Two identical branches are grafted at each randomly placed hydrosilylated vinyl group on the poly(1,2-butadiene) block of the backbone. Classical microstructures, such as BCC spheres, HEX cylinders and lamellae are obtained at different PS volume fractions. It is found that, when the branches are polydienes, BDG molecules have the same morphologies as their linear diblock counterparts. When branches are PS-PI diblock copolymers with the PS block grafting directly onto backbone, lamellae are obtained at 50upon composition and molecular architecture, BDG terpolymers can exhibit characteristic thermoplastic elastomer properties with a stress at break of 32M Pa and a strain at break of 1000

Zhu, Yuqing; Gido, Samuel P.; Velis, Gabriel; Hadjichristidis, Nikos

2002-03-01

268

The effect of gauge length on tensile strength and Weibull modulus of polyacrylonitrile (PAN)- and pitch-based carbon fibers  

Microsoft Academic Search

Carbon fibers are widely used as a reinforcement in composite materials because of their high specific strength and modulus.\\u000a Current trends toward the development of carbon fibers have been driven in two directions; ultrahigh tensile strength fiber\\u000a with a fairly high strain to failure (~2%), and ultrahigh modulus fiber with high thermal conductivity. Today, a number of\\u000a ultrahigh strength polyacrylonitrile

Kimiyoshi Naito; Jenn-Ming Yang; Yoshihisa Tanaka; Yutaka Kagawa

269

Tensile and fatigue properties of a 25 vol% SiC particulate reinforced 6090 Al composite at 300 °C  

Microsoft Academic Search

Discontinuously-reinforced metal matrix composites (MMCs) are attractive for many structural applications because the materials exhibit unusual combinations of structural, physical, and thermal properties. In this paper, the authors present the tensile and fatigue properties of a 25 vol% SiC particulate-reinforced 6090 Al composite at 300 C. Several conclusions can be drawn from this study: (1) The fatigue strength, [sigma][sub e],

T. G. Nieh; D. R. Lesuer; C. K. Syn

1995-01-01

270

Neural Networks Relating Alloy Composition, Microstructure, and Tensile Properties of ?/ ?-Processed TIMETAL 6-4  

NASA Astrophysics Data System (ADS)

Bayesian neural networks have been developed, which relate composition, microstructure, and tensile properties of the alloy TIMETAL 6-4 (nominal composition: Ti-6Al-4V (wt pct) after thermomechanical processing (TMP) in the two-phase ( ? + ?)-phase field. The developed networks are able to make interpolative predictions of properties within the ranges of composition and microstructural features that are in the population of the database used for training and testing of the networks. In addition, the neural networks have been used to conduct virtual experiments which permit the functional dependencies of properties on composition and microstructural features to be determined. In this way, it is shown that in the microstructural condition resulting from TMP in the two-phase ( ? + ?) phase field, the most significant contribution to strength is from solid solution strengthening, with microstructural features apparently influencing the balance of a number of properties.

Collins, Peter C.; Koduri, Santhosh; Welk, Brian; Tiley, Jaimie; Fraser, Hamish L.

2013-03-01

271

The effect of reinforcement on the notched and unnotched room temperature tensile properties of Al–4wt.%Cu\\/SiC p MMCs  

Microsoft Academic Search

The tensile and toughness related properties of SiC (3, 17 and 29 ?m) particulate (SiCp) reinforced Al–4wt.%Cu metal matrix composites (MMCs) produced via a powder metallurgy route were studied. The assessment of toughness related properties was carried out by notched tensile testing. The strength of the MMCs increased with decreasing size of the reinforcement. This predominated over any effect on

I. C Stone; P Tsakiropoulos

1998-01-01

272

Tensile strength of ash cake beds at high-temperature conditions  

SciTech Connect

The Energy and Environmental Research Center (EERC) is working with Electric Power Research Institute (EPRI) and a consortium of companies in partnership with the US Department of Energy (DOE) to perform the research necessary to determine the factors that cause hot-gas cleanup filters to be blinded by ash or to develop deposits that can bridge the filters and cause them to fail. The primary deliverable will be a graphics-driven computer model that can be used as an engineering tool to help predict ash-related hot-gas filter problems based on analyses of coal and sorbent, as well as system operating parameters. This paper presents preliminary testing data on determining the tensile strengths of coal ash particles at elevated temperatures and simulated combustor gas conditions. The range in temperatures for tensile testing is ambient to 900 C. The simulated gas atmosphere includes carbon dioxide, water vapor, oxygen, sulfur dioxide, sodium chloride, hydrochloric acid, and nitrogen. At present, all testing has been performed using ash from the Westinghouse advanced particle filter (APF) at the American Electric Power Service Corporation (AEP) Tidd pressurized fluidized-bed combustor (PFBC) demonstration plant in Ohio. Other sources of filter ashes, including several from non-American PFBC systems, will also be evaluated.

Dockter, B.A.; Hurley, J.P.

1996-12-31

273

Correlation analysis of the variation of weld seam and tensile strength in laser welding of galvanized steel  

NASA Astrophysics Data System (ADS)

Many advantages of laser welding technology such as high speed and non-contact welding make the use of the technology more attractive in the automotive industry. Many studies have been conducted to search the optimal welding condition experimentally that ensure the joining quality of laser welding that relies both on welding system configuration and welding parameter specification. Both non-destructive and destructive techniques, for example, ultrasonic inspection and tensile test are widely used in practice for estimating the joining quality. Non-destructive techniques are attractive as a rapid quality testing method despite relatively low accuracy. In this paper, we examine the relationship between the variation of weld seam and tensile shear strength in the laser welding of galvanized steel in a lap joint configuration in order to investigate the potential of the variation of weld seam as a joining quality estimator. From the experimental analysis, we identify a trend in between maximum tensile shear strength and the variation of weld seam that clearly supports the fact that laser welded parts having larger variation in the weld seam usually have lower tensile strength. The discovered relationship leads us to conclude that the variation of weld seam can be used as an indirect non-destructive testing method for estimating the tensile strength of the welded parts.

Sinha, Amit Kumar; Kim, Duck Young; Ceglarek, Darek

2013-10-01

274

Nd:YAG laser ablation of enamel for orthodontic use: tensile bond strength and surface modification.  

PubMed

To test the feasibility of Nd:YAG laser ablation for orthodontic use, bovine enamels were ablated at 2.5 and 3.5 W/pulse conditions. Orthodontic brackets were attached on the ablated enamel surface using a self-curing resin. For comparison, a 37% phosphoric acid solution was used to etch the enamel surface. The strength to detach the brackets was estimated for both surface treatments. Modifications of the enamel surfaces were also compared using a scanning electron microscope for both treatments. The tensile bond strengths from the laser-ablated enamels were significantly lower than that from the phosphoric acid-etched enamels. The higher laser power treatment gave a significantly higher bond strength average than with the lower laser power. The laser-ablated surfaces showed the formation of craters. The formation involved melting and solidification of enamel. Each crater had numerous micropores. Microscopically, the ablated surface was smooth, while much of the acid-etched surface contained numerous microspaces. PMID:14621004

Kwon, Yong Hoon; Kwon, Oh-Won; Kim, Hyung-Il; Kim, Kyo-Han

2003-09-01

275

Ideal tensile strength and band gap of single-walled carbon nanotubes  

NASA Astrophysics Data System (ADS)

The ideal tensile (compressive) strength, Young’s modulus, and band-gap changes of single-walled carbon nanotubes (SWNT’s) with zigzag types of (8,0), (9,0), and (10,0) and armchair of (8,8) under an uniaxial deformation are analyzed using a tight binding (TB) method parametrized by Tang et al. In addition, the first principle density functional theory based on the local density approximation (DFT) is employed as a cross-check. It is well known that the band gap of a SWNT changes according to the uniaxial strain. Most of the previous studies have represented the deformed atomic structure by an empirical potential and then applied band analysis to estimate the band gaps. However, this step-by-step process may allow errors due to the lack of transferability of the empirical potentials in the highly deformed state. In this study, in order to estimate the electronic structure change more accurately and examine the transferability of the TB potential, we used the TB and also the DFT method to find equilibrium atomic structures of the SWNT’s deformed by applied strain. At the same time, the band gaps of the equilibrium structure are estimated. We find that the TB results for ideal strengths, Young’s modulus, and band gaps are basically in good agreement with the DFT results. The band-gap changes are in qualitative agreement with Yang’s theory in which a uniform deformation is assumed. However, even though the theory predicts a zero gap for the armchair SWNT’s, we see a finite band gap of the (8,8) SWNT at the 20% tensile strain level, which is the extreme strain sustained immediately succeeding failure.

Ogata, Shigenobu; Shibutani, Yoji

2003-10-01

276

Tensile bond strength of intracanal posts in primary anterior teeth: an in vitro study.  

PubMed

The aim of this study was to measure in vitro; the tensile bond strength of three intracanal posts used in anterior primary teeth. A total of 45 single rooted primary anterior teeth were selected for the study and the crowns sectioned leaving 1mm above the cement-enamel junction. The roots were then assigned to three groups according the type of retention used. All roots were endodonticaly treated, a 4-mm of the canal was cleansed and a base of glass ionomer cement was put at the bottom of the prepared canal. The roots were then prepared to receive intracanal posts using a # 4137 diamond bur (KG Sorensen) used in a depth of 3-mm of the length of the canal All the prepared roots were acid etched with a 37% phosphoric acid gel for 15 seconds, rinsed, dried and the dentin adhesive Single Bond (3M) was applied. Group I received intracanal posts and cores made of composite resin (Filtek Z 250, 3M). Group II intracanal posts were made from a 0.6mm orthodontic wire bent as a Greek letter type (gamma), fixed with the Z 250 composite resin and cores were built with the same composite. Finally Group III received intracanal retention made of a fiber glass post (Fibrekor Post, Generic/Pentron) with 1.25 mm diameter, fixed with Z 250 and cores were made like the other groups. The samples were submitted to tension in a universal-testing machine (Instron, model 4444). Statistical analysis (ANOVA) revealed that there were no statistically significant differences between the groups. On the basis of the results of this in vitro study it was concluded that the type of intracanal post did not interfere with the tensile strength and the most frequent type of failure was of adhesive type, corresponding to 74% of the sample. PMID:12413170

Pithan, Silvia; Vieira, Ricardo de Sousa; Chain, Marcelo Carvalho

2002-01-01

277

Effect of He on the structure and bonding properties of W: A first-principles computational tensile test  

NASA Astrophysics Data System (ADS)

Using a first-principles computational tensile test (FPCTT), we have investigated the effect of helium (He) on the structure and bonding properties of tungsten (W), which is a promising plasma-facing material in nuclear fusion Tokamak. Density of states results reveal the underlying reason that the substitutional site for He is the most energetically favorable, while the tetrahedral interstitial site is more favorable than the octahedral interstitial one. The FPCTT shows that the ideal tensile strength is 29.1 GPa at the strain of 14% along the [0 0 1] direction for intrinsic W, while it decreases to 28.2 GPa at the same strain when one impurity He atom is introduced. A local bond-breaking region around He forms in the tensile process due to the presence of He, which suggests He will have a large effect on the bonding properties of W.

Liu, Yue-Lin; Zhou, Hong-Bo; Zhang, Ying; Jin, Shuo; Lu, Guang-Hong

2009-09-01

278

Tensile strength as a function of thermal history of Inconel 718 and Inconel 625 alloys for glass-ceramic headers  

SciTech Connect

Tensile strength tests were conducted on Inconel 718 specimens following a variety of heat treatments, and on as-received and heat-treated specimens of Inconel 625. A heat treatment cycle for Inconel 718 was found that represents an acceptable compromise between a thermal cycle that yields the strongest metal and one that least taxes a glass-ceramic material to which the Inconel 718 is bonded. Heat treating resulted in a moderate decrease in the tensile strength of the as-received Inconel 625.

Rey, M.C.; Henderson, W.R.

1982-06-11

279

Tensile properties of carbon nanotube reinforced aluminum nanocomposite fabricated by plasma spray forming  

Microsoft Academic Search

Uniaxial tensile tests were performed on plasma spray formed (PSF) Al–Si alloy reinforced with multiwalled carbon nanotubes (MWCNTs). The addition of CNTs leads to 78% increase in the elastic modulus of the composite. There was a marginal increase in the tensile strength of CNT reinforced composite with degradation in strain to failure by 46%. The computed critical pullout length of

T. Laha; Y. Chen; D. Lahiri; A. Agarwal

2009-01-01

280

Creep and tensile properties of press molding joined GMT-sheets  

Microsoft Academic Search

GMT-sheet is used in automobile bumper with high rigidity and strength, and its joining strength is influenced by lap length, one of the joined molding conditions. Fracture strength was calculated by dividing fracture load with cross-sectional area. Total five repeated measurements were made to obtain the average value. Tensile test was conducted at room temperature for 10 specimens. In addition,

Jin-Woo KIM; Dong-Gi LEE

2011-01-01

281

The effect of HIPing on the fatigue and tensile strength of a case, porous-coated Co-Cr-Mo alloy.  

PubMed

The process required to sinter porous Co-Cr-Mo alloys results in the formation of substrate porosity through carbide dissolution. Since hot isostatic pressing (HIPing) has been shown to eliminate casting porosity in the Co-Cr-Mo alloy, it is possible that it may be equally effective on pores that are generated from the sintering operation. The effect that HIPing a porous-coated Co-Cr-Mo material has on the fatigue and tensile properties was investigated. Fatigue testing was performed on sintered materials as well as sintered and HIPed materials, both with and without a porous coating. Further, the effect of varying coating thickness on the resulting fatigue strength of sintered and HIPed materials was studied. Light microscopy was performed in order to define the microstructural changes brought about by the various thermal cycles. Scanning electron microscopy was utilized to define the crack initiation process. The fatigue strength of uncoated "as sintered" materials was found to be reduced by 34% relative to the "as cast" condition. The same material that was HIPed revealed a fatigue strength slightly lower than the "as cast" condition. It was found that porous coatings created preferential sites for fatigue crack initiation. However, the presence of the coating did not further reduce the fatigue strength of "as sintered" materials because of the already low strength created by the sintering operation. Materials that were sintered exhibited a lowering in both tensile strength and elongation to failure relative to the "as cast" condition. The HIPing of sintered materials improved both fatigue and tensile properties relative to the "as sintered" condition. PMID:3782180

Georgette, F S; Davidson, J A

1986-10-01

282

Dimensional stability and tensile strength of irradiated Nicalon-CG and Hi-Nicalon SiC fibers  

SciTech Connect

Nicalon-CG and Hi-Nicalon fibers were characterized by measuring their length, density, and tensile strength in the unirradiated, thermal annealed, and irradiated conditions. The irradiation was conducted in the EBR-II to a dose of 43 dpa-SiC at a nominal irradiation temperature of 1,000 C. The annealed specimens were held at 1,010 C for 165 days to approximately duplicate the thermal exposure of the irradiated specimens. The results indicate the fibers that perform best in an irradiation environment are those that approach stoichiometric and crystalline SiC. Hi-Nicalon exhibited negligible densification, accompanied by an increase in tensile strength after irradiation. Nicalon-CG possessed a higher tensile strength than hi-Nicalon in the unirradiated condition, but was significantly weakened in the annealed and irradiated conditions. In addition, Nicalon-CG exhibited unacceptable irradiation-induced shrinkage. Loss o fiber tensile strength after irradiation is shown to reduce the flexural strength of irradiated composites and Nicalon-CG fiber shrinkage observed in irradiated composites.

Youngblood, G.E.; Henager, C.H. Jr.; Senor, D.J. [Pacific Northwest National Lab., Richland, WA (United States); Newsome, G.A.; Woods, J.J. [Lockheed Martin, Schenectady, NY (United States)

1997-05-01

283

Tensile properties influencing variables in eutectic Al-Si casting alloys  

Microsoft Academic Search

Efforts to identify and characterize the physical properties of aluminum castings alloys are envisaged to lead to a new guideline from which the mechanical behavior of these alloys can be accurately predicted. For aluminum-silicon (Al-Si) casting alloys the tensile properties of a specific composition are observed to vary depending on the production parameters. The difference in the tensile properties appears

M. F. Hafiz; Toshiro Kobayashi

1994-01-01

284

Strength Distribution in Paper.  

National Technical Information Service (NTIS)

Tensile strength distributions are studied in four papers samples that exhibit a variety of brittle-to-ductile properties. 1005 tensile specimens were measured in each case. The standard Gumbel and Weibull distributions, and a recently proposed double exp...

M. J. Korteoja L. I. Salminen K. J. Niskanen M. Alava

1997-01-01

285

Influence of post-superplastic forming practices on the tensile properties of aluminum-lithium alloys  

NASA Astrophysics Data System (ADS)

The effect of thermal processing following superplastic forming on the tensile properties of aluminum-lithium alloys is addressed. The starting materials consisted of alloys 8090, 2090, and X2095 (a Weldalite™ 049 variant) in the form of commercial- grade superplastic sheet. Experience dictates that post- forming practices aimed at a slightly underaged T6 temper produce balanced engineering proper-ties in these alloys. The objective of this study was to assess the potential to use a T5- type temper by elimi-nating the solution heat treatment and/or cold water quenching steps characteristic of T6 processing. The experimental procedures adopted ensured that the tensile properties compiled were representative of the bulk material Initially, the strengthening behavior of each alloy as a function of temper selection was established. Subsequently, aging practices that resulted in peak strength and balanced properties were identified for the baseline T6 temper and two T5 tempers. The implications for replacing a T6 tem-per with a T5- type temper, including rapid and slow cooling following forming, are discussed on the basis of the results.

Hales, S. J.; Lippard, H. E.

1994-06-01

286

Effect of Microwave Disinfection on Compressive and Tensile Strengths of Dental Stones  

PubMed Central

Background and aims Although microwave irradiation has been used for disinfection of dental stone casts, there are concerns regarding mechanical damage to casts during the process. The aim of this study was to evaluate the effect of microwave irradiation on the compressive strength (CS) and diametral tensile strength (DTS) of stone casts. Materials and methods In this in vitro study, 80 cylindrical type III and IV stone models (20 × 40 mm) were prepared and divided into 8 groups of 10. The DTS and CS of the specimens were measured by a mechanical testing machine at a crosshead speed of 0.5 cm/min after 7 times of frequent wetting, irradiating at an energy level of 600 W for 3 minutes and cooling. Data were analyzed by Student’s t-test. Results Microwave irradiation significantly increased DTS of type III and IV to 5.23 ± 0.64 and 8.17 ± 0.94, respectively (P < 0.01). Conclusion According to the results, microwave disinfection increases DTS of type III and IV stone casts without any effects on their CS.

Robati Anaraki, Mahmood; Moslehifard, Elnaz; Aminifar, Soran; Ghanati, Hamed

2013-01-01

287

Predicting fracture and fatigue crack growth properties using tensile properties  

Microsoft Academic Search

The safe-life assessment of components requires information such as the plane stress (Kc), plane strain (KIc), part-through fracture toughness (KIe), and the fatigue crack growth rate properties. A proposed parametric\\/theoretical approach, based on an extended Griffith theory is used to derive fracture toughness properties and generate fatigue crack growth rate data for a range of alloys. The simplicity of the

Bahram Farahmand; Kamran Nikbin

2008-01-01

288

Effects of H on Electronic Structure and Ideal Tensile Strength of W: A First-Principles Calculation  

NASA Astrophysics Data System (ADS)

We investigate the structure, energetics, and the ideal tensile strength of tungsten (W) with hydrogen (H) using a first-principles method. Both density of states (DOS) and the electron localization function (ELF) reveal the underlying physical mechanism that the tetrahedral interstitial H is the most energetically favorable. The first-principles computational tensile test (FPCTT) shows that the ideal tensile strength is 29.1 GPa at the strain of 14% along the [001] direction for the intrinsic W, while it decreases to 27.1 GPa at the strain of 12% when one impurity H atom is embedded into the bulk W. These results provide a useful reference to understand W as a plasma facing material in the nuclear fusion Tokamak.

Liu, Yue-Lin; Zhou, Hong-Bo; Jin, Shuo; Zhang, Ying; Lu, Guang-Hong

2010-12-01

289

Tensile strength as an indicator of the degree of primitiveness of undifferentiated bodies  

Microsoft Academic Search

The extremely porous structure and low strength of most comets and their fragments is opposed to the properties observed in relatively pristine chondritic asteroids, even although both are sharing important chemical similitude. Laboratory experiments and observational evidence suggest that the original extremely porous aggregates that were born from the protoplanetary-disk-forming materials were highly retentive of water and organic compounds present

Josep M. Trigo-Rodriguez; Jürgen Blum

2009-01-01

290

Size effect upon grained materials tensile strength: The increase of the statistical dispersion at the smaller scales  

Microsoft Academic Search

The present paper provides a statistical model to the size effect on grained materials tensile strength; it is based on an Extreme Value Theory approach. Since the weakest link in grained materials is usually represented by the interface between the matrix and the aggregates, it is assumed that the flaw distribution can be represented by the aggregate distribution, expressed as

A. Carpinteri; P. Cornetti; S. Puzzi

2005-01-01

291

Root tensile strength relationships and their slope stability implications of three shrub species in the Northern Apennines (Italy)  

Microsoft Academic Search

The role of root strength is important in stabilising steep hillslopes which are seasonally affected by storm-induced shallow landslides. In the Italian Apennines, steep (25–40°) slopes underlain by mudstone are generally stable if they are covered by shrubs whose roots anchor into the soil mantle. To quantify the mechanical reinforcement of roots to soil, the root tensile breaking force and

Matteo Tosi

2007-01-01

292

Role of silane coupling agent and polymeric film former for tailoring glass fiber sizings from tensile strength measurements  

Microsoft Academic Search

Tensile strengths of differently sized E-glass fibres have been characterised using a bimodal Weibull two parameters cumulative distribution function. By comparing unsized fibres, pure silanes, different film formers, and silane\\/film former combinations, a comprehensive summary on the healing effect for surface flaws in relation to the type of sizing emulsion has been obtained. The great influence of the film former,

P. Zinck; E. Mäder; J. F. Gerard

2001-01-01

293

Influence of magnetic arc oscillation and current pulsing on microstructure and high temperature tensile strength of alloy 718 TIG weldments  

Microsoft Academic Search

The aim of the present work is to study the effect of magnetic arc oscillation and current pulsing on the microstructure and high temperature tensile strength of alloy 718 tungsten inert gas weldments. The magnetic arc oscillation technique resulted in refined Laves phase with lesser interconnectivity. The full benefits of current pulsing in breaking the dendrites could not be realized

K. Sivaprasad; S. Ganesh Sundara Raman; P. Mastanaiah; G. Madhusudhan Reddy

2006-01-01

294

Tensile Strength as a Function of Thermal History of Inconel 718 and Inconel 625 Alloys for Glass-Ceramic Headers.  

National Technical Information Service (NTIS)

Tensile strength tests were conducted on Inconel 718 specimens following a variety of heat treatments, and on as-received and heat-treated specimens of Inconel 625. A heat treatment cycle for Inconel 718 was found that represents an acceptable compromise ...

M. C. Rey W. R. Henderson

1982-01-01

295

Relationships Between Tensile Strength, Ascorbic Acid, Hydroxyproline, and Zinc Levels of Rabbit Full-Thickness Incision Wound Healing  

Microsoft Academic Search

Purpose This work was carried out to follow up the healing of full-thickness incision wounds opened on the back skin of rabbits in order to gain insight into the periodical correlation among such factors as ascorbic acid, collagen (hydroxyproline), the zinc content, and tensile strength of wound tissue. The need to provide vitamin C or zinc supplements after such wound

Birsen Kaplan; Bilge Gönül; Sibel Dinçer; F. Nazl? Dinçer Kaya; Aydan Babül

2004-01-01

296

Effects of carbon percentage, Stelmor cooling rate and laying head temperature on tensile strength gain in low carbon steels  

Microsoft Academic Search

Low carbon steel wire rods are used to produce finished products such as fine wire, coat hangers, staples, and roofing nails. These products are subjected to excessively high work hardening rates during wire drawing process resulting in a variation in wire tensile strength. This research analyzes the effects of carbon percentage, StelmorRTM cooling rate and laying head temperature on the

Surya Prakash Gade

2004-01-01

297

The effects of tack welding and increasing surface area on the tensile strength of silver electric and flame soldered stainless steel joints.  

PubMed

The purposes of this study were: 1) to compare silver solder joint strength using flame and electric soldering techniques, and 2) to determine the effect of tack welding and increasing metal-to-metal contact area prior to tack welding, on the tensile strength of silver solder joints. Six methods: (flame soldered; tack welded and flame soldered; increased contact area, tack welded, and flame soldered; electrosoldered; tack welded and electrosoldered; and increased contact area, tack welded, and electrosoldered) were used to produce 15 solder joints in each group. The tensile strength of the joints were tested with Instron Universal Testing Machine. Flame soldering resulted in joints with significantly higher tensile strength (P < or = 0.001). Tack welding had no significant effect on the tensile strength of the joints. Increasing the contact area had no significant effect on the tensile strength of tack welded electric soldered joints, but significantly weakened the flame soldered joints (P < or = 0.05). PMID:8784912

Gawlik, J A; Mathieu, G P; Hondrum, S

298

Microstructure and Tensile Properties of Submerged Arc Welded 1.25Cr0.5Mo Steel Joints  

Microsoft Academic Search

This article describes the effect of heat input (controlled by welding current and welding speed) on the microstructure and tensile properties of high strength low alloy (HSLA) steel weldments produced by submerged arc welding (SAW). The SAW process was used for welding of 16 mm thick 1.25Cr-0.5Mo steel (ASTM A387 gr-11) plates. The weld joints were prepared by varying the welding

Keshav Prasad; D. K. Dwivedi

2008-01-01

299

Tensile Properties and Work Hardening Behavior of Laser-Welded Dual-Phase Steel Joints  

NASA Astrophysics Data System (ADS)

The aim of this investigation was to evaluate the microstructural change after laser welding and its effect on the tensile properties and strain hardening behavior of DP600 and DP980 dual-phase steels. Laser welding led to the formation of martensite and significant hardness rise in the fusion zone because of the fast cooling, but the presence of a soft zone in the heat-affected zone was caused by partial vanishing and tempering of the pre-existing martensite. The extent of softening was much larger in the DP980-welded joints than in the DP600-welded joints. Despite the reduction in ductility, the ultimate tensile strength (UTS) remained almost unchanged, and the yield strength (YS) indeed increased stemming from the appearance of yield point phenomena after welding in the DP600 steel. The DP980-welded joints showed lower YS and UTS than the base metal owing to the appearance of severe soft zone. The YS, UTS, and strain hardening exponent increased slightly with increasing strain rate. While the base metals had multi-stage strain hardening, the welded joints showed only stage III hardening. All the welded joints failed in the soft zone, and the fracture surfaces exhibited characteristic dimple fracture.

Farabi, N.; Chen, D. L.; Zhou, Y.

2012-02-01

300

Developmental Exposure to Xenoestrogens at Low Doses Alters Femur Length and Tensile Strength in Adult Mice1  

PubMed Central

ABSTRACT Developmental exposure to high doses of the synthetic xenoestrogen diethylstilbestrol (DES) has been reported to alter femur length and strength in adult mice. However, it is not known if developmental exposure to low, environmentally relevant doses of xenoestrogens alters adult bone geometry and strength. In this study we investigated the effects of developmental exposure to low doses of DES, bisphenol A (BPA), or ethinyl estradiol (EE2) on bone geometry and torsional strength. C57BL/6 mice were exposed to DES, 0.1 ?g/kg/day, BPA, 10 ?g/kg/day, EE2, 0.01, 0.1, or 1.0 ?g/kg/day, or vehicle from Gestation Day 11 to Postnatal Day 12 via a mini-osmotic pump in the dam. Developmental Xenoestrogen exposure altered femoral geometry and strength, assessed in adulthood by micro-computed tomography and torsional strength analysis, respectively. Low-dose EE2, DES, or BPA increased adult femur length. Exposure to the highest dose of EE2 did not alter femur length, resulting in a nonmonotonic dose response. Exposure to EE2 and DES but not BPA decreased tensile strength. The combined effect of increased femur length and decreased tensile strength resulted in a trend toward decreased torsional ultimate strength and energy to failure. Taken together, these results suggest that exposure to developmental exposure to environmentally relevant levels of xenoestrogens may negatively impact bone length and strength in adulthood.

Pelch, Katherine E.; Carleton, Stephanie M.; Phillips, Charlotte L.; Nagel, Susan C.

2011-01-01

301

Predicting tensile properties of the bulk 96.5Sn-3.5Ag lead-free solder  

NASA Astrophysics Data System (ADS)

Equations are presented for predicting tensile properties as functions of temperature and strain rate for the bulk-eutectic 96.5Sn-3.5Ag lead-free solder. At 25°C, we obtained 49.0 GPa for Young’s modulus based on acoustic measurements, which is higher than most of those measured by tensile tests that are subject to viscoelastic creep; 23.1 MPa and 26.3 MPa for yield stress and ultimate tensile strength (UTS) of specimens that are cast, annealed, and aged at a strain rate of 2.0×10-4 s-1; 48.7% for total elongation, which is larger than most of the reported values. The presence of “initial defects” in the specimens, such as porosity and void, might cause the reduction in measured total elongations.

Cheng, Yi-Wen; Siewert, Thomas A.

2003-06-01

302

Evaluation of mechanical properties and porcelain bonded strength of nickel–chromium dental alloy fabricated by laser rapid forming  

Microsoft Academic Search

The aim was to evaluate the mechanical properties and porcelain bonded strength of nickel–chromium (Ni–Cr) dental alloy fabricated\\u000a by laser rapid forming (LRF). The tensile properties and porcelain bonded strengths of LRF Ni–Cr dental alloy were evaluated\\u000a by tensile tests (five specimens per group) and three-point bending tests (ten specimens per group). The same tests for the\\u000a cast Ni–Cr dental

Yihan Liu; Zhongyi Wang; Bo Gao; Xiaoming Zhao; Xin Lin; Jiang Wu

2010-01-01

303

Influence of temperature and strain rate on tensile properties of single walled carbon nanotubes reinforced Sn–Ag–Cu lead free solder alloy composites  

Microsoft Academic Search

The effect of temperature and strain rate on the tensile properties of Sn–3.8Ag–0.7Cu (SAC387) alloy as well as SAC387 alloy reinforced with two different weight percentages (wt.%) of SWCNT was investigated. It was found that addition of 0.05wt.% SWCNT to SAC387 alloy results in an increase in yield and ultimate tensile strengths without affecting the total elongation at all temperatures

V. L. Niranjani; B. S. S. Chandra Rao; Vajinder Singh; S. V. Kamat

2011-01-01

304

Effect of recrystallization on room temperature tensile properties of an Fe[sub 3]Albased alloy. [Fe28Al5Cr0. 1Zr0. 05B  

Microsoft Academic Search

The purpose of the present study was to determine whether recrystallization alone had an effect on the room temperature tensile properties of a Fe[sub 3]Al-based alloy. The best room temperature tensile strength and ductility were attained in specimens which had been heat treated to relieve stresses produced by the fabrication process but that had a minimum number of recrystallized grains.

C. G. McKamey; D. H. Pierce

1993-01-01

305

Tensile Properties of Arabidopsis Cell Walls Depend on Both a Xyloglucan Cross-Linked Microfibrillar Network and Rhamnogalacturonan II-Borate Complexes1  

Microsoft Academic Search

The mechanical properties of plant organs depend upon anatomical structure, cell-cell adhesion, cell turgidity, and the mechanical properties of their cell walls. By testing the mechanical responses of Arabidopsis mutants, it is possible to deduce the contribution that polymers of the cell wall make to organ strength. We developed a method to measure the tensile parameters of the expanded regions

Peter Ryden; Keiko Sugimoto-Shirasu; Andrew Charles Smith; Kim Findlay; Wolf-Dieter Reiter; Maureen Caroline

2003-01-01

306

Impact of Gluma Desensitizer on the tensile strength of zirconia crowns bonded to dentin: an in vitro study.  

PubMed

This study tested the impact of Gluma Desensitizer on the tensile strength of zirconia crowns bonded to dentin. Human teeth were prepared and randomly divided into six groups (N = 144, n = 24 per group). For each tooth, a zirconia crown was manufactured. The zirconia crowns were cemented with: (1) Panavia21 (PAN), (2) Panavia21 combined with Gluma Desensitizer (PAN-G), (3) RelyX Unicem (RXU), (4) RelyX Unicem combined with Gluma Desensitizer (RXU-G), (5) G-Cem (GCM) and (6) G-Cem combined with Gluma Desensitizer (GCM-G). The initial tensile strength was measured in half (n = 12) of each group and the other half (n = 12) subjected to a chewing machine (1.2 Mio, 49 N, 5°C/50°C). The cemented crowns were pulled in a Universal Testing Machine (1 mm/min, Zwick Z010) until failure occurred and tensile strength was calculated. Data were analyzed with one-way and two-way ANOVA followed by a post hoc Scheffé test, t test and Kaplan-Meier analysis with a Breslow-Gehan analysis test (? = 0.05). After the chewing simulation, the self-adhesive resin cements combined with Gluma Desensitizer showed significantly higher tensile strength (RXU-G, 12.8 ± 4.3 MPa; GCM-G, 13.4 ± 6.2 MPa) than PAN (7.3 ± 1.7 MPa) and PAN-G (0.9 ± 0.6). Within the groups, PAN, PAN-G and RXU resulted in significantly lower values when compared to the initial tensile strength; the values of all other test groups were stable. In this study, self-adhesive resin cements combined with Gluma Desensitizer reached better long-term stability compared to PAN and PAN-G after chewing simulation. PMID:21336631

Stawarczyk, Bogna; Hartmann, Leonie; Hartmann, Rahel; Roos, Malgorzata; Ender, Andreas; Ozcan, Mutlu; Sailer, Irena; Hämmerle, Christoph H F

2011-02-19

307

Tensile properties and water vapor permeability of sodium caseinate films containing oleic acid–beeswax mixtures  

Microsoft Academic Search

Tensile and water vapor permeability properties of sodium caseinate based films were studied to optimize film composition in terms of kind and ratio of plasticizer (glycerol and sorbitol) and lipids (oleic acid and beeswax). Glycerol was more effective as plasticizer than sorbitol in the caseinate matrices; films with 90% sorbitol had similar tensile properties to those elaborated with 40–50% glycerol.

Maria José Fabra; Pau Talens; Amparo Chiralt

2008-01-01

308

Development of Heavy Gauge 60 kgf/mm(2) Class Tensile Strength Steel Plate with Low Yield Ratio for Architecture Use.  

National Technical Information Service (NTIS)

The 50 kgf/sq mm class tensile strength steel plates with low Yield Ratio (YR) have been widely applied to steel-frame buildings. On the other hand, conventional 60 kgf/sq mm class tensile strength steel plates have rarely been used in steel-frame buildin...

N. Shikanai S. Sakui H. Tagawa I. Watanabe H. Narita

1988-01-01

309

Development of Heavy Gauge 60 kgf/mm2 Class Tensile Strength Steel Plate with Low Yield Ratio for Architecture Use,  

National Technical Information Service (NTIS)

The 50 kgf/mm sup 2 class tensile strength steel plates with low Yield Ratio (YR) have been widely applied to steel-frame buildings. On the other hand, conventional 60 kgf/mm sup 2 class tensile strength steel plates have been scarcely applied to steel-fr...

N. Shikanai S. Sakui H. Tagawa I. Watanabe H. Narita

1988-01-01

310

The effect of low dose rate irradiation on the tensile properties and microstructure of austenitic stainless steel.  

SciTech Connect

To assess the effects of long-term, low-dose-rate neutron exposure on mechanical strength and ductility, tensile properties were measured on 12% and 20% cold-worked Type 316 stainless steel. Samples were prepared from reactor core components retrieved from the EBR-II reactor following final shutdown. Sample locations were chosen to cover a dose range of 1-56 dpa at temperatures from 371-440 C and dose rates from 0.5-5.8 x10{sup -7} dpa/s. These dose rates are approximately an order of magnitude lower than those of typical EBR-II test sample locations. The tensile tests for the 12% CW material were performed at 380 C and 430 C while those for the 20% CW samples were performed at 370 C. In each case, the tensile test temperature approximately matched the irradiation temperature. To help understand the tensile properties, microstructural samples with similar irradiation history were also examined. The strength and loss of work hardening increase the fastest as a function of irradiation dose for the 12% CW material irradiated at lower temperature. The decrease in ductility with increasing dose occurs more rapidly for the 12% CW material irradiated at lower temperature and the 20% cold-worked material. Post-tensile test fractography indicates that at higher dose, the 20% CW samples begin a shift in fracture mode from purely ductile to mainly small facets and slip bands, suggesting a transition toward channel fracture. The fracture for all of the 12% cold-worked samples was ductile. For both the 12% and 20% CW materials, the yield strength increases correlate with changes in void and loop density and size.

Allen, T. R.; Tsai, H.; Cole, J. I.; Yoshitake, T.; Akasaka, N.; Donomae, T.; Mizuta, S.; Ohta, J.; Dohi, K.; Kusanagi, H.

2002-09-17

311

Root diversity in alpine plants: root length, tensile strength and plant age  

NASA Astrophysics Data System (ADS)

A high diversity of plant species and functional groups is hypothesised to increase the diversity of root types and their subsequent effects for soil stability. However, even basic data on root characteristics of alpine plants are very scarce. Therefore, we determined important root characteristics of 13 plant species from different functional groups, i.e. grasses, herbs and shrubs. We excavated the whole root systems of 62 plants from a machine-graded ski slope at 2625 m a.s.l. and analysed the rooting depth, the horizontal root extension, root length and diameter. Single roots of plant species were tested for tensile strength. The age of herbs and shrubs was determined by growth-ring analysis. Root characteristics varied considerably between both plant species and functional groups. The rooting depth of different species ranged from 7.2 ± 0.97 cm to 20.5 ± 2.33 cm, but was significantly larger in the herb Geum reptans (70.8 ± 10.75 cm). The woody species Salix breviserrata reached the highest horizontal root extensions (96.8 ± 25.5 cm). Most plants had their longest roots in fine diameter classes (0.5

Pohl, M.; Stroude, R.; Körner, C.; Buttler, A.; Rixen, C.

2009-04-01

312

Microstructure of high-tensile strength brasses containing silicon and manganese  

NASA Astrophysics Data System (ADS)

The morphology, crystallography, chemistry, and distribution of the phases in commercial high-tensile strength brasses containing manganese and silicon with compositions conforming to U.S.A. Specifications C67300 (Cu-35Zn-2.5Mn-lSi) and C67400 (Cu-35Zn-2.5Mn-lSi-l.5Al) have been studied. The wrought and cast microstructures of both types of alloys consist of the copper-rich fee a phase, ordered B2 ?’ phase, and a manganese silicide Mn5Si3, with the crystal structure D88. Particles of Mn5Si3 are distributed uniformly in the as-cast alloy C67300 but tend to concentrate at the ?' boundaries in alloy C67400. Studies of the development of the microstructure show that Mn5Si3 particles form from the liquid and are also precipitated from solid solution. During cooling, the ? phase precipitates at a higher temperature in alloy C67300 (800 °C) than in alloy C67400 (500 °C); nucleation of the ? phase occurs on Mn5Si3 particles in alloy C67400. Tiny Mn5Si3 precipitates are formed in both alloys upon quenching from temperatures near the solidus. When the quenched specimens are tempered at temperatures between 400 °C and 500 CC, all of the ?' phase transforms to ? in alloy C67300, while in alloy C67400, ? precipitation occurs at the ?' boundaries and shows a Widmanstätten morphology.

Sun, Y. S.; Lorimer, G. W.; Ridley, N.

1989-07-01

313

Shear Stress Magnitude and Duration Modulates Matrix Composition and Tensile Mechanical Properties in Engineered Cartilaginous Tissue  

PubMed Central

Cartilage tissue-engineering strategies aim to produce a functional extracellular matrix similar to that of the native tissue. However, none of the myriad approaches taken have successfully generated a construct possessing the structure, composition, and mechanical properties of healthy articular cartilage. One possible approach to modulating the matrix composition and mechanical properties of engineered tissues is through the use of bioreactor-driven mechanical stimulation. In this study, we hypothesized that exposing scaffold-free cartilaginous tissue constructs to seven days of continuous shear stress at 0.001-Pa or 0.1-Pa would increase collagen deposition and tensile mechanical properties compared to that of static controls. Histologically, type II collagen staining was evident in all construct groups, while a surface layer of type I collagen increased in thickness with increasing shear stress magnitude. The areal fraction of type I collagen was higher in the 0.1-Pa group (25.2±2.2%) than either the 0.001-Pa (13.6±3.8%) or the static (7.9%±1.5%) groups. Type II collagen content, as assessed by ELISA, was also higher in the 0.1-Pa group (7.5±2.1%) compared to the 0.001-Pa (3.0±2.25%) or static groups (3.7±3.2%). Temporal gene expression analysis showed a flow-induced increase in type I and II collagen expression within 24 hours of exposure. Interestingly, while the 0.1-Pa group showed higher collagen content, this group retained less sulfated glycosaminoglycans in the matrix over time in bioreactor culture. Increases in both tensile Young's modulus and ultimate strength were observed with increasing shear stress, yielding constructs possessing a modulus of nearly 5-MPa and strength of 1.3-MPa. This study demonstrates that shear stress is a potent modulator of both the amount and type of synthesized extracellular matrix constituents in engineered cartilaginous tissue with corresponding effects on mechanical function.

Gemmiti, Christopher V.; Guldberg, Robert E.

2009-01-01

314

Strength properties of fly ash based controlled low strength materials.  

PubMed

Controlled low strength material (CLSM) is a flowable mixture that can be used as a backfill material in place of compacted soils. Flowable fill requires no tamping or compaction to achieve its strength and typically has a load carrying capacity much higher than compacted soils, but it can still be excavated easily. The selection of CLSM type should be based on technical and economical considerations for specific applications. In this study, a mixture of high volume fly ash (FA), crushed limestone powder (filler) and a low percentage of pozzolana cement have been tried in different compositions. The amount of pozzolana cement was kept constant for all mixes as, 5% of fly ash weight. The amount of mixing water was chosen in order to provide optimum pumpability by determining the spreading ratio of CLSM mixtures using flow table method. The shear strength of the material is a measure of the materials ability to support imposed stresses on the material. The shear strength properties of CLSM mixtures have been investigated by a series of laboratory tests. The direct shear test procedure was applied for determining the strength parameters Phi (angle of shearing resistance) and C(h) (cohesion intercept) of the material. The test results indicated that CLSM mixtures have superior shear strength properties compared to compacted soils. Shear strength, cohesion intercept and angle of shearing resistance values of CLSM mixtures exceeded conventional soil materials' similar properties at 7 days. These parameters proved that CLSM mixtures are suitable materials for backfill applications. PMID:17331642

Türkel, S

2007-02-03

315

Tensile properties of as-deformed 2A50 aluminum alloy in semi-solid state  

Microsoft Academic Search

Tensile properties of as-deformed 2A50 aluminum alloy were investigated in the high temperature solid and semi-solid states. The results show that temperature has almost no effect on the maximum tensile stress between 500 °C and 530 °C, and the maximum tensile stress decreases rapidly when the temperature is above 532 °C. The ductility decreases with increasing temperature and has an

Zhi-ming DU; Gang CHEN; Jun LIU; Shui-sheng XIE

2010-01-01

316

The effect of porous surface configuration on the tensile strength of fixation of implants by bone ingrowth.  

PubMed

In an attempt to gain information that could be directly applied to the design of clinical porous-surfaced prostheses intended for biological attachment by bone ingrowth, the tensile strength of the bone-implant interface was expressed as a function of 2 fundamentally different porous-surface configurations. Using powder metallurgy techniques, standard 3-hole fracture fixation plates were prepared with both a single and a multiple layer of spherically shaped metal powder particles on the bone-contacting surface to produce implants with different porous surfaces. These plates were implanted onto the lateral aspect of canine femurs for periods of 4, 6, 8, 12, 18, and 24 weeks. Mechanical tests were performed to measure the tensile strength of fixation of the implants by the ingrowth of bone. The results of the mechanical tests indicated that implants with the multiple particle layer surfce configuration develop a greater tensile strength of fixation than do implants with the single particle layer surface configuration. In addition, this fixation strength develops more quickly if the cortical bone is petaled prior to implantation. These findings should be considered when designing porous-surfaced implants intended for fixation by bone ingrowth. PMID:7408314

Bobyn, J D; Pilliar, R M; Cameron, H U; Weatherly, G C; Kent, G M

1980-06-01

317

Dynamic Tensile Properties of Steels and Aluminum Alloys for a Wide Range of Strain Rates and Strain  

NASA Astrophysics Data System (ADS)

Through intensive analysis of the tensile stress-strain curves of a variety of steel sheets over a wide range of strain rates on the order of 10-2 ˜103 s-1 obtained by using the Sensing Block Type High Speed Material Testing System, it was confirmed that the newly-partially extended constitutive model (Tanimura-Mimura Model) is useful to simulate the dynamic stress-strain curves for the entire range of deformation reaching as far as fracture over the wide strain rate range, as long as the quasi-static stress-strain curve of the material concerned is only known in advance. Dynamic tensile properties, over the wide strain rate range and the entire strain region reaching the true fracture strain, of ten kinds of aluminum alloys, which compose of a wide strength level from a commercial pure aluminum to the extra super duralumin are systematically studied. It was cleared that the aluminum alloys belonging to the one group exhibit the positive strain rate sensitivity and the aluminum alloys belonging to another group exhibit the negative sensitivity or almost non sensitivity. It was found that the values of the true fracture strain ?f are substantially not affected by the strain rates, for all the tested aluminum alloys, and are closely related to the values of the tensile strength ?B whose values are obtained by the quasi-static nominal tensile stress-strain curves.

Tanimura, Shinji; Hayashi, Hiroyuki; Yamamoto, Terumi; Mimura, Koji

318

Tensile properties of the human muscular and ligamentous cervical spine.  

PubMed

Tensile neck injuries are amongst the most serious cervical injuries. However, because neither reliable human cervical tensile tolerance data nor tensile structural data are currently available, the quantification of tensile injury risk is limited. The purpose of this study is to provide previously unavailable kinetic and tolerance data for the ligamentous cervical spine and determine the effect of neck muscle on tensile load response and tolerance. Using six male human cadaver specimens, isolated ligamentous cervical spine tests (occiput - T1) were conducted to quantify the significant differences in kinetics due to head end condition and anteroposterior eccentricity of the tensile load. The spine was then separated into motion segments for tension failure testing. The upper cervical spine tolerance of 2400 +/- 270 N (occiput-C2) was found to be significantly greater (p < 0.01) than the lower cervical spine tolerance of 1780 +/- 230 N (C4-C5 and C6-C7 segments). Data from these experiments were used to develop and validate a computational model of the ligamentous spine. The model predicted the end condition and eccentricity responses for the tensile force-displacement relationship. Cervical muscular geometry data derived from cadaver dissection and MRI imaging were used to incorporate a muscular response into the model. The cervical musculature under maximal stimulation increased the tolerance of the cervical spine from 1800 N to 4160 N. In addition, the cervical musculature resulted in a shift in the site of injury from the lower cervical spine to the upper cervical spine and offers an explanation for the mechanism of upper cervical spine tension injuries observed clinically. The results from this study predict a range in tensile tolerance from 1.8 - 4.2 kN based on the varying role of the cervical musculature. PMID:17458720

Van Ee, C A; Nightingale, R W; Camacho, D L; Chancey, V C; Knaub, K E; Sun, E A; Myers, B S

2000-11-01

319

Nanoscale steel-brass multilayer laminates made by cold rolling: Microstructure and tensile properties  

SciTech Connect

The thrust of this study is to fabricate steel-brass multilayer laminates with layer thicknesses in the nanometer range and to evaluate their mechanical properties. Repeated cold rolling of multilayer stacks was adopted to produce the laminates, because the relative simplicity and the low-cost nature of this process can allow the scaling-up of the technique to the level of commercial-scale production. This work is a continuation of a previous study, in which steel-brass laminates with layer thicknesses in the micrometer range were fabricated for the first time and their tensile properties were evaluated. The present work, however, emphasizes making multilayers with layer thicknesses in the nanometer range and evaluating their mechanical properties. The dependence of strength and ductility on the layer spacing in the nanometer range, is highlighted. It is shown that strength levels comparable to quenched and tempered low alloy steels can be achieved in the laminates by rolling down to the low end of nanometer range. The relevant strengthening mechanisms are also discussed.

Kavarana, F.H.; Ravichandran, K.S.; Sahay, S.S.

2000-05-10

320

Temperature dependence of tensile mechanical properties in SiC fiber-reinforced Ti matrix composite  

SciTech Connect

Temperature dependence of longitudinal Young's modulus, tensile strength, and interfacial shear stress in SiC(SCS-6) fiber-reinforced commercially pure Ti matrix composites have been examined experimentally in the temperature range from room temperature to 873 K. Young's modulus and tensile strength of the composite was discussed in relation to the interfacial shear stress transfer mechanism. Young's modulus was independent of interfacial shear stress, however, the tensile strength depended strongly on the interfacial shear stress. With increasing test temperature, the interfacial shear stress decreased, a behavior which originated from an insufficient stress transfer between fiber and matrix due to decrease of shear yield stress of the matrix. The tensile strength of the composite depended on the potential of shear stress transfer at the interface, and the temperature dependence of the tensile strength was quantitatively explained by the proposed in-direct stress transfer model.'' The model suggests when the length of the composite in the longitudinal direction was sufficiently long, R[sub f][bar [sigma

Kagawa, Y.; Fujita, T.; Okura, A. (Univ. of Tokyo (Japan). Inst. of Industrial Science)

1994-09-01

321

Influence of microstructure on tensile properties of spheroidized ultrahigh-carbon (1. 8 pct C) steel  

SciTech Connect

Ultrahigh-carbon steel (UHCS) containing 1.8 pct carbon was processed to create microstructures consisting of fine-spheroidized carbide particles (0.2 to 1.5-Am size range) within a fine-grained ferrite matrix (0.3 to 5-Am range) through a variety of thermomechanical processing and heat-treatment combinations. Tensile ductility, yield, and fracture strengths, and strain-hardening behavior were evaluated at room temperature. Yield strengths ranged from 640 to 1,450 MPa, and uniform tensile elongation ranged from 3 to 23 pct. Quantitative analyses revealed that a Hall-Petch type relationship exists between the yield strength and the ferrite grain size and carbide particle size within grain interiors. The fracture strength, on the other hand, was found to be uniquely dependent on the coarse carbide particle size typically found at grain boundaries. Data from other investigators on spheroidized carbon steels were shown to correlate well with the data for the UHCS (1.8 pct C) material. It was shown that the tensile ductility will increase when the difference between the fracture strength and the yield strength is increased and when the strain-hardening rate is decreased. The basis for the trends observed is that the tensile ductility is limited by the fracture process that appears to be dictated by the nucleation of cracks at large carbide particles. The results obtained indicate that UHCSs have significant potential for sheet applications where high strength and good ductility are primary requirements.

Syn, C.K.; Lesuer, D.R. (Lawrence Livermore National Lab., CA (United States)); Sherby, O.D. (Stanford Univ., CA (United States). Dept. of Materials Science and Engineering)

1994-07-01

322

Correlation of fracture toughness with tensile properties for irradiated 20% cold-worked 316 stainless steel  

Microsoft Academic Search

A correlation has been developed which allows an estimate to be made of the toughness of austenitic alloys using more easily obtained tensile data. Tensile properties measured on 20% cold-worked AISI 316 specimens made from ducts and cladding irradiated in EBR-II were used to predict values for the plane strain fracture toughness according to a model originally developed by Krafft.

M. L. Hamilton; F. A. Garner; W. G. Wolfer

1983-01-01

323

Effect of welding on microstructure and tensile properties of flowformed Ti6Al4V tubes  

Microsoft Academic Search

In this study, extra-low interstitial grade Ti-6Al-4V tubes manufactured by the flowforming process were joined by plasma arc welding. Welded tubes were subjected to a stress-relief heat treatment prior to the removal of specimens for microstructural examination, and tensile and fatigue testing. Welded tubes exhibited tensile and yield strength values of 892 and 790MPa, respectively, and elongation and reduction of

Ibrahim Ucok; Lawrence S. Kramer; Mehmet N. Gungor; Philip Wolfe; Hao Dong; Wm. Troy Tack

2005-01-01

324

Tensile and creep properties of SA533 Grade B Class 1 steel  

Microsoft Academic Search

Tensile and creep tests are being performed on several lots of base metal and weldments to determine the design stresses for 1% strain in 1000 h over the temperature range of 371 to 538[degree]C. Short-term tensile tests indicate that the strength is least for base metal, intermediate for transverse weld specimens, and greatest for weld metal. Creep tests show much

McCoy

1989-01-01

325

The effect of cryogenic cooling on the tensile properties of metal-matrix composites  

Microsoft Academic Search

Tensile specimens machined from metal-matrix, oriented-fiber composites (aluminum alloy reinforced with high strength stainless\\u000a steel wire) were heated to 260°C and cooled in air to produce a tensile residual stress state in the matrix. Some of the test\\u000a pieces were cooled to the temperature of boiling nitrogen, held at temperature for fifteen minutes, and then air warmed to\\u000a room temperature.

John Gayda; L. J. Ebert

1979-01-01

326

Root tensile strength relationships and their slope stability implications of three shrub species in the Northern Apennines (Italy)  

NASA Astrophysics Data System (ADS)

The role of root strength is important in stabilising steep hillslopes which are seasonally affected by storm-induced shallow landslides. In the Italian Apennines, steep (25 40°) slopes underlain by mudstone are generally stable if they are covered by shrubs whose roots anchor into the soil mantle. To quantify the mechanical reinforcement of roots to soil, the root tensile breaking force and the root tensile strength of three autochthonous shrub species commonly growing on stiff clay soils of the Northern Italian Apennines, Rosa canina (L.), Inula viscosa (L.) and Spartium junceum (L.), were measured by means of field and laboratory tests. For each test approximately 150 root specimens were used. The tensile force increases with increasing root diameter following a second-order polynomial regression curve. The tensile strength decreases with increasing root diameter following a power law curve. The field in situ tensile force required to break a root is always smaller than that obtained from laboratory tests for the same root diameter, although their difference becomes negligible if the root diameter is smaller than 5 mm. The influence of root tensile strength on soil shear strength was verified based on the infinite slope stability model. The root reinforcement was calculated using the number and mean diameter of roots. The factor of safety was calculated for three different soil thickness values (0.1, 0.3, and 0.6 m) and topographic slopes between 10° and 45°. The factor of safety for the combination of 0.6 m soil thickness, slopes smaller than 30°, and vegetation of I. viscosa (L.) or S. junceum (L.) is always larger than 1. If a slope is steeper, the factor of safety may be smaller than 1 for I. viscosa (L.), although it is still larger than 1 for S. junceum (L.). In the stiff clayey areas of the Northern Italian Apennines, I. viscosa (L.) mainly colonizes fan/cone/taluses and stabilises these zones up to a topographic gradient < 30° for a soil 0.6 m thick. S. junceum (L.) colonizes not only fan/cone/taluses but also headwalls and cliffs and, for a 0.6 m thick soil, it stabilises these areas up to 45°. The effectiveness of this reinforcement, however, depends strongly on the frequency of soil and seasonal grass vegetation removal due to shallow landsliding before the entrance of the shrub species.

Tosi, Matteo

2007-07-01

327

Effect of filler loading on tensile and tear properties of SMR L\\/ENR 25 and SMR L\\/SBR blends cured via a semi-efficient vulcanization system  

Microsoft Academic Search

The effects of filler loading on the tensile and tear properties of SMR L\\/ENR 25 and SMR L\\/SBR blends using a semi-efficient vulcanization system was studied. Carbon black (N330), silica (Vulcasil C) and calcium carbonate were used as the fillers and the loading range was from 0 to 40 phr. Tensile strength, M300 (tensile stress at 300% elongation) and tear

B. T. Poh; H. Ismail; K. S. Tan

2002-01-01

328

Effect of thermal aging on the tensile bond strength at reduced areas of seven current adhesives.  

PubMed

The purpose of this study was to determine the micro-tensile bond strength (MTBS) to dentin of seven adhesive systems (total and self-etch adhesives) after 24 h and 5,000 thermocycles. Dentin surfaces of human third molars were exposed and bonded with two total-etch adhesives (Adper Scotchbond 1 XT and XP Bond), two two-step self-etch adhesives (Adper Scotchbond SE and Filtek Silorane Adhesive System) and three one-step self-etch adhesives (G-Bond, Xeno V and Bond Force). All adhesive systems were applied following manufacturers' instructions. Composite buildups were constructed and the bonded teeth were then stored in water (24 h, 37 °C) or thermocycled (5,000 cycles) before being sectioned and submitted to MTBS test. Two-way ANOVA and subsequent comparison tests were applied at ? = 0.05. Characteristic de-bonded specimens were analyzed using scanning electron microscopy (SEM). After 24 h water storage, MTBS values were highest with XP Bond, Adper Scotchbond 1 XT, Filtek Silorane Adhesive System and Adper Scotchbond SE and lowest with the one-step self-etch adhesives Bond Force, Xeno V and G-Bond. After thermocycling, MTBS values were highest with XP Bond, followed by Filtek Silorane Adhesive System, Adper Scotchbond SE and Adper Scotchbond 1 XT and lowest with the one-step self-etch adhesives Bond Force, Xeno V and G-Bond. Thermal aging induced a significant decrease in MTBS values with all adhesives tested. The resistance of resin-dentin bonds to thermal-aging degradation was material dependent. One-step self-etch adhesives obtained the lowest MTBS results after both aging treatments, and their adhesive capacity was significantly reduced after thermocycling. PMID:22790477

Baracco, Bruno; Fuentes, M Victoria; Garrido, Miguel A; González-López, Santiago; Ceballos, Laura

2012-07-13

329

Characterization and modeling of the tensile properties of plain weft-knit fabric-reinforced composites  

Microsoft Academic Search

This paper describes analytical models for predicting tensile properties of knitted fabric-reinforced composites. Initially, tensile properties of plain weft-knit glass-fiber fabric-reinforced epoxy composites were determined experimentally in the wale and course directions. Elastic properties were predicted by using a ‘cross-over model’ and laminated plate theory. The analytical model expresses the crossing over of looped yarns of knitted fabric, and fiber-

S. Ramakrishna

1997-01-01

330

Fractography, fluidity, and tensile properties of aluminum/hematite particulate composites  

SciTech Connect

This paper examines the effect of hematite (iron oxide) particles on the fluidity of the molten composite as well as the tensile properties and fracture behavior of the solidified as-cast aluminum composites. The percentage of hematite in the composite was varied from 1 to 7% in steps of 2% by weight. The vortex method was employed to prepare the composites. It followed from the results obtained that the ultimate tensile strength and Young`s modulus of the composite increased while the liquid fluidity and solid ductility decreased with the increase in hematite content in the composite specimens. The fluidity of the liquid was greater in a metal mold than in a sand mold, and it decreased with an increase in reinforcing particle size and increased with pouring temperature. The presence of the reinforcing particles altered the fracture behavior of the solid composites considerably. Final fracture of the composite occurred due to the propagation of cracks through the matrix between the reinforcing particles.

Sharma, S.C.; Girish, B.M.; Kamath, R.; Satish, B.M. [R.V. Coll. of Engineering, Bangalore (India). Dept. of Mechanical Engineering

1999-06-01

331

Effect of different stages of tensile deformation on micromagnetic parameters in high-strength, low-alloy steel  

Microsoft Academic Search

The influence of tensile deformation on the magnetic Barkhausen emissions (MBE) and hysteresis loop has been studied in a\\u000a high-strength, low-alloy steel (HSLA) and its weldment. The magnetic measurements were made both in loaded and unloaded conditions\\u000a for different stress levels. The rootmean-square (RMS) voltage of the MBE has been used for analysis. This study shows that\\u000a the preyield and

S. Vaidyanathan; V. Moorthy; P. Kalyanasundaram; T. Jayakumar; Baldev Raj

1999-01-01

332

Tensile strength of radio frequency cold plasma treated PET fibers—Part I: Influence of environment and treatment time  

Microsoft Academic Search

This article reports on a series of experiments with polyethylene terepthalate (PET) treated in a radio frequency plasma reactor\\u000a using argon and oxygen as a gas fuel, for treatment times equal to 5 s, 20 s, 30 s, and 100 s. The mechanical strength modification\\u000a of PET fibers, evaluated by tensile tests on monofilaments, showed that oxygen and argon plasma

M. O. H. Cioffi; H. J. C. Voorwald; V. Ambrogi; T. Monetta; F. Bellucci; L. Nicolais

2002-01-01

333

The effects of carbon content on the microstructure and elevated temperature tensile strength of a nickel-base superalloy  

Microsoft Academic Search

This study investigates how carbon content affects the microstructure and elevated temperature tensile strength of fine-grain CM-681LC superalloy. Experimental results indicate that increasing the carbon content from 0.11 to 0.15wt% increases the total area fraction of carbides considerably. However, the two alloys exhibit similar carbide shapes and sizes, probably because the short solidification time in the fine-grain process limits the

Chao-Nan Wei; Hui-Yun Bor; Li Chang

2010-01-01

334

Tensile bond strength of sealants following Er:YAG laser etching compared to acid etching in permanent teeth.  

PubMed

The aim of this in vitro study was to assess the effect of Er:YAG laser surface treatment on the tensile bond strength of a sealant in permanent teeth. A total of 30 sound third molars were selected and embedded in cold-cure acrylic resin. The enamel surfaces were flattened by a grinding. The teeth were randomly divided into three groups and pretreated as follows: (1) 37% phosphoric acid; (2) Er:YAG laser (1.5 ml/min water spray, 100 mJ energy output, 10 Hz frequency, focal distance 17 mm); (3) Er:YAG laser + 37% phosphoric acid. The treated surfaces were isolated by double adhesive Sellotape and after insertion of a split Teflon matrix at an isolated site, sealant was applied. The specimens were thermocycled and stored at 37°C in distilled water for 72 h, then subjected to a tensile bond strength test (50 kgf at 0.5 mm/min). The mean tensile bond strengths (± SD, in megapascals) were: 18.51 ± 5.68 in group 1, 8.06 ± 2.69 in group 2, and 17.33 ± 5.04 in group 3. Data were submitted to analysis of variance and the Tukey test. No significant difference were found between groups 1 (37% phosphoric acid) and group 3 (Er:YAG laser + 37% phosphoric acid) but treatment with the Er:YAG laser alone (group 2) resulted in significantly lower tensile bond strength than seen in the other groups. In this setting, the Er:YAG laser prepared the enamel surface for sealing but did not eliminate the need for acid etching before sealant application. PMID:21336680

Shahabi, Sima; Bagheri, Hossein G; Ramazani, Kosar

2011-02-19

335

Influence of martensite content and morphology on tensile and impact properties of high-martensite dual-phase steels  

SciTech Connect

A series of dual-phase (DP) steels containing finely dispersed martensite with different volume fractions of martensite (V{sub m}) were produced by intermediate quenching of a boron- and vanadium-containing microalloyed steel. The volume fraction of martensite was varied from 0.3 to 0.8 by changing the intercritical annealing temperature. The tensile and impact properties of these steels were studied and compared to those of step-quenched steels, which showed banded microstructures. The experimental results show that DP steels with finely dispersed microstructures have excellent mechanical properties, including high impact toughness values, with an optimum in properties obtained at {approximately}0.55 V{sub m}. A further increase in V{sub m} was found to decrease the yield and tensile strengths as well as the impact properties. It was shown that models developed on the basis of a rule of mixtures are inadequate in capturing the tensile properties of DP steels with V{sub m} > 0.55. Jaoul-Crussard analyses of the work-hardening behavior of the high-martensite volume fraction DP steels show three distinct stages of plastic deformation.

Bag, A. [Bharat Earth Movers Limited, Kolar Gold Fields (India). Materials Science Lab.; Ray, K.K. [Indian Inst. of Tech., Kharagpur (India). Dept. of Metallurgical and Materials Engineering; Dwarakadasa, E.S. [Indian Inst. of Science, Bangalore (India). Dept. of Metallurgy

1999-05-01

336

The effect of custom tray material type and adhesive drying time on the tensile bond strength of an impression material/adhesive system.  

PubMed

The purpose of this investigation was to compare the tensile bond strength of one poly(vinyl siloxane) impression material/adhesive system to three different custom tray materials 10 minutes, 48 hours, and 7 days after adhesive application. One autopolymerizing (Fastray) and two light-polymerizing (Triad and Extoral) custom tray resins were examined. The Triad tray resin exhibited the significantly highest mean adhesive tensile bond strengths, and the Fastray resin exhibited the lowest. It was also observed that the 48-hour adhesive drying time group exhibited the highest mean adhesive tensile bond strengths for all the materials tested, and the 10-minute group exhibited the lowest. PMID:8003192

Dixon, D L; Breeding, L C; Brown, J S

337

Galvanic corrosion induced degredation of tensile properties in micromachined polycrystalline silicon  

NASA Astrophysics Data System (ADS)

Immersion of polycrystalline silicon in hydrofluoric acid-based solutions is often utilized in microsystem fabrication to liberate mechanical structures. The authors demonstrate, using microfabricated tensile specimens, that such etching can cause a catastrophic reduction in tensile strength and elastic modulus in silicon galvanically coupled to a metallic layer, such as commonly used gold. Galvanically corroded silicon exhibits grain-boundary attack leading to intergranular fracture and/or generalized material removal. The severity of damage and corresponding losses in strength and modulus depend on etch duration and etch chemistry. In contrast, without a metallic layer, uncorroded silicon fails transgranularly and independent of etch duration or chemistry.

Miller, David C.; Boyce, Brad L.; Gall, Ken; Stoldt, Conrad R.

2007-05-01

338

Fiber Bonding and Tensile Stress-Strain Properties of Earlywood and Latewood Handsheets.  

National Technical Information Service (NTIS)

Interfiber bonding, tensile stress-strain properties, fiber collapse, and fiber-to-fiber conformability at fiber crossings were studied on handsheets composed entirely on unbeaten earlywood and latewood loblolly pine kraft fibers. Because of a better stre...

V. L. Byrd W. E. Smith

1972-01-01

339

Effect of Chemistry Variations on the Tensile Properties of 20% Cold Worked 316 Stainless Steel.  

National Technical Information Service (NTIS)

The effect of alloy compositional variations on the 1400 exp 0 F tensile properties of 20 percent cold worked type 316 stainless steel was determined. Forty-five different alloys were used with compositional variations in carbon, nitrogen), phosphorus, su...

M. M. Paxton

1973-01-01

340

Tensile properties of particulate-reinforced metal matrix composites  

Microsoft Academic Search

Room temperature tensile tests have been carried out on MMCs, all based on the Al alloy 7075 and on monolithic material. The particulate reinforcements used were SiC in three nominal sizes, 5, 13 and 60 ?m. Three matrix ageing conditions were studied, peak aged and equivalent underaged and overaged matrix conditions, based on microhardness measurements. The effects of ageing condition

T. J. A. Doel; P. Bowen

1996-01-01

341

Microstructure and tensile properties of Inconel 718 pulsed Nd-YAG laser welds  

Microsoft Academic Search

Pulsed Nd-YAG laser welding characteristics of Inconel 718 sheet material (2mm thick) were investigated. Welds were subjected to three different post-weld heat treatments: direct aging, 980°C solution treatment+aging (980STA), and 1080°C solution treatment+aging (1080STA). Weld microstructures and room temperature tensile properties were evaluated. Weld tensile properties in direct aged condition were found to be inferior in relation to the base

G. D. Janaki Ram; A. Venugopal Reddy; K. Prasad Rao; G. M. Reddy; J. K. Sarin Sundar

2005-01-01

342

Sisal\\/Carbon Fibre Reinforced Hybrid Composites: Tensile, Flexural and Chemical Resistance Properties  

Microsoft Academic Search

The variation of mechanical properties such as tensile and flexural properties of randomly oriented unsaturated polyester\\u000a based sisal\\/carbon fibre reinforced hybrid composites with different fibre weight ratios have been studied. The chemical resistance\\u000a test of these hybrid composites to various solvents, acids and alkalies were studied. The effect of NaOH treatment of sisal\\u000a fibres on the tensile, flexural and chemical

P. Noorunnisa Khanam; H. P. S. Abdul Khalil; M. Jawaid; G. Ramachandra Reddy; C. Surya Narayana; S. Venkata Naidu

2010-01-01

343

An investigation of the effect of high-temperature cyclic straining and creep loading on tensile mechanical properties of GH4145\\/SQ alloy  

Microsoft Academic Search

The effect of the reverse cyclic straining and the creep loading on the resultant tensile mechanical properties, such as the\\u000a strength parameter (?0.2 and ?b), the ductile parameter (? and ?f) and the composite parameter of the strength and ductility, the static toughness (Ut), for the precipitation-strengthened nickel-based superalloy GH4145\\/SQ used for high-temperature turbine and valve studs\\/bolts\\u000a in power plant

Duyi Ye; Zhenlin Wang; Xiaoxia Yin

2005-01-01

344

Simultaneous enhancement of tensile/compressive strength and ductility of magnesium alloy AZ31 using carbon nanotubes.  

PubMed

AZ31 nanocomposite containing carbon nanotube (CNT) reinforcement was fabricated using solidification processing followed by hot extrusion. The CNT reinforcement was integrated with AZ31 using an Al foil method. The AZ31 nanocomposite exhibited slightly smaller grain and intermetallic particle sizes than monolithic AZ31, reasonable CNT distribution, dominant (10 - 11) texture in the transverse and longitudinal directions unlike monolithic AZ31, and 48% higher hardness than monolithic AZ31. Compared to monolithic AZ31, the AZ31 nanocomposite exhibited higher 0.2%TYS, UTS, tensile failure strain and tensile work of fracture (WOF) (+10%, +17%, +68% and +92%, respectively). Similarly, compared to monolithic AZ31, the AZ31 nanocomposite exhibited higher 0.2%CYS, UCS, average compressive failure strain and compressive WOF (+58%, +3%, +5% and +17%, respectively). Inclusive of crystallographic texture changes, the effect of CNT integration on the enhancement of tensile and compressive properties of AZ31 is investigated in this paper. PMID:20352742

Paramsothy, M; Hassan, S F; Srikanth, N; Gupta, M

2010-02-01

345

THE EFFECT OF HYDROGEN IN QUANTITIES OF UP TO 0.009% ON THE ROOM TEMPERATURE IZOD AND TENSILE STRENGTH OF COMMERCIALLY PURE TITANIUM  

Microsoft Academic Search

Tests on slowly cooled bars of titanium indicated that the Izod strength ; progressively increased as the hydrogen content was reduced from 0.009 to 0.001%. ; Hydrogen and oxygen atoms had approximately equivalent deletertous effects on the ; impact strength og titanium. The tensile strength increased when the straining ; rate was changed from the slowest to the fastest available;

Beton

1959-01-01

346

Effects of polymerization and briquetting parameters on the tensile strength of briquettes formed from coal coke and aniline-formaldehyde resin  

SciTech Connect

In this work, the utilization of aniline (C{sub 6}H{sub 7}N) formaldehyde (HCHO) resins as a binding agent of coke briquetting was investigated. Aniline (AN) formaldehyde (F) resins are a family of thermoplastics synthesized by condensing AN and F in an acid solution exhibiting high dielectric strength. The tensile strength sharply increases as the ratio of F to AN from 0.5 to 1.6, and it reaches the highest values between 1.6 and 2.2 F/AN ratio; it then slightly decreases. The highest tensile strength of F-AN resin-coke briquette (23.66 MN/m{sup 2}) was obtained from the run with 1.5 of F/AN ratio by using (NH4){sub 2}S{sub 2}O{sub 8} catalyst at 310 K briquetting temperature. The tensile strength of F-AN resin-coke briquette slightly decreased with increasing the catalyst percent to 0.10%, and then it sharply decreased to zero with increasing the catalyst percent to 0.2%. The effect of pH on the tensile strength is irregular. As the pH of the mixture increases from 9.0 to 9.2, the tensile strength shows a sharp increase, and the curve reaches a plateau value between pH 9.3 and 9.9; then the tensile strength shows a slight increase after pH = 9.9.

Demirbas, A.; Simsek, T. [Selcuk University, Konya (Turkey)

2006-10-15

347

Studies of Microtexture and Its Effect on Tensile and High-Cycle Fatigue Properties of Laser-Powder-Deposited INCONEL 718  

NASA Astrophysics Data System (ADS)

The current work studies the microstructure, texture, and mechanical properties of INCONEL 718 alloy (IN718) produced by laser direct metal deposition. The grain microstructure exhibits an alternative distribution of banded fine and coarse grain zones as a result of the rastering scanning pattern. The effects of the anisotropic crystallographic texture on the tensile and high-cycle fatigue (HCF) properties at room temperature are investigated. Tensile test results showed that the tensile strength of laser-deposited IN718 after direct aging or solution heat treatment is equivalent to the minimum-forged IN718 properties. The transverse direction (relative to the laser scanning direction) produces >10 pct stiffer modulus of elasticity but 3 to 6 pct less tensile strength compared to the longitudinal direction due to the preferential alignment of grains having <111> and <100> directions parallel to the tensile loading direction. Laser-deposited IN718 with good metallurgical integrity showed equivalent HCF properties compared to the direct-aged wrought IN718, which can be attributed to the banded grain size variation and cyclic change of inclining grain orientations resulted from alternating rastering deposition path.

Qi, Huan; Azer, Magdi; Deal, Andrew

2012-11-01

348

Effects of different disinfection and sterilization methods on tensile strength of materials used for single-use devices.  

PubMed

Driven by economic and time constraints, some medical centers and third parties are resterilizing single-use devices (SUDs) for reuse. The steam autoclave is quick, but most plastics used in SUDs cannot survive the temperature. Thus, a number of new methods of cleaning, disinfecting, and sterilizing these complex devices are being introduced on the market. The present study investigated the effects of a range of methods on the tensile strength of latex rubber, silicone elastomer, 2 different formulations of polyurethane, nylon, and high-density polyethylene (HDPE) specimens. The methods used were sodium hypochlorite bleach (Clorox), peracetic acid + hydrogen peroxide (Steris), formaldehyde gas (Chemiclave), low-temperature peracetic acid and gas plasma (Plazlyte), and low-temperature hydrogen peroxide gas plasma (Sterrad). The results showed that silicone elastomer was minimally affected, whereas the strengths of nylon, polyethylene, and latex were reduced by some of the methods. Depending on the formulation, the strength of polyurethane either increased or decreased. The data demonstrated that disinfection and sterilization can affect the tensile strength of certain materials used in medical devices. PMID:11831098

Brown, Stanley A; Merritt, Katharine; Woods, Terry O; McNamee, Scott G; Hitchins, Victoria M

349

Elevated Temperature Tensile and Creep Properties of M-252 (Bar), Inconel 700 (Bar), and Inconel 713 (Cast) Nickel Base Alloys.  

National Technical Information Service (NTIS)

Room and elevated temperature tensile and elevated temperature creep properties to 1000 hours were determined at three representative application temperatures for M-252 (bar), Inconel 700 (bar), and Inconel 713 (cast). Tabulated tensile and creep data, de...

S. O. Davis

1964-01-01

350

Tensile Properties of LE-7 Engine Material with Welded Joints. 3rd Report. Influence of Solution Treatment Conditions upon Micro Structures and Tensile Properties.  

National Technical Information Service (NTIS)

The authors studied the tensile properties of the GTA welded joint with solution treated at 1228 K and 1338 K in a previous report. This report shows the effects of solution treatment condition (time and temperature) ranging from 1228 K to 1338 K on the m...

M. Yoshida T. Hashimoto Y. Watanabe

1996-01-01

351

A scaffold-enhanced light-activated surgical adhesive technique: surface selection for enhanced tensile strength in wound repair  

NASA Astrophysics Data System (ADS)

An ex vivo study was conducted to determine the effect of the irregularity of the scaffold surface on the tensile strength of repairs formed using our Scaffold-Enhanced Biological Adhesive (SEBA). Two different scaffold materials were investigated: (i) a synthetic biodegradable material fabricated from poly(L-lactic-co-glycolic acid); and (ii) a biological material, small intestinal submucosa, manufactured by Cook BioTech. The scaffolds were doped with protein solder composed of 50%(w/v) bovine serum albumin solder and 0.5mg/ml indocyanine green dye mixed in deionized water, and activated with an 808-nm diode laser. The tensile strength of repairs performed on bovine thoracic aorta, liver, spleen, small intestine and lung, using the smooth and irregular surfaces of the above scaffold-enhanced materials were measured and the time-to-failure was recorded. The tensile strength of repairs formed using the irregular surfaces of the scaffolds were consistently higher than those formed using the smooth surfaces of the scaffolds. The largest difference was observed on repairs formed on the aorta and small intestine, where the repairs were, on average, 50% stronger using the irregular versus the smooth scaffold surfaces. In addition, the time-to-failure of repairs formed using the irregular surfaces of the scaffolds were between 50% and 100% longer than that achieved using the smooth surfaces of the scaffolds. It has previously been shown that distributing or dispersing the adhesive forces over the increased surface area of the scaffold, either smooth or irregular, produces stronger repairs than albumin solder alone. The increase in the absolute strength and longevity of repairs seen in this new study when the irregular surfaces of the scaffolds are used is thought to be due to the distribution of forces between the many independent micro-adhesions provided by the irregular surfaces.

Soller, Eric C.; Hoffman, Grant T.; Heintzelman, Douglas L.; Duffy, Mark T.; Bloom, Jeffrey N.; McNally-Heintzelman, Karen M.

2004-07-01

352

Influence of different brazing and welding methods on tensile strength and microhardness of orthodontic stainless steel wire.  

PubMed

The aim of this study was to compare the mechanical strength and microhardness of joints made by conventional brazing and tungsten inert gas (TIG) and laser welding. A standardized end-to-end joint configuration of the orthodontic wire material in spring hard quality was used. The joints were made using five different methods: brazing (soldering > 450 degrees C) with universal silver solder, two TIG, and two laser welders. Laser parameters and welding conditions were used according to the manufacturers' guidance. The tensile strengths were measured with a universal testing machine (Zwick 005). The microhardness measurements were carried out with a hardness tester (Zwick 3202). Data were analysed using one-way analysis of variance and Bonferroni's post hoc correction (P < 0.05). In all cases, brazing joints ruptured at low levels of tensile strength (198 +/- 146 MPa). Significant differences (P < 0.001) between brazing and TIG or laser welding were found. The highest means were observed for TIG welding (699-754 MPa). Laser welding showed a significantly lower mean tensile strength (369-520 MPa) compared with TIG welding. Significant differences (P < 0.001) were found between the original orthodontic wire and the mean microhardness at the centre of the welded area. The mean microhardness differed significantly between brazing (1.99 GPa), TIG (2.22-2.39 GPa) and laser welding (2.21-2.68 GPa). For orthodontic purposes, laser and TIG welding are solder-free alternatives to joining metal. TIG welding with a lower investment cost is comparable with laser welding. However, while expensive, the laser technique is a sophisticated and simple method. PMID:18617503

Bock, Jens Johannes; Fraenzel, Wolfgang; Bailly, Jacqueline; Gernhardt, Christian Ralf; Fuhrmann, Robert Andreas Werner

2008-07-09

353

Direct correlation between microstructure and mechanical tensile properties in Pb-free solders and eutectic SnPb solder for flip chip technology  

NASA Astrophysics Data System (ADS)

The relationship between the microstructure and the mechanical tensile properties of lead-free solders and eutectic SnPb solders is presented for flip chip scale interconnects. Eutectic Sn-37Pb and Sn-0.7Cu solder (in wt %) exhibited a ductile fracture after tensile testing. Eutectic Sn-3.5Ag solder (in wt %) had greater strength and exhibited a brittle fracture at the interface. The different fracture behavior of the lead-free solders was attributed to the grain size and configuration of the intermetallics. Minor additions of alloying elements to the high Sn lead-free solder dramatically affected the microstructure and mechanical properties.

Jang, J. W.; de Silva, A. P.; Lee, T. Y.; Lin, J. K.; Frear, D. R.

2001-07-01

354

Tensile flow properties of Al-based matrix composites reinforced with a random planar network of continuous metallic fibers  

SciTech Connect

Squeeze casting was used for processing two new types of composites: pure Al matrix composites reinforced with fibers of Inconel 601, and AS13 (Al-12% Si) matrix composites reinforced with fibers of Inconel 601 or stainless steel 316L. The fibers are continuous with a diameter of 12 {micro}m and their volume fraction in the composites varied from 20 to 80%. The processing conditions were such that no trace of interfacial reaction compound or of matrix precipitate resulting from the dissolution of elements of the fibers could be detected. The quality of the process was attested by Young`s modulus and electrical conductivity measurements. Tensile tests were carried out from room temperature up to 300 C. The composites with the pure Al matrix present a remarkable tensile ductility. They thus constitute convenient materials for assessing continuum plasticity models for composites. Properties of composites with the AS13 matrix are much affected by interface adhesion strength.

Boland, F.; Salmon, C.; Delannay, F. [Univ. Catholique de Louvain, Louvain-la-Neuve (Belgium). Dept. de Sciences des Materiaux et des Procedes; Colin, C. [Ecole Nationale Superieure des Mines de Paris, Evry (France)

1998-11-20

355

Effects of T4 treatment on hot rolling behavior and tensile strength of aluminum matrix composite reinforced by aluminum borate whisker with NiO coating  

Microsoft Academic Search

The Al–Si–Cu alloy matrix composite reinforced by aluminum borate whisker with NiO coating was fabricated by squeeze casting. The effects of T4 treatment on the microstructure, tensile strength, and hot rolling behavior of the composite were investigated. During T4 treatment, the NiO coating on whisker surface can react with aluminum matrix in the composite. The ultimate tensile strength of unrolled

W. D. Fei; Z. J. Li; Y. B. Li

2006-01-01

356

Tensile properties of Fe-16 at. % Al alloys  

SciTech Connect

A newly developed melting method for Fe-16 at. % Al alloy (FAPY) is described. Tensile data on the air-induction-melted (AIM) and vacuum-induction-melted (VIM) heats of FAPY after identical processing are presented. Optical, scanning electron micrographs (SEM), and microprobe analysis were carried out to explain the lower room-temperature ductility and more scatter in the data for the AIM material as opposed to the VIM material.

Sikka, V.K.

1995-02-01

357

Comparison of the irradiated tensile properties of a high-manganese austenitic steel and type 16 stainless steel  

SciTech Connect

The USSR steel EP-838 is a high-manganese (13.5%), low-nickel (4.2%) steel that also has lower chromium and molybdenum than type 316 stainless steel. Tensile specimens of 20%-cold-worked EP-838 and type 316 stainless steel were irradiated in the High Flux Isotope Reactor (HFIR) at the coolant temperature (approx. 50/sup 0/C). A displacement damage level of 5.2 dpa was reached for the EP-838 and up to 9.5 dpa for the type 316 stainless steel. Tensile tests at room temperature and 300/sup 0/C on the two steels indicated that the irradiation led to increased strength and decreased ductility compared to the unirradiated steels. Although the 0.2% yield stress of the type 316 stainless steel in the unirradiated condition was greater than that for the EP-838, after irradiation there was essentially no difference between the strength or ductility of the two steels. The results indicate that the replacement of the majority of the nickel by manganese and a reduction of chromium and molybdenum in an austenitic stainless steel of composition near that for type 316 stainless steel has little effect on the irradiated and unirradiated tensile properties at low temperatures.

Klueh, R.L.; Grossbeck, M.L.

1983-01-01

358

Microstructure effects on tensile properties of tungsten-Nickel-Iron composites  

Microsoft Academic Search

Controlled processing of heavy alloys containing 88 to 97 pct W resulted in high sintered densities and excellent bonding between the tungsten grains and matrix. For these alloys, deformation and fracture behavior were studied via slow strain rate tensile testing at room temperature. The flow stress increased and the fracture strain decreased with increasing tungsten content. The tradeoff between strength

B. H. Rabin; R. M. German

1988-01-01

359

Tensile properties of thin Au-Ni brazes between strong base materials.  

National Technical Information Service (NTIS)

It has long been known that when relatively strong base materials are joined by thin, soft, interlayer metals such as with brazing or various solid state joining processes, the ultimate tensile strength (UTS) of the bond may be several factors higher than...

M. C. Tolle M. E. Kassner

1991-01-01

360

Dynamic Tensile Properties of Iron and Steels for a Wide Range of Strain Rates and Strain  

Microsoft Academic Search

The tensile stress-strain curves of iron and a variety of steels, covering a wide range of strength level, over a wide strain rate range on the order of 10-3 ~ 103 s-1, were obtained systematically by using the Sensing Block Type High Speed Material Testing System (SBTS, Saginomiya). Through intensive analysis of these results, the strain rate sensitivity of the

Nobusato Kojima; Hiroyuki Hayashi; Terumi Yamamoto; Koji Mimura; Shinji Tanimura

2008-01-01

361

Tensile properties of thin Au-Ni brazes between strong base materials  

Microsoft Academic Search

It has long been known that when relatively strong base materials are joined by thin, soft, interlayer metals such as with brazing or various solid state joining processes, the ultimate tensile strength (UTS) of the bond may be several factors higher than the UTS of the bulk, or unconstrained, interlayer metals. However, earlier work reported by the authors confirmed that

M. C. Tolle; M. E. Kassner

1991-01-01

362

Strength properties of solvent vapour-treated pre-tensioned polypropylene films Part II Aromatic solvent vapours  

Microsoft Academic Search

The dependence of strength properties of solvent vapour-treated and pre-tensioned polypropylene films on solvent interaction parameter, ?, and non-specific cohesion force, D, and the amount of pre-tension force, has been studied. The five strength properties are yield stress, s?, initial modulus, E, draw stress, sd tensile strength, sb, and breaking factor, BF. The results show that for most solvent vapour

T. C. Uzomah; S. C. O. Ugbolue

1999-01-01

363

Apparatus for measuring tensile and compressive properties of solid materials at cryogenic temperatures  

DOEpatents

An apparatus for evaluating the tensile and compressive properties of material samples at very low or cryogenic temperatures employs a stationary frame and a dewar mounted below the frame. A pair of coaxial cylindrical tubes extend downward towards the bottom of the dewar. A compressive or tensile load is generated hydraulically and is transmitted by the inner tube to the material sample. The material sample is located near the bottom of the dewar in a liquid refrigerant bath. The apparatus employs a displacement measuring device, such as a linear variable differential transformer, to measure the deformation of the material sample relative to the amount of compressive or tensile force applied to the sample.

Gonczy, John D. (Oaklawn, IL); Markley, Finley W. (St. Charles, IL); McCaw, William R. (Burr Ridge, IL); Niemann, Ralph C. (Downers Grove, IL)

1992-01-01

364

Tests on ultimate strength of hull box girders made of high tensile steel  

Microsoft Academic Search

The experimental results of the collapse of three box girders subjected to pure bending moment are presented. The structures are made of high tensile steel of 690MPa of nominal yield stress reinforced with bar stiffeners of the same material. The moment curvature curves are presented covering the pre- and post-collapse regions. The modes of collapse for each box girder are

J. M. Gordo; C. Guedes Soares

2009-01-01

365

Tensile strength as an indicator of the degree of primitiveness of undifferentiated bodies  

NASA Astrophysics Data System (ADS)

The extremely porous structure and low strength of most comets and their fragments is opposed to the properties observed in relatively pristine chondritic asteroids, even although both are sharing important chemical similitude. Laboratory experiments and observational evidence suggest that the original extremely porous aggregates that were born from the protoplanetary-disk-forming materials were highly retentive of water and organic compounds present in their forming environment. After consolidation, many of them experienced a particular dynamic history. Some bodies, quickly scattered during the formation of the giant planets and later stored in the Kuiper Belt (KB) or the Oort Cloud (OC) regions, would have suffered a lower degree of impact processing than previously thought. In such category would be comet 81P/Wild 2, whose materials have not experienced aqueous alteration. Other bodies originally volatile-rich that were transiting other regions with higher impact rate were experiencing progressively significant compaction processing, together with subsequent aqueous alteration and loss of volatiles. The release of water from hydrated minerals or interior ices, participated in soaking the forming materials, and transforming their initial mineralogy and physical properties. As a consequence of the physico-chemical evolution promoted by impact processing of undifferentiated bodies, most of the bodies present in the inner solar system are not representative of the planetesimals. Thus, highly porous progenitors and their fragments are the preferential sources of water and organics to the early Earth, even in higher amounts than previously thought.

Trigo-Rodriguez, Josep M.; Blum, Jürgen

2009-02-01

366

Tensile strength and dilatational elasticity of giant sarcolemmal vesicles shed from rabbit muscle.  

PubMed Central

1. Mechanical properties of the surface membrane of skeletal muscle were determined on sarcolemmal vesicles (mean diameter, 71 microns) shed by rabbit psoas muscle swelling in 140 mM KC1 containing collagenase. 2. Vesicles were stressed by partial aspiration into parallel bore pipettes. The isotropic membrane tension so created caused an increase in membrane area which expresses itself in an elongation of the vesicle projection into the pipette. 3. For individual vesicles, a linear relationship between membrane tension and membrane area increase was found up to the point when the vesicle burst, i.e. sarcolemmal vesicles behaved as perfectly elastic structures. 4. The maximum tension sarcolemmal vesicles could sustain before bursting was 12.4 +/- 0.2 mN m-1 (median +/- 95% confidence interval), and the corresponding fractional increase in membrane area was 0.026 +/- 0.005 (median +/- 95% confidence interval). The elastic modulus of area expansion was 490 +/- 88 mN m-1 (mean +/- S.D.). 5. In conformity with cited comparable work on red blood cells and artificial lipid vesicles, the strength and area elasticity of the skeletal muscle membrane are considered properties of the fluid lipid matrix of the membrane and of the degree to which the bilayer is perturbed by lipid-protein interaction. Images Figure 2

Nichol, J A; Hutter, O F

1996-01-01

367

Tensile fixation strengths of absorbable meniscal repair devices as a function of hydrolysis time. An in vitro experimental study.  

PubMed

To determine the effect of hydrolysis time on the fixation strength of absorbable meniscal repair devices, adult bovine menisci were repaired with five devices and a suture. The ultimate tensile strength of the repair was then tested in six specimens immediately or after 6, 12, or 24 weeks of incubation at 37 degrees C in a saline solution containing antibiotics, antimycotics, and protease inhibitors. Immediately after implantation the Bionx Meniscus Arrow had a significantly higher failure strength (57.7 +/- 13.8 N) than the Linvatec BioStinger (35.1 +/- 6.7 N), the Innovasive Clearfix screw (34.9 +/- 13 N), the Surgical Dynamics S-D-sorb staple (9.4 +/- 4.6 N), and the Mitek Meniscal Repair System (polydioxanone) (27.2 +/- 6.0 N). However, there was no significant difference between the Bionx Meniscus Arrow and a 2-0 polydioxanone vertical suture (51.6 +/- 2.7 N). The polydioxanone-based implants demonstrated a significant decrease in failure strength at 12 and 24 weeks. Similarly, the Surgical Dynamics S-D-sorb staple lost all fixation strength by 24 weeks. The remaining devices showed no significant loss of failure strength over the 24-week period, suggesting that 24 weeks of hydrolysis does not adversely affect the ultimate holding power of poly L-lactide-based meniscal fixation devices. PMID:11292034

Arnoczky, S P; Lavagnino, M

368

Temperature-dependence mechanism of tensile strength of Si-Ti-C-O fiber-aluminum matrix composites  

SciTech Connect

The mechanism for the temperature dependence of the tensile strength of unidirectional hybrid type Si-Ti-C-O (Tyranno) fiber-reinforced aluminum matrix composite, in which SiC-particles are dispersed in the matrix, is discussed, focusing on the temperature dependencies of the stress concentration arising from broken fibers and critical length and their influences on the composite strength, by means of a shear-lag analysis and a Monte Carlo simulation. The main results are summarized as follows. The softening of the matrix at high temperatures raises the composite strength from the point of decrease in stress concentration, but on the other hand, it also reduces strength from the point of increase in critical length, which reduces the stress-carrying capacity of broken fibers over a long distance. The reason why the measured strength of composite decreased with increasing temperature could be attributed to the predominancy of the latter effect over the former one. The results of the simulation indicated that the hybridization of the composites improved room-temperature and high-temperature strengths through the strengthening of the matrix.

Ochiai, Shojiro; Hojo, Masaki; Osamura, Kozo [Kyoto Univ. (Japan). Faculty of Engineering; Matsunaga, Kenji; Waku, Yoshiharu; Yamamura, Takemi [Ube Industries, Ltd., Yamaguchi (Japan). Corporate Research and Development

1995-03-01

369

Temperature effects on the tensile properties of cast and heat treated aluminum alloy A319  

Microsoft Academic Search

In this work, the tensile properties and ductility of an Al-A319 alloy were investigated as a function of temperature and heat treatment. Tensile testing was carried out at temperatures ranging from ?90 to 400°C for the alloy in (a) the as-cast condition, (b) after solid solution at 485°C (T4) and (c) after solid solution followed by ageing at 230°C (T7).

E. Rincon; H. F. Lopez; M. M. Cisneros; H. Mancha

2009-01-01

370

Tensile properties of 9Cr–1Mo martensitic steel irradiated with high energy protons and neutrons  

Microsoft Academic Search

Tensile specimens of 9Cr–1Mo martensitic steel in three metallurgical conditions (tempered, 20% cold-worked and as-quenched) were irradiated in SINQ target-3 with high energy protons and spallation neutrons at temperatures between about 130 and 310 °C to doses between 4 and 12 dpa. Tensile properties were measured mostly at room temperature but a limited number of tests were performed at 250

J. Henry; X. Averty; Y. Dai; P. Lamagnère; J. P. Pizzanelli; J. J. Espinas; P. Wident

2003-01-01

371

Thermal and Tensile Properties of Epoxy Nanocomposites Reinforced by Silane-functionalized Multiwalled Carbon Nanotubes  

Microsoft Academic Search

Epoxy nanocomposites with unmodified multiwalled carbon nanotubes (u-MWCNTs) and silanized multiwalled carbon nanotubes (si-MWCNTs) were prepared by a cast molding method. The effects of 3-aminopropyltriethoxysilane functionalization of MWCNTs on thermal, tensile, and morphological properties of the nanocomposites were examined. The nanocomposites were characterized by thermogravimetric analysis, dynamic mechanical thermal analysis, and tensile testing. The results showed that epoxy composites based

Hee-Cheul Kim; Sun-Kuk Kim; Jeong Tai Kim; Kyong-Yop Rhee; John Kathi

2010-01-01

372

THE EFFECT OF NITRIDING ON THE ELEVATED TEMPERATURE TENSILE PROPERTIES OF SOME MOLYBDENUM-BASE ALLOYS  

Microsoft Academic Search

The elevated-temperature tensile properties of Mo0.49% Ti, Mo--0,98% Ti, ; and Mo--1.5% Zr specimens, in both the dispersion-hardened and the recrystallized ; conditions, were investigated between room temperature and 900 l C ; using two strain rates. The effect of increase in temperature and in strain rate ; on ultimate tensile stress and ductility were studied and metallographic and ;

A. K. Mukherjee; J. W. Martin

1963-01-01

373

The effect of different light-curing units on tensile strength and microhardness of a composite resin.  

PubMed

The aim of this study was to evaluate the influence of different light-curing units on the tensile bond strength and microhardness of a composite resin (Filtek Z250 - 3M/ESPE). Conventional halogen (Curing Light 2500 - 3M/ESPE; CL) and two blue light emitting diode curing units (Ultraled - Dabi/Atlante; UL; Ultrablue IS - DMC; UB3 and UB6) were selected for this study. Different light intensities (670, 130, 300, and 600 mW/cm(2), respectively) and different curing times (20s, 40s and 60s) were evaluated. Knoop microhardness test was performed in the area corresponding to the fractured region of the specimen. A total of 12 groups (n=10) were established and the specimens were prepared using a stainless steel mold composed by two similar parts that contained a cone-shaped hole with two diameters (8.0 mm and 5.0 mm) and thickness of 1.0 mm. Next, the specimens were loaded in tensile strength until fracture in a universal testing machine at a crosshead speed of 0.5 mm/min and a 50 kg load cell. For the microhardness test, the same matrix was used to fabricate the specimens (12 groups; n=5). Microhardness was determined on the surfaces that were not exposed to the light source, using a Shimadzu HMV-2 Microhardness Tester at a static load of 50 g for 30 seconds. Data were analyzed statistically by two-way ANOVA and Tukey's test (p<0.05). Regarding the individual performance of the light-curing units, there was similarity in tensile strength with 20-s and 40-s exposure times and higher tensile strength when a 60-s light-activation time was used. Regarding microhardness, the halogen lamp had higher results when compared to the LED units. For all light-curing units, the variation of light-exposure time did not affect composite microhardness. However, lower irradiances needed longer light-activation times to produce similar effect as that obtained with high-irradiance light-curing sources. PMID:19089182

Franco, Eduardo Batista; dos Santos, Patrícia Aleixo; Mondelli, Rafael Francisco Lia

2007-12-01

374

A Comparative Study of the Shear and Tensile Bond Strength using three types of Direct Bonding Adhesives on Stainless Steel Brackets - An In Vitro Study  

PubMed Central

Background: The purpose of this study was to compare the shear and tensile bond strength of three adhesive systems with increasing concentrations of filler for bonding brackets. Materials & Methods: The study was carried out on 120 extracted human premolars; randomly divided into six groups, three groups for shear bond strength & three for tensile bond strength, each subgroup consisting of 20 teeth; using light cured adhesive systems: Group 1: FORTIFY Unfilled, (unfilled penetrating resin) Group 2: ALITEF Low Filled (filler load 58% by weight) Group 3: PYRAMID Highly Filled (filler load greater than 80% by weight) with metal brackets (TP 256-650. TP orthodontic inc. Po.box 73,La Porte 46350,USA). Results: The findings showed that in vitro tensile bond strength and shear bond strength of PYRAMID [9.88/11.46 MPa resp.] is significantly greater than ALITEFLO[5.34/9.50 MPa resp.] and FORTIFY [2.65/5.39 MPa resp.]. Conclusion: Using the same bracket and force mode but different adhesive filler concentrations revealed increased shear and tensile bond strength with increased filler concentration. How to cite this article: Kumar PS, Patil C, Hullal B, Putturaj KT, Sangolgi VC, Jayasudha K. A Comparative Study of the Shear and Tensile Bond Strength using three types of Direct Bonding Adhesives on Stainless Steel Brackets - An In Vitro Study. J Int Oral Health 2013; 5(4):26-29.

Sunilkumar, P; Patil, Chandrashekhara; H, Baswaraj; Putturaj, KT; Sangolgi, Vijaykumar C; Jayasudha, K

2013-01-01

375

A Comparative Study of the Shear and Tensile Bond Strength using three types of Direct Bonding Adhesives on Stainless Steel Brackets - An In Vitro Study.  

PubMed

Background: The purpose of this study was to compare the shear and tensile bond strength of three adhesive systems with increasing concentrations of filler for bonding brackets. Materials & Methods: The study was carried out on 120 extracted human premolars; randomly divided into six groups, three groups for shear bond strength & three for tensile bond strength, each subgroup consisting of 20 teeth; using light cured adhesive systems: Group 1: FORTIFY Unfilled, (unfilled penetrating resin) Group 2: ALITEF Low Filled (filler load 58% by weight) Group 3: PYRAMID Highly Filled (filler load greater than 80% by weight) with metal brackets (TP 256-650. TP orthodontic inc. Po.box 73,La Porte 46350,USA). Results: The findings showed that in vitro tensile bond strength and shear bond strength of PYRAMID [9.88/11.46 MPa resp.] is significantly greater than ALITEFLO[5.34/9.50 MPa resp.] and FORTIFY [2.65/5.39 MPa resp.]. Conclusion: Using the same bracket and force mode but different adhesive filler concentrations revealed increased shear and tensile bond strength with increased filler concentration. How to cite this article: Kumar PS, Patil C, Hullal B, Putturaj KT, Sangolgi VC, Jayasudha K. A Comparative Study of the Shear and Tensile Bond Strength using three types of Direct Bonding Adhesives on Stainless Steel Brackets - An In Vitro Study. J Int Oral Health 2013; 5(4):26-29. PMID:24155616

Sunilkumar, P; Patil, Chandrashekhara; H, Baswaraj; Putturaj, Kt; Sangolgi, Vijaykumar C; Jayasudha, K

2013-08-28

376

Kevlar Properties Investigation Development of Kevlar Tensile Test Methods.  

National Technical Information Service (NTIS)

Testing procedures which are used for nylon parachute materials have not been satisfactory for testing their Kevlar counterparts. Kevlar's high strength and low elongation can result in premature breaks and, thus, inordinately low values of breaking stren...

S. L. Goodwin N. J. Abbott

1979-01-01

377

Interface contribution to the SiC-titanium and SiC-aluminium tensile strength prediction  

Microsoft Academic Search

Fragmentation tests of single SiC filaments embedded in an aluminium (1050 and 5083 alloys) or a titanium (Ti-6Al-4V) matrix have been analysed in an effort to obtain the interface contribution in terms that could be incorporated into a tensile fracture model for unidirectional composites. Depending on the matrix, two regimes of interfacial stress transfer can be distinguished within the whole

L. Molliex; J.-P. Favre; A. Vassel; M. Rabinovitch

1994-01-01

378

Reduction in tensile strength of cartilage precedes surface damage under repeated compressive loading in vitro  

Microsoft Academic Search

An experimental protocol for the fatiguing and tensile testing of articular cartilage has been established. Samples were taken from the interpatellar groove of bovine femurs collected post-slaughter, split into two test groups and subjected to a cyclically varying compressive load of approximately 65N for 64,800 cycles or 97,200 cycles. The cartilage was then removed from the underlying bone and two

Triona McCormack; Joseph M. Mansour

1997-01-01

379

Metalloproteases meprin ? and meprin ? are C- and N-procollagen proteinases important for collagen assembly and tensile strength  

PubMed Central

Type I fibrillar collagen is the most abundant protein in the human body, crucial for the formation and strength of bones, skin, and tendon. Proteolytic enzymes are essential for initiation of the assembly of collagen fibrils by cleaving off the propeptides. We report that Mep1a?/? and Mep1b?/? mice revealed lower amounts of mature collagen I compared with WT mice and exhibited significantly reduced collagen deposition in skin, along with markedly decreased tissue tensile strength. While exploring the mechanism of this phenotype, we found that cleavage of full-length human procollagen I heterotrimers by either meprin ? or meprin ? led to the generation of mature collagen molecules that spontaneously assembled into collagen fibrils. Thus, meprin ? and meprin ? are unique in their ability to process and release both C- and N-propeptides from type I procollagen in vitro and in vivo and contribute to the integrity of connective tissue in skin, with consequent implications for inherited connective tissue disorders.

Broder, Claudia; Arnold, Philipp; Vadon-Le Goff, Sandrine; Konerding, Moritz A.; Bahr, Kerstin; Muller, Stefan; Overall, Christopher M.; Bond, Judith S.; Koudelka, Tomas; Tholey, Andreas; Hulmes, David J. S.; Moali, Catherine; Becker-Pauly, Christoph

2013-01-01

380

The tensile properties of polyimide film at cryogenic temperatures and radiation effects on polyimide films  

Microsoft Academic Search

Polyimide films has been used as insulating component in superconducting machinery. A full understanding of the property at low temperatures and the radiation effect is very important for stabilization of superconducting coils. The tensile properties of polyimide films have been measured at 4.2 K â¼ 473 K. Stress-Strain curve profiles vary as a function of temperature. At cryogenic temperature, the

T. Tanaka; K. Hosoyama; K. Hara

1997-01-01

381

Tensile testing on the mechanical properties of weld metal in dissimilar gage tailor-welded blanks  

Microsoft Academic Search

In this paper, tailor-welded blanks (TWBs) of three dissimilar gages for the automotive body inner side panel were analyzed. The basic mechanical properties were measured through the tensile test. Based on this, a method of ¿rule of mixtures¿ for measuring the properties of weld metal in TWBs was introduced. Moreover, the error between the calculated results and the measured data

Yu Tianming; Ma Wenxing; Wang Chunyan

2009-01-01

382

Waiting Time for Coronal Preparation and the Influence of Different Cements on Tensile Strength of Metal Posts  

PubMed Central

This study aimed to assess the effect of post-cementation waiting time for core preparation of cemented cast posts and cores had on retention in the root canal, using two different luting materials. Sixty extracted human canines were sectioned 16?mm from the root apex. After cast nickel-chromium metal posts and cores were fabricated and luted with zinc phosphate (ZP) cement or resin cement (RC), the specimens were divided into 3 groups (n = 10) according to the waiting time for core preparation: no preparation (control), 15 minutes, or 1 week after the core cementation. At the appropriate time, the specimens were subjected to a tensile load test (0.5?mm/min) until failure. Two-way ANOVA (time versus cement) and the Tukey tests (P < 0.05) showed significantly higher (P < 0.05) tensile strength values for the ZP cement groups than for the RC groups. Core preparation and post-cementation waiting time for core recontouring did not influence the retention strength. ZP was the best material for intraradicular metal post cementation.

Oliveira, Ilione Kruschewsky Costa Sousa; Arsati, Ynara Bosco de Oliveira Lima; Basting, Roberta Tarkany; Franca, Fabiana Mantovani Gomes

2012-01-01

383

TENSILE PROPERTIES OF ENGINEERED CARTILAGE FORMED FROM CHONDROCYTE- AND MSC-LADEN HYDROGELS  

PubMed Central

Objective The objective of this study was to determine the capacity of chondrocyte-and mesenchymal stem cell (MSC)-laden hydrogel constructs to achieve native tissue tensile properties when cultured in a chemically defined medium supplemented with transforming growth factor-beta3 (TGF-?3). Design Cell-laden agarose hydrogel constructs (seeded with bovine chondrocytes or MSCs) were formed as prismatic strips and cultured in a chemically defined serum-free medium in the presence or absence of TGF-?3. The effects of seeding density (10 versus 30 million cells/mL) and cell type (chondrocyte versus MSC) were evaluated over a 56 day period. Biochemical content, collagenous matrix deposition and localization, and tensile properties (ramp modulus, ultimate strain, and toughness) were assessed bi-weekly. Results Results show that the tensile properties of cell seeded agarose constructs increase with time in culture. However, tensile properties (modulus, ultimate strain, and toughness) achieved on day 56 were not dependent on either the initial seeding density or the cell type employed. When cultured in medium supplemented with TGF-?3, tensile modulus increased and plateaued at a level of 300–400 kPa for each cell type and starting cell concentration. Ultimate strain and toughness also increased relative to starting values. Collagen deposition increased in constructs seeded with both cell types and at both seeding densities, with exposure to TGF-?3 resulting in a clear shift towards type II collagen deposition as determined by immunohistochemical staining. Conclusions These findings demonstrate that the tensile properties, an important and often overlooked metric of cartilage development, increase with time in culture in engineered hydrogel-based cartilage constructs. Under the free-swelling conditions employed in the present study, tensile moduli and toughness did not match that of the native tissue, though significant time-dependent increases were observed with the inclusion of TGF-?3. Of note, MSC-seeded constructs achieved tensile properties that were comparable to chondrocyte-seeded constructs, confirming the utility of this alternative cell source in cartilage tissue engineering. Further work, including both modulation of the chemical and mechanical culture environment, is required to optimize the deposition of collagen and its remodeling to achieve tensile properties in engineered constructs matching the native tissue.

Huang, Alice H.; Yeger-McKeever, Meira; Stein, Ashley; Mauck, Robert L.

2008-01-01

384

Effect of humidity and temperature on the tensile strength of polyimide\\/silicon nitride interface and its implications for electronic device reliability  

Microsoft Academic Search

A new strategy for improving, predicting, and optimizing the mechanical reliability of interfaces appearing in electronic devices, substrates, and their packages, is introduced. An essential feature of this strategy is to measure the fundamental tensile strength of interfaces devoid of any material plasticity and geometry effects and quantify changes in the measured strengths by exposing interfaces to varying levels and

Vijay Gupta; Robert Hernandez; Phillipe Charconnet

2001-01-01

385

Tensile behaviour of magnesia carbon refractories  

Microsoft Academic Search

The determination of the Young's modulus and the tensile strength of heterogeneous refractories are the subjects of this paper. Great differences have been observed for a similar material according to both the usual tests performed and the interpretation proposed to define these properties. The causes of the discrepancies of the Young's modulus under compression and tensile loading are examined in

N. Schmitt; Y. Berthaud; J. Poirier

2000-01-01

386

Effect of temperature and microstructure on tensile and tensile creep properties of titanium silicon carbide in air  

NASA Astrophysics Data System (ADS)

The ternary carbide, Ti3SiC2, combines some of the best attributes of ceramics and metals. It is stable in inert atmospheres to temperatures above 2200°C, stiff and yet is readily machinable, oxidation, fatigue and thermal shock resistant and damage tolerant. Thus, Ti3SiC 2 is good candidate material for high temperature structural application. The aim of this work was to characterize its tensile and tensile creep properties. The mechanical behavior of Ti3SiC2 is characterized by a brittle-to-ductile (BTD) transition that is a function of strain rate. Its high strain rate sensitivity (?0.50--0.6) is in the range that is more typical for superplastic materials, although it does not exhibit other attributes of superplasticity. Polycrystalline samples do not exhibit linear elastic behavior in tension even at room temperature. Room temperature loading-unloading tests result in closed hysteresis loops when the stress exceeds ?120 MPa, suggesting that the mechanical response can be described as anelastic (viscoelastic). At high temperatures (1200°C) intense stress relaxation takes place; cycling loading-unloading tests at high temperature and low strain rates, demonstrate that the samples continue to elongate even during unloading, suggesting that Ti3SiC2 deforms viscoplastically. Tensile creep curves exhibit primary, steady state and tertiary regimes. The minimum creep rate can be represented by power law equation with a stress exponent of 1.5 for fine-grained (3--5 mum) samples, and 2 for coarse-grained (100--300 mum) ones. For both microstructures the activation energy for creep is ?450 kJ/mol. The dependence on grain size is quite weak, implying that diffusion creep and/or creep mechanisms based on grain boundary sliding do not play a central role. Results of strain transient dip tests suggest that large internal stresses are developed during creep. Those internal stresses are believed to result in recoverable (anelastic) strains during unloading. The response on small stress decreases in strain-transient creep tests suggests that the steady state creep is recovery controlled. Finally, it is important to note that the mechanical response of Ti 3SiC2 is quite similar to hexagonal ice. Both materials, if loaded rapidly are brittle, but if loaded slowly are quite plastic. This stems from the fact that both are plastically very anisotropic; deformation occurs overwhelmingly by basal slip. In both cases, stress concentrations, and the rate at which they can be relaxed, dictate the nature of the mechanical response.

Radovic, Miladin

387

Tensile testing of SiC whiskers  

SciTech Connect

The room temperature tensile mechanical properties of SiC whiskers have been examined using a micro-tensile-test apparatus. SiC whiskers exhibit an average tensile strength of 8.4 GPa for a 5 mm tested length, and an average elastic modulus of 581 GPa. These results indicate that SiC whiskers possess significant potential as short-fiber reinforcement elements in ceramic matrix composites.

Petrovic, J.J.

1984-01-01

388

Impact Tensile Properties of Friction Welded Butt Joints between 6061 Aluminum Alloy and Type 304 Stainless Steel  

Microsoft Academic Search

The tensile strength and energy absorption for dissimilar metal friction welds between 6061 Al alloy and Type 304 stainless steel at high rates of loading are determined using the split Hopkinson bar. Cylindrical tensile specimens machined from as-welded butt joints of 13 mm in diameter are used in both static and impact tests. Friction welding is conducted using a brake

Takashi Yokoyama

2003-01-01

389

Tensile deformation behavior of a sub-micrometer Al 2O 3\\/6061Al composite  

Microsoft Academic Search

A 0.3?m Al2O3\\/6061Al composite with 33% volume fraction of Al2O3 was fabricated by the patented squeeze-casting technology. The tensile properties were studied, and the dynamic tensile deformation behavior was investigated by an in situ TEM tensile technique. The as-cast composite exhibits excellent tensile properties with a fracture strength of 504MPa, and the strength increases to 579MPa after a T6 treatment.

Qiang Zhang; Gaohui Wu; Longtao Jiang

2008-01-01

390

Influences of Welding Processes on Microstructure, Hardness, and Tensile Properties of AZ31B Magnesium Alloy  

NASA Astrophysics Data System (ADS)

This article reports the influences of welding processes such as gas tungsten arc welding (GTAW), friction stir welding (FSW), and laser beam welding (LBW) on tensile properties of AZ31B magnesium alloy. The lowest hardness distribution profile (LHDP) is constructed across the weld section to identify the fracture path. From this investigation, it is found that LBW joints exhibited superior tensile properties compared to GTAW and FSW joints and this is mainly due to the formation of very fine grains in the fusion zone and absence of heat-affected zone (HAZ).

Padmanaban, G.; Balasubramanian, V.; Sarin Sundar, J. K.

2010-03-01

391

Properties of cold-rolled high-strength steel sheets  

Microsoft Academic Search

For high-strength steel sheets, a new concept has become necessary,viz, the relation between strength and formability. When the relation between tensile strength and elongation is appraised for\\u000a ranking in terms of the strengthening mechanism, it is found that the substitutional solid-solution hardening type is excellent\\u000a and the precipitation hardening type is inferior. In batch annealing, the phosphorus-added aluminum-killed steel sheets

K. Toda; H. Gondoh; H. Takechi; H. Masui

1976-01-01

392

Tensile strength at elevated temperature and its applicability as an accelerated testing methodology for unidirectional composites  

NASA Astrophysics Data System (ADS)

The applicability of a macroscopic time-temperature superposition principle (TTSP) to unidirectional composite strength is discussed based on the microscopic Simultaneous Fiber-Failure (SFF) model that has been presented by Koyanagi et al. (J. Compos. Mater. 43:1901-1914, 2009a). The SFF model estimates composite strengths as functions of fiber, matrix, and interface strengths. This paper first investigates the applicability of SFF to the complicated temperature dependence of composite strengths, i.e., one composite exhibits significant temperature dependence and another does not, considering the temperature dependence of the components, which results in successful estimations for the two composite systems used in the present study. The long-term durability predicted by the SFF and that predicted by the TTSP are then compared. They typically correspond to each other in various cases; accelerated testing methodology (ATM) employing TTSP is thus proved to be valid from the micromechanical viewpoint, assuming the SFF applicability.

Koyanagi, Jun; Nakada, Masayuki; Miyano, Yasushi

2012-02-01

393

Effects of environment and temperature on ceramic tensile strength–grain size relations  

Microsoft Academic Search

Overall strength (s)–grain size (G), i.e. s–G-1\\/2, relations retain the same basic two-branched character to at least 1200–1300°C. However, some polycrystalline as well as single crystal strength shifts or deviations are seen relative to each other, and especially relative to Young's moduli versus temperature for poly- and single crystals. The variety and complexity of these deviations are illustrated mainly by

R. W. RICE

1997-01-01

394

Quench sensitivity and tensile property inhomogeneity in 7010 forgings  

Microsoft Academic Search

7xxx (Al–Zn–Mg–Cu) alloys develop their strength, through the controlled decomposition (ageing) of a supersaturated solid solution to produce a precipitation hardened microstructure. The supersaturated solid solution is normally produced by water quenching from the solution heat treatment temperature. The kinetics of phase transformations occurring during cooling from the solution heat treatment temperature are limited at small undercoolings by the small

J. S Robinson; R. L Cudd; D. A Tanner; G. P Dolan

2001-01-01

395

Tensile properties of austempered ductile iron under thermomechanical treatment  

Microsoft Academic Search

A new processing method was investigated for improving the strength and elongation of austempered ductile iron (ADI) by grain\\u000a refinement of parent austenite using thermomechanical treatment. The material was deformed at the austenitization temperature\\u000a by single and multipass rolling before the austempering treatment. The effects of the amount of deformation, austenitization\\u000a temperature, austempering temperatures, reaustenitization, and secondary deformation on the

J. Achary

2000-01-01

396

Effect of laser welding on the titanium composite tensile bond strength.  

PubMed

The aim of this study was to analyze the shear bond strength between commercially pure titanium, with and without laser welding, after airbone-particle abrasion (Al(2)O(3)) and 2 indirect composites. Sixty-four specimens were cast and divided into 2 groups with and without laser welding. Each group was divided in 4 subgroups, related to Al(2)O(3) grain size: A - 250 microm; B - 180 microm; C- 110 microm; and D - 50 microm. Composite rings were formed around the rods and light polymerized using UniXS unit. Specimens were invested and their shear bond strength at failure was measured with a universal testing machine at a crosshead speed of 2.0 mm/min. Statistical analysis was carried out with ANOVA and Tukey's test (alpha=0.05). The highest bond strength means were recorded in 250 microm group without laser welding. The lowest shear bond strength means were recorded in 50 microm group with laser welding. Statistically significant differences (p<0.05) were found between all groups. In conclusion, airborne particle abrasion yielded significantly lower bond strength as the Al(2)O(3) particle size decreased. Shear bond strength decreased in the laser welded specimens. PMID:20126909

Galo, Rodrigo; Ribeiro, Ricardo Faria; Rodrigues, Renata Cristina Silveira; Pagnano, Valéria de Oliveira; de Mattos, Maria da Glória Chiarello

2009-01-01

397

Tensile Properties of the Murine Ventral Vertical Midline Incision  

PubMed Central

Background In clinical surgery, the vertical midline abdominal incision is popular but associated with healing failures. A murine model of the ventral vertical midline incision was developed in order to study the healing of this incision type. Methodology/Principal Findings The strength of the wild type murine ventral abdominal wall in the midline was contained within the dermis; the linea alba made a negligible contribution. Unwounded abdominal wall had a downward trend (nonsignificant) in maximal tension between 12 and 29 weeks of age. The incision attained 50% of its final strength by postoperative day 40. The maximal tension of the ventral vertical midline incision was nearly that of unwounded abdominal wall by postwounding day 60; there was no difference in unwounded vs. wounded maximal tension at postwounding day 120. Conclusions/Significance After 120 days of healing, the ventral vertical midline incision in the wild type mouse was not significantly different from age-matched nonwounded controls. About half of the final incisional strength was attained after 6 weeks of healing. The significance of this work was to establish the kinetics of wild type incisional healing in a model for which numerous genotypes and genetic tools would be available for subsequent study.

Carlson, Mark A.; Chakkalakal, Dennis

2011-01-01

398

Microstructure effects on tensile properties of tungsten-Nickel-Iron composites  

Microsoft Academic Search

Controlled processing of heavy alloys containing 88 to 97 pct W resulted in high sintered densities and excellent bonding\\u000a between the tungsten grains and matrix. For these alloys, deformation and fracture behavior were studiedvia slow strain rate tensile testing at room temperature. The flow stress increased and the fracture strain decreased with increasing\\u000a tungsten content. The tradeoff between strength and

B. H. Rabin; R. M. German

1988-01-01

399

Tensile and fatigue properties of a thermomechanically treated 7475 aluminium alloy  

Microsoft Academic Search

High-purity Al-Zn-Mg alloy was thermomechanically treated. The process included solution treatment, pre-ageing, cold-working by rolling and final ageing. Pre-ageing was carried out at 100°C (TAHA1) and room temperature (TAHA2). Experimental results indicated that the TAHA1 process improved the tensile strength significantly while the TAHA2 process improved the fatigue life more substantially. Fatigue crack initiation sites were examined carefully by scanning

M. T. Jahn; Jin Luo

1988-01-01

400

Tensile and fracture toughness properties of unirradiated and neutron irradiated titanium alloys  

Microsoft Academic Search

In the unirradiated condition the Ti6Al4V (?+?) alloy has slightly higher tensile strength and noticeably lower ductility compared to that of the Ti5Al2.5Sn (?) alloy both at 50 and 350 °C. The fracture toughness behaviour of both alloys is similar at ambient temperature. At 350 °C, on the other hand, the fracture toughness of the (?) alloy is lower compared

S. Tähtinen; P. Moilanen; B. N. Singh; D. J. Edwards

2002-01-01

401

The elevated temperature tensile properties of S-200E commercially pure beryllium  

SciTech Connect

Experiments were performed at 300-100 C in longitudinal and transverse orientations at quasi-static strain rate 5.5 {times} 10{sup {minus}4}s{sup {minus}1}. Results show that the stress-strain curve is smooth, without yield points or serrations. Yield stress and ultimate tensile stress decrease monotonically with temperature. Similar strengths were measured for both orientations. Failure elongation vs temperature is complex.

Henshall, G.A.; Torres, S.G.; Hanafee, J.E.

1995-03-01

402

Effects of Braiding on Tensile Properties of Four-Strand Human Hamstring Tendon Grafts  

Microsoft Academic Search

Background: Anterior cruciate ligament reconstruction is commonly performed with autogenous hamstring tendon grafts.Purpose: To ascertain the effects of braiding on ultimate tensile strength and stiffness of hamstring tendon graft.Study Design: Controlled laboratory study.Methods: Sixteen fresh-frozen semitendinosus and gracilis tendons were harvested from eight matched (right and left) human cadaveric specimens. Both sets of hamstring tendons from each matched pair were

Peter J. Millett; Bruce S. Miller; Matthew Close; William I. Sterett; William Walsh; Richard J. Hawkins

2003-01-01

403

Physical Property Measurements: Unconfined Compressive Strength (UCS)  

NSDL National Science Digital Library

This site, by the Colorado School of Mines, addresses the properties of a measurement technique called unconfined compression strength (UCS). Along with defining the technique, the website shows different experiments, pictures and diagrams associated with UCS. This well organized work will be a valuable asset for any geology or engineering classroom.

Ozdemir, Levent

2008-09-17

404

Influence of Uniaxial Tensile Stress on the Mechanical and Piezoelectric Properties of Short-period Ferroelectric Superlattice.  

PubMed

Tetragonal ferroelectric/ferroelectric BaTiO(3)/PbTiO(3) superlattice under uniaxial tensile stress along the c axis is investigated from first principles. We show that the calculated ideal tensile strength is 6.85 GPa and that the superlattice under the loading of uniaxial tensile stress becomes soft along the nonpolar axes. We also find that the appropriately applied uniaxial tensile stress can significantly enhance the piezoelectricity for the superlattice, with piezoelectric coefficient d(33) increasing from the ground state value by a factor of about 8, reaching 678.42 pC/N. The underlying mechanism for the enhancement of piezoelectricity is discussed. PMID:20671792

Duan, Yifeng; Wang, Chunmei; Tang, Gang; Chen, Changqing

2009-11-28

405

Tensile bond strength of a composite resin cement for bonded prosthesis to various dental alloys.  

PubMed

The development of composite resin cements that chemically bond to dental alloys has improved the construction of resin-bonded prostheses. Composite resins can be selected for various situations, but specific clinical situations may require different alloys. This study evaluated the ability of a composite resin cement to bond to various dental alloys of different compositions. Ten pairs of disks for each alloy (two NiCr, two NiCrBe, one CuAl, one gold type IV, and one gold for metal ceramic) were bonded to a composite resin cement after air abrasion was performed with aluminum oxide. The disks were then rinsed in tap water and were ultrasonically cleaned in distilled water for 2 minutes. The tensile tests exhibited greater values for alloys ultrasonically cleaned, and the best results were recorded by NiCr and NiCrBe alloys. PMID:7473275

Rubo, J H; Pegoraro, L F

1995-09-01

406

Effect of thermal aging on the room temperature tensile properties of AISI type 316LN stainless steel  

Microsoft Academic Search

Round tensile specimens of AISI type 316LN stainless steel, thermally aged at 1123 K for 0, 2, 10, 25, 100, 500 and 1000 h, were tested for tensile properties at room temperature at a strain rate of 7.7×10?3 s?1. The changes in tensile properties were correlated to the transmission electron microscopic studies. The various stages of nitrogen repartitioning including Cr–N

P. Shankar; H Shaikh; S Sivakumar; S Venugopal; D Sundararaman; H. S Khatak

1999-01-01

407

On the Compressive and Tensile Dynamic Strength of Magnesium Aluminate Spinel  

NASA Astrophysics Data System (ADS)

Polycrystalline transparent Magnesium Aluminate Spinel (MAS) is an attractive material for a wide range of optical, electronic, structural and armor applications. Transparent MAS samples of 20-30 mm diameter and 3-5 mm thickness has been successfully fabricated by means of Field Assisted Sintering Technology. The dynamic response of MAS was investigated by plate impact experiments. The values of the Hugoniot Elastic Limit (HEL) and the spall strength were derived from the VISAR records of the velocities of the free sample surface or of the sample/window (PMMA) interface. The dependence of the HEL and the spall strength on the impact stress, as well as, correlation between the spall strength and the width of the loading pulse are discussed.

Hayun, Shmuel; Paris, Vitaly; Dariel, Moshe; Zaretsky, Eugene; Frage, Nahum

2009-06-01

408

Wound healing in man: tensile strength of healing wounds in some patient groups.  

PubMed Central

The healing of test wounds was studied in 108 patients, in whom some impairment of wound healing was suspected. A 5 cm skin wound was performed in the forearm and the strength of the wound was tested after 5 days using the technique described by Sandblom and associates with two measurements in each wound. No differences in wound strength could be registered between the two wounds in each patient, between males and females nor in patients with malignant disease compared to other patients. Patients with low serum protein or serum albumin values had significantly weaker wounds than patients with normal protein values. Patients over 80 years of age had wounds somewhat weaker than those below 70, the difference having a statistical significance of 6%. The wound strength in patients was compared to values found elsewhere for wounds in rabbits, rats, and piglets. The pigs had much higher values than others, rabbits slightly stronger than and rats about equal to humans.

Lindstedt, E; Sandblom, P

1975-01-01

409

Elastic properties, strength and damage tolerance of pultruded composites  

NASA Astrophysics Data System (ADS)

Pultruded composites are candidate materials for civil engineering infrastructural applications due their higher corrosion resistance and lower life cycle cost. Efficient use of materials like structural members requires thorough understanding of the mechanism that affects their response. The present investigation addresses the modeling and characterization of E-glass fiber/polyester resin matrix pultruded composites in the form of sheets of various thicknesses. The elastic constants were measured using static, vibration and ultrasonic methods. Two types of piezoelectric crystals were used in ultrasonic measurements. Finally, the feasibility of using a single specimen, in the form of a circular disk, was shown in measuring all the elastic constants using ultrasonic technique. The effects of stress gradient on tensile strength were investigated. A large number of specimens, parallel and transverse to the pultrusion direction, were tested in tension, 3-point flexure, and 4-point flexure. A 2-parameter Weibull model was applied to predict the tensile strength from the flexure tests. The measured and Weibull-predicted ratios did not show consistent agreement. Microstructural observations suggested that the flaw distribution in the material was not uniform, which appears to be a basic requirement for the Weibull distribution. Compressive properties were measured using a short-block compression test specimen of 44.4-mm long and 25.4-mm wide. Specimens were tested at 0°, 30°, 45°, 60° and 90° orientations. The compression test specimen was modeled using 4-noded isoparametric layered plate and shell elements. The predicted elastic properties for the roving layer and the continuous strand mat layer was used for the finite element study. The damage resistance and damage tolerance were investigated experimentally. Using a quasi-static indentation loading, damage was induced at various incrementally increased force levels to investigate the damage growth process. Damage parameters were measured in the form of dent depth, back surface crack length, and damage area. The compression tests were performed, using an end-gripped compression test fixture, on both the damaged specimens and open-hole specimens. A relationship between the compressive strength and hole-diameter was established. The compressive strength of damaged specimens was compared to determine the "equivalent-hole-diameter." A correlation between damage parameters and the "equivalent-hole-diameter" was established to find a parameter that could be used as a measure of damage resistance and damage tolerance of pultruded composite structures.

Saha, Mrinal Chandra

410

Tensile properties of nicalon fiber-reinforced carbon following aerospace turbine engine testing  

NASA Astrophysics Data System (ADS)

The durability of coated Nicalon silicon carbide fiber-reinforced carbon (SiC/C) as the flap and seal exhaust nozzle components in a military aerospace turbine engine was studied. Test specimens machined from both a flap and a seal component were tested for residual strength following extended ground engine testing on a General Electric F414 afterburning turbofan engine. Although small amounts of damage to the protective exterior coating were identified on each component following engine testing, the tensile strengths were equal to the as-fabricated tensile strength of the material. Differences in strength between the two components and variability within the data sets could be traced back to the fabrication process using witness coupon test data from the manufacturer. It was also observed that test specimens machined transversely across the flap and seal components were stronger than those machined along the length. The excellent retained strength of the coated SiC/C material after extended exposure to the severe environment in the afterburner exhaust section of an aerospace turbofan engine has resulted in this material being selected as the baseline material for the F414 exhaust nozzle system.

Pierce, J. L.; Zawada, L. P.; Srinivasan, R.

2003-06-01

411

Microstructure and tensile properties of thixoformed A356 alloy  

Microsoft Academic Search

In the research work presented here, mechanical properties of a thixoformed A356 alloy were measured and compared with the mechanical properties of rheocast and gravity-cast alloy with the same composition. In the thixoforming process, a 60% solid fraction rheocast alloy was reheated to 600 °C or 610 °C, held about 10 min, and then reduced by 30% or 50% reduction of cross section.

S. Tahamtan; M. A. Golozar; F. Karimzadeh; B. Niroumand

2008-01-01

412

Effect of small additions of silicon, iron, and aluminum on the room-temperature tensile properties of high-purity uranium  

Microsoft Academic Search

Eleven binary and ternary alloys of uranium and very low concentrations of iron, silicon, and aluminum were prepared and tested for room-temperature tensile properties after various heat treatments. A yield strength approximately double that of high-purity derby uranium was obtained from a U-400 ppM Si-200 ppM Fe alloy after beta solution treatment and alpha aging. Higher silicon plus iron alloy

Ludwig

1983-01-01

413

Tensile and fracture properties of primary heat transport system piping material.  

National Technical Information Service (NTIS)

The fracture mechanics calculations in leak-before-break analysis of nuclear piping system require material tensile data and fracture resistance properties in the form of J-R curve. There are large variations in fracture parameters due to variation in che...

P. K. Singh J. Chattopadhyay H. S. Kushwaha

1997-01-01

414

Mechanical and electrostatic properties of carbon nanotubes under tensile loading and electric field  

Microsoft Academic Search

Coupled mechanical and electronic behaviours of single walled open carbon nanotubes (CNTs) under applied electric field and tensile loading are investigated by the use of quantum mechanics as well as quantum-molecular dynamics techniques based on the Roothaan-Hall equations and the Newton motion laws. Different failure mechanisms and mechanical properties are found for CNTs subjected to electric fields and that subjected

Yufeng Guo; Wanlin Guo

2003-01-01

415

Influence of Carburization on the Room Temperature Tensile Properties of High Temperature Alloys.  

National Technical Information Service (NTIS)

The influence of both thermal exposure and carburization at 800 deg C and above on the room temperature tensile properties of INCOLOY 800 H, INCONEL 617, HASTELLOY X and NIMONIC 86 was studied and the results were compared with literature data. The room t...

P. J. Ennis D. F. Lupton H. Nickel H. Schuster

1982-01-01

416

Effect of Porosity on Tensile Properties of Cast Particle Reinforced MMC  

Microsoft Academic Search

The aim of this study is to investigate the effect of porosity on the tensile properties of cast discontinuous reinforced metal matrix composite (DRMMC) at room temperature. Aluminum silicon alloy reinforced with silicon carbide particles of ≈ 20 &mgr;m size are fabricated via conventional and modified stir casting methods. Specimens are cast at varied content of silicon carbide particles for

S. N. A. S. Ahmad; J. Hashim; M. I. Ghazali

2007-01-01

417

Effect of strain rate and temperature on the tensile properties of Type 308 SMA weld metal  

Microsoft Academic Search

From annual meeting of the American Welding Society; Houston, - Texas, ; USA (6 May 1974). A study was made of the effect of deformation rate on the ; elevated-temperature tensile properties of one material of interest, stainless ; steel Type 308 shielded metal arc (SMA) weld metal. Testing was performed at ; strain rates from 3 x 10 to

Steichen

1973-01-01

418

Fractography, fluidity, and tensile properties of aluminum\\/hematite particulate composites  

Microsoft Academic Search

This paper examines the effect of hematite (iron oxide) particles on the fluidity of the molten composite as well as the tensile properties and fracture behavior of the solidified as-cast aluminum composites. The percentage of hematite in the composite was varied from 1 to 7% in steps of 2% by weight. The vortex method was employed to prepare the composites.

S. C. Sharma; B. M. Girish; R. Kamath; B. M. Satish

1999-01-01

419

EFFECTS OF MODERATELY HIGH STRAIN RATES ON THE TENSILE PROPERTIES OF METALS  

Microsoft Academic Search

Data are plotted to show typical effects of increasing the strain rate ; to nearly 100 in.\\/in.-min at room and elevated temperatures on the tensile ; properties of a number of commercial alloys. The alloys covered include Al ; alloys, Be, steels, stainless steels, superalloys, and Ti alloys. The trends ; illustrated by the graphs are summarized. A bibliography of

D. P. Moon; J. E. Campbell

1961-01-01

420

The influence of composition gradients on tensile properties of weld metal  

Microsoft Academic Search

In this study, the effects of weld metal microsegregation, as altered by post-weld heat treatments, on both low and high temperature tensile properties were investigated on an alloy system which exhibits significant segregation of the major alloying elements without complex transformations or precipitation. Monel alloy 400, which consists primarily of nickel and copper, was chosen as a model system. This

I. D. Choi; D. K. Matlock; D. L. Olson

1988-01-01

421

Evaluation of a sugar based edible adhesive utilizing a tensile strength tester  

Technology Transfer Automated Retrieval System (TEKTRAN)

A new method to evaluate adhesives has been developed and utilized to formulate a recently patented adhesive based on sugar and citric acid. Factors affecting adhesive performance were uncovered, such as reduced strength due to improper heating time, and an optimal curing temperature of 60oC was ac...

422

Correlation of fracture toughness with tensile properties for irradiated 20% cold-worked 316 stainless steel  

SciTech Connect

A correlation has been developed which allows an estimate to be made of the toughness of austenitic alloys using more easily obtained tensile data. Tensile properties measured on 20% cold-worked AISI 316 specimens made from ducts and cladding irradiated in EBR-II were used to predict values for the plane strain fracture toughness according to a model originally developed by Krafft. Some microstructural examination is required to determine a parameter designated as the process zone size. In contrast to the frequently employed Hahn-Rosenfeld model, this model gives results which agree with recent experimental determinations of toughness performed in the transgranular failure regime.

Hamilton, M.L.; Garner, F.A.; Wolfer, W.G.

1983-08-01

423

Optimization of Injection Molding Process for Tensile and Wear Properties of Polypropylene Components via Taguchi and Design of Experiments Method  

Microsoft Academic Search

This study analyzes the wear and the tensile properties of polypropylene (PP) components, which are applied to the interior coffer of automobiles. The specimens are prepared under different injection molding conditions by changing the melting temperature, the injection speed, and the injection pressure via three computer-controlled progressive strokes. The wear and tensile properties are adopted as the quality targets. Experiments

Yu-Hsin Lin; Wei-Jaw Deng; Cheng-Hung Huang; Yung-Kuang Yang

2007-01-01

424

Effect of the Position of Immobilization Upon the Tensile Properties in Injured Achilles Tendon of Rat  

PubMed Central

Objective To examine the effect of the posture of immobilization upon the tensile properties in injured Achilles tendon of rat for an initial period of immobilization. Methods Forty-two Sprague-Dawley rats were used in the present study. Eighteen rats received a total tenotomy of the right Achilles tendon to mimic total rupture and were divided into three groups comprising of 6 rats each. Ankles of group A were immobilized at 60° of plantarflexion. Ankles of group B were immobilized at neutral position. Whereas, those of group C were immobilized at 60° of dorsiflexion. Other 18 rats received hemitenotomy to mimic partial rupture and were divided into three groups. The remaining 6 rats were kept free as control. After 14 days, we dissected the tendons and analyzed maximum force, stiffness, and energy uptake during pulling of the tendons until they ruptured. The tendons of 6 rats in each group and control were reserved for histology. Picrosirius staining was done for the analysis of collagen organization. Results In total tenotomy, tensile properties were significantly different between the control and the intervention groups (p<0.05). Group C showed relatively higher values than the groups A and B with respect to tensile properties (p>0.05). In partial tenotomy, tensile properties were significantly different between the control and the intervention groups (p<0.05). Group C showed significantly higher value than other intervention groups in terms of maximum force and energy uptake (p<0.05). The semiquantitative histologic grading scores were assigned for collagen organization. The scores for dorsiflexion posture were higher than the ones for plantarflexion. Conclusion Dorsiflexion posture in partial ruptured Achilles tendon showed better functional recovery than other immobilized postures. In total ruptured case, the tensile properties showed increasing tendency in dorsiflexion posture.

Min, Yong; Kwon, Young-Bae; Lee, Min-Ho

2013-01-01

425

An Investigation of the Tensile Strength of a Composite-To-Metal Adhesive Joint  

NASA Astrophysics Data System (ADS)

The present study examines the feasibility of a simple concept composite-to-metal butt joint through the performance of both numerical and experimental studies. The composite part is made of glass/epoxy unidirectional layers made with the vacuum bag method. The geometry of the joint is typical for marine applications and corresponds to a low stiffness ratio. Two major parameters are investigated, namely the overlap length and the surface preparation of the steel adherent. Manufacturing of specimens and the procedure of the tensile tests are described in detail, giving hints for obtaining a better quality joint. Axial elongation and strains at various places of the joint were monitored and also numerically calculated. The tests revealed that the joint is quite effective, irrespectively of the steel surface preparation method. The failure loads are comparable and in some cases superior to other corresponding values found in the literature. The numerical models proved to adequately predict the structural response of the joint up to the loading where debonding starts.

Tsouvalis, Nicholas G.; Karatzas, Vassilios A.

2011-04-01

426

Pressure-Sensitivity and Tensile Strength of AN Elastomer at High Strain Rates  

NASA Astrophysics Data System (ADS)

Pressure-shear plate impact experiments have been conducted to study the mechanical response of an elastomer (polyurea) at very high strain rates: 105-106 s-1. Thin samples are cast between two hard steel plates. Longitudinal waves reverberating through the sample are used to determine the slope of the isentrope at compressive stresses greater than, say, 500 MPa-the initial pressure at impact. Shear waves measure the shearing resistance at the pressure attained after the ``ring-up'' of the pressure in the sample is complete. In the current work, release wave experiments and plane wave simulations are used to extend the isentrope into the tensile regime-and ultimately to failure. The previous work is also extended to determine the pressure-sensitivity of the material's shearing resistance at high shearing rates and low pressures. To achieve the latter, the impact configuration is designed so that an unloading longitudinal wave reflected from the rear surface of the target assembly arrives at the sample midway through its loading by the incident shear wave. As a result, the sample is sheared at high strain rates-at both high and low pressure-during a single experiment.

Jiao, T.; Clifton, R. J.; Grunschel, S. E.

2007-12-01

427

Apparatus for measuring tensile and compressive properties of solid materials at cryogenic temperatures  

DOEpatents

An apparatus for evaluating the tensile and compressive properties of material samples at very low or cryogenic temperatures employs a stationary frame and a dewar mounted below the frame. A pair of coaxial cylindrical tubes extend downward towards the bottom of the dewar. A compressive or tensile load is generated hydraulically and is transmitted by the inner tube to the material sample. The material sample is located near the bottom of the dewar in a liquid refrigerant bath. The apparatus employs a displacement measuring device, such as a linear variable differential transformer, to measure the deformation of the material sample relative to the amount of compressive or tensile force applied to the sample. 7 figs.

Gonczy, J.D.; Markley, F.W.; McCaw, W.R.; Niemann, R.C.

1992-04-21

428

Strength and shrinkage properties of mortar containing a nonstandard high-calcium fly ash  

Microsoft Academic Search

A laboratory study was undertaken to assess the compressive and flexural tensile strength and drying shrinkage properties of mortar mixtures containing high-calcium nonstandard Afsin-Elbistan fly ash (FA). Possibility of using Afsin-Elbistan FA in cement-based materials as shrinkage-reducing or compensation agent was also discussed. Five mortar mixtures including control Portland cement (PC) and FA mortar mixtures were prepared. FA replaced the

Cengiz Duran Ati?; Alaettin Kiliç; Umur Korkut Sevim

2004-01-01

429

Effect of strain rate on the tensile strength of copper shaped charge jet  

Microsoft Academic Search

The jet is produced by a cylindrical 45-mm shaped charge inside a conical copper liner with 120° apex angle. The data on rotating shaped charge penetration are used to estimate the strength of a copper jet under radial tension due to the action of centrifugal force. The value of 0.07 to 0.15 GPa is obtained, which is close to the

V. V. Silvestrov; N. N. Gorshkov

1996-01-01

430

Determination of the ultimate tensile strength of rocks by the unaixial compression test data  

Microsoft Academic Search

Based on the hypothesized material-independent relationship of the normal and shear stresses on the plane of shear, the authors\\u000a have plotted an envelope of Mohr’s circles, that represents a rock strength condition in the compression stress domain. The\\u000a relation of the maximal principal stresses extends to the tension domain as a hyperbola, and its parameters can be obtained\\u000a only in

B. A. Rychkov; Zh. Y. Mamatov; E. I. Kondrat’eva

2009-01-01

431

Tensile bond strength to and SEM evaluation of ground and intact enamel surfaces  

Microsoft Academic Search

Objectives: The aim of this study was to evaluate the bonding of four commercially available adhesive systems to ground and intact enamel surfaces.Methods: Extracted human teeth were used to measure the microtensile bond strength to enamel and a field-emission scanning electron microscopy (FE-SEM) was used to observe the bonded interface and the effect of the surface conditioning of each material.

N Kanemura; H Sano; J Tagami

1999-01-01

432

Developing an Empirical Relationship to Predict Tensile Strength of Friction Stir Welded AA2219 Aluminum Alloy  

Microsoft Academic Search

AA2219 aluminum alloy (Al-Cu-Mn alloy) has gathered wide acceptance in the fabrication of lightweight structures requiring\\u000a a high strength-to-weight ratio and good corrosion resistance. Friction stir welding (FSW) process is an emerging solid state\\u000a joining process in which the material that is being welded does not melt and recast. This process uses a nonconsumable tool\\u000a to generate frictional heat in

K. Elangovan; V. Balasubramanian; S. Babu

2008-01-01

433

Optimizing friction stir welding parameters to maximize tensile strength of AA2219 aluminum alloy joints  

Microsoft Academic Search

AA2219 aluminium alloy (Al-Cu-Mn alloy) has gathered wide acceptance in the fabrication of lightweight structures requiring\\u000a a high strength-to-weight ratio and good corrosion resistance. In contrast to the fusion welding processes that are routinely\\u000a used for joining structural aluminium alloys, the friction stir welding (FSW) process is an emerging solid state joining process\\u000a in which the material that is being

S. Babu; K. Elangovan; V. Balasubramanian; M. Balasubramanian

2009-01-01

434

Microstructures and tensile properties of as-cast iron-aluminide alloys  

SciTech Connect

Room-temperature tensile properties of as-cast Fe{sub 3}Al, Fe{sub 3}Al with chromium, and Fe{sub 3}Al-based FA-129 alloy have been investigated. Tensile properties have been obtained in air in the as-cast condition for all three alloys. Samples of FA-129 alloy have also been tested in oxygen and water vapor environments, and after homogenization at 700, 900, and 1200C. Transmission electron microscopy has been used to characterize ordered phases and optical metallography and scanning electron microscopy have been used to characterize the microstructure and fracture morphology. Tensile properties in the as-cast condition exhibited an environmental effect; tensile ductilities in an oxygen atmosphere were greater than those obtained in laboratory air. Homogenized samples of FA-129 alloy exhibited almost twice the ductility of the as-cast condition. Results indicate that the low ductility of as-cast Fe{sub 3}Al-based alloys may be related to the relatively large grain size in the as-cast condition and the presence of the DO{sub 3} ordered phase. Microstructural characterization of the homogenized samples and comparison of the as-cast and homogenized microstructures may provide a clue to the poor ductility in the as-cast condition.

Viswanathan, S.; McKamey, C.G.; Maziasz, P.J.; Sikka, V.K.

1994-09-01

435

Influence of post-superplastic forming practices on the tensile properties of aluminum-lithium alloys  

Microsoft Academic Search

The effect of thermal processing following superplastic forming on the tensile properties of aluminum-lithium alloys is addressed.\\u000a The starting materials consisted of alloys 8090, 2090, and X2095 (a Weldalite™ 049 variant) in the form of commercial- grade\\u000a superplastic sheet. Experience dictates that post- forming practices aimed at a slightly underaged T6 temper produce balanced\\u000a engineering proper-ties in these alloys. The

S. J. Hales; H. E. Lippard

1994-01-01

436

Influence of post-superplastic forming practices on the tensile properties of aluminum-lithium alloys  

Microsoft Academic Search

The effect of thermal processing following superplastic forming on the tensile properties of aluminum-lithium alloys is addressed. The starting materials consisted of alloys 8090, 2090, and X2095 (a Weldalite™ 049 variant) in the form of commercial- grade superplastic sheet. Experience dictates that post- forming practices aimed at a slightly underaged T6 temper produce balanced engineering proper-ties in these alloys. The

S. J. Hales; H. E. Lippard

1994-01-01

437

Relationship between Microstructure and Tensile Properties of PET\\/Silica Nanocomposite Fibers  

Microsoft Academic Search

The influence of silica nanoparticles on the tensile properties of poly(ethylene terephthalate)(PET) fibers was investigated. The results showed that mechanical properties of PET fibers were improved through nano?silica incorporation. Two maxima of the modulus?strain curves of PET\\/silica nanocomposites (PETS) fibers are always higher than those of pure PET (PET0) fibers. The results of microstructure investigations suggested that the amorphous orientation

Xian Zhang; Xingyou Tian; Jin Zheng; Xiayin Yao; Wentao Liu; Ping Cui; Yong Li

2008-01-01

438

Report on thermal aging effects on tensile properties of ferritic-martensitic steels.  

SciTech Connect

This report provides an update on the evaluation of thermal-aging induced degradation of tensile properties of advanced ferritic-martensitic steels. The report is the first deliverable (level 3) in FY11 (M3A11AN04030103), under the Work Package A-11AN040301, 'Advanced Alloy Testing' performed by Argonne National Laboratory, as part of Advanced Structural Materials Program for the Advanced Reactor Concepts. This work package supports the advanced structural materials development by providing tensile data on aged alloys and a mechanistic model, validated by experiments, with a predictive capability on long-term performance. The scope of work is to evaluate the effect of thermal aging on the tensile properties of advanced alloys such as ferritic-martensitic steels, mod.9Cr-1Mo, NF616, and advanced austenitic stainless steel, HT-UPS. The aging experiments have been conducted over a temperature of 550-750 C for various time periods to simulate the microstructural changes in the alloys as a function of time at temperature. In addition, a mechanistic model based on thermodynamics and kinetics has been used to address the changes in microstructure of the alloys as a function of time and temperature, which is developed in the companion work package at ANL. The focus of this project is advanced alloy testing and understanding the effects of long-term thermal aging on the tensile properties. Advanced materials examined in this project include ferritic-martensitic steels mod.9Cr-1Mo and NF616, and austenitic steel, HT-UPS. The report summarizes the tensile testing results of thermally-aged mod.9Cr-1Mo, NF616 H1 and NF616 H2 ferritic-martensitic steels. NF616 H1 and NF616 H2 experienced different thermal-mechanical treatments before thermal aging experiments. NF616 H1 was normalized and tempered, and NF616 H2 was normalized and tempered and cold-rolled. By examining these two heats, we evaluated the effects of thermal-mechanical treatments on material microstructures and associated mechanical properties during long-term aging at elevated temperatures. Thermal aging experiments at different temperatures and periods of time have been completed: 550 C for up to 5000 h, 600 C for up to 7500 h, and 650 C for more than 10,000 h. Tensile properties were measured on thermally aged specimens and aging effect on tensile behavior was assessed. Effects of thermal aging on deformation and failure mechanisms were investigated by using in-situ straining technique with simultaneous synchrotron XRD measurements.

Li, M.; Soppet, W.K.; Rink, D.L.; Listwan, J.T.; Natesan, K. (Nuclear Engineering Division)

2012-05-10

439

Strength–duration properties in diabetic polyneuropathy  

Microsoft Academic Search

We sought to examine the changes in the strength–duration time constant (SDTC) of the median nerve in diabetic polyneuropathy. The SDTC is a measure of axonal excitability and depends on the biophysical properties of the axonal membrane. It may provide some information about Na+ channel functioning. Forty-nine diabetic patients (30 men, 19 women; mean age, 54.6±9.4 years) and 15 age-matched

Deniz Yerdelen; Filiz Koç; Hilmi Uysal; Yakup Sarica

2007-01-01

440

Microstructure evolution and its influence on thermal expansion and tensile properties of the superalloy IN738LC at high temperatures  

NASA Astrophysics Data System (ADS)

Three major aspects of the superalloy IN738LC are studied in this dissertation: (i) precipitate microstructure evolution, (ii) tensile mechanical properties, and (iii) thermal expansion characteristics. IN738LC is a Ni-base, gammasp' Nisb3Al(Ti) precipitate-strengthened alloy. This alloy includes ˜20-43 volume % gammasp' and also some (Ta,Ti)C at the grain boundaries and in the matrix. Different heat treatments were carried out to study the precipitate evolution mechanisms and kinetics in this superalloy. It was found that the proper solution treatment producing the single-phase supersaturated solid solution condition is 1235sp°C/4h/WQ. Solution treatment at 1200sp°C/4h/WQ, however, produces a refined precipitate microstructure. Aging treatments after both of these solution treatments give similar microstructures. The precipitates grow in cuboidal form after agings at 1120-1130sp°C/24h. However, longer aging times (>48h) yield a duplex-size precipitate morphology in this temperature range. Likewise, the duplex-size morphology develops at 1140sp°C, but in a much shorter time (5 min.), and it is stable in the range 1140-1150sp°C. Activation energy calculations showed that the precipitate microstructure becomes more unstable and it dissolves into the matrix when the temperature increases above 1150sp°C, and in the range 1160-1225sp°C, a unimodal stable, fine-size precipitate microstructure develops. XRD studies showed that different precipitate microstructures possess different preferred orientations. Precipitates tend to have the \\{220\\} or \\{200\\} orientation. Whereas most of the precipitate microstructures have single texture, the duplex-size precipitate microstructure has the \\{111\\} and \\{200\\} preferred orientations for the matrix and the precipitates, respectively. Tensile mechanical and thermal expansion tests proved that the size and morphology of the precipitate phase is very effective in determining the magnitude of these properties. Generally, microstructures having fine-size precipitates show higher yield strength, and elasticity modulus; in contrast, microstructures with coarser precipitates exhibit more elongation, strain-harden more, and acquire higher tensile strength. Tensile fracture is usually of the cleavage type with fine precipitates and ductile with the coarse ones. Thermal expansivity of the microstructures with fine precipitates is in general less than that of the microstructures with coarse precipitates.

Balikci, Ercan

1998-11-01

441

Effect of Tempering Time on Microstructure, Tensile Properties, and Deformation Behavior of a Ferritic Light-Weight Steel  

NASA Astrophysics Data System (ADS)

In the present study, a ferritic light-weight steel was tempered at 973 K (700 °C) for various tempering times, and tensile properties and deformation mechanisms were investigated and correlated to microstructure. ?-carbides precipitated in the tempered band-shaped martensite and ferrite matrix, and the tempered martensite became more decomposed with increasing tempering time. Tempering times for 3 days or longer led to the formation of austenite as irregular thick-film shapes mostly along boundaries between the tempered martensite and the ferrite matrix. Tensile tests of the 1-day-tempered specimen showed that deformation bands were homogeneously spread throughout the specimen, and that the fine carbides were sufficiently deformed inside these deformation bands resulting in high strength and ductility. The 3-day-tempered specimen showed a small amount of boundary austenite, which readily developed voids or cracks and became sites for fracture. This cracking at boundary austenites became more prominent in the 7- and 15-day-tempered specimens, as the volume fraction of boundary austenites increased with increasing tempering time. These findings suggested that, when the steel was tempered at 973 K (700 °C) for an appropriate time, i.e., 1 day, to sufficiently precipitate ?-carbides and to prevent the formation of boundary austenites, that the deformation occurred homogeneously, leading to overall higher mechanical properties.

Han, Seung Youb; Shin, Sang Yong; Lee, Byeong-Joo; Lee, Sunghak; Kim, Nack J.; Kwak, Jai-Hyun

2013-01-01

442

THE EFFECTS OF FAST REACTOR IRRADIATION CONDITIONS ON THE TENSILE PROPERTIES OF TWO FERRITIC/MARTENSITIC STEELS  

SciTech Connect

Tensile testing has been performed at 25 and at ~400°C on two ferritic/martensitic steels (JFMS and HT-9) after irradiation in FFTF to up to ~70 dpa at 373 to 433°C. As observed in previous studies, this range of irradiation temperatures has a significant effect on hardening. The percent increase in yield stress decreases with increasing irradiation temperature from 373 to 433ºC. The JFMS alloy, which has 0.7 wt. % silicon, exhibits approximately a factor of two increase in yield strength between tests at 427°C and at 373°C, and shows an increase in hardening with increasing dose. A comparison of the JFMS tensile properties to the properties of other ferritic/martensitic steels suggests that this hardening is due to precipitation of a Si-rich Laves phase in this alloy. The HT-9 alloy, which contains more chromium and more carbon but less silicon (0.2 wt. %), less molybdenum and less nickel, hardens during irradiation at 373°C, but shows less hardening for irradiations performed at 427ºC and no increase in yield stress with increasing dose beyond 10 dpa.

Maloy, Stuart A.; Toloczko, Mychailo B.; McClellan, K. J.; Romero, T. J.; Kohno, Y.; Garner, Francis A.; Kurtz, Richard J.; Kimura, Akihiko

2006-09-15

443

The effects of fast reactor irradiation conditions on the tensile properties of two ferritic/martensitic steels  

NASA Astrophysics Data System (ADS)

Tensile testing has been performed at 25 and at ˜400 °C on two ferritic/martensitic steels (JFMS and HT-9) after irradiation in FFTF to up to ˜70 dpa at 373 433 °C. As observed in previous studies, this range of irradiation temperatures has a significant effect on hardening. The percent increase in yield stress decreases with increasing irradiation temperature from 373 to 433 °C. The JFMS alloy, which has 0.7 wt% silicon, exhibits approximately a factor of two increase in yield strength between tests at 427 and at 373 °C, and shows an increase in hardening with increasing dose. A comparison of the JFMS tensile properties to the properties of other ferritic/martensitic steels suggests that this hardening is due to precipitation of a Si-rich laves phase in this alloy. The HT-9 alloy, which contains more chromium and more carbon but less silicon (0.2 wt%), less molybdenum and less nickel, hardens during irradiation at 373 °C, but shows less hardening for irradiations performed at 427 °C and no increase in yield stress with increasing dose beyond 10 dpa.

Maloy, Stuart A.; Toloczko, M. B.; McClellan, K. J.; Romero, T.; Kohno, Y.; Garner, F. A.; Kurtz, R. J.; Kimura, A.

2006-09-01

444

Heat-Treatment Effects on the Microstructure and Tensile Properties of Powder Metallurgy Ti-6Al-4V Alloys Modified with Boron  

NASA Astrophysics Data System (ADS)

The Ti-6Al-4V (Ti-64) alloys modified with two levels of boron (1B and 1.7B (wt pct)) representing hypoeutectic and hypereutectic compositions, produced via a prealloyed powder metallurgy approach, were subjected to various standard heat treatments of Ti-64 to study the microstructural evolution and its influence on tensile properties. Boron-modified Ti-64 (Ti-64B) alloys exhibited differences in microstructural response to heat treatment compared to that of Ti-64 due to variations in constituent phase fractions and the influence of TiB on the beta-to-alpha phase transformation kinetics. The tensile elastic modulus of Ti-64B alloys increased nearly linearly with the boron content (or TiB volume fraction) and the increase could be satisfactorily predicted with an isostrain rule of mixtures (ROMs) and the Halpin-Tsai model. The Ti-64-1B possessed a good combination of tensile strength (1200 to1370 MPa) and ductility (10 to 13 pct), while Ti-64-1.7B exhibited high strength (1300 to 1695 MPa) and modest ductility (2 to 3.5 pct). Coarse primary TiB particles present in Ti-64-1.7B were found to initiate premature failure. Strength modeling revealed that load sharing by the micron-sized TiB whiskers provides the major contribution for the increase in yield strength.

McEldowney, Dale J.; Tamirisakandala, Seshacharyulu; Miracle, Daniel B.

2010-04-01

445

Tensile properties of candidate structural materials for high power spallation sources at high helium contents  

NASA Astrophysics Data System (ADS)

Low activation 9%Cr martensitic steels EUROFER97, pure tantalum, and low carbon austenitic stainless steel 316L were homogeneously implanted with helium to concentrations up to 5000 appm at temperatures from 70 °C to 400 °C. The specimens were tensile tested at room temperature and at the respective implantation temperatures. In all materials the helium caused an increased in strength and reduction in ductility, with both changes being generally larger at lower implantation and testing temperatures. After implantation some work hardening was retained in 316L and in tantalum, while it almost completely disappeared in EUROFER97. After tensile testing, fracture surfaces were analysed by scanning electron microscopy (SEM). Implantation caused reduction of necking, but up to concentrations of 2500 appm He fracture surface still showed transgranular ductile appearance. Completely brittle intergranular fracture was observed in tantalum at 9000 appm He and is also expected for EUROFER97 at this concentration, according to previous results on similar 9%Cr steels.

Jung, P.; Henry, J.; Chen, J.

2005-08-01

446

Variation of Lap Shear Tensile Strength of Polycarbonate Mild Steel Adhesive Joints with DC Glow Discharge Modified Polycarbonate  

NASA Astrophysics Data System (ADS)

It has been observed that the wettability/surface energy of polycarbonate (PC) changes with the variation in process parameters, such as discharge power and time of exposure of DC glow discharge. The wettability of the PC surface has been measured by the contact angle measurements of two test liquids, such as water and formamide, by the sessile drop method. The lap shear tensile strength (LSTS) of PC to the mild steel (MS) adhesive joint has been measured with both the as-received polymer and those exposed under DC glow discharge. An appreciable increase in the LSTS has been attained for samples treated under DC glow discharge at a lower power level and also at a short exposure time at higher power. This increase in LSTS is attributed to increased polar surface energy with increasing power and time of exposure. After a certain level of surface modification of the PC, the strength of the adhesive joint deteriorates, while the total surface energy and its polar component may increase continuously. The subsurface damage taking place particularly at long exposure times and at higher power may lead to deterioration of LSTS in spite of a strong interface between the polymer and the adhesive. In such a case, the joint is observed to fracture not across the interface but through the subsurface. The optimum exposure limits the subsurface damage while creating a strong interface.

Panwar, Amrish K.; Barthwal, S. K.; Ray, S.

2007-01-01

447

Tensile strength and elongation of laser-welded Ti and Ti-6AL-7NB.  

PubMed

This study established data demonstrating the possible laser-welded strengths of cast Ti and Ti-6Al-7Nb and compared them to those of two dental-casting alloys. Cast plates of Ti, Ti-6Al-7Nb, gold, and Co-Cr alloy were prepared. After polishing the surfaces to be welded, two plates were abutted and welded using an Nd:YAG laser at a pulse duration of 10 ms, spot diameter of 1 mm, and voltage of 200 V. Five specimens were prepared for each metal by welding either three or five spots unilaterally or bilaterally. The fracture load and percent elongation were measured at a crosshead speed of 1.0 mm/min. The bilaterally welded specimens performed significantly greater than unilaterally welded specimens in both fracture load and elongation whether they were welded with three or five spots per side. The bilaterally welded Ti and Ti-6Al-7Nb specimens were nearly as strong as their corresponding control specimens, whereas the gold and Co-Cr specimens were approximately half as strong. When a large proportion of the cross-sectional area of the joint is laser welded, the strength of the laser-welded portion of the cast Ti and Ti-6Al-7Nb may approach or equal that of the nonwelded metal frameworks. PMID:15368227

Watanabe, Ikuya; Topham, D Scott

2004-10-15