Gauge Length Effect on the Strength of Silicon Carbide and Sapphire Filaments

1990 ◽  
Vol 24 (2) ◽  
pp. 220-232 ◽  
Author(s):  
A.K. De ◽  
K.K. Phani
Keyword(s):  
Silicon Carbide ◽  
Gauge Length ◽  
Length Effect

An Attempt to Quantify the Translation of Fiber Bundle Tenacity into Yarn Tenacity

1976 ◽  
Vol 46 (11) ◽  
pp. 822-827 ◽  
Author(s):  
P. Neelakantan ◽  
T. A. Subramanian
Keyword(s):  
Fiber Bundle ◽  
Breaking Load ◽  
Gauge Length ◽  
Length Effect ◽  
The Real ◽  
Yarn Tenacity

The concept of a real yarn tenacity, derived by making an allowance for fiber obliquity and for the fibers that do not contribute to the yarn breaking load, has been postulated. An equation has been derived to enable the calculation of real yarn tenacity. In the case of man-made fibers that exhibit only a very weak gauge-length effect in their bundle tenacity, the real yarn tenacity has been shown to be equal to the fiber bundle tenacity at all levels of twist beyond the minimum required to ensure an interlocking structure. In the case of cotton, the effective gauge length for which the bundle tenacity is equal to the real yarn tenacity has been found to depend upon the level of twist in the yarn, being of the order of 1 mm for yarns that have more than the optimum twist.

Gauge length effect on the tensile properties of leather

2006 ◽  
Vol 101 (2) ◽  
pp. 1202-1209 ◽  
Author(s):  
Palanisamy Thanikaivelan ◽  
Dennis C. Shelly ◽  
Seshadri S. Ramkumar
Keyword(s):  
Tensile Properties ◽  
Gauge Length ◽  
Length Effect

Length effect on the performance of lumber in tension

1990 ◽  
Vol 17 (6) ◽  
pp. 911-918 ◽  
Author(s):  
Frank Lam ◽  
Erol Varoglu
Keyword(s):  
Tensile Strength ◽  
Reliability Index ◽  
Strength Properties ◽  
Gauge Length ◽  
Short Term ◽  
Length Effect ◽  
Performance Factor ◽  
First Order Second Moment ◽  
Tension Members ◽  
Term Performance

A study was conducted to evaluate the effect of gauge length on the short-term performance of visually graded Select Structural and No. 2 kiln-dried nominal 38 × 89 mm spruce-pine-fir lumber in tension parallel-to-grain. The short-term tensile strength properties of three groups of lumber, matched for modulus of elasticity and having gauge lengths of 2642, 3683, 4877 mm, were obtained from test results where the effect of gauge length was isolated from the effect of grade. The performance of the lumber was evaluated by first-order second-moment reliability analyses. In the analyses, the lumber was treated as single tension members under uniform tensile stress along the member length, undergoing snow load conditions at various locations in Canada. The results indicate that the performance factor for Select Structural spruce-pine-fir lumber in tension parallel-to-grain should be multiplied by a factor of 0.92 to adjust for doubling the length from 2500 to 5000 mm to achieve a common reliability index of 3.0. The effect of doubling the length from 2500 to 5000 mm on the performance of No. 2 spruce-pine-fir lumber appears to be negligible. Key words: length effect, tensile strength, lumber, performance factor, reliability index.

Irradiation behavior of pyrolytic silicon carbide

1983 ◽  
Vol 41 ◽  
pp. 72-73
Author(s):  
R. J. Lauf
Keyword(s):  
Silicon Carbide ◽  
Fission Products ◽  
Thermodynamics And Kinetics ◽  
Neutron Fluences ◽  
Fuel Particles ◽  
Sic Coatings ◽  
Irradiation Behavior ◽  
Kinetics Of ◽  
Htgr Fuel

Fuel particles for the High-Temperature Gas-Cooled Reactor (HTGR) contain a layer of pyrolytic silicon carbide to act as a miniature pressure vessel and primary fission product barrier. Optimization of the SiC with respect to fuel performance involves four areas of study: (a) characterization of as-deposited SiC coatings; (b) thermodynamics and kinetics of chemical reactions between SiC and fission products; (c) irradiation behavior of SiC in the absence of fission products; and (d) combined effects of irradiation and fission products. This paper reports the behavior of SiC deposited on inert microspheres and irradiated to fast neutron fluences typical of HTGR fuel at end-of-life.

Microstructural Evaluation of Silicon Carbide Whisker Reinforced Alumina Fabricated with Carbon-Coated Whiskers

1991 ◽  
Vol 49 ◽  
pp. 920-921
Author(s):  
K. B. Alexander ◽  
P. F. Becher
Keyword(s):  
Silicon Carbide ◽  
High Resolution Electron Microscopy ◽  
Ceramic Composites ◽  
Interface Debonding ◽  
Resolution Electron ◽  
Microstructural Evaluation ◽  
Carbon Coated ◽  
Electron Energy Loss ◽  
Interfacial Films ◽  
Debonding Process

The presence of interfacial films at the whisker-matrix interface can significantly influence the fracture toughness of ceramic composites. The film may alter the interface debonding process though changes in either the interfacial fracture energy or the residual stress at the interface. In addition, the films may affect the whisker pullout process through the frictional sliding coefficients or the extent of mechanical interlocking of the interface due to the whisker surface topography.Composites containing ACMC silicon carbide whiskers (SiCw) which had been coated with 5-10 nm of carbon and Tokai whiskers coated with 2 nm of carbon have been examined. High resolution electron microscopy (HREM) images of the interface were obtained with a JEOL 4000EX electron microscope. The whisker geometry used for HREM imaging is described in Reference 2. High spatial resolution (< 2-nm-diameter probe) parallel-collection electron energy loss spectroscopy (PEELS) measurements were obtained with a Philips EM400T/FEG microscope equipped with a Gatan Model 666 spectrometer.

TEM of grain growth and phase transformations during creep of SCS-6 silicon carbide fibers

1995 ◽  
Vol 53 ◽  
pp. 350-351
Author(s):  
L. A. Giannuzzi ◽  
C. A. Lewinsohn ◽  
C. E. Bakis ◽  
R. E. Tressler
Keyword(s):  
Silicon Carbide ◽  
Creep Rate ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Primary Creep ◽  
Excess Carbon ◽  
Silicon Carbide Fibers ◽  
Sic Fiber ◽  
Carbon Core ◽  
Grain Width

The SCS-6 SiC fiber is a 142 μm diameter fiber consisting of four distinct regions of βSiC. These SiC regions vary in excess carbon content ranging from 10 a/o down to 5 a/o in the SiC1 through SiC3 region. The SiC4 region is stoichiometric. The SiC sub-grains in all regions grow radially outward from the carbon core of the fiber during the chemical vapor deposition processing of these fibers. In general, the sub-grain width changes from 50nm to 250nm while maintaining an aspect ratio of ~10:1 from the SiC1 through the SiC4 regions. In addition, the SiC shows a <110> texture, i.e., the {111} planes lie ±15° along the fiber axes. Previous has shown that the SCS-6 fiber (as well as the SCS-9 and the developmental SCS-50 μm fiber) undergoes primary creep (i.e., the creep rate constantly decreases as a function of time) throughout the lifetime of the creep test.

The Effect of Path Length and Display Size on Memory for Spatial Information

2012 ◽  
Vol 59 (3) ◽  
pp. 147-152 ◽  
Author(s):  
Katherine Guérard ◽  
Sébastien Tremblay
Keyword(s):  
Path Length ◽  
Potential Role ◽  
Spatial Information ◽  
Recall Performance ◽  
Minor Role ◽  
Length Effect ◽  
Serial Memory ◽  
Fixed Reference ◽  
A Minor

In serial memory for spatial information, some studies showed that recall performance suffers when the distance between successive locations increases relatively to the size of the display in which they are presented (the path length effect; e.g., Parmentier et al., 2005) but not when distance is increased by enlarging the size of the display (e.g., Smyth & Scholey, 1994). In the present study, we examined the effect of varying the absolute and relative distance between to-be-remembered items on memory for spatial information. We manipulated path length using small (15″) and large (64″) screens within the same design. In two experiments, we showed that distance was disruptive mainly when it is varied relatively to a fixed reference frame, though increasing the size of the display also had a small deleterious effect on recall. The insertion of a retention interval did not influence these effects, suggesting that rehearsal plays a minor role in mediating the effects of distance on serial spatial memory. We discuss the potential role of perceptual organization in light of the pattern of results.

The list-length effect occurs in cued recall with the retroactive design but not the proactive design.

2020 ◽  
Vol 74 (1) ◽  
pp. 12-24 ◽  
Author(s):  
Tyler M. Ensor ◽  
Dominic Guitard ◽  
Tamra J. Bireta ◽  
William E. Hockley ◽  
Aimée M. Surprenant
Keyword(s):  
List Length ◽  
Cued Recall ◽  
Length Effect ◽  
List Length Effect
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