Tensile-elongation curves

Figure 1 also shows the decrease in tensile elongation (a common measure of ductiUty) that accompanies the strength increase with cold working. Whereas these particular rolling curves include up to 70% reduction in thickness, pure copper is capable of being roUed much further without fracturing. 

The area of the polar diagram is related to variables such as refining and wet press pressure. The load-elongation curve during tensile testing also shows marked differences in the two directions (Figure 4.8). 

The trapezoid test method (ASTM Dll 17) is recommended for determining the tear resistance of nonwoven fabrics. An outline of a trapezoid is marked on a 7.5 x 15 — cm specimen, and the nonparallel sides are clamped in the jaws of the tensile-testing machine. The load is applied to the specimen in such a way that the tear propagates across the specimen width. The value of the breaking load is obtained from the load—elongation curve and is determined primarily by the bonding or interlocking of the fibers of the composite structure. 

Fig. 17. The stress-elongation curve obtained from Nitinol by applying a uniaxial tensile load at temperature below the TTR. The portion of the curve, 0 - A represents the zone of easy plastic flow. A - B illustrates elastic recovery, and B - 0 is recovery (contraction) possible by heating to above the TTR. - reference [49]...

Typical force-elongation curves of some manufactured and natural staple fibers and textile-type manufactured filaments are shown in Figs 12.1 and 12.2. Table 12.1 gives the values of some of the physical and tensile properties of textile fibers. 

The tensile test shows a steady course of the tensile force-elongation curve, where a linear relationship exists only at low tensile forces. There are only small deviations from a linear course at approximately half-rupture. The tensile strength increases with increasing density. The degree of heat-sealing has an effect here also. 

As a result, zones A, B, and C have comparatively a basic, neutral, and acidic character, respectively. Increasing the DC electric current leads to the overall acidification of the gel sample (see Fig. 6, curve 4) due to the easy ionization of the acidic groups. Consequently, this narrows the zones B and C and expands zone A. Polybetaine hydrogel membranes of isopropyl-2-[2 -(trimethylammonium)ethyl phosphoryl] ethyl fumaramate and 2-hydroxyethyl methacrylate effectively enhance the water content in comparison with poly(2-hydroxyethyl methacrylate) [224]. The content of water in hydrogel membranes increases, but the amount of adsorbed BSA decreases with the increase of the betaine content in the feed. The values of the tensile strength and tensile elongation of the hydrogel reach 68.4 g mm and 239%, respectively. 

The raw data from a tensile test (Fig. 11-20) are obtained in terms of force and corresponding elongation for a test specimen of given dimensions. The area under such a force-elongation curve can be equated to the impact strength of an isotropic polymer specimen if the tensile test is performed at impact speeds. Show that this area is proportional to the work necessary to rupture the sample. 

Table 1. Mechanical properties of selected pressure-infiltrated ceramic particle reinforced aluminium composites Young s modulus (E), yield and ultimate tensile strengths (aQ2, Outs), tensile elongation ( 0, and fracture toughness parameters. Toughness Kic was measured from J-R curves on pure A1 matrix composites and by chevron-notch fracture testing on Al-Cu...

Fig. 45. Influence of the radiation dose on the mechanical properties of polystyrene. Curve 1, tensile strength curve 2, elongation curve 3, elastic modulus curve 4, shear strength curve 5, impact strength.

The mechanical properties of the polylmide film were measured in tension tests. To do this polylmide films were cast and cured on glass substrates. The films were removed and tensile test specimens were stamped from the films using a die. The specimens were then pulled to fracture at a cross-head speed of 10 mm/min. The mechanical properties obtained from the load-elongation curves are given in Table I. 

Other important parameters of load-elongation curves are the Hookean limit (Figure 8-2, Point A), the turnover point (Figure 8-2, Point B), the percentage extension to break, the stress to break (the tensile strength), the... 

Tensile hysteresis curve (ASTM D 4848). A complex load elongation or stress-strain curve obtained under either of two conditions ... 

When a specimen is stretched less than the breaking elongation and allowed to relax by removal of the strain according to a predetermined procedure. ( = tensile recovery curve, work recovery curve, and strain recovery curve.)... 

FIGURE 15.14 The tensile strength (curve I) and elongation at break (curve 2) of TPE as a... 

Physical Properties The usual values of tensile strength, tensile modulus, and ultimate elongation at various temperatures can be obtained from the typical stress-strain curves shown in Figs. 22-01 and 22-02. Such properties as tensile strength and modulus are inversely proportional to temperature, whereas elongation reaches a maximum value at about 300°C. Other factors, such as humidity, film thickness, and tensile elongation rates, were found... 

The magnitude of the rotation could be related approximately to the overall strain according to the ideas of Schmidt-Boas " by assuming an incremental slip, always parallel to the current c-axis. Furthermore they were able to explain the observed load-elongation curve by assuming the existence of a constant flow stress on the c-slip system. This requires decreasing axial loads as the slip plane rotates towards the tensile axis, because of the rapidly reducing cross-sectional area (see Fig. 7). 

The tensile properties were determined using a Instron tensile tester (model 4411) following the ASTM D-638 procedure and using type 1 test specimen dimensions. The crosshead speed was set at 50 mm.min-i and 5 samples were tested for each composition. Tensile stress at yield, tensile strength at break and elongation at break were determined from the recorded force versus elongation curve. 

The samples for the tensile tests were prepared according to the specifications of the Japanese Industrial Standard (JIS), No.l4B. The load-elongation curve was obtained for a crosshead speed of 1.0 nun/min. The hardness of the specimens was measured using the Vickers hardness method at 1 kgf for 15 s. 

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