Re: Torque
by Robert Cimrman

In examples/large_deformation/hyperelastic.py a rotation by displacements is applied. By using a similar function the vectors defining the force couples could be defined for dw_surface_ltr (IMHO). Does it make sense?
r.
----- Reply message -----
From: "Andre Smit" <freev...(a)gmail.com>
To: <sfepy...(a)googlegroups.com>
Subject: Torque
Date: Sat, Dec 18, 2010 05:10
What is the best way to apply a torque load to a model?
--
Andre
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1 year, 1 month

1D line elements in SfePy
by Nimish

I am currrently looking for FEM packages to help me solve a system of
beams and columns, basically a collection of 1D bernoulli/timoshenko
line elements.
I started reading SfePy docs and i am getting the idea that doing the
above is not really possible here, am i right?
Are only 2D area elements permitted in SfePy?
Or is there any direct support for solving 1D line elements too..
Cheers
Nimish
3 years, 2 months

interactive solution analysis
by seismo_phil

Hi again,
Further to my previous post on d_surface_flux, I thought I should be able
to evaluate the surface heat flux myself, by solving the problem
interactively and calculating the surface gradient myself. I use:
pb, state = solve_pde('flndrs2d.py')
t = state.get_parts()['t']
which returns temperatures. Now all I need are the corresponding
coordinates. So I try:
xy = pb.get_mesh_coors()
But of course the coordinates vector is longer than the temperature one, I
presume because the ebcs have resulted in removal of the corresponding
DOFs. Is there anyway I can either (a) restore the full temperature vector,
so I have temperatures at all the nodes, even the ones with ebcs applied,
or (b) get the coordinates for only those nodes which do not have ebcs
applied, i.e. coordinates that correspond to the temperatures returned by
state.get_parts()? I tried pb.remove_bcs(), but was unsure if that affects
anything other than the stiffness matrix. Again, any suggestions?
Many thanks,
- Phil
5 years

load.f dependent on region
by seismo_phil

Hi,
I have another question relating to the thermal diffusion problem I am
working on. There is a background heat production distributed throughout
the volume, but the heat production for any given cell will depend on which
region the cell is in, where region is determined by cell group. I.e., all
cells of group 1 are defined to comprise region 1, and they have a heat
production that is different from that in region 2.
So far the examples I've seen have a load that depends only on coordinate.
Is there any example in which the load depends on the region?
Many thanks,
- Phil
5 years

d_surface_flux problem
by seismo_phil

Hello,
I'm still working on the same thermal diffusion problem I referred to in
the "thermal diffusion - Dirichlet vs. Neumann BCs" thread. The problem is
attached file "flndrs2d.py" and *appears* to give a reasonable solution,
but I still need to calculate heat flux out the top of the model. So,
following Robert's suggestion i added a post_process hook that evaluates
d_surface_flux:
def post_process(out, problem, state, extend=False):
"""
Calculate gradient of the solution.
"""
flux = problem.evaluate('d_surface_flux.2.Gamma_Top(coef.val, t)',
mode='eval', copy_materials=False, verbose=False)
print flux
When I call this using my rather complicated materials definition in the
attached file, d_surface flux fails with the following error:
File
"/Users/philcummins/Library/Enthought/Canopy_64bit/User/lib/python2.7/site-packages/sfepy/discrete/functions.py",
line 114, in get_constants
nqp = qps.shape[ig][1]
KeyError: 1
(after a lengthy traceback). If I change the materials definition to a very
simple one:
materials = {
'flux' : ({'val' : 0.03},),
'coef' : ({'val' : 1.0},),
}
Then d_surface_flux appears to evaluate OK, but it just returns a single
value of zero. (I am expecting a vector). I'm not sure what to try next,
any suggestions?
Many thanks
- Phil
P.S. I have also attached a coarsened mesh file, in case anyone wants to
try to run it. But you need to remove the "2km" in the name of the mesh
file in flndrs2d.py if you want it to work.
5 years

Evaluate a solution in the arbitrary point in the domain
by Alec Kalinin

Dear SfePy users,
Is it possible to evaluate a solution not only in the FEM mesh node, but in
any arbitrary point in the domain with the given (x, y, z) coordinates?
For example, consider Dirichlet problem for Poisson equation. We apply
essential boundary conditions on the surface nodes and after the problem
has been solved we have the solution vector, i.e. vector of values in the
FEM mesh nodes. But I want to know the solution in point v(x, y, z) that is
not FEM mesh node. What is the best way to obtain solution in this point v?
Sincerely,
Alec Kalinin
5 years