How Can Poisson's Ratio Reach -1?

[I_am_no1]

v = [tex]\epsilon[/tex]_trans/ [tex]\epsilon[/tex]_axial

where

ν is the resulting Poisson's ratio,
[tex]\epsilon[/tex]_trans is transverse strain
[tex]\epsilon[/tex]_axial is axial strain
and Poissions Ratio have range and its not more then 0.5 and not less then -1?

so my question is how its value can turn "-1"?

As its already neative and its axial strain or transverse strain one must be negative so the value of Poissions Ratio will turn positive! what do you say!

 

[tiny-tim]

Hi I_am_no1!

These are auxetic materials … see http://en.wikipedia.org/wiki/Auxetic"

 

[sir-pinski]

Poisson's ratio is a material property that describes the relationship between the transverse strain and axial strain of a material when subjected to an external force. It is represented by the symbol ν and is typically expressed as a decimal value. The range of Poisson's ratio is from -1 to 0.5, meaning it can take on values between -1 and 0.5.

As for how the value can turn -1, it is possible for Poisson's ratio to have a negative value. This occurs when the material experiences a negative transverse strain, meaning it becomes thinner when stretched. This is a rare phenomenon and is only observed in certain materials, such as auxetic materials.

It is important to note that Poisson's ratio is not always negative and can also be positive or zero. It depends on the material's response to external forces. A material with a positive Poisson's ratio will become thicker when stretched, while a material with a zero Poisson's ratio will maintain its shape when subjected to an external force.

In summary, Poisson's ratio has a range of -1 to 0.5 and its value can turn negative when the material experiences a negative transverse strain. It is a unique material property that helps in understanding the behavior of materials under external forces.