Work-to-break

Fig. 41. Typical stress—strain curve. Points is the yield point of the material the sample breaks at point B. Mechanical properties are identified as follows a = Aa/Ae, modulus b = tensile strength c = yield strength d = elongation at break. The toughness or work to break is the area under the curve.

Standard Test Methods for Tire Yarns, Cords, and Woven Fabrics. ASTM standard D885M-94 includes test methods for characterizing tire cord twist, break strength, elongation at break, modulus, tenacity, work-to-break, toughness, stiffness, growth, and dip pickup for industrial filament yams made from organic base fibers, cords twisted from such yams, and fabrics woven from these cords that are produced specifically for use in the manufacture of pneumatic tires. These test methods apply to nylon, polyester, rayon, and aramid yams, tire cords, and woven fabrics. 

Figure 22. Correlations between the interfacial term, AX, derived from Fig. 14, and the enthalpy of formation of the oxide MO, corrected for the work to break metal-metal bonds. I, II, in mean first, second, and third periods of the periodic table of elements. From Ref. 26, updated. (From R. Guidelli, ed, Electrified Interfaces in Physics, Chemistry, and Biology, p. 252, Fig. 3. Copyright 1992 Kluwer Academic Publishers. Reproduced with permission.)...

Works-made-for-hire, 7 787 Work-to-break, 19 743 World Association of Nuclear Operators (WANO), 17 538. See also Global entries... 

The active site is a particular shape and locks into a corresponding shape in a reactant molecule. When this has happened, the enzyme can work to break up the reactant (Figure 7.17). 

Instron Three-Point Bending Failure. Three-point bending tests have also been conducted on notched Izod specimens at crosshead rates of 0.02-20 inches/min (Figure 5). Plots of work to break obtained from the areas under the Instron force-displacement traces show abrupt ductile-brittle transitions these are displaced to lower temperatures as the test rate is decreased. However the temperature interval between ductile-brittle transitions of the two materials remains about the same. The force-displacement trace for each specimen shows a yield point with a ductile failure but a sharp termination when the sample breaks in a brittle fashion. 

If the addition of a second phase tinqily alters the modulus of a brittle polymer, without affecting the intrinsk flaw tize a or the fracture surface energy Gic, then Eq. (1) predicts that the fracture stress will proportional to It follows that the strain at break will be proportional so that the work to break in... 

Faflure in multiphase polymers and polymer composites (non-fibrous) is reviewed by Professor Bucknall. Several examples are presented in which the effect of adding a dispersed second phase to a polymer can be either beneficial or deleterious to stress, strain, or work to break. It is shown that two basic modes of local plastic deformation may be operative, namely crazing and shear band formation. 

Tensile Tests. Tensile tests were done on an Instron tensile tester un er ambient coi dition at strain rates, , ranging from 1.0 X 10 to 5.5 x 10 sec. Experiments were done in triplicate at each strain rate. Stress, a, and strain, , at yield (not shown) were determined using tSe 0.2% offset method (5). Stress,, and strain, , at break and the work to break, W, (the area under the stress-strain curve) were also calculated. The latter was evaluated via a computer program using a Simpson s Rule method. 

Figure 4. Plot of work to break for PMMA vs. strain rate for specimens with the...

FIGURE 10.29 Work-to-break (W/,) versus energy dissipated W ) on stretching almost to the breaking elongation. (From Grosch et al. (1966).)... 

Figure 3.18. Tensile stress-strain curves at 23°C for (a) 70/30 SAN resin and (b) a mechanical blend of 70/30 SAN with 25 wt % NBR. Although the final breaking stress is lower, the polyblend requires much more work to break than the simple SAN copolymer. (Bergen, 1968.)...

Tensile properties n. Tensile properties are linear density, tenacity, knot tenacity, loop tenacity, breaking strength, tensile strength, elongation at break, tensile module, work to break, yield point, creep, and elasticity. 

Chemical resistance Knotstrength Floats on water Moisture sensitivity Electrical/insulation Work to break (highspeed) X-Ray transparancy Low temperature Mechanical properties Flammability... 

COPEUN, and COPUN single networks, and their PSN-reinforced SINs. In each case, the PSN tends to reinforce the castor oil elastomer, in a manner similar to carbon black reinforcing SBR. The modulus, strain to break, and work to break are vastly increased. The pertinent values are summarized in Table 7.4. ... 

Abrasion and Mar Resistance. Abrasion is the wearing away of a surface marring is a disturbance of a surface that alters its appearance (see Weak). A study of the mechanical properties of a series of floor coatings with known wear life concluded that work-to-break values best represented the relative wear lives... 

---