When you characterize a nonlinear material in Advanced Material Exchange, you must specify the environment you wish to use for the structural analysis. At this time, Advanced Material Exchange does not interpolate between environments. If you have both tensile and compressive data, you must select an environment for each response.
If you plot the idealized response of your nonlinear material, you can select the environment to use below the displayed plot. Select one tensile, and one compressive (if applicable) environment and click OK.
If you do not view the plot of the nonlinear material, you must use the Select Environment button.
(Material > > Select Environment).