Strain Contours
Contours of strain can be viewed by selecting either Volumetric Strain or Maximum Shear Strain from the Interpret toolbar list.
Volumetric Strain
(i.e. the sum of the strain components in the x, y and z directions). For plane strain analysis the out-of-plane (z) strain = 0, therefore the volumetric strain = 
.Maximum Shear Strain
where 
= major principal strain, and 
= minor principal strain. For plane strain analysis these correspond to the major and minor principal stress directions in the x-y plane.