SfePy February 2012

sfepy@python.org

8 participants
15 discussions

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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Modeling an adjustable X-ray optic
by Tom Aldcroft 21 May '13

21 May '13

I'm working on modeling a next-generation X-ray mirror for which the shape can be actively controlled by use of many thin piezo-electric actuators mounted on the mirror surface. The mirror is basically a glass conical paraboloid with a 1 meter radius and 200 micron thickness (e.g. http://en.wikipedia.org/wiki/X-ray_optics). Our project is currently using a proprietary FEA package, but the model setup and turnaround time is slow, in part because there is only one part-time engineer who can run it. SfePy looks like a great package and we're hoping that it could be used to automate running a large number of different cases. I've spent some time reading the documentation but I have a few questions that I hope can be answered before going too much further. I want to apologize in advance if some of my wording is imprecise, I have a physics background but this topic is a bit outside my realm... - Is SfePy appropriate for this problem? - If a specify a grid with about 800 x 400 points (azimuthal, axial) and about 10 boundary conditions (corresponding to mount points), what is the rough order of magnitude of time to compute the solution? Is it seconds, minutes, hours, or days? - The linear elastic examples show a problem with a specified displacement. How do I specify an input force? The piezo essentially provides a tensile force along the surface. - Is there a way to specify the problem and solve in cylindrical coordinates? This is the natural coordinate system. - How do I specify 6-DOF constraints which correspond to the mirror mounts? Thanks in advance for any help! Tom Aldcroft

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time counting
by Md. Golam Rashed 06 Apr '12

06 Apr '12

is it possible to measure the total time spent in an analysis?

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31 Mar '12

I want to write a paper themed on, doing simulation using scripting language with legacy code. As a civil engineer (structural), i find the tensile strength of concrete test presented in sfepy primer quite suitable to use in my writing. will this cause any copyright problem??? And secondly, can anybody detail the process of wrapping python around C in sfepy?? just to make sure my understanding is right. Thanks!

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sfepy.org update
by Robert Cimrman 29 Feb '12

29 Feb '12

Hi, I have updated the front page of our main web site [1]: now its sources are in doc/ directory of sfepy sources and the page is generated by sphinx. I have also added news from the google site and other links. Any feedback would be appreciated, namely on broken links and obsolete/wrong information. I will then remove the duplicate information from [2]. If things go well, there should be a regular release (2012.1) soon, so testing and feedback in this direction would also be welcome. r. [1] http://sfepy.org [2] http://code.google.com/p/sfepy/

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thank you
by David Mashburn 29 Feb '12

29 Feb '12

Sfepy developers, I wanted to introduce myself and first of all say thank you for the hard work you have put into sfepy. The breadth of this little program is somewhat astounding and I really think it is going to be a boon to me in my research in biomechanics. I have been looking through the code of sfepy, and I had a comment about base/base.py: I notice that your problem definition files are loaded with import/ reload. I do something similar in my project (http://code.google.com/p/ seedwater/, https://github.com/davidmashburn/SeedWaterSegmenter) and recently switched to using the "imp" module and the load_module function: """ import imp ... fid=open(seedPointsFile,'U') Seeds = imp.load_module('Seeds',fid,'Seeds.py',('.py','U',1)) fid.close() """ If I remember right, it not only avoided messing with sys.path, but actually executed significantly faster in some circumstances. You may already know about this and/or have a reason not to use it, but I thought I would share my experiences. Thanks again and look forward to using more of this great project! -David

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ANN: SfePy 2012.1
by Robert Cimrman 27 Feb '12

27 Feb '12

I am pleased to announce release 2012.1 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. The code is based on NumPy and SciPy packages. It is distributed under the new BSD license. Home page: http://sfepy.org Downloads, mailing list, wiki: http://code.google.com/p/sfepy/ Git (source) repository, issue tracker: http://github.com/sfepy Highlights of this release -------------------------- - initial version of linearizer of higher order solutions - rewrite variable and evaluate cache history handling - lots of term updates/fixes/simplifications - move web front page to sphinx docs For full release notes see http://docs.sfepy.org/doc/release_notes.html#id1 (rather long and technical). Best regards, Robert Cimrman and Contributors (*) (*) Contributors to this release (alphabetical order): Tom Aldcroft, Vladimír Lukeš, Matyáš Novák, Andre Smit

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2012.1?
by Robert Cimrman 27 Feb '12

27 Feb '12

Hi, are there any outstanding issues preventing a regular release today/tomorrow? (Things work ok for me :)) r.

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Vtk import and real mesh volume
by henri meric 26 Feb '12

26 Feb '12

Hi every one, I would like to know how to get the volume of a mesh the mesh is built with meshpy (not my work) and save as a vtk I need as a first step to get the volume of the mesh I can't find a way to do it quickly. Hope anyone would be able to help me. thanks

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Re: Revisit viscoelastic materials
by Robert Cimrman 21 Feb '12

21 Feb '12

Hi Andre, the time history terms *th were neglected during the easier_terms and cython updates. I have planned to update them next week or so as I need them working again. So wait please a few days, I will try to fix them asap. r. ----- Reply message ----- From: "freevryheid" <freev...(a)gmail.com> To: <sfepy...(a)googlegroups.com> Subject: Revisit viscoelastic materials Date: Sun, Jan 29, 2012 13:44 No examples or tests for the dw_lin_elastic_th or dw_lin_elastic_eth terms. Attached problem fails with the following error. Any suggestions to point me in the right direction. Andre --------------------------------------------------------------------------- TypeError Traceback (most recent call last) /home/grassy/sfepy/simple.py in <module>() 123 124 if __name__ == '__main__': --> 125 main() /home/grassy/sfepy/simple.py in main() 120 parametric_hook = conf.get_function(opts.parametric_hook) 121 app.parametrize( parametric_hook ) --> 122 app() 123 124 if __name__ == '__main__': /home/grassy/sfepy/sfepy/applications/application.pyc in call_basic(self, **kwargs) 27 28 def call_basic( self, **kwargs ): ---> 29 return self.call( **kwargs ) 30 31 def call_parametrized( self, **kwargs ): /home/grassy/sfepy/sfepy/applications/simple_app.pyc in call(self) 115 post_process_hook=self.post_process_hook, 116 post_process_hook_final=self.post_process_hook_final, --> 117 pre_process_hook=self.pre_process_hook) 118 119 return out /home/grassy/sfepy/sfepy/solvers/generic.pyc in solve_direct(conf, options, problem, step_hook, post_process_hook, post_process_hook_final, pre_process_hook, nls_status) 214 step_hook=step_hook, 215 post_process_hook=post_process_hook, --> 216 nls_status=nls_status) 217 else: 218 ## /home/grassy/sfepy/sfepy/solvers/generic.pyc in solve_evolutionary_op(problem, save_results, return_history, step_hook, post_process_hook, nls_status) 134 135 ii = 0 --> 136 for ts, state in time_solver( state0 ): 137 138 if step_hook is not None: /home/grassy/sfepy/sfepy/solvers/ts.pyc in __call__(self, state0, conf, step_fun, step_args) 189 output( self.format % (time, step + 1, self.ts.n_step) ) 190 --> 191 state = step_fun( self.ts, state0, *step_args ) 192 state0 = state.copy(deep=True) 193 yield self.ts, state /home/grassy/sfepy/sfepy/solvers/generic.pyc in time_step_function(ts, state0, problem, nls_status) 80 ev = problem.get_evaluator() 81 try: ---> 82 vec_r = ev.eval_residual(state(), is_full=True) 83 except ValueError: 84 output('initial residual evaluation failed, giving up...') /home/grassy/sfepy/sfepy/fem/evaluate.pyc in eval_residual(self, vec, is_full) 50 try: 51 pb = self.problem ---> 52 vec_r = pb.equations.eval_residuals(vec) 53 54 except StopIteration, exc: /home/grassy/sfepy/sfepy/fem/equations.pyc in eval_residuals(self, state, by_blocks, names) 560 out = self.create_stripped_state_vector() 561 --> 562 self.evaluate(mode='weak', dw_mode='vector', asm_obj=out) 563 564 return out /home/grassy/sfepy/sfepy/fem/equations.pyc in evaluate(self, mode, dw_mode, term_mode, asm_obj) 503 for eq in self: 504 eout = eq.evaluate(mode=mode, dw_mode=dw_mode, term_mode=term_mode, --> 505 asm_obj=asm_obj) 506 if mode != 'weak': 507 out[eq.name] = eout /home/grassy/sfepy/sfepy/fem/equations.pyc in evaluate(self, mode, dw_mode, term_mode, asm_obj) 730 term_mode=term_mode, 731 standalone=False, --> 732 ret_status=True) 733 term.assemble_to(asm_obj, val, iels, mode=dw_mode) 734 /home/grassy/sfepy/sfepy/terms/terms.pyc in evaluate(self, mode, diff_var, standalone, ret_status, **kwargs) 1501 1502 _args = tuple(args) + (mode, term_mode, diff_var) -> 1503 fargs = self.get_fargs(*_args, **kwargs) 1504 1505 n_elr, n_qpr, dim, n_enr, n_cr = self.get_data_shape(varr) TypeError: get_fargs() takes at most 3 arguments (8 given) -- You received this message because you are subscribed to the Google Groups "sfepy-devel" group. To view this discussion on the web visit https://groups.google.com/d/msg/sfepy-devel/-/eNJ3ZUbDbuYJ. 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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SfePy February 2012