Stress-strain curves of fibers

Figure 13.6 (a) Elongation as a function of wind-up speed for partially oriented yarn, (b-d) Stress-strain curves of fibers of PET blends with 3% copolyester of 1,4-phenyleneterephthalate and p-oxybenzoate (CLOTH) and 3% copolymer of 6-oxy-2-naphthalene and p-oxybenzoate (CO), spun at 3500, 4000 and 4500 m/min (1) PET control (2) 3 % CLOTH (3) 3 % CO the loci of the theoretical extensions of the PET control are shown as dashed curves [17]. From Orientation suppression in fibers spun from melt blends, Brody, H., J. Appl. Polym. Sci., 31, 2753 (1986), copyright (1986 John Wiley Sons, Inc.). Reprinted by permission of John Wiley Sons, Inc. 

Figure 25.2 Stress-strain curves of fibers with different moduli of elasticity...

FIGURE 5.4 Transcrystallinity induced by a CNT fiber, (a) Tensile test specimens, (i) Nontranscrystalline spherulitic iPP. (ii) Transcrystalline iPP interphase cleaved from the CNT fiber, (iii) Transcrystalline polymer with embedded CNT fiber, (b) Stress-strain curves of fibers shown in (a). (From S. Zhang et al., Polymer, 49, 2008, 1356-1364.)... 

A schematic stress-strain curve of an uncrimped, ideal textile fiber is shown in Figure 4. It is from curves such as these that the basic factors that define fiber mechanical properties are obtained. 

Fig. 4. Idealized stress-strain curves of an uncrimped textile fiber point 1 is the proportional limit, point 2 is the yield point, and point 3 is the break or...

The elasticity of a fiber describes its abiUty to return to original dimensions upon release of a deforming stress, and is quantitatively described by the stress or tenacity at the yield point. The final fiber quaUty factor is its toughness, which describes its abiUty to absorb work. Toughness may be quantitatively designated by the work required to mpture the fiber, which may be evaluated from the area under the total stress-strain curve. The usual textile unit for this property is mass pet unit linear density. The toughness index, defined as one-half the product of the stress and strain at break also in units of mass pet unit linear density, is frequentiy used as an approximation of the work required to mpture a fiber. The stress-strain curves of some typical textile fibers ate shown in Figure 5. 

Fig. 5. Stress—strain curves of some textile fibers (17). To convert N/mm to psi, multiply by 145.

Fig. 6. The effect of rate of extension on the stress—strain curves of rayon fibers at 65% rh and 20°C. The numbers on the curves give the constant rates of...

Stress—Strain Curve. Other than the necessity for adequate tensile strength to allow processibiUty and adequate finished fabric strength, the performance characteristics of many textile items are governed by properties of fibers measured at relatively low strains (up to 5% extension) and by the change ia these properties as a function of varyiag environmental conditions (48). Thus, the whole stress—strain behavior of fibers from 2ero to ultimate extension should be studied, and various parameters should be selected to identify characteristics that can be related to performance. 

Fig. 4. The stress—strain curves of a wool fiber at different relative humidities.

Fig. 6-13 Stress-strain curves of different fiber materials.

FIGURE 12.18 Stress-strain curves of rubber-fiber composites developed for solid rocket motor insulator A, ethylene-propylene-diene monomer (EPDM) rubber-carbon fiber composites B, EPDM mbber-melamine fiber composites C, EPDM mbber-aramid fiber composites and D, EPDM rubber-aramid pulp composites. 1 and 2 stands for unaged and aged composites respectively. Carbon fiber- and melamine fiber-reinforced composites contain resorcinol, hexamine, and silica in the concentrations 10, 6 and 15, respectively and aramid fiber- and aramid pulp-based composites contain resorcinol, hexamine, and silica in the concentrations 5, 3 and 15, respectively. (From Rajeev, R.S., Bhowmick, A.K., De, S.K., and John, B., Internal communication. Rubber Technology Center, Indian Institute of Technology, Kharagpur, India, 2002.)... 

Fig. 10. Stress-strain curves of 2D-C/SiC with optimized fiber/matrix bonding...

Typical tension stress-strain curves of baseline and irradiated unidirectional T300/934 composites tested in [0] and [90] orientations at three different temperatures (121 are shown in Figures 11 and 12. Irradiation had essentially no effect on the fiber-dominated tensile modulus of the [0] specimen and caused only a small (10-15%) reduction in strength at the low and elevated temperatures. For the matrix-dominated [90] laminates, irradiation caused a very substantial decrease in strength at three test temperatures (-38% at -157°C, -26% R.T., -13% 121°C). Irradiation increased the modulus at -157°C and R.T. (10 - 15%), but lowered it at 121°C (-15%). These results are consistent with results obtained on the neat resin specimens discussed above. 

Figure 11.11 shows the stress-strain curves of PET, PTT and PBT fibers [4], Both PTT and PBT have a knee or a plateau region at about 5 and 7 % strains respectively, whereas PET stress increases smoothly with strain and does not have the plateau region. Table 11.6 compares the moduli of the three polyesters before and after annealing. The modulus of PET is nearly four times higher than those of PTT and PBT. After annealing, the PET modulus decreased by nearly half due to relaxation and loss of orientation. However, the PTT modulus increased by... 

Figure 11.11 Stress-strain curves of PET, PTT and PBT fibers [69]. From Jake-ways, R., Ward, I. M., Wilding, M. A., Desborough, I. J. and Pass, M. G., J. Polym. Sci., Polym. Phys. Ed., 13, 799-813 (1975), Copyright (1975 John Wiley Sons, Inc.). This material is used by permission of Wiley-Liss, Inc., a subsidiary of John Wiley Sons, Ltd...

In cross-ply laminates, the stress-strain behavior is slightly nonlinear, as illustrated in Figure 5.123. The stress-strain behavior of a unidirectional lamina along the fiber axis is shown in the top curve, while the stress-strain behavior for transverse loading is illustrated in the bottom curve. The stress-strain curve of the cross-ply composite, in the middle, exhibits a knee, indicated by strength ajc, which corresponds to the rupture of the fibers in the 90° ply. The 0° ply then bears the load, until it too ruptures at a composite fracture strength of ct/. 

Figure 11.4. Typical stress-strain curve of a PVA/nanotube composite. The material is a fiber containing 25wt% of MWNTs in a PVA matrix (molecular weight 195 000,99% hydrolized).

Figure 11.7. (a) Stress-strain curve of a raw wet-spun fiber (the inset focuses on the elastic regime), (b) stress-strain curves of wet-spun fibers that have been hot-stretched at 180°C, at various draw-ratios, from 0 (raw) to 800%. 

Figure 3.7 Tensile stress-strain curves of a variety of different materials steel, cellulose, tendon, and frame silk. Note the high fracture energy (area under the stress-strain curve) of the frame silk fiber. The strain-to-failure of frame silk can be as high as 30% (after Gosline et al., 1986).

Figure 4.8 cont.) (b) Specific stress-strain curves of Lycra (Spandex) and natural rubber fibers (Wilson, 1967,1968). 

Figure 4.24 Tensile and compressive stress-strain curves of PBZO fibers under different conditions as spun, as coagulated, and heat-treated (Martin and Thomas, 1989 Kumai 1990a). Note the very low strength in compression.

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