Uniaxial Tension and Compression Input Data

How do you use uniaxial tension and compression data for rubber?

You can use test data directly with the response function hyperelastic model. This does not require any curve fitting and will use the data exactly. You must separate and enter the uniaxial tension and compression data directly. You also need to define the compressibility, either by including pressure-volume test data or specifying the material compressibility parameter. Details of the response function hyperelastic model can be found in the Ansys Help sections here.

Curve-fit to hyperelastic model:

If you want to perform curve fitting on predefined hyperelastic models, you should include both compression and tension in the uniaxial test data. Be sure to put the values in ascending order, and there should be a (0,0) data point.