Determination of elastic modulus

Determination of Elastic Modulus Varying as a Function of Strain during a Cycle. To determine the elastic modulus which varies as a function of strain, we superimpose a small amplitude, high frequency... 

Sakurada, I., Nukushina, Y., Ito, T. Experimental determination of elastic modulus of crystalline regions in oriented polymers. J. Polym. Sci. 57, 651-660 (1962)... 

Special software (HILLGUS) was also developed for material characterizations such as the determination of the modulus of elasticity for building materials. 

In a uniaxial tension test to determine the elastic modulus of the composite material, E, the stress and strain states will be assumed to be macroscopically uniform in consonance with the basic presumption that the composite material is macroscopically Isotropic and homogene-ous. However, on a microscopic scSeTBotFTfhe sfre and strain states will be nonuniform. In the uniaxial tension test,... 

The peculiarities of dynamic properties of filled polymers were described above in connection with the discussion of the method of determining a yield stress according to frequency dependence of elastic modulus (Fig. 5). Measurements of dynamic properties of highly filled polymer melts hardly have a great independent importance at present, first of all due to a strong amplitude dependence of the modulus, which was observed by everybody who carried out such measurements [3, 5]. 

Actually, crosslinks control the molecular packing and indeed significantly affect the elastic modulus of the material. As the intermolecular energy of kink formation is also determined by elastic modulus, the yield stress will definitely vary with modulus and thus the cross -linking density. In other words, crosslinks may not seriously affect the activation segment configuration in the molecular chain but will indirectly control the yield stress. 

Different instrumentation is needed for the determination of meaningful modulus values over wide viscosity and elasticity ranges. 

For anisotropic materials torsion is discussed in the books by Love, Lekhnitskii175 and Hearmon185. The torque M now depends not upon one elastic constant only, as in the isotropic case, but upon two. This makes the determination of shear modulus by a torsion test a difficult task and requires careful experimentation. Early work on this for polymers was done by Raumann195, by Ladizesky and Ward205 and by Arridge and Folkes165. 

The first part of the graph is linear for most materials and is used to determine the elastic modulus or E-modulus according to Hooke s law in formula ... 

A tensile test on the peel arm is used to obtain the parameters of elastic modulus, plastic modulus and yield strain. In this test, it has been necessary to use an extensometer for measuring strain at small magnitudes (i.e. up to about 2%) in order to obtain sufficient accuracy in the determination of Ei. It is also important to continue the tensile test to fracture, in order to define enough of the plastic region for an accurate... 

Bending beam theory calculation of elastic modulus, 361-362 calculation of glass temperature, 362 calculation of thermal expansion coefficient, 362 layer stress determination, 361 Benzophenone-3,3, 4,4 -tetracarboxydi-anhydride-oxydianiline-m-phenylenediamine (BTDA-ODA-MPDA) polyimide, properties, 115-116 Bilayer beam analysis schematic representation of apparatus, 346,348/ thermal stress, 346 Binary mixtures of polyamic acids curing, 116-124 exchange reactions, 115 Bis(benzocyclobutenes) heat evolved during polymerization vs. 

ASTM D 790 also describes determination of the modulus of elasticity (MOE), or flexural modulus, which is the ratio of stress to corresponding strain. It is calculated by drawing a tangent to the steepest initial straight-line portion of the load-deflection curve, which is essentially a load at which the specimen deflects by 1 in. 

A part of this peculiar variation in the stress-strain phase angle difference comes from the variation of elastic modulus with the phase angle. Therefore, to determine the phase angle difference which is caused by the nonelastic contribution, it is necessary to determine and to subtract the contribution from the variation of elastic modulus as a function of the strain. 

A further group of pellets tested were 2.0mm thick, 28mm diameter llmol% scandia, and the preferred mixed dopant zirconia. Fig. 5 shows the results of many slow tests to determine the dependence of elastic modulus with temperature. This is similar to the behaviour of yttria zirconia under temperature, where a significant drop is evidenced irom approximately 300°C upwards. For mechanical integrity the decrease in elastic modulus is good news because it means there is more flexibility to relieve any loads on the electrolyte material by strain. Note that the effect of the binder is to decrease the elastic modulus. There is a 7% reduction at room temperature -and this is very similar to that which would be expected by the increase of 5% porosity indicated by the difference in density. ... 

The elastic modulus for stretching human hair, determined in our laboratories at 60% RH and room temperature, is 3.89 x 10 °dynes/cm. Methods other than load-elongation have been used to determine the elastic modulus of hair fibers. These methods [10,11] are described later in this chapter. 

If a polymer sample is subjected to a mechanical stress or to an electric field the structure responds, i.e. relaxes, in such a way as to reach an equilibrium under the stress or the field. This response generally involves some rearrangement of the structural units of the polymer, i.e. changes in the proportions of the various conformational or orientational states of its molecules, and it is the nature of these changes and the extent to which they take place that determine the elastic modulus or dielectric constant of the polymer. In the rest of this section and in section 5.7.3 it is assumed that the equilibrium ratio of the numbers of molecules in a particular pair of states between which jumps take place is actually influenced by the stress or electric field. This is so for many such pairs of states, but not for all pairs (see sections 7.6.1 and 9.2.5). 

Testing of plastics - Tensile test (withdrawn replaced by ISO 527-3 1995) Testing of plastics - Determination of the modulus of elasticity by tensile, compression and flexural test (withdrawn replaced by ISO 527-3 1995)... 

The shear moduli, G, the elasticity modulus and G , the viscosity modulus, were determined. The elasticity modulus is defined as the relationship of elastic pressure (in phase) to the applied force and is dependent on the ability of a substance to store energy elastically. It represents a measure of the number of interactions in a specific system. The value of the elasticity modulus G is proportional to the... 

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