What is Poisson’s Ratio?
The negative ratio of transverse strain to lateral or axial strain is known as Poisson's ratio. It is identified by the Greek letter "nu" and is named after Siméon Poisson.
The Poisson’s ratio is represented as mew (μ) or 1m. In the same context, different materials have different Poisson ratios. The maximum value of Poisson's ratio is 0.5, and the minimum value is 0. In exception, human tissue is (-1) Poisson's ratio. There is no unit of Poisson's Ratio. Different values of Poisson's ratio are listed below -
Types of Material
0.10 - 0.20
0.20 - 0.30
0.25 - 0.33
0.33 - 0.36
0.45 - 0.50
0.265 - 0.34
0.30 - 0.45
0.10 - 0.50
Poisson’s Ratio Formula
Poisson’s ratio is formulated as a ratio of change in diameter to the original diameter or lateral changes to the linear changes as change in length to the original length. These changes in dimension are known as a strain. So basically, Poisson's ratio is the strain ratio in lateral to linear dimension.
Poisson’s ratio = Lateral strain/Linear strain
Poisson’s ratio (μ) = (Change in width, diameter, thickness/Original width, diameter, thickness)/(Change in length/Original length)
Poisson’s ratio (μ) = (δd/d)/(δL/L)
1/m = Lateral strain/Linear strain
Range of 1/m is 0 ≤ μ ≤ 0.5. Only in exception case is this limit as the minimum value as -1.
Poisson’s Ratio of Steel
The Poisson's ratio of material changes as per the type of material. Soft materials like rubber, copper, and brass have a higher Poisson's ratio, while hard materials like steel, wrought iron, and concrete have a low Poisson's ratio. In comparison to all, we need steel as mild steel, structural steel, and hysd steel bar. The Poisson’s ratio of steel is given below.
High Carbon steel