Hello,
I am using SfePy to compute the strain fields for an isotropic material in both 2D and 3D with displacement boundary conditions in the x boundaries and periodic boundary conditions on the other boundaries. The corners on the x line/plane are also fixed in all directions. Below are links to the files for both simulations.
3D
https://github.com/PyMKS/pymks/blob/issue66-3Dexample/pymks/elasticFEModel3D.py
2D
https://github.com/PyMKS/pymks/blob/issue66-3Dexample/pymks/elasticFEModel.py
In both of these files, the displacements are currently being returned and not the strain. In both models, the displacements fields should run from 0.0 to 3.0 in the x-direction and be zero in the other direction(s). The 2D example gives the expected values, while the 3D example does not. Below are the displacements of one row of vertices in each of the directions.
2D
x - displacement [[ 0. 1. 2. 3.]]
y - displacement [[ 0.00000000e+00 -1.87759988e-15 -2.87436852e-15 -3.24740235e-15]]
3D
x - displacement [[ 0. 4.2962163 5.88616087 3.]]
y - displacement [[ 0. 13.22615623 13.19390252 24.60315355]]
z - displacement [[ 0. 11.78213038 11.78213038 16.76530931]]
Any thoughts? Do I have the periodic boundary conditions correct or do I need to do something similar to what was suggested in this post https://groups.google.com/forum/#!topic/sfepy-devel/VpVHXS7Jh0Q, but in 3D?
Thanks,
David