Poisson’s Ratio: Understanding Material Deformation

by Yuvi K - December 25, 2023

Poisson Ratio: Meaning & Explained

Poisson’s ratio is a key property of materials which determine their deformation during loading. It is a measure of the ratio of transverse strain to axial strain, and was named after French mathematician and physicist Simeon-Denis Poisson. It is usually represented mathematically as ‘ν’ and pronounced as ‘nu’, and its value is usually in between -1 and 0.5. It holds a lot of importance in materials science, manufacturing processes, and everyday life.

Poisson’s ratio Explained

Consider a cube which has been compressed along one of its sides, resulting in it transforming into a cuboid. As the cube is compressed, the cube’s transverse dimensions (breadth and height) would reduce while the axial dimension (length) would increase. The ratio of the decrease in transverse strain to the increase in axial strain is known as the Poisson’s ratio.

Materials Behaviour in terms of Poisson’s Ratio

Most materials have a negative Poisson’s ratio, which means that when extension and compression forces are applied to a material in one direction, dimension in other directions would at least be reduced if not increased. There are also a few materials which may have a positive Poisson’s ratio which means they become thicker or wider in opposition to the direction in which the forces are applied.

Table Showing Poisson’s ratio in Various Materials

Poisson’s ratio is a measure of the deformation of a material in directions perpendicular to the direction of loading.

Significance of Poisson’s ratio

Poisson’s ratio is significant for many reasons:

Engineering: Poisson’s ratio is important while doing engineering design and calculations. It is taken into consideration while predicting the behaviour of different materials under strain or during composite layup.

Architecture: Its importance in architecture lies in predicting the behaviour of materials like glass, for instance, on which the building designs are based.

Manufacture: It is also used by manufacturers to see how a material should be treated to obtain the desired configuration.

Medicine: Poisson’s ratio is also used in medical treatments. It is used to predict the change in the dimensions of a material when it is subjected to strain, which is beneficial in many medical scenarios like treating fractures or performing operations.

Poisson’s ratio in Hindi

पॉयसन की अनुपात मात्रिक तंत्र और गुणवत्ता प्रणाली में ऐसी भूमिका निभाती है जो वस्तुओं की लगाव से विकसित तौली लागू होती है। यह एक तरह का अंतर है उभराव के ऊपर की तरह औसत ऊर्जा में। यह सामान्य रूप से पॉयसन के नाम से प्रस्तुत किया जाता है, और इस अंतर को पॉयसन अनुपात (ν) में विवरण किया जाता है। इसके चित्रों में यह मान -1 से 0.5 तक होता है।

Conclusion

Poisson’s ratio is an important property which determines the behaviour of materials when external forces are applied to them. It is applicable in many different fields like engineering, architecture, and manufacturing. Knowledge of Poisson’s ratio is used everywhere for the prediction of material behaviour in opposition to the direction of the force applied to them.