Poisson's coefficient relates imparted strain in transverse load direction with the longitudinal strain.
This coefficient gives information about the volume variation that is experienced by isotropic materials when a hydrostatic load is applied to them.
The following expression shows that it does not see values greater than 0.5. The value of 0.5 corresponds with incompressible materials.





Poisson coefficient can be calculated by means of the relation E and G. Also, it can be calculated by measuring the thickness reduction and the elongation.