The Mechanical Models tab of Thermoplastics material dialog displays the Ramberg-Osgood co-efficients of the material.
These values are for users who want to run a structural analysis in the non-linear region of the Stress-Strain curve.
Note: These values in no way alter the Moldflow analysis.
To access this dialog, right-click 
in the Study Tasks pane, then select Details from the drop-down menu.