Torsional shear

Other Fiber Deformations. Deformations such as bending, torsion, shear, and compression are of practical importance in textile apphcations. Bending and twisting of yams, both influential in the development of bulk and stretch in filament yams, are also important in the production of staple yams. Bending characteristics are important in cmsh resistance in carpets. Bending and shear are factors that influence the hand and drape of apparel fabrics, whereas compression influences the recovery of fabrics after such processes as winding. 

Torsional shear stresses r resulting from torque caused by loads offset from the vessel axis. These loads will normally be small, and need not be considered in preliminary vessel designs. 

Allen and Alsalim 22 compared the effect of various pretreatments of stainless steel (martensitic structure) on the torsional shear strength of napkin ring joints formed with an epoxy adhesive (Redux 319 (Bonded Structures Ltd.)). They concluded that... 

Figure 5. Torsional shear properties of two 3D composites subjected to similar processing.

Figure 10,17 Birefringence interference patterns in torsional shearing flow between parallel plates of MBBA, illuminated by monochromatic light and observed between crossed polarizers. The images on the left were obtained at a rotation speed, of 2.09 x 10 sec , while those on the right were obtained at 4.18 x 10 sec >, From top to bottom, the gap is 44, 94, and 194 ixm. (From Wahl and Fischer, reprinted with permission from Mol. Cryst. Liq. Cryst. 22 359, Copyright 1973, Gordon and Breach Publishers.)...

Elastomers are cross-linked macromolecules above the glass transition temperature. The cross-link density is the fundamental engineering quantity which, for instance, determines the modulus of elasticity. Usually, it is measured during vulcanization of well-defined rubber samples in a vulcameter by the moment necessary to perform a given torsional shear of the test sample. Swelling experiments can be performed alternatively, but are problematic for filled elastomers. Such measurements are based on the assumption that the measured quantity does not vary over the sample volume. Inhomogeneous cross-link densities can be determined from the surface hardness, but volumetric resolution is achieved by conventional methods only after cutting the sample. 

With the adhesive strength rB being replaced by the torsional shear strength rT of the adhesive, the torsional moment to be transmitted results... 

Dynamic torsional shear experiments were conducted on a Rheometric Scientific ARES rheometer. The samples were cut 6.35 cm in length strips, 0.30 cm thick. The single frequency temperature ramp test was taken at 1 Hz from -100°C to 150°C at 2°C/min in the linear strain regime (0.01 to 2.00%). 

FIGURE 4.5 Geometry of torsional shear flow. (Adapted from Middleman, S. (1975). Advances in polymer science and engineering applications to food rheology, in Theory, Determination and Control of Physical Properties of Food Materials, Rha, C., Ed., Reidel D. Publishing Company, Dordrecht, Holland.)... 

The effect of water immersion (57°C) on the torsional shear strength of Versamid 140 (O) and DETA ( ) room temperature cured adhesive joints. 

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