Mailman 3 February 2017 - SfePy

Material Parameters of Individual Nodes
by derj...＠web.de April 11, 2022

April 11, 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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new interactive example with time stepping
by Robert Cimrman March 13, 2017

March 13, 2017

Hi, I have just updated the time stepping solvers in sfepy for interactive use, as demonstrated in the new example [1]. For basic use, ignore the probing code - the time stepper can be used as simply as: tss = SimpleTimeSteppingSolver({'t0' : 0.0, 't1' : 100.0, 'n_step' : 11}, problem=problem) tss.init_time() for step, time, state in tss(): pass r. [1] http://sfepy.org/doc-devel/examples/diffusion/time_poisson_interactive.html

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ANN: SfePy 2017.1
by Robert Cimrman Feb. 28, 2017

Feb. 28, 2017

I am pleased to announce release 2017.1 of SfePy. Description ----------- SfePy (simple finite elements in Python) is a software for solving systems of coupled partial differential equations by the finite element method or by the isogeometric analysis (limited support). It is distributed under the new BSD license. Home page: http://sfepy.org Mailing list: http://groups.google.com/group/sfepy-devel Git (source) repository, issue tracker: https://github.com/sfepy/sfepy Highlights of this release -------------------------- - spline-box parametrization of an arbitrary field - conda-forge recipe (thanks to Daniel Wheeler) - fixes for Python 3.6 For full release notes see http://docs.sfepy.org/doc/release_notes.html#id1 (rather long and technical). Cheers, Robert Cimrman --- Contributors to this release in alphabetical order: Siwei Chen Robert Cimrman Jan Heczko Vladimir Lukes Matyas Novak

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Type Error running examples
by Christopher Jones Feb. 2, 2017

Feb. 2, 2017

I am getting the following error while trying to run 'its2d_interactive.py'. C:\Python36\Lib\site-packages\sfepy\linalg>python C:\Python36\Lib\site-packages\sfepy\examples\linear_elasticity\its2D_interactive.py Traceback (most recent call last): File "C:\Python36\Lib\site-packages\sfepy\examples\linear_elasticity\its2D_interactive.py", line 51, in <module> from examples.linear_elasticity.its2D_2 import stress_strain ModuleNotFoundError: No module named 'examples' I have been getting this error when ever I try to run examples. I tried changing the forward slashes to back slashes with no effect. I installed most of the dependencies from PIP, and installed a pre-built binary from Gohlke's LFD python libs page. I've tried running from the console as seen in the above error. I've also tried running from IDLE, for python 3.6. ANd I get no error messages from the IDLE console but also, I get no output file. I'm running IDLE with elevated privelage and I created the output directory inside the sfepy install directory, i.e. C:\Python36\Lib\site-packages\sfepy\examples\results... Ok, I see this error. I was not in the sfepy base directory. I changed this and got output in the console with the following error: C:\Python36\Lib\site-packages\sfepy>python C:\Python36\Lib\site-packages\sfepy\examples\linear_elasticity\its2D_interactive.py sfepy: using values: sfepy: Young's modulus: 2000.0 sfepy: Poisson's ratio: 0.4 sfepy: vertical load: -1000.0 sfepy: uniform mesh refinement level: 0 sfepy: reading mesh [line2, tri3, quad4, tetra4, hexa8] (C:\Python36\lib\site-packages\sfepy/meshes/2d/its2D.mesh)... sfepy: ...done in 0.00 s Traceback (most recent call last): File "C:\Python36\Lib\site-packages\sfepy\examples\linear_elasticity\its2D_interactive.py", line 293, in <module> main() File "C:\Python36\Lib\site-packages\sfepy\examples\linear_elasticity\its2D_interactive.py", line 175, in main domain = FEDomain('domain', mesh) File "C:\Python36\lib\site-packages\sfepy\discrete\fem\domain.py", line 50, in __init__ gel.poly_space = PolySpace.any_from_args(key, gel, 1) File "C:\Python36\lib\site-packages\sfepy\discrete\fem\poly_spaces.py", line 272, in any_from_args return table[key](name, geometry, order) File "C:\Python36\lib\site-packages\sfepy\discrete\fem\poly_spaces.py", line 444, in __init__ self.nodes, self.nts, node_coors = self._define_nodes() File "C:\Python36\lib\site-packages\sfepy\discrete\fem\poly_spaces.py", line 465, in _define_nodes nodes = nm.zeros((n_nod, n_v), nm.int32) TypeError: 'float' object cannot be interpreted as an integer Any ideas? Thanks, Chris

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