Mailman 3 April 2017 - SfePy - {{ block.super }

Material Parameters of Individual Nodes
by derj...＠web.de 12 Apr '22

12 Apr '22

Hello! It's a great tool you built there! I'd like to use it for some kind of topology optimisation. Is there an "idiomatic" way to set the material parameters of individual nodes? Thank you very much! JonnyB

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Calculate total force from cauchy stress
by Patricia Garcia Cañadilla 17 Jan '19

17 Jan '19

Dear Robert, I have a 2D body of hyperelastic material which contracts and I would like to compute the total force developed by the body from the cauchy stress. I am trying to follow some of your indications I found in this group, but I still couldn't make it works. Could you please help me to fix the problem? I am getting the following error: key = (region.name, integral.order, integration) AttributeError: 'dict' object has no attribute 'name' I am trying to do the following, inside stress_strain post-processing function: def stress_strain(out, problem, state, extend = False ): from sfepy.base.base import Struct from sfepy.mechanics.tensors import StressTransform from sfepy.mechanics.tensors import transform_data from sfepy.discrete.common.mappings import get_normals ev = problem.evaluate field = problem.fields['displacement'] region = problem.domain.regions['Gamma'] integral = problem.integrals['i2'] n = get_normals(field,integral,regions) stress = ev('dw_tl_fib_a.1.Omega(f1.fmax, f1.eps_opt, f1.s, f1.fdir, f1.act, v, u )',mode='qp', term_mode= 'stress'); F = ev('ev_def_grad.1.Omega(u)',mode='el_avg'); transform = StressTransform(F) Cstress = transform.get_cauchy_from_2pk(stress) T = Cstress*n; Force = ev('ev_surface_integrate.2.Gamma(T)') And here it is part of the problem configuration file. fields = { 'displacement': ('real', 'vector', 'Omega', 1), } materials = { 'solid' : (None, 'get_elastic_pars'), 'load' : (None, 'linear_tension'), 'f1' : 'get_pars_fibres1', } variables = { 'u': ('unknown field', 'displacement', 0), 'v': ('test field', 'displacement', 'u'), } regions = { 'Omega' : 'all', 'Fix1' : ('vertices in x < %.10f' % (fix_point + eps2), 'facet'), 'Fix2' : ('vertices in x > %.10f' % (fix_point - eps2), 'facet'), 'Fix' : ('r.Fix1 *v r.Fix2', 'facet'), 'Gamma' : ('vertices of surface','edge'), } ebcs = { 'fixb' : ('Fix', {'u.all' : 0.0}), } integrals = { 'i1' : ('v', 1), 'i2' : ('s', 2), }

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Re: Torque
by Robert Cimrman 09 Mar '18

09 Mar '18

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 -- You received this message because you are subscribed to the Google Groups "sfepy-devel" group. To post to this group, send email to sfepy...(a)googlegroups.com. To unsubscribe from this group, send email to sfepy-devel...(a)googlegroups.com. For more options, visit this group at http://groups.google.com/group/sfepy-devel?hl=en.

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Re: unsubscribe
by David Pugh 24 Apr '17

24 Apr '17

On Sat, Apr 22, 2017 at 10:25 AM, Radko Bankras <radko(a)bankras.net> wrote: > > _______________________________________________ > SfePy mailing list > sfepy(a)python.org > https://mail.python.org/mm3/mailman3/lists/sfepy.python.org/ >

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Re: Wrong results in lineral_viscoelastic.py from examples. What may cause this?
by Robert Cimrman 22 Apr '17

22 Apr '17

On 04/20/2017 02:07 PM, Robert Cimrman wrote: > On 04/20/2017 01:49 PM, fatune(a)gmail.com wrote: >> When I try lineral_viscoelastic.py from examples and then see results via >> postproc.py I see 5 blocks of blue colors which differs from results show in >> manual. The result is the same no matter how many time steps I set or which >> time step I currently see in Maya. > > Try moving the sliders / set another time step. That should change the colors > of the blocks. If not, send here the output of the "./simple.py > examples/linear_elasticity/linear_viscoelastic.py" command. > >> When I run it like this: >> >> python examples/linear_elasticity/linear_viscoelastic.py block.h5 >> >> I see error because there is no block.h5 yet. So instead firstly I run: >> >> ./simple.py examples/linear_elasticity/linear_viscoelastic.py >> >> which creates block.h5 file, and then: >> >> ./postporc.py block.h5 > > Try running > > ./postproc.py -b --step=-1 block.h5 > > r. > >> >> >> I try to understand the logic of simulating viscoelastic behaviour over time >> through the Sfepy. That seems too complicated to me yet. But even standard >> example didn't work for me. What may cause the problem?

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unsubscribe
by Radko Bankras 22 Apr '17

22 Apr '17

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Re: How to calculate electrostatic field using sfepy?
by Robert Cimrman 21 Apr '17

21 Apr '17

... so it leads to solving the Poisson's equation - see the files in examples/diffusion/ for inspiration. r. On 04/21/2017 08:50 AM, Eduard Rohan wrote: > Hi, > > as the electrostatic (not magnetic) field leads to solving an elliptic BVP, > SfePy can be used > Best regards > Eduard > > On 04/21/2017 07:43 AM, Дмитрий Блеклов wrote: >> Hi everyone! >> Can I using sfepy for calculating electrostatic field? >> If yes, can you describe ways to do this? >> With Best Regards, >> Bleklov Dmitry! >> >> >>> On 21 Apr 2017, at 08:25, Robert Cimrman <cimrman3(a)ntc.zcu.cz> wrote: >>> >>>> On 21.4.2017 01:47, fatune(a)gmail.com wrote: >>>> Thank you for your answer Robert. It works now. It works even when I set >>>> --step=2. But now I have two following questions: >>>> >>>> 1. What is the purpose of step and time sliders in mayavi2 window? The >>>> resulting image of my meshes (including color map and absolute values) >>>> doesn't change no matter what value do I set via those sliders. But when I >>>> set --step option while running postproc I see different results for >>>> different steps. >>> The sliders should have the same effect as --step - if not, there is a bug >>> somewhere. What are your sfepy and mayavi versions? >>> >>> BTW. if you change the >>> >>> 'output_format' : 'h5' >>> >>> in options to >>> >>> 'output_format' : 'vtk' >>> >>> the example will create a sequence of VTK files, that you can view in >>> another viewer, like paraview, or the mayavi application. >>> >>>> 2. While I see that stress changes when I increase total time of the >>>> modulation, I don't see that mesh deforms. Is it ever possible to do in >>>> sfepy to deform mess over time. Or I should deform the mesh each step by >>>> myself via displacment vectors. >>> Do you mean that for the visualization purposes? If yes, see >>> examples/linear_elasticity/linear_elastic.py - namely the -d option to >>> postproc.py in the docstring - you may want to increase the relative scaling >>> parameter there. Or use the appropriate filter in paraview/mayavi manualy. >>> >>> r. >>> _______________________________________________ >>> SfePy mailing list >>> sfepy(a)python.org >>> https://mail.python.org/mm3/mailman3/lists/sfepy.python.org/ >> _______________________________________________ >> SfePy mailing list >> sfepy(a)python.org >> https://mail.python.org/mm3/mailman3/lists/sfepy.python.org/ >

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How to calculate electrostatic field using sfepy?
by Дмитрий Блеклов 21 Apr '17

21 Apr '17

Hi everyone! Can I using sfepy for calculating electrostatic field? If yes, can you describe ways to do this? With Best Regards, Bleklov Dmitry! > On 21 Apr 2017, at 08:25, Robert Cimrman <cimrman3(a)ntc.zcu.cz> wrote: > >> On 21.4.2017 01:47, fatune(a)gmail.com wrote: >> Thank you for your answer Robert. It works now. It works even when I set >> --step=2. But now I have two following questions: >> >> 1. What is the purpose of step and time sliders in mayavi2 window? The >> resulting image of my meshes (including color map and absolute values) >> doesn't change no matter what value do I set via those sliders. But when I >> set --step option while running postproc I see different results for >> different steps. > > The sliders should have the same effect as --step - if not, there is a bug somewhere. What are your sfepy and mayavi versions? > > BTW. if you change the > > 'output_format' : 'h5' > > in options to > > 'output_format' : 'vtk' > > the example will create a sequence of VTK files, that you can view in another viewer, like paraview, or the mayavi application. > >> 2. While I see that stress changes when I increase total time of the >> modulation, I don't see that mesh deforms. Is it ever possible to do in >> sfepy to deform mess over time. Or I should deform the mesh each step by >> myself via displacment vectors. > > Do you mean that for the visualization purposes? If yes, see examples/linear_elasticity/linear_elastic.py - namely the -d option to postproc.py in the docstring - you may want to increase the relative scaling parameter there. Or use the appropriate filter in paraview/mayavi manualy. > > r. > _______________________________________________ > SfePy mailing list > sfepy(a)python.org > https://mail.python.org/mm3/mailman3/lists/sfepy.python.org/

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Unsubscribe please
by Christopher Jones 20 Apr '17

20 Apr '17

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Wrong results in lineral_viscoelastic.py from examples. What may cause this?
by fatune＠gmail.com 20 Apr '17

20 Apr '17

When I try lineral_viscoelastic.py from examples and then see results via postproc.py I see 5 blocks of blue colors which differs from results show in manual. The result is the same no matter how many time steps I set or which time step I currently see in Maya. When I run it like this: python examples/linear_elasticity/linear_viscoelastic.py block.h5 I see error because there is no block.h5 yet. So instead firstly I run: ./simple.py examples/linear_elasticity/linear_viscoelastic.py which creates block.h5 file, and then: ./postporc.py block.h5 I try to understand the logic of simulating viscoelastic behaviour over time through the Sfepy. That seems too complicated to me yet. But even standard example didn't work for me. What may cause the problem?

1 0

How to properly build a mesh?
by rmk236＠gmail.com 19 Apr '17

19 Apr '17

I am trying to build a custom rectangle mesh, but it seems that I am failing to do a proper one. I wrote a small python script to build the rectangle, using Delaunay triangulation [1]. This results in a file [2] that looks OK when compared with '/meshes/2d/rectangle_tri.mesh'. However, when I try to use this file into the a slightly modified version of '/examples/linear_elasticity/linear_elastic_interactive.py' [3], it raises an orientation error [4]. I really don't undestand what seems to be the issue here. Is it an ordering in the triangular elements? Does Sfepy presupose a specific ordering? [1] http://www.codesend.com/view/b6612f600b38f6f8552dc89ce072c938/ [2] http://www.codesend.com/view/25adf8bbe8e29f151d068b7ba08b4c82/ [3] http://www.codesend.com/view/910a5af4ba2a2b46f8a83572a7280529/ [4] Error below: > sfepy: reading mesh [line2, tri3, quad4, tetra4, hexa8] (MyMesh.mesh)... > sfepy: ...done in 0.00 s > sfepy: warning: bad element orientation, trying to correct... > sfepy: warning: bad element orientation, trying to correct... > Traceback (most recent call last): > File "./linear_mod.py", line 98, in <module> > main() > File "./linear_mod.py", line 44, in main > domain = FEDomain('domain', mesh) > File "/home/homeGlobal/lcampos/.local/lib/python2.7/site-packages/sfepy-2017.1-py2.7-linux-x86_64.egg/sfepy/discrete/fem/domain.py", line 61, in __init__ > self.fix_element_orientation() > File "/home/homeGlobal/lcampos/.local/lib/python2.7/site-packages/sfepy-2017.1-py2.7-linux-x86_64.egg/sfepy/discrete/fem/domain.py", line 146, in fix_element_orientation > raise RuntimeError('elements cannot be oriented! (%s)' % key) > RuntimeError: elements cannot be oriented! (2_3)

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new mailing list
by Robert Cimrman 10 Apr '17

10 Apr '17

Hi everyone, I have transitioned our mailing list over to https://mail.python.org/mm3/mailman3/lists/sfepy.python.org/ As you can see, your subscription has been transferred, but you might need to tweak you e-mail delivery settings. Best regards, r.

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migrating to @python.org
by Robert Cimrman 09 Apr '17

09 Apr '17

Hi everyone, as described in [1] I will do the move from Google groups to a new Mailman 3 mailing list on Python.org. I will try to do that on Monday 10.4. - all existing subscriptions will be transferred to the new list, and I will also port the content. Best regards, r. [1] https://github.com/sfepy/sfepy/issues/387

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Calculate diffusive flux from solution in interactive mode
by Scott Calabrese Barton 09 Apr '17

09 Apr '17

I've made a lot of progress learning sfepy this weekend but I'm stuck on post-processing. I'm in interactive mode (using Jupyter) using a toy model that solves the laplace equation on a rectangle with dirichlet conditions on the ends (image below). Now, I'd like to evaluate the flux at designated positions, say on a line or a set of points. I'm able to evaluate the flux field using: flux=pb.evaluate('ev_diffusion_velocity.3.Omega(s.D, c)', copy_materials=False, mode='qp') where 'c' is the solution field variable and s is the material. This produces a set of flux vectors at quadrature points. What I can't seem to do is put this data in a proper field variable so that I can evaluate it with probes, say for example at the boundaries. I've looked at the examples but have found them too complex to reduce to a few lines of code. Can anyone suggest the easiest way to get this data into a field variable? <https://lh3.googleusercontent.com/-IGio8BtAJJE/WOF2SY3wmCI/AAAAAAAAAKI/q9S1…>

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From Solidworks to sfepy
by François Gingras 09 Apr '17

09 Apr '17

Hi all, I am new using Sfepy and I am trying to get a part from solidworks, mesh it (using whatever) and then do some FEA on Sfepy. So right now, I exported the part in STEP and used GMSH to generate the mesh. But the VTK/MESH mesh file contain more dans 1 cell type. So Sfepy pop this error : "meshes with several cell kinds are not supported!" I am trying to figure how to have only one cell kind. Is this seem right? Solidwork -> Step file -> Gmsh -> mesh/vtk file -> sfepy

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Finding versions of VTK and pysparce
by Gary Roach 09 Apr '17

09 Apr '17

Debian linux stretch OS Intel i5750 processor 64bit KDE desktop Directory structure: /root/anaconda3/lib/python3.5/site-packages/sfepy Home Directory structure: /home/gary/Downloads I am still trying to get a clean installation of sfepy. I am still missing vtk and pysparce libraries. I need to get components that are compatible with an amd-64, python3.x system. Any help with finding these packages and help with their installation will be sincerely appreciated. Thank you for your responses Gary R

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migration of mailing list
by Robert Cimrman 05 Apr '17

05 Apr '17

Hi everyone, I consider migrating this mailing list over to mailman on Python.org, see [1]. Let me know if you have any suggestions/recommendations. Best regards, r. [1] https://github.com/sfepy/sfepy/issues/387

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SfePy April 2017