Tensile test equipment

Load frames for tensile testing are available in a range from less than 1 kN to over 300 kN. Environmental chambers that fit around the sample can be used to study low- or high-temperature behaviour, and are typically available to control temperatures in the range - 70-250°C. 

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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... 

Blatz and Ko19 added a special attachment to their uniaxial tensile testing equipment (Fig. 5). In this, a sheet specimen of rubber is stretched by chucks attached to its four edges, but, differing from the apparatus of Rivlin and Saunders, the chucks can be moved smoothly on the rigid tracks so that it is possible to strech... 

The mechanical properties of both fibres and textile stmctures are important to determine the suitability of dmg-releasing textiles in various applications. Tensile strength and extension to break values can be determined using standard tensile testing equipment. These values provide a good indication of the mechanical durability of the textiles before and after treatment with bioactive agents. Kumar and co-workers have reported that the bioactive textiles used in regenerative medical applications... 

Tensile tests at 75 °F were made on standard tensile testing equipment. For tests at —320°F, specially constructed cryostats for the liquid-nitrogen coolant were used. All specimens were completely submerged in liquid nitrogen for a minimum of five minutes... 

Fig. 1, Schematic iiiustration of two grip designs used in current tensile test equipment,...

When the stress is calculated as the applied force or load divided by the original cross-section area of the sample, it is called the nominal stress. This is what is measured in much tensile test equipment. However, when the sample is stretched, in order for the volume to remain constant, the cross-section area decreases. Then the applied force or load divided by the actual changing cross section area is called the true stress. In what follows, we shall use only Young s modulus when describing the mechanical properties of solid polymers. However, the essential property of a liquid is that it flows under the influence of a shearing stress. Consequently, when we come to look at molten or hquid polymers, we shall deal with shear moduli (Figure 4.2) and the related property of viscosity. 

Tensile ASTM D638 Tensile strength, elongation to break Tensile testing equipment... 

Of the desired properties, tensile strength and Young s modulus are relatively easy to measure with tensile testing equipment which has been cryostated for low temperature service. A load cell was used to measure force on the specimen, and a dial gage indicated the corresponding elongation, while a low temperature fluid surrounded the specimen. The entire stress-strain curve can be obtained in this way. 

The molded I-beam and welded butt and shear joint samples were then tested in tension using tensile testing equipment (Instron - Model 4468) and the loads at failure recorded. The crosshead speed was set at 5.08 mm/min. All the welded samples failed at the weld interface. For butt welds the failure stress was calculated by dividing the load by the cross sectional area of the web. 

Methods used for the tensile testing of single fibers and fibers taken from yams and tows are discussed in ASTM D3822 and D2101. Measurement equipment used in fiber tensile testing is described in ASTM D76. An overview of test procedures and their significance is also available (3,10). 

Dynamic shear moduli are conveniently determined with automated equipment, for instance, with the torsion pendulum. However, moduli derived from dynamic tests are often higher than the results from static tests for lack of relaxation. Examples are shown in Table 3.3. Young s moduli of the polymers A, B, C, D, derived from tensile tests (frequency 0.01 Hz) are compared with shear moduli S determined with the torsion pendulum (frequency > 1 Hz). For rubberlike materials is 3S/E = 1, according to Eq. 

ISO 5893 2002 Rubber and plastics test equipment - Tensile, flexural and compression types (constant rate of traverse) - Specification ISO 6237 2003 Adhesives - Wood-to-wood adhesive bonds - Determination of shear strength by tensile loading... 

ISO 844 2001 Rigid cellular plastics - Determination of compression properties ISO 3386-1 1986 Polymeric materials, cellular flexible - Determination of stress-strain characteristics in compression - Part 1 Low-density materials ISO 3386-2 1997 Flexible cellular polymeric materials - Determination of stress-strain characteristics in compression - Part 2 High-density materials ISO 5893 2002 Rubber and plastics test equipment - Tensile, flexural and compression types (constant rate of traverse) - Specification ISO 7743 2004 Rubber, vulcanized or thermoplastic - Determination of compression stress-strain properties... 

Material Properties. The elementary form of the analysis used requires the following properties of propellant during cure tensile modulus, effective bulk modulus, and propellant volume change. Each of these properties changes with temperature and time elapsed since casting. Because of the unusual nature of the material (sticky, wet, explosive, gravel ), special tests, equipment, and techniques were developed for these measurements. 

Whilst all aspects of a laboratory s operation require systematic control, it is the calibration of test equipment which gives rise to most problems and which is also the most expensive. All test equipment and every parameter of each instrument requires formal calibration. For example, it is not good enough to calibrate the force scale of a tensile machine, there are also requirements for speed of traverse, etc. plus associated cutting dies and dial gauges. 

In practice, tensile tests on ceramic objects are hardly ever done because it is difficult to clasp them between the jaws of the testing equipment. The object is damaged by the jaw and a crack is very likely the result and this could be the place where the sample will break. The price of the test dumbbells is also a drawback of this type... 

Linder rotating furnace procedure, 36 research and control methods, 32 tablet disintegration test, 36 tensile testing, 32 see also Strength of agglomerates Suppliers of size enlargement equipment, 177... 

Tensile tests at low to intermediate displacement rates (i.e. 1, 10, 100 and 500 mm/min) were performed by an Instron tensile tester model 4502 equipped with a 1 kN load cell. Temperature in the range from 0°C to 70°C was controlled by an Instron thermostatic chamber model 3119. Tests at the moderately high displacement rate of 60000 mm/min (1 m/s) were carried out at room temperature by an instrumented CEAST impact pendulum in the tensile configuration. Load data were collected at a sampling time of 30 p.s and load vs displacement curves were provided directly by the CEAST software (DAS 4000 Extended Win Acquisition System Ver. 3.30). 

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