SfePy July 2015

sfepy@python.org

9 participants
16 discussions

Material Parameters of Individual Nodes
by derj...＠web.de 11 Apr '22

11 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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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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new interactive example with time stepping
by Robert Cimrman 13 Mar '17

13 Mar '17

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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1D line elements in SfePy
by Nimish 22 Jan '16

22 Jan '16

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

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Re: [sfepy-devel] Re: not working fater upgrading
by Robert Cimrman 31 Jul '15

31 Jul '15

On 07/31/2015 08:18 PM, Patricia Garcia Cañadilla wrote: > Here they are all the files > > Thanks a lot :) > For running "python SimulateCell_phanthom_20150722.py": Try replacing the line time_solver(save_results=True,post_process_hook=stress_strain) with: time_solver.init_time() for out in time_solver(save_results=True, post_process_hook=stress_strain): step, time, state = out Then the time-stepping solver will run. However, the nonlinear solver does not converge, due to a singular matrix - check your boundary conditions. Random notes: as it is the mesh is read three times (once when executing the file, then when loading it into the Problem and third when the Problem creates the mesh). Try putting moving all code from the module into a function, that will be called in main(). Some a general clean-up might be worth doing :) Let me know if the above helps. r.

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not working fater upgrading
by Patricia Garcia Cañadilla 31 Jul '15

31 Jul '15

Hi! I was runnind some code under sfepy2014.3 version and today I've upgraded to 2015.3 and now my simulations only do 1 iteration and stop when it should do 100 hundred. Why?

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Re: [sfepy-devel] Re: not working fater upgrading
by Robert Cimrman 31 Jul '15

31 Jul '15

I do not see a reason here, why all the time steps are not computed. Could you send me a complete problem description file, so that I could run it myself? Thanks, r. On 07/31/2015 07:10 PM, Patricia Garcia Cañadilla wrote: > In my main code I had this: > > problem = Problem.from_conf(conf, init_equations=False) > problem.setup_default_output() > problem.set_equations({'eq' : conf.equations['balance']}) > problem.time_update(ebcs=conf.ebcs) > state_el = problem.solve() > time_solver = problem.get_time_solver() > time_solver(save_results=True,post_process_hook=stress_strain) > ts = problem.get_timestepper() > > Ans these were my solvers: > > # Solvers etc. > solver_0 = { > 'name' : 'ls', > 'kind' : 'ls.scipy_direct', > } > > solver_1 = { > 'name' : 'newton', > 'kind' : 'nls.newton', > > 'i_max' : 7, > 'eps_a' : 1e-10, > 'eps_r' : 1.0, > 'macheps' : 1e-16, > 'lin_red' : 1e-2, # Linear system error < (eps_a * lin_red). > 'ls_red' : 0.1, > 'ls_red_warp': 0.001, > 'ls_on' : 1.1, > 'ls_min' : 1e-5, > 'check' : 0, > 'delta' : 1e-6, > 'problem' : 'nonlinear', # 'nonlinear' or 'linear' (ignore i_max) > } > > solver_2 = { > 'name' : 'ts', > 'kind' : 'ts.simple', > > 't0' : 0, > 't1' : 1, > 'dt' : None, > 'n_step' : 101, # has precedence over dt! > } >

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Interactive use of point loads
by Dennis Perchak 29 Jul '15

29 Jul '15

I have been trying to understand how to use the interactive version of point loads. As I understand it, the load have as many rows as the number of points you are applying the load to and the columns must be equal to the spatial dimension. I modified one of the examples for my own problem but get errors when I try to run it: (Program & mesh file attached). If I use simple displacements as a boundary condition, it works just fine. Any help would be appreciated. Dennis Traceback (most recent call last): File "preambleLoadAA.py", line 105, in <module> main() File "preambleLoadAA.py", line 91, in main vec = pb.solve() File "C:\Users\l620546\AppData\Local\Enthought\Canopy\User\lib\site-packages\s fepy\discrete\problem.py", line 984, in solve vec = solvers.nls(vec0, status=self.nls_status) File "C:\Users\l620546\AppData\Local\Enthought\Canopy\User\lib\site-packages\s fepy\solvers\nls.py", line 303, in __call__ vec_r = fun(vec_x) File "C:\Users\l620546\AppData\Local\Enthought\Canopy\User\lib\site-packages\s fepy\discrete\evaluate.py", line 52, in eval_residual vec_r = self.problem.equations.eval_residuals(vec) File "C:\Users\l620546\AppData\Local\Enthought\Canopy\User\lib\site-packages\s fepy\discrete\equations.py", line 655, in eval_residuals self.evaluate(mode='weak', dw_mode='vector', asm_obj=out) File "C:\Users\l620546\AppData\Local\Enthought\Canopy\User\lib\site-packages\s fepy\discrete\equations.py", line 591, in evaluate term_mode=term_mode, asm_obj=asm_obj) File "C:\Users\l620546\AppData\Local\Enthought\Canopy\User\lib\site-packages\s fepy\discrete\equations.py", line 824, in evaluate term.assemble_to(asm_obj, val, iels, mode=dw_mode) File "C:\Users\l620546\AppData\Local\Enthought\Canopy\User\lib\site-packages\s fepy\terms\terms.py", line 1483, in assemble_to dc = vvar.get_dof_conn(dc_type, ig) File "C:\Users\l620546\AppData\Local\Enthought\Canopy\User\lib\site-packages\s fepy\discrete\variables.py", line 1364, in get_dof_conn dc = self.adof_conns[key] KeyError: ('u', 'TopLoad', 'point', 20, False)

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PETSc: Segmentation Violation
by derj...＠web.de 29 Jul '15

29 Jul '15

Hello, thanks for the efforts on SfePy and even adding a parallel solver. Unfortunately, the parallel examples don't work for me. I've tried with petsc4py 3.6.0 and PETSc 3.6.0 as well as 3.6.1. I appned the error message from the command "python examples/multi_physics/biot_parallel_interactive.py output-parallel". When run in parallel the message is basically the same, but multiple times. Best regards

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syntax error at line 310 of build_helpers.py
by Ouyang 25 Jul '15

25 Jul '15

Hi Robert I just git a copy of sfepy from the site today and get error from build_helpers.py by "python setup.py install" SyntaxError is at line 310 pkg_info = pkg_name + (' (optional)' if optional else '') at if optional else '' ouyang

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SfePy July 2015