Directional property uniaxial load

The Poisson ratio can be used to characterize the mechanical property of a solid. It is defined as the negative quotient of the strain in the transverse direction to the strain applied in the longitudinal direction. For a uniaxial loading along the c-axis ... 

The important point to note from this Example is that in a non-symmetrical laminate the behaviour is very complex. It can be seen that the effect of a simple uniaxial stress, or, is to produce strains and curvatures in all directions. This has relevance in a number of polymer processing situations because unbalanced cooling (for example) can result in layers which have different properties, across a moulding wall thickness. This is effectively a composite laminate structure which is likely to be non-symmetrical and complex behaviour can be expected when loading is applied. 

As the third major measurement to try to determine the remaining properties G 2 S, consider uniaxial tension loading at 45° to the 1-direction on a flat piece of iamina, i.e., a 45° off-axis test, as shown in Figure 2-26. By measurement of alone, obviously... 

Table 4.4 summarizes the physical properties of common metals used for diaphragms. Young s modulus is a measure of the stiffness of elastic materials and is defined as the ratio of stress (uniaxial) versus the strain (uniaxial), i.e. the ratio of the change in length of an elastic material as a function of a tensile or compressive load. The Poisson s ratio is a measure of a material s tendency to contract under a tensile load, i.e. the contraction in the direction normal to the direction in which the material is stretched. The symbol for the shear modulus of elasticity is G. 

Cross-sectional area versus load stress is an important parameter for evaluating the tensile strength of materials. To assess the mechanical properties of a uniaxial structure with many fine voids such as that of the one-step-drawn P(3HB-co-3HV) fiber after isothermal crystallization, one needs to know its true cross-sectional area. We therefore derived the cross-sectional areas of the oriented fiber from the cross-sectional images perpendicular to the drawing direction using image analysis... 

A direct simple method to study the viscoelastic properties of a given sample is the creep experiment It is carried out by instantaneously applying a constant force, which is then followed by a measurement of the resulting deformation as a function of time. Figure 5.1 indicates schematically a possible result, referring to the case where an uniaxial tensile load is applied, which then leads to an elongation AL. In general, it will be found that the creep curve represents a superposition of three contributions... 

Fig. 5.13 Measured load plotted as a function of extension for the four sets of samples of the model linear polymer subjected to uniaxial tension increasing at a rate of 5 bar ps"f Data for each set are averaged over five samples, the four sets are based on polyethylene model PE I. The samples were prepared directly in the glassy state and sets A-D have different configurational properties (see Table 5.1) as a result of different preparation procedures.

Finally, the uniaxial behavior of the composite material is anisotropic, i.e., depending on the loading direction with respect to the material axes, namely, the directions parallel and normal to the bed joints. The compressive strength of masomy in the direction normal to the bed joints has been traditionally regarded as the sole relevant structural material property, at least until the recent introduction of numerical methods for masonry structures. A test frequently used to obtain this uniaxial compressive strength is the... 

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