Auxetic materials have a negative

Poisson's ratio when stretched becoming thicker in a direction perpendicular to the direction of the applied force.

The observations of Dzegniuk (1970) and Sroka (1973) regarding the [mu] factor value we can infer that the corresponding range of values of the

Poisson's ratio [nu] is:

In these tests, it can be observed that the viscous

Poisson's ratio increases in compression, but remains virtually constant in tension.

The matrix will be assumed as an elastic material: Young's modulus [E.sub.M] =10 MPa and

Poisson's ratio [v.sub.M] = 0.495.

Figure 5 shows the effect of the changes in

Poisson's ratio [v.sup.s], on the radial displacement and the amplitude of the circumferential stress.

[15] believed that the plastic zone has a close relationship with

Poisson's ratio of rock mass.

Evidently, the domain of definition of any single-valued continuous function that can be selected to approach the

Poisson's ratio of this intermediate phase between fiber and matrix is the interval [[r.sub.f], [r.sub.i].

Based on strain measurements of the composites,

Poisson's ratio of the composites was calculated.

Limits to

Poisson's ratio in isotropic materials--general result for arbitrary deformation.

These elastic constants include the

Poisson's ratio, which characterizes the resultant strain in the y-direction for a material under longitudinal deformation in the x-direction[7].

Materialization of specimens possessing

Poisson's ratio was implemented by performing three-axial compression with heat treatment.

As we all know, the stress is independent from Young's modulus E and

Poisson's ratio v for SS model.