Stress-strain tensile test

Pieces of the compression-moulded sheets were pressed into dogbone-shaped specimens of thickness 1.7 mm and a gauge width of 15 mm for the tensile tests. Stress-strain curves were obtained at room temperature with a Zwick tensile tester at a strain rate of 0.0001 s. The samples were strained up to 3.6% strain and the strain was measured with an extensometer with a gauge length of 50 mm. The tensile tests were done only on the composites with 50 vol% glass beads, with different amounts of the silane. 

As a result of the tensile test, stress-strain diagrams of the samples investigated are shown in Fig. 6. 

O3, h). .. etc. from this family of curves, which form the relaxation curve. Furthermore, by determining the stress which belongs to a specified strain in the relaxation test after a long test time, one can experimentally verify the only calculated tensile test stress-strain-curves for very small deformation rates. The isochronous stress-strain diagram also directly indicates the non-linearity of the visco-elastic behaviour otherwise the curves would be straight lines. 

Instron for testing tensile strength, stress, strain, and creep characteristics... 

Copolymer test specimens were prepared by pressing slabs for 0.5-3 min at temperatures approximately 20°C above the copolymer melting point, followed by cooling under pressure to room temperature in 5-10 min. Test samples were conditioned at 24°C and 50% relative humidity for at least 48 hr before testing. Stress-strain and tear-strength measurements were made on 0.6 to 0.8-mm-thick specimens. Thicker specimens yield lower values for tensile strength and elongation at break. The test methods used were ... 

In tensile tests at strain-rates of e = 2 x 10 -2 x 10" s" intrinsic crazing of PC has been observed in a temperature range of 120-135 °C, i.e. about 15-30 °C below the glass transition temperature Figure 2 shows a nominal stress-strain curve... 

Figure 4. Tensile engineering stress-strain curves of (a) Cu tested at 22 °C and (b) Ti tested at 250 °C. Both were tested at a strain rate of 10 3 s 1. The processing conditions for each curve...

Fig. 2.10-2 Characterization of the mechanical properties of a material by measuring the stress-strain behavior in a tensile test. Stress 9 = force/initial cross-sectional area of sample e, where is the modulus of elasticity and strain s - (L—Lo)/Lq.

Figure 2.15 Measurement of tensile strength (stress/strain) of a sample of material. A force (in newtons, N) is applied to a dumbbell test sample of Initial length L (in cm) and initial section S (in cm. The mobile jaw is moving at a slow speed and the relative strain (AL/L x 100) is measured.

The material properties of the ACL are mainly determined from the stress-strain relationship of tensile tests. Stress is applied force per unit cross-sectional area, while strain is deformation divided by initial length. The stress-strain relationships of collagenous tissues are usually nonlinear they increase slowly at low strain in the so-called toe region, have constant slope at middle strains in the linear region, and then decrease at high strain in the prefailure region (Fig. 6.1). It is known that... 

The most important mechanical property of natural rubber blended materials is their tensile or stress-strain relationship as shown in Figure 20.1. Stress is the force applied to produce deformation of a unit area of a test specimen. The standard unit of this value presents in Pascals (Pa) or pounds per square inch (psi). Strain is the ratio of elongation or deformation to the gauge length of the test specimen per unit of the original length. It is expressed as a... 

The maximum mentioned above as occurring in region 2 corresponds to the condition (12.2). This condition involves the nominal stress only, and the existence or otherwise of a maximum in the true stress is unspecified by the physical arguments employed so far. Observations show that a maximum in true stress may arise or may not, depending on the polymer and test conditions. This is well illustrated in the work of Amoedo and Lee [7]. In Figure 12.5, two sets of tensile true stress-strain curves are shown, one set for... 

Keywords polyamide (PA), polyethyleneterephthalate (PET), tensile properties, stress, strain, tensile strength, break. Young s modulus, elasticity, system compliance, grips, ASTM, ISO, design, test... 

Tensile Testing. The most widely used instmment for measuring the viscoelastic properties of soHds is the tensile tester or stress—strain instmment, which extends a sample at constant rate and records the stress. Creep and stress—relaxation can also be measured. Numerous commercial instmments of various sizes and capacities are available. They vary greatiy in terms of automation, from manually operated to completely computer controlled. Some have temperature chambers, which allow measurements over a range of temperatures. Manufacturers include Instron, MTS, Tinius Olsen, Apphed Test Systems, Thwing-Albert, Shimadzu, GRC Instmments, SATEC Systems, Inc., and Monsanto. 

Test Method for Tensile Stress—Strain of Carbon and Graphite... 

Elements that can dissolve in copper, such as zinc, tin, and nickel for example, increase annealed strength by varying amounts depending on the element and the quantity in solution. The effect of selected solution hardening elements on tensile properties of annealed copper aUoys is iUustrated by the data in Table 4, where the yield strength is the stress at 0.2% offset strain in a tensile test. 

The plastic behaviour of a material is usually measured by conducting a tensile test. Tensile testing equipment is standard in all engineering laboratories. Such equipment produces a load/displacement (F/u) curve for the material, which is then converted to a nominal stress/nominal strain, or cT l , curve (Fig. 8.10), where... 

In a tensile test, as the load increases, the specimen at first is strained elastically, that is reversibly. Above a limiting stress - the elastic limit - some of the strain is permanent this is plastic deformation. 

Sketch curves of the nominal stress against nominal strain obtained from tensile tests on (a) a typical ductile material, (b) a typical non-ductile material. The following data were obtained in a tensile test on a specimen with 50 mm gauge length and a cross-sectional area of 160 mm. ... 

ASTM C 749-92, "Standard Test Method for Tensile Stress-Strain of Carbon and Graphite". ASTM Standards Vol. 15.01, pp. 196 207, Pub. American Society for Testing of Materials, Philadelphia, USA (1994). 

This equation is the basis of linear viscoelasticity and simply indicates that, in a tensile test for example, for a fixed value of elapsed time, the stress will be directly proportional to the strain. The different types of response described are shown schematically in Fig. 2.1. 

J7 In a tensile test on a plastic, the material is subjected to a constant strain rate of 10 s. If this material may have its behaviour modelled by a Maxwell element with the elastic component f = 20 GN/m and the viscous element t) = 1000 GNs/m, then derive an expression for the stress in the material at any instant. Plot the stress-strain curve which would be predicted by this equation for strains up to 0.1% and calculate the initial tangent modulus and 0.1% secant modulus from this graph. 

As shown in Fig. 3.4 stress-strain tests on uniaxially aligned fibre composites show that their behaviour lies somewhere between that of the fibres and that of the matrix. In regard to the strength of the composite, Ocu, the rule of mixtures has to be modified to relate to the matrix stress, o at the fracture strain of the fibres rather than the ultimate tensile strength, o u for the matrix. 

The mechanical properties were obtained using a tensile machine at room temperature and for a strain rate of 1000%/h. Each reported value of the modulus was an average of five tests. The tensile modulus Et was taken as the slope of the initial straight line portion of the stress-strain curve. 

Test rate and property The test rate or cross-head rate is the speed at which the movable cross-member of a testing machine moves in relation to the fixed cross-member. The speed of such tests is typically reported in cm/min. (in./min.). An increase in strain rate typically results in an increase yield point and ultimate strength. Figure 2-14 provides examples of the different test rates and temperatures on basic tensile stress-strain behaviors of plastics where (a) is at different testing rates per ASTM D 638 for a polycarbonate, (b) is the effects of tensile test-... 

---