plot the stress-strain curve

[bright-men]

There was a problem when I finished running fepx according to the tutorials and output the stress-strain curve：
$ gnuplot plot_stress_strain.gp
"plot_stress_strain.gp" line 12: warning: Cannot find or open file "post.forces.z1"
"plot_stress_strain.gp" line 12: No data in plot

Besides, there is no file "post.forces.z1" when I finished simulation.

FEPX: Version 2.0.0
NEPER: Version 4.8.2

[tmivaniski]

Hello, I guess that you should change the file name. The results in the simulation file is z0, z1... for example.. replace "post.forces.z1" to "z1"

[mkasemer]

There are some known issues with regards to the tutorials and examples in the current FEPX version that we are working to fix.

In the meantime, you can print the equivalent stress and equivalent strain values as output, and use the resmesh option in neper -S to find the domain-averaged (i.e., macroscopic) values. These would be sufficient to plot the stress-strain curve.

[tmivaniski]

Could you write a simple example command here?

Thank you very much

[mkasemer]

Of course. With a simulation complete (and having printed both stress_eq and strain_eq), try the following:

neper -S /path/to/simulation.sim -resmesh stress_eq,strain_eq

This should create a new directory with mesh level (domain-averaged) quantities:

/path/to/simulation.sim/results/mesh/

This will contain your domain-averaged quantities, in a similar structure as previous (per-step files).

[tmivaniski]

Thank you, Sr.

Really appreciate it.

[bright-men]

Which folder should it be running in? I changed "post.forces.z1" to "z1". I put the file "plot_stress_strain.gp" in "../simple_simulation" or "/home/m/Documents/test/simple_simulation/simulation.sim/results/forces" and run it with "gnuplot plot_stress_strain.gp", but it didn't work.