Mailman 3 April 2017 - SfePy

Material Parameters of Individual Nodes
by derj...＠web.de April 12, 2022

April 12, 2022

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 Jan. 17, 2019

Jan. 17, 2019

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 March 9, 2018

March 9, 2018

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 April 24, 2017

April 24, 2017

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 April 22, 2017

April 22, 2017

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 April 22, 2017

April 22, 2017

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Re: How to calculate electrostatic field using sfepy?
by Robert Cimrman April 21, 2017

April 21, 2017

... 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 April 21, 2017

April 21, 2017

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 April 20, 2017

April 20, 2017

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Wrong results in lineral_viscoelastic.py from examples. What may cause this?
by fatune＠gmail.com April 20, 2017

April 20, 2017

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?

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