Elasticity or Young modulus

These are determined from a stress-strain curve of material and include the values of breaking stress (N/denier), referred to as tenacity, breaking strain (%), and initial modulus (also referred to as the elastic or Young modulus). The tenacity values can be converted from the textile (ut) to the engineering or SI ((7e) values by the relation shown below. Exactly the same relation can... 

The proportionality constant (E) is the elastic or Youngs modulus [20]. It is a measure of the stiffness or resistance against deformation. The material behaves elastically up to the yield point (P at which the stress is called yield stress (o ). Beyond this point the material behaves as a plastic, rather than as an elastic solid. Brittle materials can be distinguished from plastic materials by the absence of the P stress increases proportionally with strain until the material breaks. 

The ratio of stress to strain in the initial linear portion of the stress—strain curve indicates the abiUty of a material to resist deformation and return to its original form. This modulus of elasticity, or Young s modulus, is related to many of the mechanical performance characteristics of textile products. The modulus of elasticity can be affected by drawing, ie, elongating the fiber environment, ie, wet or dry, temperature or other procedures. Values for commercial acetate and triacetate fibers are generally in the 2.2—4.0 N/tex (25—45 gf/den) range. 

E modulus of elasticity or Young s EVOH ethylene-vinyl alcohol... 

What does the modulus of elasticity, or Young s modulus, indicate ... 

Table 1.4 reports values of the modulus of elasticity, or Young s modulus. This is another mechanical property which represents the stiffness of the material, or its resistance to elastic strain. More precisely, Young s modulus is the stress required to produce a unit strain by changing sample length. Table 1.4 shows that the modulus is considerably higher in the carbides and nitrides than in the metals, with values resembling those of the ceramic materials. Diamond, again, is special. 

Pad porosity is inversely related to its density. Many physical properties of the polyurethan pad are strongly dependent upon its porosity (or density). The hardness and Young s modulus (elastic or storage modulus) of porous pads have a clear linear correlation with the density (or porosity) of the pads [1]. It is obvious that nonporous (noncell) pads have much smaller variability in density and other physical properties compared to porous pads. Nonporous pads have much higher strength, modulus, hardness, and elongation than porous pads. 

Elastic modulus or Young modulus arc frequently used to characterize filled sys-... 

Here, l0 is the original length of the elastomer, and / is the length of the elastomer under load. There are no units for strain. To get an idea of the elasticity of an object, we discuss the modulus of elasticity, or Young s modulus, also denoted by E. This value is the slope of the stress-strain curve and is a measure of the material s tendency to deform in an elastic manner. Its units are typically megapascals and it is represented by... 

The elastic or Young s modulus is the initial slope of the stress-strain curve and gives a measure of the resistance to deformation of the material. The ultimate tensile strength is the stress required to rupture the sample, and the ultimate elongation is the extent of elongation at which the rupture of the sample occurs. 

In general, the elastic or Young s modulus M, a characteristic property of a material, is a measure of the... 

Where E is the elastic, or Young s, modulus with units of N m" or Pa. Such measurements are normally carried out in tension or bending, when the sample is a soft material or a liquid then measurements are normally carried out in shear mode, thus a shear modulus (G) is measured. The two moduli are related to one another by ... 

The second derivative, which determines the curvature, of the potential energy well near r, is constant for a given material and temperature, leading to Hooke s law F = Ku. The constant K is proportional to the elastic, or Young s modulus... 

The tensile modulus (also elastic, or Young s modulus) E is the stress-to-strain ratio within its proportional limit for a material under tensile loading (in practice, the initial slope of the stress-strain curve). The tensile strength represents the maximum tensile stress observed when the specimen is being pulled. It may or may not coincide with the ultimate strength, ie, the tensile stress at specimen failure. In tough materials it can be equal to the jdeld stress. The flexural modulus is the stress-to-strain ratio within its proportional limit for a material... 

Other penetrometer-indentometers include transducers to sense the position and movement of the probe and microprocessors for temperature control and data collection and reduction. These instruments are used mainly to measure softening points, which are not glass transitions but are usually close to those values. Because a softening point is indicative of behavior under load, it is often more useful for predicting performance than the Tg. Penetrometer-indentometers can also be used to measure indentation hardness, creep, creep recovery, and modulus. Examples of such instruments include the TA Instruments, Mettler, Perkin-Elmer, Seiko, and Shimadzu thermomechanical analyzers (TMAs). They can be used to generate modulus and modulus-temperature data from indentation-time plots by applying the Hertz equation (eq. 36) (170,296), where E is the elastic or Young s modulus, jx the Poisson s ratio, r the radius of the hemispherical indentor, P the force on the indentor (mass load x g), h the indentation, and ifk the indentation hardness. 

Mechanical properties of PET depend on its final form and hence on the fabrication process (see section 4.6). PET materials can be obtained under the form of amorphous or semi-crystalline films, oriented films or fibers. The simplest way to evaluate the mechanical property of a material is the establishment of stress-strain curves (Figure 4.1). From these curves, it is easy to obtain the Modulus of elasticity (or Young s Modulus), the strength to break (o and the strain to break (e. These values are collected in Table 4.1 for amorphous, semi-crystalline and glass fiber reinforced PET material (film obtained by injection). 

Here, E is the slope of the line shown in dotted lines in Figure A.5, and referred to as the modulus of elasticity or Young s modulus. The index n is... 

The slope of the curve where stress and strain are almost proportional represents a measure of the material s stiffness. In this region the ratio of stress to strain is known as the modulus of elasticity or Young s modulus. At the first bend in the curve (1) the stress value represents the yield point and is a measure of the strength of the material and its resistance to permanent deformation. Before the yield point is reached... 

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