Stretching modulus

Some tests, while undergoing deformation, are usually referred to as static in that they are performed at slow speeds or low cycles. Examples of these tests are stretch modulus, ultimate tensile, and elongation to break, ie, a measure of total energy capabiUties or mpture phenomena. 

Fig. 11. Stretching (a) and bending (b) of a membrane with the corresponding elastic stretching modulus and elastic bending modulus k. In case of stretching, the stress a is...

Some tests, while imdergoing deformation, are usually referred to as static, in that they are performed at slow speeds or low cycles. Examples of these tests are stretch modulus, ultimate tensile strength, and elongation to break, ie, a measure of total energy capabihties or rupture phenomena. Dynamic properties are measured by continuous cycles of varying deformation (tension, compression, or shear), at varying frequencies which can be set close to that which a component would experience in a tire. These properties are more correlative to many tire performance parameters. 

The peristaltic force [625] originates from the configurational confinement related to the peristaltic (squeezing) mode of deformation of a fluid bilayer (Figure 4.39b). This mode of deformation consists in fluctuation of the bilayer thickness at fixed position of the bilayer midsurface. The peristaltic deformation is accompanied with extension of the bilayer surfaces. Israelachvili and Wennerstrom [625] demonstrated that the peristaltic disjoining pressure is related to the stretching modulus, of the bilayer ... 

Only a simplified version of the fluid plate model is presented here to establish a crude relationship between the stretching modulus and the bending rigidity of fluid monolayers. The resulting formulas, frequently used in the literature, permit some estimates and serve to illustrate the role of the reference surface. 

There are several methods for the experimental measurement of. One of these, [1] consists of determination of the effective stretching modulus of a membrane fluctuating at very low tensions. The principles of the method are shown on Figure 14.1. 

Properties of undrawn PFA fibers as a function of testing temperature are listed in Table 8.45. It is important to note that the values in Table 8.45 refer to the as-extmded fiber directly from the die and prior to any stretching. Modulus dropped off significantly while... 

When the particle is brought into contact with the membrane, the membrane will deform in order to increase the amount of its surface area that adheres to the particle. This is driven by the decrease in energy upon adhesion, and is opposed by the increase in bending energy, which depends upon k, and the increase in stretching energy, which depends upon the stretching modulus K and the membrane tension X. 

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