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1

Diametral and compressive strength of dental core materials  

Microsoft Academic Search

Statement of problem. Strength greatly influences the selection of core materials. Many disparate material types are now recommended for use as cores. Cores must withstand forces due to mastication and parafunction for many years. Purpose. This study compared the compressive and diametral tensile strengths of 8 core materials of various material classes and formulations (light-cured hybrid composite, autocured titanium containing

George C. Cho; Leslie M. Kaneko; Terence E. Donovan; Shane N. White

1999-01-01

2

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

3

A novel dentin bond strength measurement technique using a composite disk in diametral compression.  

PubMed

New methods are needed that can predict the clinical failure of dental restorations that primarily rely on dentin bonding. Existing methods have shortcomings, e.g. severe deviation in the actual stress distribution from theory and a large standard deviation in the measured bond strength. We introduce here a novel test specimen by examining an endodontic model for dentin bonding. Specifically, we evaluated the feasibility of using the modified Brazilian disk test to measure the post-dentin interfacial bond strength. Four groups of resin composite disks which contained a slice of dentin with or without an intracanal post in the center were tested under diametral compression until fracture. Advanced nondestructive examination and imaging techniques in the form of acoustic emission (AE) and digital image correlation (DIC) were used innovatively to capture the fracture process in real time. DIC showed strain concentration first appearing at one of the lateral sides of the post-dentin interface. The appearance of the interfacial strain concentration also coincided with the first AE signal detected. Utilizing both the experimental data and finite-element analysis, the bond/tensile strengths were calculated to be: 11.2 MPa (fiber posts), 12.9 MPa (metal posts), 8.9 MPa (direct resin fillings) and 82.6 MPa for dentin. We have thus established the feasibility of using the composite disk in diametral compression to measure the bond strength between intracanal posts and dentin. The new method has the advantages of simpler specimen preparation, no premature failure, more consistent failure mode and smaller variations in the calculated bond strength. PMID:22266033

Huang, Shih-Hao; Lin, Lian-Shan; Rudney, Joel; Jones, Rob; Aparicio, Conrado; Lin, Chun-Pin; Fok, Alex

2012-01-15

4

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

5

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

6

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

7

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

8

A new analytic solution for the diametral point load strength test on finite solid circular cylinders  

Microsoft Academic Search

This paper presents an exact analytic solution for a finite isotropic circular cylinder of diameter D and length 2L subjected to the diametral point load strength test (PLST). Two displacement functions are introduced to uncouple the equations of equilibrium, and two new series expressions for these functions are proposed in terms of the Bessel and modified Bessel functions of the

K. T. Chau; X. X. Wei

2001-01-01

9

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

10

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

11

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

12

Tensile fracture of doubly-convex cylindrical discs under diametral loading  

Microsoft Academic Search

Doubly-convex cylindrical gypsum discs have been fractured under the action of two diametrically opposed in-plane forces. The disc diameter was constant throughout the test series. The ratio of cylinder length to diameter ranged from 0.06 to 0.30; the ratio of cylinder diameter to radius of curvature of the disk faces was varied from 0 to 1.43. The fracture loads obtained

K. G. Pitt; J. M. Newton

1988-01-01

13

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

14

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

15

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

16

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

17

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

18

Transverse strength of SCS6 silicon carbide fibers  

Microsoft Academic Search

A diametral compression test was used to measure the transverse strength of SCS-6 SiC fibers before and after heat treatment. Subjecting fibers to diametral compression successfully produced transverse tensile failure in the form of fiber cracking along the same diametral plane in which the compressive load was applied. An analysis of the hoop stress along the diametral plane, in which

Jeffrey I. Eldridge; Jonathan P. Wiening; Terry S. Davison; Marek-Jerzy Pindera

1993-01-01

19

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

20

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

21

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

22

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

23

Tensile strength measurements of frangible bullets using the diametral compression test  

Microsoft Academic Search

Frangible bullets are designed to disintegrate on impact against rigid surfaces to avoid ricochet hazards in recreational shooting ranges or law enforcement training facilities. Their impact behavior against protective soft body armor is therefore quite different than conventional lead bullets, which are designed to expand on impact rather than shatter into fragments. Models to predict the impact of frangible bullets

Steven P. Mates; Richard Rhorer; Stephen Banovic; Eric Whitenton; Richard Fields

2008-01-01

24

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

25

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

26

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

27

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

28

A novel dentin bond strength measurement technique using the composite disk in diametral compression  

PubMed Central

We evaluated the feasibility of using the modified Brazilian disk test to measure the post-dentin interfacial bond strength. Advanced nondestructive examination and imaging techniques in the form of acoustic emission (AE) and digital image correlation (DIC) were used innovatively to capture the fracture process in real time. DIC showed strain concentration first appearing at one of the lateral sides of the post-dentin interface. The appearance of the interfacial strain concentration also coincided with the first AE signal detected. The new method has the advantages of simpler specimen preparation, no premature failure, more consistent failure mode and smaller variations in the calculated bond strength.

Huang, Shih-Hao; Lin, Lian-Shan; Rudney, Joel; Jones, Rob; Aparicio, Conrado; Lin, Chun-Pin

2012-01-01

29

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

30

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

31

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

32

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

33

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

34

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

35

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

36

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

37

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

38

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

39

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

40

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

41

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

42

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

43

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

44

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

45

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

46

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

47

[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

48

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

49

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

50

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

51

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

52

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

53

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

54

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

55

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

56

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

57

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

58

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

59

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

60

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

61

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

62

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

63

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

64

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

65

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

66

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

67

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

68

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

69

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

70

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

71

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

72

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

73

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

74

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

75

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

76

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

77

Deformation and failure of polymer bonded explosives under diametric compression test  

Microsoft Academic Search

The tensile deformation and failure of polymer bonded explosives (PBXs), a particulate composite, is studied in this paper. Two HMX-based PBXs with different binder were selected for study. A diametric compression test, in which a disc-shaped specimen is loaded diametrically, was chosen to generate tensile failure in the materials. The quasi-static tensile properties and the tensile creep properties were studied

Pengwan Chen; Huimin Xie; Fenglei Huang; Tao Huang; Yansheng Ding

2006-01-01

78

Computer simulation of fatigue under diametrical compression  

SciTech Connect

We study the fatigue fracture of disordered materials by means of computer simulations of a discrete element model. We extend a two-dimensional fracture model to capture the microscopic mechanisms relevant for fatigue and we simulate the diametric compression of a disc shape specimen under a constant external force. The model allows us to follow the development of the fracture process on the macrolevel and microlevel varying the relative influence of the mechanisms of damage accumulation over the load history and healing of microcracks. As a specific example we consider recent experimental results on the fatigue fracture of asphalt. Our numerical simulations show that for intermediate applied loads the lifetime of the specimen presents a power law behavior. Under the effect of healing, more prominent for small loads compared to the tensile strength of the material, the lifetime of the sample increases and a fatigue limit emerges below which no macroscopic failure occurs. The numerical results are in a good qualitative agreement with the experimental findings.

Carmona, H. A. [Centro de Ciencias e Tecnologia, Universidade Estadual do Ceara, 60740-903 Fortaleza, Ceara (Brazil); IfB, HIF, E18, ETH, Hoenggerberg, 8093 Zuerich (Switzerland); Kun, F. [Department of Theoretical Physics, University of Debrecen, P.O. Box 5, H-4010 Debrecen (Hungary); Andrade, J. S. Jr. [Departamento de Fisica, Universidade Federal do Ceara, 60451-970 Fortaleza, Ceara (Brazil); Herrmann, H. J. [IfB, HIF, E18, ETH, Hoenggerberg, 8093 Zuerich (Switzerland)

2007-04-15

79

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

80

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

81

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

82

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

83

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

84

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

85

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

86

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

87

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

88

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

89

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

90

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

91

Effective Size Analysis of the Diametral Compression (Brazil) Test Specimen  

SciTech Connect

This study considers the finite element analysis (FEA) simulation and Weibull effective size analysis for the diametral compression (DC) or Brazil specimen loaded with three different push-rod geometries. Those geometries are a flat push-rod, a push-rod whose radius of curvature is larger than that for the DC specimen, and a push-rod whose radius of curvature matches that of the DC specimen. Such established effective size analysis recognizes that the tensile strength of structural ceramics is typically one to two orders of magnitude less than its compressive strength. Therefore, because fracture is much more apt to result from a tensile stress than a compressive one, this traditional analysis only considers the first principal tensile stress field in the mechanically loaded ceramic component for the effective size analysis. The effective areas and effective volumes were computed as function of Weibull modulus using the CARES/Life code. Particular attention was devoted to the effect of mesh sensitivity and localized stress concentration. The effect of specimen width on the stress state was also investigated. The effects of push-rod geometry, the use of steel versus WC push-rods, and considering a frictionless versus no-slip interface between push-rod and specimen on the maximum stresses, where those stresses are located, and the effective area and effective volume results are described. Of the three push-rod geometries, it is concluded that the push-rod (made from WC rather than steel) whose radius of curvature matches that of the DC specimen is the most apt to cause fracture initiation within the specimen's bulk rather than at the loading interface. Therefore, its geometry is the most likely to produce a valid diametral compression strength test. However, the DC specimen remains inefficient in terms of its area and volume efficiencies; namely, the tensile strength of only a few percent of the specimen's entire area or volume is sampled. Given the high probability that a valid (or invalid) test can be proven by ceramic fractographic practices suggests that this test method and specimen is questionable for use with relatively strong structural ceramics.

Jadaan, Osama M. [University of Wisconsin, Platteville; Wereszczak, Andrew A [ORNL

2009-04-01

92

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

93

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

94

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

95

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

96

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

97

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

98

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

99

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

100

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

101

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

102

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

103

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

104

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

105

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

106

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

107

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

108

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

109

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

110

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

111

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

112

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

113

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

114

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

115

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

116

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

117

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. ...

118

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

119

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

120

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.

121

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

122

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

123

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

124

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

125

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

126

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

127

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

128

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

129

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

130

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

131

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

132

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

133

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

134

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

135

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

136

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

137

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

138

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

139

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

140

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

141

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

142

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

143

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

144

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

145

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

146

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

147

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

148

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

149

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

150

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

151

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

152

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

153

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

154

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

155

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

156

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

157

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

158

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

159

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

160

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

161

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

162

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

163

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

164

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

165

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

166

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

167

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

168

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

169

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

170

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

171

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

172

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

173

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

174

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

175

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

176

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

177

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

178

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

179

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

180

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

181

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

182

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

183

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

184

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

185

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

186

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

187

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

188

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

189

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

190

Transverse strength of SCS-6 silicon carbide fibers  

SciTech Connect

A diametral compression test was used to measure the transverse strength of SCS-6 SiC fibers before and after heat treatment. Subjecting fibers to diametral compression successfully produced transverse tensile failure in the form of fiber cracking along the same diametral plane in which the compressive load was applied. An analysis of the hoop stress along the diametral plane, in which the effects of the C core were included, showed that there is a large tensile hoop stress concentration in the SiC sheath at the interface between the C core and the SiC sheath, where the stress is 6.3 times greater than the stress present in a solid SiC fiber under identical loading. This high tensile hoop stress concentration promotes crack initiation near the core and significantly limits the capability of these fibers to withstand transverse compressive loading. The maximum tensile hoop stresses, located at the interface between the C core and SiC sheath, at the measured failure loads were 850 MPa for the as-received SCS-6 fiber and 1,210 MPa for fibers exposed to a 1-h heat treatment at 1,850 C in 138 MPa of Ar.

Eldridge, J.I. (NASA, Cleveland, OH (United States). Lewis Research Center); Wiening, J.P.; Davison, T.S.; Pindera, M.J. (Univ. of Virginia, Charlottesville, VA (United States). School of Engineering and Applied Science)

1993-12-01

191

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

192

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

193

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

194

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

195

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

196

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

197

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

198

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

199

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

200

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

201

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

202

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

203

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

204

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

205

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

206

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

207

Modelling and Simulation of Tensile Fracture in High Velocity Compacted Metal Powder  

NASA Astrophysics Data System (ADS)

In cold uniaxial powder compaction, powder is formed into a desired shape with rigid tools and a die. After pressing, but before sintering, the compacted powder is called green body. A critical property in the metal powder pressing process is the mechanical properties of the green body. Beyond a green body free from defects, desired properties are high strength and uniform density. High velocity compaction (HVC) using a hydraulic operated hammer is a production method to form powder utilizing a shock wave. Pre-alloyed water atomised iron powder has been HVC-formed into circular discs with high densities. The diametral compression test also called the Brazilian disc test is an established method to measure tensile strength in low strength material like e.g. rock, concrete, polymers and ceramics. During the test a thin disc is compressed across the diameter to failure. The compression induces a tensile stress perpendicular to the compressed diameter. In this study the test have been used to study crack initiation and the tensile fracture process of HVC-formed metal powder discs with a relative density of 99%. A fictitious crack model controlled by a stress versus crack-width relationship is utilized to model green body cracking. Tensile strength is used as a failure condition and limits the stress in the fracture interface. The softening rate of the model is obtained from the corresponding rate of the dissipated energy. The deformation of the powder material is modelled with an elastic-plastic Cap model. The characteristics of the tensile fracture development of the central crack in a diametrically loaded specimen is numerically studied with a three dimensional finite element simulation. Results from the finite element simulation of the diametral compression test shows that it is possible to simulate fracturing of HVC-formed powder. Results from the simulation agree reasonably with experiments.

Jonsén, P.; Häggblad, H.-A.?.

2007-05-01

208

Modelling and Simulation of Tensile Fracture in High Velocity Compacted Metal Powder  

SciTech Connect

In cold uniaxial powder compaction, powder is formed into a desired shape with rigid tools and a die. After pressing, but before sintering, the compacted powder is called green body. A critical property in the metal powder pressing process is the mechanical properties of the green body. Beyond a green body free from defects, desired properties are high strength and uniform density. High velocity compaction (HVC) using a hydraulic operated hammer is a production method to form powder utilizing a shock wave. Pre-alloyed water atomised iron powder has been HVC-formed into circular discs with high densities. The diametral compression test also called the Brazilian disc test is an established method to measure tensile strength in low strength material like e.g. rock, concrete, polymers and ceramics. During the test a thin disc is compressed across the diameter to failure. The compression induces a tensile stress perpendicular to the compressed diameter. In this study the test have been used to study crack initiation and the tensile fracture process of HVC-formed metal powder discs with a relative density of 99%. A fictitious crack model controlled by a stress versus crack-width relationship is utilized to model green body cracking. Tensile strength is used as a failure condition and limits the stress in the fracture interface. The softening rate of the model is obtained from the corresponding rate of the dissipated energy. The deformation of the powder material is modelled with an elastic-plastic Cap model. The characteristics of the tensile fracture development of the central crack in a diametrically loaded specimen is numerically studied with a three dimensional finite element simulation. Results from the finite element simulation of the diametral compression test shows that it is possible to simulate fracturing of HVC-formed powder. Results from the simulation agree reasonably with experiments.

Jonsen, P.; Haeggblad, H.-A. [Division of Solid Mechanics, Department of Applied Physics and Mechanical Engineering, Luleaa University of Technology, 971 87 Luleaa (Sweden)

2007-05-17

209

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

210

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

211

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

212

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

213

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

214

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

215

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

216

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

217

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

218

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

219

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

220

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

221

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

222

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

223

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

224

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

225

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

226

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

227

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

228

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

229

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

230

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

231

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

232

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

233

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

234

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

235

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

236

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

237

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

238

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

239

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...

240

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

241

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

242

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

243

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

244

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

245

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

246

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

247

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

248

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

249

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

250

Diametric Quadrilaterals with Two Equal Sides  

ERIC Educational Resources Information Center

|If you take a circle with a horizontal diameter and mark off any two points on the circumference above the diameter, then these two points together with the end points of the diameter form the vertices of a cyclic quadrilateral with the diameter as one of the sides. We refer to the quadrilaterals in question as diametric. In this note we consider…

Beauregard, Raymond A.

2009-01-01

251

Effect of cooling rate on dendrite arm spacing (DAS), eutectic cell count (ECC) and ultimate tensile strength (UTS) of austempered chilled ductile iron  

Microsoft Academic Search

This paper presents the results obtained and the deductions made from a series of microstructural studies and strength tests involving austempered chilled ductile iron which was sand cast using a variety of end chills (metallic, non-metallic, water-cooled and sub-zero, respectively). The effect of cooling rate on the dendrite arm spacing, eutectic cell count and the ultimate tensile strength were evaluated.

Joel Hemanth

1999-01-01

252

Estimation of tensile strengths at 4K of 316LN forging and hot rolled plate for the ITER toroidal field coils  

NASA Astrophysics Data System (ADS)

A prediction method for both yield and tensile strengths of stainless steels from room temperature to liquid helium temperature (4K) has been developed by JAEA in order to rationalize qualification tests of cryogenic structural materials used in large superconducting magnet for a fusion device. This method is to use quadratic curves which are expressed as a function of carbon and nitrogen contents and strengths at room temperature. This study shows results of tensile tests at 4K and confirmation of accuracy of prediction method for tensile strengths at 4K for large forgings and thick hot rolled plates of austenitic stainless steels, which can be used in the actual coil case of the International Thermonuclear Experimental Reactor (ITER) toroidal field (TF) coils. These products are 316LN having high nitrogen and maximum thickness is 600mm. As the results, it was confirmed that the materials which satisfied ITER design requirement can be manufactured and the tensile strengths of these products at 4K can be predicted by using appropriate quadratic curves.

Iguchi, M.; Saito, T.; Kawano, K.; Takano, K.; Tsutsumi, F.; Chida, Y.; Nakajima, H.

2012-06-01

253

Effect of Interfacial Reaction on the Tensile Strength of Sn-3.5Ag/Ni-P and Sn-37Pb/Ni-P Solder Joints  

NASA Astrophysics Data System (ADS)

This work investigates the effect of interfacial reaction on the mechanical strength of two types of solder joints, Sn-3.5Ag/Ni-P and Sn-37Pb/Ni-P. The tensile strength and fracture behavior of the joints under different thermal aging conditions have been studied. It is observed that the tensile strength decreases with increasing aging temperature and duration. Associated with the tensile strength decrease is the transition of failure modes from within the bulk solder in the as-soldered condition toward failures at the interface between the solder and the intermetallic compounds (IMCs). For the same aging treatment, the strength of the Sn-3.5Ag/Ni-P joint degrades faster than that of Sn-37Pb/Ni-P. The difference between the two types of joints can be explained by the difference in their interfacial reaction and growth kinetics. An empirical relation is established between the solder joint strength and the Ni3Sn4 intermetallic compound thickness.

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

2007-01-01

254

Comparative evaluation of tensile bond strengths of total-etch adhesives and self-etch adhesives with single and multiple consecutive applications: An in vitro study  

PubMed Central

Aim: This study evaluates the effect of single and multiple consecutive applications of adhesives on the tensile bond strength. The currently available adhesives follow either the total-etch or the self-etch concept. However, in both techniques the uniformity and thickness of the adhesive layer plays a significant role in the development of a good bond. Materials and Methods: Sixty composite-dentin bonded specimens were prepared using a total-etch adhesive (Gluma) and another 60 using a self-etch adhesive (AdheSE). Each group was further divided into six subgroups based on the number of applications, i.e., single application and multiple (2, 3, 4, 6, and 8) applications. The tensile bond strength was tested with the Instron universal testing machine. The values were analyzed with one-way ANOVA and multiple range tests by Tukey's HSD procedure to identify those subgroups that had significantly higher bond strength. Results: The results indicate that with total-etch adhesive the bond strength increases significantly as the number of applications are increased from one to two or from two to three”, for self-etch adhesive the bond strength obtained with two applications is significantly higher than that with one application. However, for both adhesive systems, there was a decrease in the tensile bond strength values with further applications. Conclusion: We conclude that, in the clinical setting, the application of multiple coats of total etch adhesive improves bonding.

Mandava, Deepthi; P, Ajitha; Narayanan, L Lakshmi

2009-01-01

255

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

256

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

257

Tensile strength and creep behaviour of austenitic stainless steel type 18Cr - 12Ni with niobium additions at 700°C  

NASA Astrophysics Data System (ADS)

The effect of niobium additions up to 2.36 wt% on the creep behavior of a series of seven extra low carbon 18Cr-12Ni austenitic stainless steels at 700°C has been investigated. Grain size and hardness measurements, hot tensile tests and constant stress creep tests from 90 to 180 MPa were carried out for each alloy, in the solution treated condition at 1050, 1200 and 1300°C followed by quench in water. The mechanical behavior at high temperature was related to the amount of NbC precipitation occurring during the tests. Solid solution and intermetallic compound effects were also considered. Creep data analysis was done to determine the parameters of the creep power-law equation dot epsilon = A.?n and the Monkman-Grant relation dot epsilon.tmR = K. Niobium-carbide precipitation in these steels reduces the secondary stage dependence of strain rate with applied stress, resulting in n-values which indicate the possibility of operation of various creep mechanisms. The creep strength during the secondary stage is primarily controlled by the amount of NbC available for precipitation. However, the rupture times increase progressively with niobium content, as the amount of undissolved carbide particles in grain boundaries and the Laves phase precipitation increase.

Sordi, V. L.; Bueno, L. O.

2010-07-01

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 bond strength of silicone-based soft denture liner to two chemically different denture base resins after various surface treatments.  

PubMed

This study evaluated the effect of various surface treatments on the tensile bond strength of a silicone-based soft denture liner to two chemically different denture base resins, heat-cured polymethyl methacrylate (PMMA), and light-activated urethane dimethacrylate or Eclipse denture base resin. PMMA test specimens were fabricated and relined with a silicone-based soft denture liner (group AC). Eclipse test specimens were prepared according to the manufacturer's recommendation. Before they were relined with a silicone-based soft denture liner, each received one of three surface treatments: untreated (control, group EC), Eclipse bonding agent applied (group EB), and laser-irradiated (group EL). Tensile bond strength tests (crosshead speed = 5 mm/min) were performed for all specimens, and the results were analyzed using the analysis of variance followed by Tukey's test (p = 0.05). Eclipse denture base and PMMA resins presented similar bond strengths to the silicone-based soft denture liner. The highest mean force was observed in group EL specimens, and the tensile bond strengths in group EL were significantly different (p < 0.05) from those in the other groups. PMID:22447403

Akin, Hakan; Tugut, Faik; Guney, Umit; Kirmali, Omer; Akar, Turker

2012-03-25

260

The effect on the tensile bond strength of orthodontic brackets of titanium tetrafluoride (TiF 4) application after acid etching  

Microsoft Academic Search

Titanium tetrafluoride (TiF4) was applied to acid-etched enamel surfaces to study the effect on surface structure and tensile bond strength of orthodontic brackets. Three groups of 20 premolars each were compared in debonding tests. Group l received a 1% and Group ll received a 4% topical TiF4 treatment after acid etching. Group lIl served as control, that is, no fluoride

Tamer Büyükyilmaz; Bjørn Øgaard; Sverre Dahm

1995-01-01

261

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

262

????????????????????????????????????????????????? ?????????????????????????????? ????????????????????????????????????????????????????? Effects of carboxymethylcellulose on tensile strength, water vapor transmission rate and oil resistance of mung bean protein-based films  

Microsoft Academic Search

????????: ??????????????????????????????????????????????????????????????????????? ?????????? ????????????????????????????????????????????? ??????????????????????????????????????? ????? (0, 0.1, 0.3 ??? 0.5% ?????????????????????????????) ?????????????????????????? ???????????????????????????????????????????????????????? 30:70 ??????????? (?????????\\/?????? ?????????) ?????????????????????????? 85 ????????????? ???????? 25 ???? ????????????????????? ???? 225 ?????????????? ????????????????????????????? 60 ???????????? ?????????????? 10 ??????? ????????????????????????????????????? ????????????????????????????????????? 480 ??????? ??????????????????????????????????????????????????????? ????????????????????????????????? ??? ?????????????????????????????????????????? Abstract : The objective of this research was to investigate the effects of addition of carboxymethylcellulose on tensile

Nathamol Chindapan; Soonthorn Somsuai

263

The Effect of Composition and Tensile Strength on the Susceptibility of Alloy Steels to Cadmium Plating (Hydrogen) Embrittlement.  

National Technical Information Service (NTIS)

Sustained load, fracture toughness and bend tests were made to determine the susceptibility to cadmium plating (hydrogen) embrittlement of a range of 3% chromium-molybdenum-vanadium steels of different carbon contents, impurity contents, and tensile stren...

P. F. Langstone

1968-01-01

264

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

265

Compressive and tensile failure of inclined well bores and determination of in situ stress and rock strength  

Microsoft Academic Search

In this paper we investigate the occurrence of compressive and tensile failures of arbitrarily inclined well bores under a wide variety of stress conditions. The principal assumptions in this analysis are that the rock is isotropic and that it deforms elastically to the point of failure. As has been shown by previous investigators, for a given stress state and well

Pavel Peska; Mark D. Zoback

1995-01-01

266

Tensile strength and creep behaviour of austenitic stainless steel type 18Cr – 12Ni with niobium additions at 700°C  

Microsoft Academic Search

The effect of niobium additions up to 2.36 wt% on the creep behavior of a series of seven extra low carbon 18Cr-12Ni austenitic stainless steels at 700°C has been investigated. Grain size and hardness measurements, hot tensile tests and constant stress creep tests from 90 to 180 MPa were carried out for each alloy, in the solution treated condition at

V L Sordi; L O Bueno

2010-01-01

267

Tensile strength and creep behaviour of austenitic stainless steel type 18Cr - 12Ni with niobium additions at 700°C  

Microsoft Academic Search

The effect of niobium additions up to 2.36 wt% on the creep behavior of a series of seven extra low carbon 18Cr-12Ni austenitic stainless steels at 700°C has been investigated. Grain size and hardness measurements, hot tensile tests and constant stress creep tests from 90 to 180 MPa were carried out for each alloy, in the solution treated condition at

V. L. Sordi; L. O. Bueno

2010-01-01

268

Effect of low fluency dentin conditioning on tensile bond strength of composite bonded to Er:YAG laser-prepared dentin: a preliminary study.  

PubMed

Several studies in the literature have previously shown that the bond strength of a composite bonded to dentin is almost equivalent as when dentin is prepared by either bur or Er:YAG laser. The aim of this preliminary study is to assess the hypothesis that dentin conditioning at low fluency by means of Er:YAG laser can improve the value of adhesion of composites resin to dentin. Sixty surfaces of caries-free human third molars extracted for orthodontic purposes were randomly divided into five groups of 12 teeth. The bur group was the control, prepared using bur, group L was prepared using Er:YAG 200 mJ, SSP (50 µs), 20 Hz, 15 seconds of sweeping, for groups L80, L100, L120, they were prepared first, with the same parameters of the group L 200, and then they received a conditioning, which is, respectively, 15 s of irradiations at: 80 mJ (SSP, 10 Hz), 100 mJ (SSP, 10 Hz), and 120 mJ (SSP, 10 Hz). All samples were restored in a single-component adhesive system: Xenon (DENTSPLY), and ceramX (DENTSPLY) as the resin composite. The specimens were submitted to tensile bond strength test using a universal testing machine. Data were submitted to statistical analysis using ANOVA coupled to a Tukey-Kramer test at the 95% level. The mean values in MPa were 33.3 for group B, 36.73 for group L 200, 41.7 for group L80, 37.9 for group L100, and 39.1 for group L120. Our results showed that dentin conditioning at a low fluency of 12.58 J/cm(2) per pulse, with 80 mJ output energy and 50-µs pulse duration can significantly improve tensile bond strength of a composite bonded to Er:YAG laser-prepared dentine. PMID:20309596

Bahrami, B; Askari, N; Tielemans, M; Heysselaer, D; Lamard, L; Peremans, A; Nyssen-Behets, C; Nammour, S

2010-03-23

269

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

270

Effect of metal as part of fillet on the tensile shear strength of adhesively bonded single lap joints  

Microsoft Academic Search

The effect of fillet containing metallic components on the strength of adhesively bonded single lap joints has been undertaken by alternating the shape and size of metallic components as a part of fillet or whole fillet at the end of the joints. Mild carbon steel and epoxy structural adhesive were used to prepare single lap-shear joints. Three types of steel

Min You; Yong Zheng; Xiao-Ling Zheng; Wen-Jun Liu

2003-01-01

271

Prediction of tensile strength of friction stir welded aluminium matrix TiC p particulate reinforced composite  

Microsoft Academic Search

The usage of particulate reinforced metal matrix composite (MMC) is steadily increasing due to its properties such as high specific strength, high specific modulus and good wear resistance. Aluminium matrix composite (AMC) plays an important role to meet the above requirements. Effective utilization of AMC is based on not only its production but also on fabrication methods. Among AMCs, those

S. Gopalakrishnan; N. Murugan

2011-01-01

272

Aligned electrospun siloxane-doped vaterite/poly(l-lactide) composite fibremats: evaluation of their tensile strength and cell compatibility.  

PubMed

Siloxane-doped vaterite (SiV)/poly(l-lactide) hybrid-composite (SiPVH) has been developed in our group as the bone repair material and successfully fabricated into a non-woven electrospun fibremat. The aim of this work is to prepare aligned electrospun SiPVH fibremats with varied SiV content and compare their tensile properties and cell compatibilities using mouse osteoblast-like cells. It was observed that the maximum stress exhibited some non-linear trend as a function of SiV content: the highest stress value was reached with 30?wt.% SiV and decreased significantly with more than 40?wt.% SiV. Cellular morphology and proliferation were taken under examination on both aligned and random electrospun SiPVH fibremats. The cells started to orient themselves only 3?h after seeding on the aligned fibremat and they continued to elongate along the fibres. The number of the cells cultured up to seven days on both random and aligned fibremats was well comparable; therefore the alignment did not show negative effect on the cellular proliferation. PMID:23914946

Tujunen, Noora-Maria; Fujikura, Kie; Obata, Akiko; Kasuga, Toshihiro

2013-08-06

273

The effect of microstructure and processing variables on the yield to ultimate tensile strength ratio in a Nb–Ti and a Nb–Ti–Mo line pipe steel  

Microsoft Academic Search

In a hot rolled Nb–Ti and a Nb–Ti–0.09%Mo micro-alloyed steel, the ratio of yield strength to tensile strength (YS\\/UTS) was found to be a function of the microstructure and cooling rate in those tests where no coiling simulation and no prior deformation. The coarse bainite or acicular ferrite, which was formed at high cooling rates, raised the YS\\/UTS ratio under

Zhenghua Tang; Waldo Stumpf

2008-01-01

274

Tenacite et Recristallisation des Alliages 7010 et 7475: Fatigue Oligocyclique de l'Alliage 7010 (Tensile Strength and Recrystallization of the 7010 and 7475 Alloys: Low Cycle Fatigue of the 7010 Alloy).  

National Technical Information Service (NTIS)

The influence of recrystallization of Al-Zn-Mg-Cu alloys is studied. Recrystallizations from 5% to 70% were obtained in the 7475 alloy by modification of the conditions of solution. The tensile strength is not affected by the rate of recrystallization, bu...

G. Lapasset C. Renon J. L. Raviart

1983-01-01

275

Temperature-dependent tensile strength, surface roughness diagnostics, and magnetic support and positioning of polymer ICF shells. Final report, October 1, 1993--April 30, 1995  

SciTech Connect

During the course of this grant, we perfected emissivity and accommodation coefficient measurements on polymer ICF shells in the temperature range 250 to 350 K. Values for polystyrene shells are generally between 10{sup -2} and 10{sup -3}, which are very advantageous for ICF at cryogenic temperatures. Preliminary results on Br doped target shells indicate an accommodation coefficient, presumably associated with surface roughness on an atomic scale, about an order of magnitude larger than for ordinary polystyrene target shells. We also constructed apparatus with optical access for low temperature tensile strength and emissivity measurements, and made preliminary tests on this system. Magnetic shells were obtained both from GDP coating and from doping styrene with 10 manometer size ferromagnetic particles. The magnetic properties were measured through electron spin resonance (ESR). These experiments confirm the applicability of the Curie law, and establish the validity of using ESR measurements to determine shell temperature in the low temperature regime from 4K to 250K, thus complementing our presently accessible range. The high electron spin densities (> 10{sup 20}/CM{sup 3}) suggest magnetic levitation should be feasible at cryogenic temperatures. This work has resulted in two conference presentations, a Technical Report, a paper to be published in Fusion Technology, and a Master`s Thesis.

Honig, A.

1995-12-15

276

Comparative evaluation of tensile bond strength of a polyvinyl acetate-based resilient liner following various denture base surface pre-treatment methods and immersion in artificial salivary medium: An in vitro study  

PubMed Central

Background and Aim: This study was formulated to evaluate and estimate the influence of various denture base resin surface pre-treatments (chemical and mechanical and combinations) upon tensile bond strength between a poly vinyl acetate-based denture liner and a denture base resin. Materials and Methods: A universal testing machine was used for determining the bond strength of the liner to surface pre-treated acrylic resin blocks. The data was analyzed by one-way analysis of variance and the t-test (? =.05). Results: This study infers that denture base surface pre-treatment can improve the adhesive tensile bond strength between the liner and denture base specimens. The results of this study infer that chemical, mechanical, and mechano-chemical pre-treatments will have different effects on the bond strength of the acrylic soft resilient liner to the denture base. Conclusion: Among the various methods of pre-treatment of denture base resins, it was inferred that the mechano-chemical pre-treatment method with air-borne particle abrasion followed by monomer application exhibited superior bond strength than other methods with the resilient liner. Hence, this method could be effectively used to improve bond strength between liner and denture base and thus could minimize delamination of liner from the denture base during function.

Philip, Jacob M.; Ganapathy, Dhanraj M.; Ariga, Padma

2012-01-01

277

Effect of Friction Welding Condition on Joining Phenomena and Tensile Strength of Friction Welded joint between Pure Copper and Low Carbon Steel  

NASA Astrophysics Data System (ADS)

This paper describes the effect of the friction welding condition on the joining phenomena and tensile strength of friction welded joint between pure copper (OFC) and low carbon steel (LCS). When the joint was made at friction pressure of 30 MPa with friction speed of 27.5 s-1, OFC transferred to the half radius region of the weld interface on the LCS side, and then transferred toward the entire weld interface. The temperatures at the centerline, half radius and periphery portions on the weld interface of the LCS side were almost the same after the initial peak. When the joint was made at a friction time of 2.4 s, i.e. the friction torque was close to the initial peak, that had obtained approximately 40% joint efficiency and fractured from the weld interface with a little OFC adhering to the weld interface on the LCS side. The joint efficiency increased with increasing forge pressure, and it reached approximately 80% at a forge pressure of 180 MPa. This joint fractured at the softened OFC region adjacent to the weld interface. On the other hand, OFC transferred to the peripheral region of the weld interface on the LCS side when the joint was made at friction pressure of 90 MPa with friction speed of 27.5 s-1. However, OFC transfer was not obtained at the central region because the temperature at the periphery portion was higher than that of the other portions. The joint efficiency increased with increasing friction time, and it obtained approximately 74% at a friction time of 1.2 s. Moreover, all joints fractured between the OFC side and the weld interface, although the joints were made with higher forge pressure. To obtain higher joint efficiency and fracture in the OFC side, the joint should be made with low friction pressure and high forge pressure, and with the friction time at which the friction torque reaches the initial peak.

Kimura, Masaaki; Kusaka, Masahiro; Kaizu, Koichi; Fuji, Akiyoshi

278

Psychosis and autism as diametrical disorders of the social brain  

Microsoft Academic Search

Autistic-spectrum conditions and psychotic-spectrum conditions (mainly schizophrenia, bipolar disorder, and major depression) represent two major suites of disorders of human cognition, affect and behavior that involve altered development and function of the social brain. We describe evidence that a large set of phenotypic traits exhibit diametrically-opposite phenotypes in autistic-spectrum vs. psychotic-spectrum conditions, with a focus on schizophrenia. This suite of

Bernard Crespi; Christopher Badcock

2008-01-01

279

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

280

The theoretical strength of rubber: numerical simulations of polyisoprene networks at high tensile strains evidence the role of average chain tortuosity  

NASA Astrophysics Data System (ADS)

The ultimate stress and strain of polyisoprene rubber were studied by numerical simulations of three-dimensional random networks, subjected to tensile strains high enough to cause chain rupture. Previously published molecular chain force extension models and a numerical network construction procedure were used to perform the simulations for network crosslink densities between 2 × 1019 and 1 × 1020 cm-3, corresponding to experimental dicumyl-peroxide concentrations of 1-5 parts per hundred. At tensile failure (defined as the point of maximum stress), we find that the fraction of network chains ruptured is between 0.1% and 1%, depending on the crosslink density. The fraction of network chains that are taut, i.e. their end-to-end distance is greater than their unstretched contour length, ranges between 10% and 15% at failure. Our model predicts that the theoretical (defect-free) failure stress should be about twice the highest experimental value reported. For extensions approaching failure, tensile stress is dominated by the network morphology and purely enthalpic bond distortion forces and, in this regime, the model has essentially no free parameters. The average initial chain tortuosity (?) appears to be an important statistical property of rubber networks; if the stress is scaled by ? and the tensile strain is scaled by ?-1, we obtain a master curve for stress versus strain, valid for all crosslink densities. We derive an analytic expression for the average tortuosity, which is in agreement with values calculated in the simulations.

Hanson, David E.; Barber, John L.

2013-10-01

281

Micromechanism of failure in off-centre tensile loading of fusion welded joints in 1422 high-strength aluminium–lithium alloy  

Microsoft Academic Search

The results of the investigation of the micromechanisms of failure and special features of the morphology of fracture of various sections of fusion welded joints in 1422 aluminium–lithium alloy in relation to the position of the stress concentrator with respect to applied load in off-centre tensile loading are presented.

T. M. Labur; A. Ya. Ishchenko; T. G. Taranova; G. M. Grigorenko; V. A. Kostin; A. A. Chaika

2011-01-01

282

Micromechanism of failure in off-centre tensile loading of fusion welded joints in 1422 high-strength aluminium–lithium alloy  

Microsoft Academic Search

The results of the investigation of the micromechanisms of failure and special features of the morphology of fracture of various sections of fusion welded joints in 1422 aluminium–lithium alloy in relation to the position of the stress concentrator with respect to applied load in off-centre tensile loading are presented.

T. M. Labur; A. Ya. Ishchenko; T. G. Taranova; G. M. Grigorenko; V. A. Kostin; A. A. Chaika

2012-01-01

283

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

284

Effects of process time and thread on tensile shear strength of Al alloy lap joint produced by friction stir spot welding  

Microsoft Academic Search

In automotive applications, friction stir spot welding (FSSW) has been practically used in the construction of aluminium car bodies. In this study, the weld strength and factors governing the weld strength in the friction stir spot welded aluminium alloy 6061-T6 were examined. The weld strength increased with the process time during FSSW up to 3 s, beyond which it decreased. The

Mitsuo Fujimoto; Daisuke Watanabe; Natsumi Abe; Sato S. Yutaka; Hiroyuki Kokawa

2010-01-01

285

In-Situ Observations on the Fracture Mechanism of Diffusion-Alloyed Ni-Containing Powder Metal Steels and a Proposed Method for Tensile Strength Improvement  

Microsoft Academic Search

The mechanical properties of Ni-containing powder metal (PM) steels are usually inferior to those of their wrought counterparts.\\u000a The main problem is attributed to the non-uniform Ni distribution, in addition to the problems caused by porosity. The effects\\u000a of this non-uniform alloying on the mechanical properties were investigated in this study using mini tensile bars that were\\u000a made of diffusion-alloyed

M. W. Wu; K. S. Hwang; H. S. Huang

2007-01-01

286

A Study of the Effect of Tool Pin Profiles on Tensile Strength of Welded Joints Produced Using Friction Stir Welding Process  

Microsoft Academic Search

Friction Stir Welding (FSW) has evolved into a process focused on joining of arc-weldable (5xxx and 6xxx) and which are difficult to weld (2xxx and 7xxx) aluminium alloys. The method described in this paper for the prediction of tensile properties and optimization can eliminate the need for performing experiments on the basis of conventional trial and error method. The present

C. N. Suresha; B. M. Rajaprakash; Sarala Upadhya

2011-01-01

287

Notch Effect on Tensile Deformation Behavior of 304L and 316L Steels in Liquid Helium and Hydrogen  

Microsoft Academic Search

Tensile tests of type 304L and 316L steels were carried out using round bar specimens with a notch in liquid helium, hydrogen, liquid nitrogen and at ambient temperature. The obtained tensile strengths were compared with the tensile strengths of smooth specimens. For smooth specimens, tensile strength increased with a decrease in temperature and the strengths in liquid helium and hydrogen

K. Shibata; H. Fujii

2004-01-01

288

STRENGTH OF A C-SPHERE FLEXURE SPECIMEN  

SciTech Connect

A 'C-Sphere' flexure strength specimen geometry was conceived and developed to measure a relevant strength of bearing-grade Si{sub 3}N{sub 4} balls and to relate that to surface-located strength-limiting flaws and to ultimately link those flaw populations to rolling contact fatigue performance. A slot was machined into the balls to a set depth to produce the C-sphere geometry. C-sphere specimens were then diametrally compressed to produce a monotonically increasing flexure or hoop tensile stress at their surface that caused their fracture. The strength was determined using the combination of failure load, C-sphere geometry, and FEA, and the stress field was used to determine C-sphere effective areas and effective volumes as a function of Weibull modulus. A description of the specimen and the aforementioned analysis are provided and a comparison of C-sphere flexure strength distributions of two bearing grade Si{sub 3}N{sub 4} materials (NBD200 and SN101C) is given.

Wereszczak, Andrew A [ORNL; Wang, Wei [ORNL; Jadaan, Osama M. [University of Wisconsin, Platteville; Lance, Michael J [ORNL; Lin, Hua-Tay [ORNL

2007-01-01

289

The effect of bone ingrowth depth on the tensile and shear strength of the implant-bone e-beam produced interface.  

PubMed

New technologies, such as selective electron beam melting, allow to create complex interface structures to enhance bone ingrowth in cementless implants. The efficacy of such structures can be tested in animal experiments. Although animal studies provide insight into the biological response of new structures, it remains unclear how ingrowth depth is related to interface strength. Theoretically, there could be a threshold of ingrowth, above which the interface strength does not further increase. To test the relationship between depth and strength we performed a finite element study on micro models with simulated uncoated and hydroxyapatite (HA) coated surfaces. We examined whether complete ingrowth is necessary to obtain a maximal interface strength. An increase in bone ingrowth depth did not always enhance the bone-implant interface strength. For the uncoated specimens a plateau was reached at 1,500 ?m of ingrowth depth. For the specimens with a simulated HA coating, a bone ingrowth depth of 500 ?m already yielded a substantial interface strength, and deeper ingrowth did not enhance the interface strength considerably. These findings may assist in optimizing interface morphology (its depth) and in judging the effect of bone ingrowth depth on interface strength. PMID:21858722

Tarala, M; Waanders, D; Biemond, J E; Hannink, G; Janssen, D; Buma, P; Verdonschot, N

2011-08-21

290

Importance of mini-dumbbell specimen to access tensile strength of restored dentine: historical background and the future perspective in dentistry  

Microsoft Academic Search

Objectives. The development of adhesive resins to dentine enables resin restorations to be more durable. Several bond strength measurement techniques for measuring adhesion have been proposed. A standardised method is needed which produced higher and more consistent bond strength values which allow bond stability and the bonding mechanism to be studied. Our aim was to investigate mainly the adhesives and

Nobuo Nakabayashi

2004-01-01

291

Revisiting the Recommended Geometry for the Diametrally Compressed Ceramic C-Ring Specimen  

SciTech Connect

A study conducted several years ago found that a stated allowable width/thickness (b/t) ratio in ASTM C1323 (Standard Test Method for Ultimate Strength of Advanced Ceramics with Diametrally Compressed C-Ring Specimens at Ambient Temperature) could ultimately cause the prediction of a non-conservative probability of survival when the measured C-ring strength was scaled to a different size. Because of that problem, this study sought to reevaluate the stress state and geometry of the C-ring specimen and suggest changes to ASTM C1323 that would resolve that issue. Elasticity, mechanics of materials, and finite element solutions were revisited with the C ring geometry. To avoid the introduction of more than 2% error, it was determined that the C ring width/thickness (b/t) ratio should range between 1-3 and that its inner radius/outer radius (ri/ro) ratio should range between 0.50-0.95. ASTM C1323 presently allows for b/t to be as large as 4 so that ratio should be reduced to 3.

Jadaan, Osama M. [University of Wisconsin, Platteville; Wereszczak, Andrew A [ORNL

2009-04-01

292

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

293

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

294

Development of alternative as-rolled alloys to replace quenched and tempered steels with tensile strength in the range of 600–800 MPa  

Microsoft Academic Search

The fierce competition between steelworks and different alloy design approaches are the motivation behind the development of new microalloyed structural steels which must satisfy increasingly severe mechanical strength and toughness requirements. Other equally desirable aspects for these new materials are the suppression of heat treatments after hot rolling and better weldability, which makes this alloy evolution even more complex. As

Antonio Augusto Gorni; Paulo Roberto Mei

2005-01-01

295

Development of Controlled-Rolled 70 kgf/mm(2) and 80 kgf/mm(2) Class High Tensile Strength Steel Plate for Weld Structure.  

National Technical Information Service (NTIS)

To meet demands for higher strength steel plates for construcion machines with excellent cold formability and weldability, as-rolled HT70 steel plates (TS: 686 MPa) having a maximum thickness of 25.4 mm and as-rolled HT80 (TS: 784 MPa) steel plates of 12....

K. Amano O. Tanigawa C. Shiga T. Okumura

1989-01-01

296

Tensile experiments and SEM fractography on bovine subchondral bone  

Microsoft Academic Search

Subchondral bone undecalcified samples, extracted from bovine femoral heads, are subjected to a direct tensile load. The Young's modulus of each sample is determined from repeated tests within the elastic limit. In a last test, the tensile load is increased up to the specimen failure, determining the ultimate tensile strength. The investigation is performed on both dry and wet specimens.

P. Braidotti; E. Bemporad; T. D’Alessio; S. A. Sciuto; L. Stagni

2000-01-01

297

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

298

Tensile Failure of Tungsten-Nickel-Cobalt  

NASA Astrophysics Data System (ADS)

Spall experiments were conducted on a 91W-Ni-Co alloy. The spall strength was 2.6 GPa. At 410 m/s, which is well above the spall strength, the damage consists of isolated voids. The failure starts mainly as grain cleavage. This result is very consistent with earlier measurements in which very rapid tensile failure was induced by transverse impact.

Bless, Stephan; Chau, Ricky

2005-07-01

299

Microsample tensile testing of nanocrystalline metals  

Microsoft Academic Search

A novel non-contact strain measurement technique has been employed to measure the tensile properties of extremely small ‘microsamples’ of pure high-density ultrafine-grained Al (ufg-Al) nanocrystalline Cu (n-Cu) and nanocrystalline Ni (n-Ni). These microsample tests confirmed the absence of Young's modulus variations for metals with grain sizes approaching 25 nm. Significant strength enhancements were associated with the nanocrystalline specimens; the tensile

M. Legros; B. R. Elliott; M. N. Rittner; J. R. Weertman; K. J. Hemker

2000-01-01

300

Experimental Analysis of Work-piece's Diametrical Error in Ultrasonic-Vibration-Assisted Turning  

NASA Astrophysics Data System (ADS)

Vibration at an ultrasonic frequency is superimposed on the ordinary cutting motion in ultrasonic-vibration-assisted turning (UAT). This combinatory cutting motion results in reduction of the cutting force and surface roughness, and improvement of the dimensional tolerances compared with conventional turning (CT). The advantages obtainable from UAT has made this process suitable for machining hard-to-cut and brittle materials such as super-alloys and ceramics, as well as ordinary materials. The elastic deflection of work-pieces is primarily responsible for the diametrical errors of the machined parts. This is of course more obvious for slender work-pieces. The influence of UAT process on the diametrical error has not yet been investigated. This has been partly undertaken by the authors of the present paper. It has been experimentally illustrated in this paper that ultrasonic vibration superimposed on the tool tip can result in reduction of the diametrical error and thus reduced scrap rate is ensued.

Soleimanimehr, H.; Nategh, M. J.; Gholamzadeh, B.

2011-01-01

301

Experimental Analysis of Work-piece's Diametrical Error in Ultrasonic-Vibration-Assisted Turning  

SciTech Connect

Vibration at an ultrasonic frequency is superimposed on the ordinary cutting motion in ultrasonic-vibration-assisted turning (UAT). This combinatory cutting motion results in reduction of the cutting force and surface roughness, and improvement of the dimensional tolerances compared with conventional turning (CT). The advantages obtainable from UAT has made this process suitable for machining hard-to-cut and brittle materials such as super-alloys and ceramics, as well as ordinary materials. The elastic deflection of work-pieces is primarily responsible for the diametrical errors of the machined parts. This is of course more obvious for slender work-pieces. The influence of UAT process on the diametrical error has not yet been investigated. This has been partly undertaken by the authors of the present paper. It has been experimentally illustrated in this paper that ultrasonic vibration superimposed on the tool tip can result in reduction of the diametrical error and thus reduced scrap rate is ensued.

Soleimanimehr, H.; Nategh, M. J.; Gholamzadeh, B. [Tarbiat Modares University, Tehran (Iran, Islamic Republic of)

2011-01-17

302

Strength analysis of yttria-stabilized tetragonal zirconia polycrystals  

Microsoft Academic Search

This paper reports the tensile strength of YâOâ-stabilized ZrOâ polycrystals (Y-TZP) measured by a newly developed tensile testing method with a rectangular bar. The tensile strength of Y-TZP was lower than that of the three-point bend strength, and the shape of the tensile strength distribution was quite different from that of the three-point bend strength distribution. It was difficult to

Kenichi Noguchi; Yukihisa Matsuda; Manabu Oishi; Takaki Masaki; Sadao Nakayama; Masahiro Mizushina

1990-01-01

303

Are the Autism and Positive Schizotypy Spectra Diametrically Opposed in Empathizing and Systemizing?  

ERIC Educational Resources Information Center

|Crespi and Badcock's (Behaviour Brain Sci 31: 241-261, 2008) novel theory, which presents autism and positive schizophrenia as diametrical opposites on a cognitive continuum, has received mixed support in the literature to date. The current study aimed to further assess the validity of this theory by investigating predictions in relation to…

Russell-Smith, Suzanna N.; Bayliss, Donna M.; Maybery, Murray T.; Tomkinson, Rosy L.

2013-01-01

304

Unbalanced magnetic forces in permanent magnet brushless machines with diametrically asymmetric phase windings  

Microsoft Academic Search

A general analytical model, formulated in 2-D polar coordinates, is developed to predict the unbalanced magnetic force which results in permanent magnet brushless AC and DC machines having a diametrically asymmetric disposition of slots and phase windings. It is shown that the unbalanced magnetic force can be significant in machines having a fractional ratio of slot number to pole number,

D. Ishak; Z. Q. Zhu; D. Howe

2005-01-01

305

Unbalanced Magnetic Forces in Permanent-Magnet Brushless Machines With Diametrically Asymmetric Phase Windings  

Microsoft Academic Search

A general analytical model, formulated in 2-D polar coordinates, is developed to predict the unbalanced magnetic force, which results in permanent-magnet brushless ac and dc machines having a diametrically asymmetric disposition of slots and phase windings. It is shown that the unbalanced magnetic force can be significant in machines having a fractional ratio of slot number to pole number, particularly

Z. Q. Zhu; Dahaman Ishak; David Howe; Chen Jintao

2007-01-01

306

Effects of coating and diametric load on fiber Bragg gratings as cryogenic temperature sensors  

Microsoft Academic Search

Cryogenic temperature sensing was demonstrated using pressurized fiber Bragg gratings (PFBGs) with polymer coating of various thicknesses. The PFBG was obtained by applying a small diametric load to a regular fiber Bragg grating (FBG). The Bragg wavelengths of FBGs and PFBG were measured at temperatures from 295 K to 4.2 K. The temperature sensitivities of the FBGs were increased by

Meng-Chou Wu; Ruth H. Pater; Stanton L. DeHaven

2008-01-01

307

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

308

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

309

Tensile behavior of functionally graded steels produced by electroslag remelting  

Microsoft Academic Search

Tensile behavior of functionally graded steels produced by electroslag refining has been studied. Functionally graded steels\\u000a containing layers of ferrite, austenite, bainite, and martensite may be fabricatedvia diffusion of alloying elements during electroslag remelting. Tensile strength of the composites depends on the composition\\u000a and number of layers and those have been modeled based on the tensile behavior of individual phases.

J. Aghazadeh Mohandesi; R. Parastar Namin; M. H. Shahosseinie

2006-01-01

310

Experimental study on tensile mechanical behaviors of 5A06 aluminum alloy under short time elevated temperature  

NASA Astrophysics Data System (ADS)

In this work, the tensile mechanical properties of 5A06 aluminum alloy are tested in the temperature range 20°C ~ 500°C on an MTS 810 material testing machine. The curves of the tensile stress vs. strain, the Young's modulus vs. temperature, the yield strength vs. temperature, and the tensile strength vs. temperature are obtained. Results shows that the elastic modulus, yield stress and tensile strength decrease with increasing temperature .Based on the experiment results, the functions of the elastic modulus, yield strength and tensile strength versus temperature are represented by polynomial. The simplified constitutive model JC finally is established under the high temperature considering the thermal softening.

Li, Weifen; Niu, Wei; Hao, Zhiming; Li, Minghai; Hu, Shaoqun; Chen, Yongmei

2009-12-01

311

Tensile testing of a single ultrafine polymeric fiber  

Microsoft Academic Search

Due to the difficulty in handling micro and nanoscale fibers and measuring the small load required for deformation, mechanical properties of these fibers have not been widely characterized. In this study, tensile test of a single-strand polycaprolactone electrospun ultrafine fiber was performed using a nano tensile tester. The tested fiber exhibited the characteristic low strength and low modulus but high

E. P. S. Tan; S. Y. Ng; C. T. Lim

2005-01-01

312

Shear and tensile bond testing for resin cement evaluation  

Microsoft Academic Search

Objectives. The aim of this study was to compare the tensile and shear bond strengths of one experimental and four commercially available resin cements following the ISO document TR 110405 for bond measurement.Methods. Tensile and shear bond tests were performed using bovine enamel and dentin as the tooth substrate with each of the resin cements. Resin composite rods were cemented

Yuichi Kitasako; Michael F. Burrow; Toru Nikaido; Naoko Harada; Shigehisa Inokoshi; Toshimoto Yamada; Toshio Takatsu

1995-01-01

313

Tensile testing of polysilicon  

Microsoft Academic Search

Tensile specimens of polysilicon are deposited on a silicon wafer; one end remains affixed to the wafer and the other end has a relatively large paddle that can be gripped by an electrostatic probe. The overall length of the specimen is less than 2 mm, but the smooth tensile portion can be as small as 1.5×2m in cross section and

W. N. Sharpe; K. T. Turner; R. L. Edwards

1999-01-01

314

Indirect and direct tensile behavior of Devonian oil shales  

SciTech Connect

Ultimate indirect tensile strengths of Devonian oil shales across the bedding planes is a mechanical property parameter important to predicting how oil shale will break. This is particularly important to in-situ fragmentation. The Split Cylinder Test was used to determine the indirect tensile strengths between the bedding planes. Test specimens, cored perpendicular to the bedding planes, representing oil shales of different oil yields taken from Silver Point Quad in DeKalb County, Tennessee and Friendship in Scioto County, Ohio, were subjected to the Split Cylinder Test. Linear regression equations relating ultimate tensile strength across the bedding planes to volume percent of organic matter in the rock were developed from the test data. In addition, direct tensile strengths were obtained between the bedding planes for the Tennessee oil shales. This property is important for the design of horizontal fractures in oil shales. Typical results were presented.

Chong, K.P.; Chen, J.L.; Dana, G.F.; Weber, J.A.

1984-03-01

315

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

316

Weldability evaluation of high tensile plates using GMAW process  

Microsoft Academic Search

High tensile plates, SAILMA-450 high impact (HI) (yield strength, 45 kg\\/mm2 minimum; ultimate tensile strength, 57 kg\\/mm2 minimum; elongation, 19% minimum; Charpy impact energy 2.0 kg.m at ?20 C minimum) were successfully developed at the Steel\\u000a Authority of India Ltd., up to 32 mm plate thickness. Since then the steel has been extensively used for the fabrication of\\u000a impellers, bridges,

R. Datta; D. Mukerjee; K. L. Rohira; R. Veeraraghavan

1999-01-01

317

Instrumented tensile-impact tests of bone  

Microsoft Academic Search

An instrumented pendulum-type impact tester was used to obtain tensile-impact properties for compact bone. Load-time histories\\u000a throughout impact were recorded. Impact tests on 50 longitudinally oriented fresh-beef-bone samples yielded a proportional\\u000a limit of 9.64.1 ksi (66.228.2 MPa), an ultimate stress of 17.65.3 ksi (121.336.5 MPa) and an energy-absorption capacity\\u000a of 14285 in. Ib\\/in.2 (2490014900 J\\/m2). A static tensile strength of

S. Saha; W. C. Hayes

1974-01-01

318

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

319

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

320

Assessing the Strength Enhancement of Heterogeneous Networks of Miscible Polymer Blends  

NASA Astrophysics Data System (ADS)

At the typical crosslink densities of elastomers, the failure properties vary inversely with mechanical stiffness, so that compounding entails a compromise between stiffness and strength. Our approach to circumvent this conventional limitation is by forming networks of two polymers that: (i) are thermodynamically miscible, whereby the chemical composition is uniform on the segmental level; and (ii) have markedly different reactivities for network formation. The resulting elastomer consists of one highly crosslinked component and one that is lightly or uncrosslinked. This disparity in crosslinking causes their respective contributions to the network mechanical response to differ diametrically. Earlier results showed some success with this approach for thermally crosslinked blends of 1,2-polybutadiene (PVE) and polyisoprene (PI), as well as ethylene-propylene copolymer (EPM) and ethylene-propylene-diene random terpolymer (EPDM), taking advantage of their differing reactivities to sulfur. In this work we demonstrate the miscibility of polyisobutylene (PIB) with butyl rubber (BR) (a copolymer of PIB and polyisoprene) and show that networks in which only the BR is crosslinked possess greater tensile strengths than neat BR over the same range of moduli.

Giller, Carl; Roland, Mike

2013-03-01

321

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

322

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

323

Notch Effect on Tensile Deformation Behavior of 304L and 316L Steels in Liquid Helium and Hydrogen  

SciTech Connect

Tensile tests of type 304L and 316L steels were carried out using round bar specimens with a notch in liquid helium, hydrogen, liquid nitrogen and at ambient temperature. The obtained tensile strengths were compared with the tensile strengths of smooth specimens. For smooth specimens, tensile strength increased with a decrease in temperature and the strengths in liquid helium and hydrogen show similar values in both steels. For notched specimen of 304L steel, tensile strength (including fracture strength) increased noticeably from ambient to liquid nitrogen temperature but showed a large decrease in liquid helium and hydrogen. In liquid hydrogen and helium, the tensile strength is a little lower in liquid hydrogen than in liquid helium and both strengths are lower than tensile strengths of smooth specimens. For notched specimen of 316L steel, an increase in tensile strength from ambient to liquid nitrogen temperature was not so large and a decrease from liquid nitrogen to liquid hydrogen was small. The tensile strengths in liquid helium and hydrogen were nearly same and higher than those of smooth specimens. Different behavior of serration was observed between liquid helium and hydrogen, and between 304L and 316L steels. The reasons for these differences were discussed using computer simulation.

Shibata, K. [Department of Materials Engineering, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Fujii, H. [Steel R and D Laboratory, Nippon Steel Corporation, Shintomi, Futtsu-shi, Chiba-ken, 293-8511 (Japan)

2004-06-28

324

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

325

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

326

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

327

Tensile tests of ropes of very long aligned multiwall carbon nanotubes  

Microsoft Academic Search

We have directly measured the Young's modulus and tensile strength of multiwall carbon nanotubes by pulling very long (~2 mm) aligned nanotube ropes with a specially designed stress-strain puller. This puller can apply an axial force to the rope and simultaneously measure the corresponding rope elongation and the change in rope resistance. The average Young's modulus and tensile strength obtained

Z. W. Pan; S. S. Xie; L. Lu; B. H. Chang; L. F. Sun; W. Y. Zhou; G. Wang; D. L. Zhang

1999-01-01

328

Tensile testing of microsamples  

Microsoft Academic Search

Structural analysis has advanced rapidly to the point where lack of knowledge about the local inhomogeneity and anisotropic nature of the materials prevents the accurate prediction of the behavior; models can incorporate local material properties provided they can be experimentally determined. Conventional tensile techniques are unable to test speciments from submillimeter-sized regions, and micro-hardness measurements do not reveal directional variations.

D. A. LaVan; W. N. Sharpe

1999-01-01

329

Controlling factors in tensile deformation of nanocrystalline cobalt and nickel  

NASA Astrophysics Data System (ADS)

In an effort to understand and enhance the tensile ductility of truly nanocrystalline metals, we have investigated and compared the mechanical behavior, especially the tensile behavior, of hexagonal close-packed (hcp) nanocrystalline cobalt (˜20 nm) and face-centered cubic (fcc) nanocrystalline nickel (˜28 nm). Although both materials exhibit obvious plasticity in tension, their uniform tensile ductility, tensile elongation-to-failure, and fracture behavior are drastically different. In-situ synchrotron x-ray diffraction and ultra-small angle x-ray scattering reveal distinct deformation disparity in terms of residual strain development, texture evolution, nanovoid formation, and subsequent strain-hardening and strain-rate-hardening behavior. The dependence of tensile property on the strain rate and temperature is examined and discussed. Factors that influence the strength and ductility of nanocrystalline metals are considered and prioritized according to the current findings. A new Hall-petch relationship is proposed for nanocrystalline nickel.

Wang, Y. M.; Ott, R. T.; van Buuren, T.; Willey, T. M.; Biener, M. M.; Hamza, A. V.

2012-01-01

330

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

331

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

332

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

333

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

334

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

335

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

336

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

337

Stress intensity factors of two diametrically opposed edge cracks in a thick-walled functionally graded material cylinder  

Microsoft Academic Search

A method is developed to evaluate stress intensity factors for two diametrically-opposed edge cracks emanating from the inner surface of a thick-walled functionally graded material (FGM) cylinder. The crack and the cylinder inner surfaces are subjected to an internal pressure. The thermal eigenstrain induced in the cylinder material due to nonuniform coefficient of thermal expansion after cooling from the sintering

A. M. Afsar; M. Anisuzzaman

2007-01-01

338

The enhancement of transformation induced plasticity effect on austenitic stainless steels by cyclic tensile loading and unloading  

Microsoft Academic Search

The effect of loading modes of tensile deformation on the mechanical properties of a metastable austenite stainless steel has been investigated. The stress–strain curves, microstructures and fraction of the martensite are measured and analyzed separately. The results of tensile test indicate that a special loading mode referred as cyclic tensile loading and unloading can improve the strength and the formability

Yong Xu; Shihong Zhang; Hongwu Song; Ming Cheng; Haiqu Zhang

2011-01-01

339

The Principles of Strength and Fatigue in Optical Fibers  

Microsoft Academic Search

Tensile strength is defined as the applied stress (tensile load per unit cross-sectional area) recorded at the instant of rupture for a test specimen. Historically, attempts to catalogue and report the intrinsic strength of glass were frustrated by considerable dispersion in the acquired measurement data. In addition to large variability, typical strength values were found to be one, two or

J. Carr; S. Saikkonen

1986-01-01

340

Tailoring the Wet Strength of Linerboard Via Dielectric Barrier Discharge  

Microsoft Academic Search

Atmospheric dielectric?barrier discharge treatments were shown to be a facile and direct means of enhancing the wet?strength tensile properties of softwood kraft linerboard furnish. The improvements in wet?tensile strength were shown to vary between 10–190% depending on the charge of cold plasma applied. These benefits were accompanied with a minor increase in dry tensile strength and slight decrease dry tear

E. E. Johansson; T. J. Elder; A. J. Ragauskas

2006-01-01

341

PBX 9502 TENSILE ANALYSIS  

SciTech Connect

With the recent creation of the PX HE Core Surveillance Database, individual specimen surveillance values can be easily compared to the corresponding individual qualification values to evaluate for trends. A review of the data shows a broad scatter in measured stress-strain values. Using the available HE surveillance database, it is clear that the surveillance measurements from the two Cycle 15 charges fall within the range of qualification stress and strain values recorded previously for PBX 9502 lots and that no apparent stockpile-age related trends are evident in the tensile stress-strain data. As a result of this investigation, some changes are being made to the core surveillance specifications to minimize the effects on tensile data scatter due to temperature and humidity differences and method to method changes. These data analyses do point out the need for a comprehensive understanding of the effect of a number of variables, i.e. formulation and pressing method, density, stockpile age, lot-to-lot variations, temperature, and humidity on the mechanical property behavior of HE composite materials. Too often data have been compared without the relevant details made available to determine if the test conditions were nominally the same or different. These results also point out the critical need to establish useful stress-strain limits for qualification and surveillance testing of HEs.

Idar, D.J.; Larson, S.A. [and others

2000-10-01

342

Tensile strengthening in the nickel-base superalloy IN738LC  

NASA Astrophysics Data System (ADS)

The tensile properties of superalloy IN738LC with different precipitate microstructures are evaluated at room temperature, 650 °C, 750 °C, and 85 °C at two different strain rates. The properties can be presented in two groups based on the comparable closeness of the values obtained—those of microstructures C and M, with coarse and medium size precipitates, and those of microstructures F and D, with fine and duplex size (medium + fine) precipitates. Preferred orientations, lattice parameters, and metallography are used to characterize the microstructure and tensile testing to determine the yield strength, tensile strength, and strain hardening coefficients. An anomalous increase in yield strength is observed, which occurs at temperatures about 100 °C higher with higher strain rate than with lower strain rate applied. The experimental results show that the yield strength is influenced by preferred orientations and precipitate size, while the tensile strength is effected by the size and morphology of precipitates.

Balikci, E.; Raman, A.; Mirshams, R. A.

2000-06-01

343

Tensile behavior of a sintered steel at elevated temperatures  

SciTech Connect

The tensile behavior of a sintered steel is perfectly described by the empirical Ramberg-Osgood equation, and also can be modeled by the Bodner-Partom formulation. Tensile properties of the sintered steel strongly depend on temperature. At 300 C the Young`s modulus is 24% lower and the yield strength is 44% lower than those at ambient temperature respectively. The strain hardening behavior of the sintered steel differs from that of dense metals. The sintered steel has higher strain hardening at elevated temperatures than at room temperature; while the wrought metal behaves normally, strain hardening reduces with increasing temperature. The tensile fracture mode of the sintered steel remains the same as dimple coalescence from 23 to 300 C. The low tensile ductility of the sintered steel is attributed to micro-scale necking in the ligament between pores.

Shan, Z.H.; Leng, Y.; Mai, Y.W. [Hong Kong Univ. of Science and Technology, Kowloon (Hong Kong). Dept. of Mechanical Engineering

1995-07-01

344

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

345

Ceramic granule strength variability and compaction behavior  

SciTech Connect

Diametral compression strength distributions and the compaction behavior and of irregular shape 150--200 {mu}m ceramic granules and uniform-size 210 {mu}m glass spheres were measured to determine how granule strength variability relates to compaction behavior of granular assemblies. High variability in strength, represented by low Weibull modulus values (m<3) was observed for ceramic granules having a distribution of sizes and shapes, and for uniform-size glass spheres. Compaction pressure data were also analyzed using a Weibull distribution function, and the results were very similar to those obtained from the diametral compression strength tests for the same material. This similarity suggests that it may be possible to model granule compaction using a weakest link theory, whereby an assemblage of granules is viewed as the links of a chain, and failure of the weakest granule (i.e., the weakest link) leads to rearrangement and compaction. Additionally, with the use of Weibull statistics, it appears to be possible to infer the variability in strength of individual granules from a simple pressure compaction test, circumventing the tedious task of testing individual granules.

Glass, S.J.; Ewsuk, K.G.; Readey, M.J.

1995-08-01

346

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

347

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

348

Bonding characteristics in NiAl intermetallics with O impurity: a first-principles computational tensile test  

Microsoft Academic Search

We have performed a first-principles computational tensile test on NiAl intermetallics with O impurity along the [001] crystalline direction on the (110) plane to investigate the tensile strength and the bonding characteristics of the NiAl-O system. We show that the ideal tensile strength is largely reduced due to the presence of O impurity in comparison with pure NiAl. The investigations

Xue-Lan Hu; Ying Zhang; Guang-Hong Lu; Tianmin Wang

2009-01-01

349

Calculating limits for torsion and tensile loads on drill pipe  

SciTech Connect

Drill pipe used for drilling horizontal and extended reach holes experiences much higher torsional and tensile loads than normally seen while drilling vertical holes. This is particularly true for rigs with top drives vs. rigs with rotary tables. When pipe is rotated while pulling out of the hole, which is commonly done on top drive rigs, the drill pipe can experience high tensile and torsional loading simultaneously. These conditions increase the probability of overload on tool joints and require that the drill pipe and tool joint selection process include consideration of combined loading. Calculating the required drill pipe strength for vertical holes is straightforward and spelled out in Section 5 of API RP7G. In vertical hole applications, pipe is almost always selected for its tensile capacity and the torsional strength of the pipe generally does not require special consideration. In Section 4 of API Sec 7, API recommends that the tool joints have a torsional strength of 80% of the pipe`s torsional strength; this is usually adequate. The torsional strength and tensile strength of commonly used drill pipe and tool joint combinations are tabulated in Tables 2 through 10 of API RP7G. Appendix A.8.3 in API RP7G shows a method for plotting a graphical representation of the combined torsional and tensile operational limits of tool joints. How to calculate the limits of the drill pipe tube is shown in Appendix A.9.2. This paper defines terms and limits, and discusses building and using a diagram to determine safe loads.

Bailey, E.I. [Stress Engineering Service Inc., Houston, TX (United States); Smith, J.E. [Grant Prideco, Houston, TX (United States)

1998-02-01

350

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

351

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

352

Application of reliability and fiber probabilistic strength distribution concepts to composite vessel burst strength design  

Microsoft Academic Search

A composite pressure vessel design approach that is based on reliability and probabilistic fiber strength distribution concepts is discussed. The method is based on the fiber strain-strength interference reliability theory. The way in which fiber strength distribution parameters generated by two tensile tests of impregnated carbon fiber strands can be used in pressure vessel strength design is examined. It is

David Cohen

1992-01-01

353

Application of slip-band visualization technique to tensile analysis of laser-welded aluminum alloy  

Microsoft Academic Search

Recently we have developed a new optical interferometric technique capable of visualizing slip band occurring in a deforming solid-state object. In this work we applied this technique to a tensile analysis of laser-welded aluminum plate samples, and successfully revealed stress concentration that shows strong relationships with the tensile strength and the fracture mechanism. We believe that this method is a

Muchiar; Sanichiro J. Yoshida; Rini Widiastuti; A. Kusnowo; Kunimitsu Takahashi; Shunichi Sato

1997-01-01

354

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

355

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

356

The Effect of Variability in the Powder/Liquid Ratio on the Strength of Zinc Phosphate Cement  

PubMed Central

Aim. To investigate (a) variability in powder/liquid proportioning and (b) effect of variability on diametral tensile strength (DTS), in a zinc phosphate cement. Statistical analyses (? = 0.05) were by Student's t-test in the case of powder/liquid ratio and one-way ANOVA and Tukey HSD for pair-wise comparisons of mean DTS. The Null hypotheses were that (a) the powder-liquid mixing ratios would not differ from the manufacturer's recommended ratio (b) DTS of the set cement samples using the extreme powder/liquid ratios would not differ from those made using the recommended ratio. Methodology. 34 dental students dispensed the components according to the manufacturer's instructions. The maximum and minimum powder/liquid ratios, together with the manufacturer's recommended ratio, were used to prepare samples for DTS testing. Results. Powder/liquid ratios ranged from 2.386 to 1.018. The mean ratio (1.644) was not significantly different from the recommended value of 1.718 (P = 0.189). DTS values for the maximum and minimum ratios were both significantly different from each other (P < 0.001) and from the mean value obtained from the recommended ratio (P < 0.001). Conclusions. Variability exists in powder/liquid ratio for hand dispensed zinc phosphate cement. This variability can affect the DTS of the set material.

McKenna, Jill E.; Ray, Noel J.; McKenna, Gerald; Burke, Francis M.

2011-01-01

357

The effect of variability in the powder/liquid ratio on the strength of zinc phosphate cement.  

PubMed

Aim. To investigate (a) variability in powder/liquid proportioning and (b) effect of variability on diametral tensile strength (DTS), in a zinc phosphate cement. Statistical analyses (? = 0.05) were by Student's t-test in the case of powder/liquid ratio and one-way ANOVA and Tukey HSD for pair-wise comparisons of mean DTS. The Null hypotheses were that (a) the powder-liquid mixing ratios would not differ from the manufacturer's recommended ratio (b) DTS of the set cement samples using the extreme powder/liquid ratios would not differ from those made using the recommended ratio. Methodology. 34 dental students dispensed the components according to the manufacturer's instructions. The maximum and minimum powder/liquid ratios, together with the manufacturer's recommended ratio, were used to prepare samples for DTS testing. Results. Powder/liquid ratios ranged from 2.386 to 1.018. The mean ratio (1.644) was not significantly different from the recommended value of 1.718 (P = 0.189). DTS values for the maximum and minimum ratios were both significantly different from each other (P < 0.001) and from the mean value obtained from the recommended ratio (P < 0.001). Conclusions. Variability exists in powder/liquid ratio for hand dispensed zinc phosphate cement. This variability can affect the DTS of the set material. PMID:22190935

McKenna, Jill E; Ray, Noel J; McKenna, Gerald; Burke, Francis M

2011-12-08

358

The effect of potential investment expansion and hot strength on the fit of full crown castings made with phosphate-bonded investment.  

PubMed

In an earlier investigation, it was shown that when full crowns are cast in gypsum-bonded investments, their relative inaccuracy is affected by both the investment's potential expansion and its hot strength. This study repeated the earlier one, but used a high-melting gold alloy and two phosphate-bonded investments. The investments were used under conditions which gave a range of potential expansions and hot strengths. Casting inaccuracies were determined both diametrally and axially. All castings showed distortion, which varied under the different conditions. All were oversized axially, by amounts varying from + 0.8% to +2.3%. Diametral inaccuracies ranged from -0.2% to +0.7%. Investment expansion had a strong effect on axial inaccuracy, but a negligible effect on diametral inaccuracy. Conversely, hot strength had a strong effect on diametral inaccuracy, but only a very weak effect on axial inaccuracy. With phosphate-bonded investments, both potential expansion and hot strength are important parameters of relative casting inaccuracy. In combination, these properties showed very strong correlations with both diametral and axial inaccuracies. The observed distortions were the result of anisotropic mould expansion and anisotropic alloy shrinkage. The best fit, and least distortion, occurred with an investment setting under dry conditions. PMID:9250842

Earnshaw, R; Morey, E F; Edelman, D C

1997-07-01

359

Tensile characteristics of coreless silicon carbide fiber exposed to some environments  

Microsoft Academic Search

The present paper deals with the tensile strength and the fracture mode of coreless silicon carbide fibers exposed to various environments. The fibers had no change in strength by an isothermal heating of 700 C for 100 hours and a hydrostatic pressurizing of 980 MPa, but the fiber strength decreased with the exposure time by being exposed to a liquid

H. Fukunaga; K. Goda

1985-01-01

360

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

361

An Investigation on the Influence of Cutting-Force's Components on the Work-piece Diametrical Error in Ultrasonic-Vibration-Assisted Turning  

NASA Astrophysics Data System (ADS)

Work-piece deformation during turning process results in diametrical error which is attributable to changes occurring in the depth of cut. The accurate modeling of diametrical error is important for providing efficient means of reducing the error. Due to continuous change of work-piece's stiffness along its axis and the moving cutting force, estimation of diametrical error requires a special effort especially in ultrasonic-vibration-assisted turning (UAT). Different cutting force components will produce different orders of error magnitude. Contradictory results are reported in the literature in this respect. In the present paper, the effect of cutting force components on diametrical error has been analyzed and subsequently verified by experimental results for UAT and conventional processes. The error in radial direction was dominant.

Soleimanimehr, H.; Nategh, M. J.

2011-01-01

362

Tensile and Bearing Failure at a Loaded Hole in a Finite Width Orthotropic Laminate.  

National Technical Information Service (NTIS)

Analytical and finite element results were used to obtain a simple expression for the maximum tensile stress concentration factor near a pin-loaded hole in a finite width orthotropic laminate. Experimental data were obtained for joint failure strength as ...

P. A. Smith K. J. Pascoe

1986-01-01

363

Estimation of fibre and interfacial shear strength by using a single-fibre composite  

Microsoft Academic Search

The fibre\\/matrix interfacial shear strength is often estimated from the fragmentation process of a fibre in a single-fibre composite loaded in tension. The interfacial shear strength is calculated from a knowledge of the critical length and the tensile strength of the fibre. Unfortunately, if the tensile strength of fibres distributes widely and increases with decreasing fibre length, then problems arise

Masatoshi Shioya; Akira Takaku

1995-01-01

364

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

365

Fracture strength of polysilicon at stress concentrations  

Microsoft Academic Search

Mechanical design of MEMS requires the ability to predict the strength of load-carrying components with stress concentrations. The majority of these microdevices are made of brittle materials such as polysilicon, which exhibit higher fracture strengths when smaller volumes or areas are involved. A review of the literature shows that the fracture strength of polysilicon increases as tensile specimens get smaller.

Jörg Bagdahn; O. Jadaan

2003-01-01

366

Tests for Strength Characteristics of a Schistose Gneiss. Preliminary Tests.  

National Technical Information Service (NTIS)

This report presents the strength characteristics of schistose gneiss as revealed by laboratory tests for shear, compressive, and tensile strength of the material. Unconfined compression and direct tension tests were made of intact rock while triaxial com...

E. J. Deklotz T. L. Neff W. J. Heck

1965-01-01

367

[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

368

Strength distributions of adhesive bonded and adhesive/rivet combined joints  

NASA Astrophysics Data System (ADS)

The tensile and shear strengths of adhesive and adhesive/rivet combined joints are statistically evaluated, and the probability of failure is calculated for these two types of joints. Attention is given to the effects of the adhesive/rivet combination on mean tensile shear strength and coefficient of variation. The adhesive joint's strength distribution was well approximated by Weibull or doubly-exponential distribution function; tensile shear strength is significantly improved by the combination with rivets.

Imanaka, Makoto; Haraga, Kosuke; Nishikawa, Tetsuya

1992-11-01

369

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

370

Tensile Testing: A Simple Introduction  

ERIC Educational Resources Information Center

|Tensile testing may be used to decide, say, which steel to use in various constructions. Analogous testing can be done simply in the classroom using plasticine and helps to introduce pupils to the various properties studied in materials science.|

Carr, Martin

2006-01-01

371

Manufacturing of Plutonium Tensile Specimens  

SciTech Connect

Details workflow conducted to manufacture high density alpha Plutonium tensile specimens to support Los Alamos National Laboratory's science campaigns. Introduces topics including the metallurgical challenge of Plutonium and the use of high performance super-computing to drive design. Addresses the utilization of Abaqus finite element analysis, programmable computer numerical controlled (CNC) machining, as well as glove box ergonomics and safety in order to design a process that will yield high quality Plutonium tensile specimens.

Knapp, Cameron M [Los Alamos National Laboratory

2012-08-01

372

Effects of high-temperature hydrogen exposure on room temperature tensile properties and fatigue crack growth behaviour of TiAl base alloy  

Microsoft Academic Search

Tensile, notched tensile, and fatigue crack growth tests of hydrogen-exposed (in 0.1 MPa 99.9995% H2 at 800°C for 6 and 24 h) TiAl base alloy were carried out in ambient air. The results are compared with those of the material before exposure. By the H2 exposure, the tensile ductility and tensile strength were reduced significantly, and greater reduction in the

Y. Iino; K. W. Gao; K. Okamura; L. J. Qiao; W. Y. Chu

2002-01-01

373

Tensile experiments and SEM fractography on bovine subchondral bone.  

PubMed

Subchondral bone undecalcified samples, extracted from bovine femoral heads, are subjected to a direct tensile load. The Young's modulus of each sample is determined from repeated tests within the elastic limit. In a last test, the tensile load is increased up to the specimen failure, determining the ultimate tensile strength. The investigation is performed on both dry and wet specimens. The measured Young's modulus for dry samples is 10.3+/-2.5GPa, while that of wet samples is 3.5+/-1.2GPa. The ultimate tensile strengths are 36+/-10 and 30+/-7.5MPa for dry and wet specimens, respectively. SEM micrographs of failure surfaces show characteristic lamellar bone structures, with lamellae composed of calcified collagen fibers. Rudimentary osteon-like structures are also observed. Failure surfaces of wet samples show a marked fiber pull-out, while delamination predominates in dry samples. The obtained results are interpreted on the basis of the deformation mechanisms typical of fiber-reinforced laminated composite materials. PMID:10854890

Braidotti, P; Bemporad, E; D'Alessio, T; Sciuto, S A; Stagni, L

2000-09-01

374

Strength of nonuniformly oxidized PGX graphite  

SciTech Connect

Flexural and tensile tests were performed on PGX graphite oxidized to produce a steep surface oxidation gradient. Companion tensile specimens were oxidized under different conditions to produce uniform oxidation throughout the specimen, and their tensile strength and Young's modulus were measured. The flexural strength, flexural elastic modulus, and tensile strength were reduced much less by surface oxidation than by uniform oxidation. The test data were in good agreement with a simple linear elastic model in which Young's modulus at any point is a function of oxidation burnoff, and the strain at failure is independent of oxidation. The unoxidized interior of the specimens appears unaffected by the surface burnoff and remains able to fulfill its load-bearing function. 18 figures, 8 tables.

Price, R.J.; Beavan, L.A.

1981-05-01

375

Tensile-strained germanium microdisks  

NASA Astrophysics Data System (ADS)

We show that a strong tensile strain can be applied to germanium microdisks using silicon nitride stressors. The transferred strain allows one to control the direct band gap emission that is shifted from 1550 nm up to 2000 nm, corresponding to a biaxial tensile strain around 1%. Both Fabry-Perot and whispering gallery modes are evidenced by room temperature photoluminescence measurements. Quality factors up to 1350 and limited by free carrier absorption of the doped layer are observed for the whispering gallery modes. We discuss the strain profile in the microdisks as a function of the disk geometry. These tensile-strained microdisks are promising candidates to achieve Ge laser emission in compact microresonators.

Ghrib, A.; El Kurdi, M.; de Kersauson, M.; Prost, M.; Sauvage, S.; Checoury, X.; Beaudoin, G.; Sagnes, I.; Boucaud, P.

2013-06-01

376

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

377

Tensile creep of dental amalgam.  

PubMed

Rather than the usual compressive dental creep, various types of one week old dental amalgams were continuously monitored in tensile creep. Testing was done at 37, 45 and 50 degrees C, in a specially designed apparatus capable of 0 to 60 degrees C while maintaining a constant true tensile stress of 17 MPa. For the first time, the classical four stages of creep were observed at elevated temperatures in the low Cu amalgams, including creep rupture. The high Cu systems displayed only transient creep up to 50 degrees C and no rupture. Approximately one half the stress was needed in tension to provide the equivalent creep in compression. PMID:7082735

Greener, E H; Szurgot, K; Lautenschlager, E P

1982-04-01

378

The tensile strengths of viscous liquids under dynamic loading  

Microsoft Academic Search

Under similar conditions of transient loading the cavitation thresholds of syrup and olive oil are 130 × 106 dyne\\/cm2 and 29 × 106 dyne\\/cm2 respectively. For fluids with a viscosity (?) in the range 0.01 to 400 P the cavitation threshold pressure Pc is given by the empirical relation Pc = ??0.2. This result can be interpreted on the basis

T H Bull

1956-01-01

379

Laser Forming of Tailored Blanks of High Tensile Strength Steels  

NASA Astrophysics Data System (ADS)

Tailor welded blanks with two different materials (SPCC-SPFC980Y) were V bent by laser forming which is a bending method with thermal stress induced by rapid heating by means of laser irradiation, and it is suitable for bending of large spring back sheets since spring back is not affected. Forming conditions for SPCC part and SPFC980Y part were changed. A 50W CW YAG laser was employed with laser scanning number of 10 and defocus length of 25mm. When same laser power (38W) was employed for SPCC and SPFC980Y parts, bending angle of SPCC part was greater than that of SPFC980Y part. However, when laser power was 40W for SPFC980Y part and 36W for SPCC part, the bending angle of both parts were almost same and this means constant bending angle was obtained by controlling the laser power. Uniform bending angle was also obtained by controlling the laser scanning velocity as well as the laser power.

Otsu, Masaaki; Ishii, Akira; Takashima, Kazuki

380

Tensile strengths of problem shales and clays. Master's thesis  

SciTech Connect

The greatest single expense faced by oil companies involved in the exploration for crude oil is that of drilling wells. The most abundant rock drilled is shale. Some of these shales cause wellbore stability problems during the drilling process. These can range from slow rate of penetration and high torque up to stuck pipe and hole abandonment. The mechanical integrity of the shale must be known when the shalers are subjected to drilling fluids to develop an effective drilling plan.

Rechner, F.J.

1990-01-01

381

Size effect in tensile strength caused by stress fluctuations  

Microsoft Academic Search

The randomness of microstructure heterogeneous materials leads to creation of microscopic random stress fields within the bulk of the material under loading. Although in average the microscopic stresses coincide with the macroscopic (e.g., externally applied) stress, the local differences (stress fluctuations) can be high, the magnitude increasing with the volume of the heterogeneous material. In the case of uniform macroscopic

Arcady V. Dyskin; Marcel R. A. Van Vliet; Jan G. M. Van Mier

2001-01-01

382

Tensile Strength Prediction in Concrete Using Nondestructive Testing Techniques  

Microsoft Academic Search

Field studies have suggested that wave velocities through concrete samples decrease with increasing damage. However, to date there has been no replication of this effect in a laboratory setting allowing for a controlled experiment to quantify this effect. The primary objective was to see how the exposure of concrete to sulfate solutions related to surface-wave velocity and through-wave velocity. The

Scott R. Cumming; Andrew J. Boyd; Christopher C. Ferraro

2006-01-01

383

Tensile deformation and fracture behavior of a ductile phase reinforced dispersion strengthened copper composite  

Microsoft Academic Search

Niobium particle reinforced aluminum oxide (Al2O3) dispersion strengthened copper composite is an attractive and emerging engineered material for applications requiring high strength, high thermal and electrical conductivities and resistance to softening at elevated temperatures. In this paper, the microstructure, tensile deformation and fracture behavior of the composite is examined. The strength of the material decreases with an increase in temperature

T. S. Srivatsan; J. D. Troxell

1999-01-01

384

Tensile deformation and fracture behavior of an oxide dispersion strengthened copper alloy  

Microsoft Academic Search

Dispersion strengthened copper has recently emerged as a potentially viable and attractive engineering material for applications requiring high strength, high thermal and electrical conductivities and resistance to softening at elevated temperatures. In this paper, the microstructure, tensile deformation and fracture behavior of an oxide dispersion strengthened copper alloy is examined. The strength of the dispersion strengthened microstructure decreases with an

T. S Srivatsan; N Narendra; J. D Troxell

2000-01-01

385

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

386

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

387

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

388

The tensile fatigue of wire rope: A new approach  

SciTech Connect

The fatigue behaviour in air and seawater of zinc coated steel wire taken from a 40 mm diameter wire rope has been studied. Seawater had little effect on short term tensile strength but it reduced fatigue life by an amount which increased with increasing mean stress and decreasing test frequency. The application of fretting during fatigue testing resulted in very low endurances, which were similar to those measured in fatigue tests on wire ropes.

Thorpe, T.W.; Rance, A.

1983-05-01

389

Studies on high-tensile proof tests of optical fibers  

Microsoft Academic Search

By conducting high-tensile proof tests on optical fibers in order to eliminate weak points such as cracks or flaws, fiber strength is improved, but fiber length becomes shorter because of fiber breakage during proof tests. When the application is for submarine optical-fiber on cables, the upper limit of proof-test strain is determined based on theoretical and experimental studies on fiber

Yoshiaki Miyajima

1983-01-01

390

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

391

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

392

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

393

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

394

Tensile and Compressive Mechanical Behavior of a CoCrCuFeNiAl0.5 High Entropy Alloy  

NASA Astrophysics Data System (ADS)

A high entropy alloy of composition CoCrCuFeNiAl0.5 is mainly composed of a face centered cubic (FCC) solid solution phase. The tensile and compressive properties of the alloy were investigated; the alloy exhibited a tensile strength of 707 MPa, together with a large plastic strain limit of 19%.

Wang, Fangjun; Zhang, Yong; Chen, Guoliang; Davies, Hywel A.

395

A Tensile Deformation Model for In-situ Dendrite/Metallic Glass Matrix Composites.  

PubMed

In-situ dendrite/metallic glass matrix composites (MGMCs) with a composition of Ti46Zr20V12Cu5Be17 exhibit ultimate tensile strength of 1510?MPa and fracture strain of about 7.6%. A tensile deformation model is established, based on the five-stage classification: (1) elastic-elastic, (2) elastic-plastic, (3) plastic-plastic (yield platform), (4) plastic-plastic (work hardening), and (5) plastic-plastic (softening) stages, analogous to the tensile behavior of common carbon steels. The constitutive relations strongly elucidate the tensile deformation mechanism. In parallel, the simulation results by a finite-element method (FEM) are in good agreement with the experimental findings and theoretical calculations. The present study gives a mathematical model to clarify the work-hardening behavior of dendrites and softening of the amorphous matrix. Furthermore, the model can be employed to simulate the tensile behavior of in-situ dendrite/MGMCs. PMID:24085187

Qiao, J W; Zhang, T; Yang, F Q; Liaw, P K; Pauly, S; Xu, B S

2013-10-02

396

A Tensile Deformation Model for In-situ Dendrite/Metallic Glass Matrix Composites  

PubMed Central

In-situ dendrite/metallic glass matrix composites (MGMCs) with a composition of Ti46Zr20V12Cu5Be17 exhibit ultimate tensile strength of 1510?MPa and fracture strain of about 7.6%. A tensile deformation model is established, based on the five-stage classification: (1) elastic-elastic, (2) elastic-plastic, (3) plastic-plastic (yield platform), (4) plastic-plastic (work hardening), and (5) plastic-plastic (softening) stages, analogous to the tensile behavior of common carbon steels. The constitutive relations strongly elucidate the tensile deformation mechanism. In parallel, the simulation results by a finite-element method (FEM) are in good agreement with the experimental findings and theoretical calculations. The present study gives a mathematical model to clarify the work-hardening behavior of dendrites and softening of the amorphous matrix. Furthermore, the model can be employed to simulate the tensile behavior of in-situ dendrite/MGMCs.

Qiao, J. W.; Zhang, T.; Yang, F. Q.; Liaw, P. K.; Pauly, S.; Xu, B. S.

2013-01-01

397

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

398

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

399

Cavitation Strength of Liquids with Large Molecules  

NASA Astrophysics Data System (ADS)

The cavitation strength of liquids has been studied at atmospheric pressure by applying tensile stress pulses of duration up to 3 ?s and amplitude up to 20 MPa within the temperature range from room temperature to the temperature of explosive boiling-up of the liquid. At high temperatures, where in absolute value the tensile strength does not exceed 1-2 times the critical pressure, agreement between classical nucleation theory and experiment is observed within the experimental error. With a decrease of the temperature the tensile strength of the liquid increases, but the experimental values of the breaking strength are lower than those predicted from theory. The dependence of the degree of discrepancy between theory and experiment on the number of atoms in the molecules of the liquids investigated is shown.

Vinogradov, Vladimir E.; Pavlov, Pavel A.

2013-09-01

400

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

401

Inert strength of pristine silica glass fibers  

SciTech Connect

Silica glass fibers have been produced and tested under ultra high vacuum (UHV) conditions to investigate the inert strength of pristine fibers in absence of reactive agents. Analysis of the coefficient of variation in diameter ({upsilon}{sub d}) vs the coefficient of variation of breaking strength ({upsilon}{sub {sigma}}) does not adequately explain the variation of breaking stress. Distribution of fiber tensile strength data suggests that the inert strength of such fibers is not single valued and that the intrinsic strength is controlled by defects in the glass. Furthermore, comparison of room temperature UHV data with LN{sub 2} data indicates that these intrinsic strengths are not temperature dependent.

Smith, W.L.; Michalske, T.A.

1993-11-01

402

Tensile and compressive deformation of polypyridobisimidazole (PIPD)-based `M5' rigid-rod polymer fibres  

Microsoft Academic Search

The tensile and compressive deformation behaviour of a new type of heterocyclic rigid-rod polymer fibre, polypyridobisimidazole `PIPD' or `M5', produced by the spinning of liquid-crystalline solutions, have been studied. The Young's moduli and tensile strengths for the two different PIPD or M5 fibres have been determined to be greater than 300GPa and 4GPa, respectively. Molecular deformation in the fibres has

J. Sirichaisit; R. J. Young

1999-01-01

403

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

404

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

405

The tensile behavior of carbon fibers at high temperatures up to 2400 °C  

Microsoft Academic Search

The tensile behavior of four different brands of carbon fibers (a rayon-based, a PAN-based, and 2 pitch-based fibers) has been investigated at various temperatures up to 2400 °C. The tests were carried out using an original fiber testing apparatus. Various mechanical properties including strength and Young's modulus, as well as Weibull statistical parameters were extracted from test data. Typical tensile

Cédric Sauder; Jacques Lamon; René Pailler

2004-01-01

406

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

407

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

408

High Temperature Tensile Testing of Modified 9Cr-1Mo after Irradiation with High Energy Protons  

SciTech Connect

This study examines the effect of tensile test temperatures ranging from 50 C to 600 C on the tensile properties of a modified 9Cr-1Mo ferritic steel after high energy proton irradiation at about 35 C-67 C to doses from 1 to 3 dpa and 9 dpa. For the specimens irradiated to doses between 1 and 3 dpa, it was observed that the yield strength and ultimate strength decreased monotonically as a function of tensile test temperature, whereas the uniform elongation remained at approximately 1% for tensile test temperatures up to 250 C and then increased for tensile test temperatures up to and including 500 C. At 600 C, the uniform elongation was observed to be less than the values at 400 C and 500 C. Uniform elongation of the irradiated material tensile tested at 400 C to 600 C was observed to be greater than the values for the unirradiated material at the same temperatures. Tensile tests on the 9 dpa specimens followed similar trends.

Toloczko, Mychailo B.; Hamilton, Margaret L.; Maloy, S A.

2003-05-15

409

Tensile softening of metallic-glass-matrix composites in the supercooled liquid region  

NASA Astrophysics Data System (ADS)

A Ti-based metallic-glass-matrix composite exhibits tensile softening (necking) in the supercooled liquid region, accompanied by a large tensile ductility and a fragmentation of dendrites. Subjected to high temperatures, concurrent crystallization does not occur, suggesting a good thermal stability of the glass matrix. The presence of high-volume-fractioned dendrites lowers the rheology of the viscous glass matrix at high temperatures, which results in an absence of super elongation as monolithic bulk metallic glasses (BMGs). A tensile strength of 970 MPa is higher than those of most BMGs under varying strain rates, ascribing to the retardation of softening by the dendrites.

Qiao, J. W.; Zhang, Y.; Jia, H. L.; Yang, H. J.; Liaw, P. K.; Xu, B. S.

2012-03-01

410

Tensile Behavior of Intercritically Annealed 10 pct Mn Multi-phase Steel  

NASA Astrophysics Data System (ADS)

The exceptional elongation obtained during tensile testing of intercritically annealed 10 pct Mn steel, with a two phase ferrite-austenite microstructure at room temperature, was investigated. The austenite phase exhibited deformation-twinning and strain-induced transformation to martensite. These two plasticity-enhancing mechanisms occurred in succession, resulting in a high rate of work hardening and a total elongation of 65 pct for a tensile strength of 1443 MPa. A constitutive model for the tensile behavior of the 10 pct Mn steel was developed using the Kocks-Mecking hardening model.

Lee, Sangwon; De Cooman, Bruno C.

2013-10-01

411

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

412

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

413

Inverse problem of material distribution for desired fracture characteristics in a thick-walled functionally graded material cylinder with two diametrically-opposed edge cracks  

Microsoft Academic Search

This study concerns the inverse problem of evaluating the optimum material distribution for desired fracture characteristics in a thick-walled functionally graded material (FGM) cylinder containing two diametrically-opposed edge cracks emanating from the inner surface of the cylinder. The thermal eigenstrain developed in the cylinder material due to nonuniform coefficient of thermal expansion as a result of cooling from sintering temperature

A. M. Afsar; M. Anisuzzaman; J. I. Song

2009-01-01

414

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

415

Strength of porcelain fused to titanium beams  

Microsoft Academic Search

The purposes of this study were to measure strengths of layered porcelain fused to titanium beams, determine failure modes, and investigate the porcelain-titanium interface. A three-point flexural test and formulas derived especially for this purpose were used. The strength of layered porcelain-ceramic beams was limited by the cohesive tensile or compressive strengths of the porcelain, not by the porcelaintitanium interfacial

Shane N. White; Ly Ho; Angelo A. Caputo; Edward Goo

1996-01-01

416

Ultrahigh strength polyethylene by hot drawing of surface growth fibers  

Microsoft Academic Search

Hot drawing at 150°C has been applied to high molecular weight polyethylene fibers produced by flow induced crystallization in a Couette apparatus, referred to as the ‘surface growth’ technique. A distinct improvement of the tensile properties of the fibers was noticed upon drawing. A tensile strength at break of 4.7 GPa was reached. Drawability is discussed in relation to fiber

J. Smook; J. C. Torfs; P. F. van Hutten; A. J. Pennings

1980-01-01

417

Study on ARALL failure behavior under tensile loading  

SciTech Connect

This paper studies the failure behavior of ARALL (Aramid Aluminum Laminate) under tensile loading by means of acoustic emission (AE), optical metallography (OM) and scanning electronic microscope (SEM), and analyzes the fracture appearance of ARALL and its fracture characteristics. The damage models of ARALL are concluded in this paper. The results show that ARALL will yield under tensile loading, and its strength will decrease as the content of resin increases. During fracture process, AE amplitude distribution curves show that there are three obvious peaks, which respectively correspond to separation of the interface between fibers and resin, local delamination damage and fracture of a small quantity of fibers, and delamination damage of large area and final fracture of a large numbers of fibers. Dynamic damage and fracture process of ARALL can be detected by AE.

Yan Hai; Ren Rongzhen; Tao Chunhu; Li Hongyun [Inst. of Aeronautical Materials, Beijing (China)

1996-12-15

418

Tensile stress acoustic constants of unidirectional graphite/epoxy composites  

SciTech Connect

Previously, the stress acoustic constants (SACs) of unidirectional graphite/epoxy composites were measured to determine the nonlinear moduli of this material. These measurements were made under compressive loading in order to obtain the sufficient number of values needed to calculate these moduli. However, because their strength in tension along fiber directions can be several times greater, most composites are used under tensile loading. Thus, it is important to characterize the nonlinear properties of these materials in tension as well. The SACs which are defined as the slope of the normalized change in ultrasonic natural velocity as a function of stress were measured in a unidirectional laminate of T300/5208 graphite/epoxy. Tensile load was applied along the fiber axis with the ultrasonic waves propagating perpendicular to the fiber direction. Changes in velocity were measured using a pulsed phase locked loop ultrasonic interferometer with the nominal frequency of the ultrasonic waves being 2.25 MHz. 6 refs.

Prosser, W.H. (NASA, Langley Research Center, Hampton, VA (USA))

1990-03-01

419

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

420

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

421

[Bond strength of dental luting cements to titanium castings].  

PubMed

This study compared the tensile bond strength of dental luting cements to the titanium castings with gold alloy (Type IV), 12% Au-Ag-Pd alloy and Ni-Cr alloy in dental clinical practice. In this experimental condition, the zinc phosphate cement did not adhere to any dental casting alloy tested. The tensile bond strength of polycarboxylate cement to the titanium castings was 96 kg/cm2, about two times as high as that gold alloy (Type IV). The tensile bond strength of the glass ionomer cement to titanium castings was 32 kg/cm2, about two times as high as that of dental precious alloys. The tensile bond strength of the adhesive resin cement to titanium castings was 220 kg/cm2, about three times as high as that of dental precious alloys. PMID:2134816

Hibino, Y; Kuroiwa, A; Kurosawa, S; Kanke, S; Hashimoto, H

1990-01-01

422

Effects of adhesive fillers on the strength of tubular single lap adhesive joints  

Microsoft Academic Search

When an adhesively bonded joint is exposed to a high environmental temperature, the tensile load capability of the adhesively bonded joint decreases because the elastic modulus and failure strength of the adhesive decrease. In this paper, the elastic modulus and failure strength of the adhesive as well as the tensile load capability of the tubular single lap adhesively bonded joint

Dai Gil Lee; Jin Kook Kim; Durk Hyun Cho

1999-01-01

423

Analysis of knitted fabric reinforced composites: Part II. Stiffness and strength  

Microsoft Academic Search

The influence of the knit structure on the stiffness and strength in tensile and in share loading of glass warp knitted fabric epoxy composites is studied. The average strength depends on the fibre content and on the linear density of the yarn. The anisotropy in tensile and shear properties is related to the orientation tensor components a1111 and a1122, respectively.

B. Gommers; I. Verpoest; P. Houtte

1998-01-01

424

In situ tensile fracture toughness of surficial cohesive marine sediments  

NASA Astrophysics Data System (ADS)

This study reports the first in situ measurements of tensile fracture toughness, K IC, of soft, surficial, cohesive marine sediments. A newly developed probe continuously measures the stress required to cause tensile failure in sediments to depths of up to 1 m. Probe measurements are in agreement with standard laboratory methods of K IC measurements in both potter's clay and natural sediments. The data comprise in situ depth profiles from three field sites in Nova Scotia, Canada. Measured K IC at two muddy sites (median grain size of 23-50 ?m) range from near zero at the sediment surface to >1,800 Pa m1/2 at 0.2 m depth. These profiles also appear to identify the bioturbated/mixed depth. K IC for a sandy site (>90% sand) is an order of magnitude lower than for the muddy sediments, and reflects the lack of cohesion/adhesion. A comparison of K IC, median grain size, and porosity in muddy sediments indicates that consolidation increases fracture strength, whereas inclusion of sand causes weakening; thus, sand-bearing layers can be easily identified in K IC profiles. K IC and vane-measured shear strength correlate strongly, which suggests that the vane measurements should perhaps be interpreted as shear fracture toughness, rather than shear strength. Comparison of in situ probe-measured values with K IC of soils and gelatin shows that sediments have a K IC range intermediate between denser compacted soils and softer, elastic gelatin.

Johnson, Bruce D.; Barry, Mark A.; Boudreau, Bernard P.; Jumars, Peter A.; Dorgan, Kelly M.

2012-02-01

425

Micro- and nanoscale tensile testing of materials  

NASA Astrophysics Data System (ADS)

This article reviews concepts and techniques for performing instrumented tensile testing of materials at small dimensions. State-of-the-art methods to probe tensile behavior of micro- and nanoscaled materials span many orders of magnitudes of force and displacement, often requiring a custom solution for each new material discovery. We discuss the experimental opportunities, challenges, and pitfalls in concert with the scientific insights revealed from tensile investigations at length scales where conventional wisdom is challenged on how materials deform.

Gianola, D. S.; Eberl, C.

2009-03-01

426

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

427

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

428

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

429

Revealing Extraordinary Intrinsic Tensile Plasticity in Gradient Nano-Grained Copper  

NASA Astrophysics Data System (ADS)

Nano-grained (NG) metals are believed to be strong but intrinsically brittle: Free-standing NG metals usually exhibit a tensile uniform elongation of a few percent. When a NG copper film is confined by a coarse-grained (CG) copper substrate with a gradient grain-size transition, tensile plasticity can be achieved in the NG film where strain localization is suppressed. The gradient NG film exhibits a 10 times higher yield strength and a tensile plasticity comparable to that of the CG substrate and can sustain a tensile true strain exceeding 100% without cracking. A mechanically driven grain boundary migration process with a substantial concomitant grain growth dominates plastic deformation of the gradient NG structure. The extraordinary intrinsic plasticity of gradient NG structures offers their potential for use as advanced coatings of bulk materials.

Fang, T. H.; Li, W. L.; Tao, N. R.; Lu, K.

2011-03-01

430

INFUENCE OF SPECIMEN TYPE AND LOADING CONFIGURATION ON THE FRACTURE STRENGTH OF SiC LAYER IN COATED PARTICLE FUEL  

SciTech Connect

Internal pressurization and diametrical loading techniques were developed to measure the fracture strength of the chemical vapor deposition (CVD) silicon carbide (SiC) coatings in nuclear fuel particles. Miniature tubular and hemispherical shell specimens were used for both test methods. In the internal pressurization test an expansion load was applied to the inner surface of a specimen by use of a compressively loaded elastomeric insert (polyurethane). In the crush test a diametrical compressive load was applied to the outer surface(s) of a specimen. The test results revealed that the fracture strengths from four test methods obeyed Weibull's two-parameter distribution, and the measured values of the Weibull modulus were consistent for different test methods. The fracture strengths measured by crush test techniques were larger than those by internal pressurization tests. This is because the internal pressurization produces uniform stress distribution while the diametrical loading technique produces severely localized stress distribution. The test method dependence of fracture strength was explained by the size effect predicted by effective surface.

Byun, Thak Sang [ORNL; Hong, Seong Gu [ORNL; Katoh, Yutai [ORNL; Snead, Lance Lewis [ORNL

2006-01-01

431

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

432

Tensile characteristics of coreless silicon carbide fiber exposed to some environments  

SciTech Connect

The present paper deals with the tensile strength and the fracture mode of coreless silicon carbide fibers exposed to various environments. The fibers had no change in strength by an isothermal heating of 700 C for 100 hours and a hydrostatic pressurizing of 980 MPa, but the fiber strength decreased with the exposure time by being exposed to a liquid aluminum environment. The cause was made clear from a SEM observation of the fracture modes and a discussion has been done about the strength distribution function of the fibers from the viewpoint of the characteristics of the fracture modes. 7 references.

Fukunaga, H.; Goda, K.

1985-12-01

433

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

434

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

435

Micro-tensile testing system  

DOEpatents

A micro-tensile testing system providing a stand-alone test platform for testing and reporting physical or engineering properties of test samples of materials having thicknesses of approximately between 0.002 inch and 0.030 inch, including, for example, LiGA engineered materials. The testing system is able to perform a variety of static, dynamic, and cyclic tests. The testing system includes a rigid frame and adjustable gripping supports to minimize measurement errors due to deflection or bending under load; serrated grips for securing the extremely small test sample; high-speed laser scan micrometers for obtaining accurate results; and test software for controlling the testing procedure and reporting results.

Wenski, Edward G. (Lenexa, KS)

2007-07-17

436

Micro-tensile testing system  

DOEpatents

A micro-tensile testing system providing a stand-alone test platform for testing and reporting physical or engineering properties of test samples of materials having thicknesses of approximately between 0.002 inch and 0.030 inch, including, for example, LiGA engineered materials. The testing system is able to perform a variety of static, dynamic, and cyclic tests. The testing system includes a rigid frame and adjustable gripping supports to minimize measurement errors due to deflection or bending under load; serrated grips for securing the extremely small test sample; high-speed laser scan micrometers for obtaining accurate results; and test software for controlling the testing procedure and reporting results.

Wenski, Edward G. (Lenexa, KS)

2007-08-21

437

An end-effect model for the single-filament tensile test  

Microsoft Academic Search

The effect of cross-sectional shape on tensile strength of pitch-based carbon fibres was investigated by extensive single-filament testing. For this study, round and trilobal pitch-based carbon fibres were produced at similar processing conditions. The application of a variety of distributions, including the simple Weibull distribution, to the strength data indicated two sources of failure, one source being the accentuation of

E. G. Stoner; D. D. Edie; S. D. Durham

1994-01-01

438

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

439

Defects in hexed gold prosthetic screws: A metallographic and tensile analysis  

Microsoft Academic Search

Statement of Problem. Prosthetic gold screw fracture remains a clinical problem in implant prosthodontics. Purpose. This study examined hexed gold prosthetic screws for internal defects and determined the effect of these defects on tensile strength. The microstructure, microhardness, and major constituents of the alloys also were determined. Material and Methods. Four intact hexed gold prosthetic screws, 1 from each of

Sameer K. Rambhia; William W. Nagy; Raymond A. Fournelle; Virendra B. Dhuru

2002-01-01

440

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

441

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

442

The effect of annealing on tensile deformation behavior of nanostructured SPD titanium  

Microsoft Academic Search

Tensile behavior of titanium was studied at room temperature in the as-processed condition (using severe plastic deformation by high pressure torsion) and also in various annealed states. It was found that controlled annealing could lead to enhancement of both strength and ductility of this material. The origin of this phenomenon is discussed in the context of TEM\\/HREM and SEM observations.

R. Z. Valiev; A. V. Sergueeva; A. K. Mukherjee

2003-01-01

443

Effect of interface fracture on the tensile deformation of fiber-reinforced elastomers  

Microsoft Academic Search

The influence of interface properties (strength and toughness) on the tensile behavior of fiber-reinforced elastomers deformed perpendicularly to the fibers was studied using computational micromechanics. Numerical simulations were performed by means of the finite element analysis of a representative volume element of the composite microstructure. The effect of finite deformations and of interface fracture was included in the simulations, the

Joaquín Moraleda; Javier Segurado; Javier Llorca

2009-01-01

444

Comparison of tensile and compressive characteristics of vinyl ester\\/glass microballoon syntactic foams  

Microsoft Academic Search

The present study is focused on the synthesis and characterization of vinyl ester\\/glass microballoon syntactic foams. Tensile and compressive properties of vinyl ester matrix syntactic foams are characterized. Results show that the compressive strength and moduli of several syntactic foam compositions are comparable to those of the neat matrix resin. Due to the lower density of syntactic foams, the specific

Nikhil Gupta; Raymond Ye; Maurizio Porfiri

2010-01-01

445

Creep and tensile behavior of lead-rich, lead-tin solder alloys  

Microsoft Academic Search

The tensile and creep deformation of a series of high lead solders with 2% to 10% tin over a temperature range of 0°C to 100°C is discussed. The yield strength is strongly influenced by the precipitation of the tin phase, which depends on temperature and tin content. The creep rupture behavior follows the Monkman-Grant relationship. It is found that the

H. J. Frost; R. T. Howard; P. R. Lavery; S. D. Lutender

1988-01-01

446

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

447

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

448

Adequacy of the tensile\\/elongation test as a quality control criterion for vehicle tires  

Microsoft Academic Search

Most tire failures in Saudi Arabia result in severe vehicle crashes. Tire failures, such as tread separation and blowouts, are the most notable events that occur on a daily basis. This paper deals with the elongation and tensile strength of the tire rubber as quality control criteria in evaluating vehicle tires. Specimens from six different tire brands were subjected to

Nedal T. Ratrout; Isam A. Mahmoud

2006-01-01

449

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

450

Accelerated Aging of Laboratory Handsheets: Retention of Folding Endurance, Internal Tear, Bursting Strength, and Tensile Strength.  

National Technical Information Service (NTIS)

This report represents a study of the accelerated aging of chemically modified handsheets in air and nitrogen at 90C and 50 percent or 0 percent relative humidity. The handsheets were prepared from a commercial wood pulp that had been either (a) untreated...

E. J. Parks R. L. Hebert

1971-01-01

451

Study on the Strength of GFRP/Stainless Steel Adhesive Joints Reinforced with Glass Mat  

NASA Astrophysics Data System (ADS)

The adhesive strengths of glass fiber reinforced plastics/metal adhesive joints reinforced with glass mat under tensile shear loads and tensile loads were investigated analytically and experimentally. First, the stress singularity parameters of the bonding edges were analyzed by FEM for various types of adhesive joints reinforced with glass mat. The shear stress and normal stress distributions near the bonding edge can be expressed by two stress singularity parameters. Second, tensile shear tests were performed on taper lap joint and taper lap joint reinforced with glass mat and tensile tests were performed on T-type adhesive joint and T-type adhesive joint reinforced with glass mat. The relationships between the loads and the crosshead displacements were measured. We concluded that reinforcing adhesive joints has a greater effect on strength under tensile load than under tensile shear load. The adhesive joints strength reinforced with glass mat can be evaluated by using stress singularity parameters.

Iwasa, Masaaki

452

Shear Strength  

NSDL National Science Digital Library

Dr. John Atkinson, of the University of the West of England, developed a site for undergraduate students wanting to learn more about soil classification. His site addresses issues such as: shear strength, peak strength, and residual strength testing. Filled with charts, diagrams, statistics, the information is pertinent and easily understood by almost any audience.

Atkinson, John

2008-10-07

453

Application of Gurson-Tvergaard-Needleman Constitutive Model to the Tensile Behavior of Reinforcing Bars with Corrosion Pits  

PubMed Central

Based on meso-damage mechanics and finite element analysis, the aim of this paper is to describe the feasibility of the Gurson–Tvergaard–Needleman (GTN) constitutive model in describing the tensile behavior of corroded reinforcing bars. The orthogonal test results showed that different fracture pattern and the related damage evolution process can be simulated by choosing different material parameters of GTN constitutive model. Compared with failure parameters, the two constitutive parameters are significant factors affecting the tensile strength. Both the nominal yield and ultimate tensile strength decrease markedly with the increase of constitutive parameters. Combining with the latest data and trial-and-error method, the suitable material parameters of GTN constitutive model were adopted to simulate the tensile behavior of corroded reinforcing bars in concrete under carbonation environment attack. The numerical predictions can not only agree very well with experimental measurements, but also simplify the finite element modeling process.

Xu, Yidong; Qian, Chunxiang

2013-01-01

454

Tensile behavior of pb-sn solder/cu joints  

NASA Astrophysics Data System (ADS)

Solders of nominal 95Pb-5Sn and 60Sn-40Pb were used to join Cu plates. The effect of ternary additions of In, Ag, Sb, and Bi to the near-eutectic solder were also investigated. Bulk solder and interfacial joint microstructures were characterized for each solder alloy. The solder joints were strained to failure in tension; joint strength and failure mode were determined. 95Pb-5Sn/Cu and 60Sn-40Pb/Cu specimens were tested both as-processed and after reflow. 95Pb-5Sn/Cu as-processed and reflow specimens failed in tension in a ductile mode. Voids initiated at ?-Sn precipitates in the as-processed specimens and at the Cu3Sn intermetallic in the reflow specimens. 60Sn-40Pb/Cu failed transgranularly through the Cu6Sn5 intermetallic in both the as-processed and reflow conditions. The joint tensile strength of the reflow specimens was approximately half that of the as-processed specimens for both the high-Pb and near-eutectic alloys. The Cu6Sn{5} intermetallic dominated the tensile failure mode of the near-eutectic solder/Cu joints. The fracture path of the near-eutectic alloys with ternary additions depended on the presence of Cu6Sn5 rods in the solder within the Cu plates. Specimens with ternary additions of In and Ag contained only interfacial intermetallics and exhibited interfacial failure at the Cu6Sn5. Joints manufactured with ternary additions of Sb and Bi contained rods of Cu6Sn5 within the solder. Tensile failure of the Sb and Bi specimens occurred through the solder at the Cu6Sn5 rods.

Quan, Lenora; Frear, Darrel; Grivas, Dennis; Morris, J. W.

1987-05-01

455

A Method of Estimating the Strength of Adhesive Bonded Joints of Metals  

Microsoft Academic Search

The strength of adhesive bonded joints is investigated both analytically and experimentally. The deformed states of lap joints under tensile shear loading are analysed by the finite element method on the assumption of elastic deformation. A method of using the adhesive strength law is proposed to estimate the joint strength. The adhesive strength law is experimentally determined by subjecting butt

Kozo Ikegami; Toshio Sugibayashi

1987-01-01

456

Mechanical behavior of ultrahigh strength ultrahigh carbon steel wire and rod  

Microsoft Academic Search

Ultrahigh-carbon steels (UHCSS) can achieve very high strengths in wire or rod form. These high strengths result from the mechanical work introduced during wire and rod processing. These strengths have been observed to increase with carbon content. In wire form, tensile strengths approaching 6000 MPa are predicted for UHCS containing 1. 8%C. In this paper, we will discuss the influence

D. R. Lesuer; C. K. Syn; O. D. Sberby; W. D. Whittenherger

1997-01-01

457

RC beam with variable stiffness and strength  

Microsoft Academic Search

Shape memory alloys (SMA) show a temperature depending stiffness and strength. A reinforced concrete (RC) beam with SMA wires was tested and compared with a conventional RC beam. Furthermore, tensile and pull-out tests with the SMA wires are presented. By using the constrained recovery effect, it was possible to produce a changeable prestress in the RC beam.

Christoph Czaderski; Bernd Hahnebach; Masoud Motavalli

2006-01-01

458

Material Strength in Polymer Shape Deposition Manufacturing  

Microsoft Academic Search

Shape Deposition Manufacturing (SDM) is a layered manufacturing process involving an iterative combination of material addition and material removal. Polymer SDM processes have used castable thermoset resins to build a variety of parts. The strength of such parts is determined by the bulk material properties of the part materials and by their interlayer adhesion. This paper describes tensile testing of

J. W. Kietzman; F. B. Prinz

459

A Statistical Theory of Composite Materials Strength  

Microsoft Academic Search

A statistical tensile failure theory of composite materials with uniaxially oriented fibers is proposed. In the theory, the strength of fibers is assumed to be a statistical quantity and the fibers around a broken fiber are supposed to be subjected to localized stress concentra tions. The number of broken fibers in a layer of composite as a function of average

Yuntian Zhu; Benlian Zhou; Guanhu He; Zongguang Zheng

1989-01-01

460

Rate Sensitivity of High Strength Syntactic Foam.  

National Technical Information Service (NTIS)

A series of dynamic experiments was performed on high crush strength syntactic foam to characterize how rate affects the compressive and tensile properties of the material. The Investigation was carried out as part of a larger effort to develop a rate sen...

R. Doleski S. Plunkett W. Tucker

2003-01-01