Third Invariant of Strain#

Third Invariant of strain = {yes | no}

Description / Usage#

The strain tensor is associated with the deformation of the mesh. Its third invariant indicates the volume change from the stress-free state (IIIE = 1.0 indicates no volume change). This variable is called IIIE in the output EXODUS II file.

The permissible values for this postprocessing option are:


Calculate the third invariant.


Do not calculate the third invariant.


Following is a sample card:

Third Invariant of strain = yes

Technical Discussion#

The mathematical definition of the third invariant is related to the determinant of the strain tensor, which is defined for the various constitutive equations in the manual entry for the Solid Constitutive Equation card.


No References.