Torsion properties

Fig. 4. Torsion properties versus temperature for the nickel alloys (— —) Nknonic 115 and (-------) Nknonic 90 and for (—) 0.48% C steel (2). To convert...

Torsion property As noted, the shear modulus is usually obtained by using pendulum and oscillatory rheometer techniques. The torsional pendulum (ASTM D 2236 Dynamic Mechanical Properties of Plastics by Means of a Torsional Pendulum Test Procedure) is a popular test, since it is applicable to virtually all plastics and uses a simple specimen readily fabricated by all commercial processes or easily cut from fabricated products. 

Geometry and Torsional Properties of Candidate Materials. From a mechanics standpoint, a driveshaft can be approximated as a thin, rotating tube. The first critical frequency, Ncr, in units of rev/min (rpm), of a simply supported thin rotating tube is given by... 

Closely related in topographical structure, but with different and quite unique torsional properties, are the (3-isopropyl-substituted analogues of tyrosine 41,421 and phenylalanine. 43,441 All four isomers of each amino acid analogue have been prepared by asymmetric synthesis. In addition, the highly topographically constrained amino acid 3-isopropyl-2, 6 -dimethyl-tyrosine has been prepared by asymmetric synthesis/451... 

Feughelinaii (1959) has drawn similar conclusions for small stresses from a study of torsional properties of the fibers. 

Spectroscopists sometimes use additional terms in their Fourier series expansion to describe torsional properties in molecules. We have not found any... 

Hirsch [65] studied the elongation of hair under a steadily increasing load, together with a rotational movement. He attempted to explain this combination of stretching and torsion in terms of molecular structure. See the section on the torsional properties of hair in this chapter. 

Previously, the major drawback to the simple torsion pendulum method was that it could not be used while the hber is immersed in liquids because of the damping effect of the liquid. However, Wolfram and Albrecht [83] have devised an ingenius scheme to overcome this obstacle by inserting the hber into a small glass capillary tube, thus permitting the torsional properties of hair hbers (and other hbers) to be measured in both air and liquids. Other methods are available [79,80,84] for measurement of the rigidity of hbers immersed in liquids. For additional details, see the references indicated and the texts by Meredith and Hearle [84] and Morton and Hearle [76]. 

The torsional modulus for human hair by the pendulum method is lower than either the stretching or the bending modulus at 60% to 65% RH. However, water has a greater effect on torsional properties than on either stretching or bending for both human hair and wool hber (see data describing these three different elastic moduli in Table 8-5 and 8-6). 

For wool hber, the effect of water on the torsional properties is almost 3 to 4 times as great as on the bending or stretching properties, whereas for human hair the effect is nearly a factor of 2 between 65% and 100% RH (see Table 8-6). 

If one takes ratios of dry to wet torsional moduli in Table 8-7, it is apparent that there is a greater effect of moisture on the torsional properties of waved hair than on those of unaltered hair. The torsional behavior of hair, more than the tensile behavior, is dependent on the cuticle or the external... 

The formability and high temperature tensile and torsion properties of ternary alloys have been discussed by [1984Mue] and [1987Klo], while the fracture behavior of phase separated alloys has been presented by [1980Jin2]. 

K10] Mechanical tests Hardness, formability, tensile and torsion properties... 

Sawada Y, Shindo A, Torsional properties of carbon-fibers, Carbon, 30(4), 619-629, 1992. Swanson SR, Merrick M, Toombes GR, Comparison of torsion tube and losipescu in-plane shear test results for a carbon fibre reinforced epoxy composite, Composites, 16, 8220, 1985. 

A rubber or elastomer is a polymer with viscoelasticity [1-3], Since rubbers are amorphous polymers above the glass transition temperature, considerable segmental motion is possible, making them relatively soft and deformable, with better elongation, compression, and torsional properties than other polymeric materials. Elastomers and rubbers thus come back fairly close to their original size and shape after the stress is released. The primary uses for these materials include tires, hoses, seals, adhesives, and molded flexible parts, among many others. 

Torsional Properties of Plastics," with E. P. Sharp, translated... 

Torsion properties satisfied the quality order, with no significant difference between fluorinated and unfluorinated materials. 

The recovered material met the requirements of the quahty order in respect of torsional properties. 

The increased interactions and film-forming properties also contribute towards styling effects. All-round bounce makes the hair appear vital and dynamically aesthetic. The bounce behavior of a hair curl can be determined in an automated test arrangement (Fig. 44) which investigates the torsional properties of hair fibers (bending modulus) and hair curls (stretch forces, attenuation, frequency, and amplitude of oscillation). 

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