Consider the following example scenario.
NX Nastran non-linear statics (SOL 106) has been used to analyse a structure for which non-linear material properties have been defined and where the load is sufficient for the material to undergo plastic deformation.
Both stress and strain results can be plotted as a function of the load factor. However, how to generate a stress vs strain graph of these same results?
Within the 'post-processing navigator':
Plot stress results (contour plot)
Plot stress vs load factor as an xy graph
Save the graph to an '.afu' file (say 'stress_strain.afu')
Plot strain results (contour plot)
Plot strain vs load factor as an xy graph
Save the graph to the same '.afu' file ('stress_strain.afu')
Within the 'xy function navigator':
Expand out the 'afu files - xy tabular function/associated afu/(stress_strain.afu)' item to reveal the graphs
Select both graphs, then 'rhmb, two functions' and select the second of the two options presented (function 2 -> function 1)
A stress vs strain plot will be generated
Alternatively, another method to create the same xy graph plot is detailed within the NX 11 Help Documentation article entitled:
Create a two function plot