This calculator presents three methods to determine the Poisson ratio of an object. Poisson ratio is the ratio of lateral strain and longitudinal (or axial) strain of a deformed object.
Calculators
Three methods to calculate Poisson ratio:
Method 1) Strains
Method 2) Shear Modulus
Method 3) Length & Width Dimensions
Explanation
Poisson ratio is a measure of how a material deforms when it is stretched or compressed. It is the ratio of the change in width to the change in length of a material.
The ratio between the change in diameter, ΔD, and the original diameter, D is the lateral strain. The ratio between the change of the length, ΔL, and the original length, L, is the axial strain. The ratio between the lateral strain and the axial strain is the Possion ratio.
Object deforming due to being compressed longitudinally
For isotropic materials (materials with the same properties in all directions), the Poisson ratio could also be calculated using the Shear Modulus and Stiffness of the object using the following formulae:
E=2G(1+v)
.
Poisson ratio typically vary from 0 to 0.5.
A Poisson ratio of 0.5 means the material expands laterally as much as it contracts longitudinally when under axial compression, and vice versa.
A Poisson ratio of 0 indicates that the material experiences no lateral strain when under axial load, and vice versa.
Auxetics are materials that have a negative Poisson ratio, which means they expand laterally when stretched longitudinally and vice versa.
Examples of Poisson ratio for common materials:
Rubber, is an example of a material with a high Poisson ratio of around 0.5. When stretched, its length increases, but its width also decreases; when compressed, its length decreases, but its width increases.
Cork, is an example of a material with a low Poisson ratio of almost 0. When stretched, its length increases, but its width does not decrease; when compressed, its length decreases, but its width does not increase.
Concrete has a Poisson ratio of 0.2 as codified in AS 3600
Structural steel has a Poisson ratio of 0.25 as codified in AS 4100