Mike Rife
Ansys Employee

Hi Lovisa

In traditional FEA parlance a contour plot is a color-coded plot of some field result plotting on the FEM.  Which is what that strain energy density plot you posted is showing.  If I understand the isoline plot you show, then the strain energy density can be calculated from the materials specific strain energy density function for differing values of lambda (principal stretch ratios).  Stretch ratios are engineering strain plus 1.