Mailman 3 May 2015 - SfePy

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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How Gmsh can creat hexahedra by save as .mesh file
by Kid Guo 04 Jun '15

04 Jun '15

Hi I'm using SfePy to solve a problem.Firstly, I creat a simple cube by Gmsh and save as my.mesh file. Now I am using sfepy/examples/multi_physics/biot.py to calculate.but it something wrong. Then I open the "/meshes/3d/cube_medium_hexa.mesh",in the "cube_medium_hexa.mesh" file,it consists Vertices and Hexahedra.But in my mesh file,it only consists Vertices,Edges and Triangles,no Hexahedra. When I run the biot.py, there aren't any results I want. How can I save .mesh file including Hexahedra? I think it is the main probelm. Regards, Kid

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Elasticity with periodic boundary condition
by Ronghai Wu 03 Jun '15

03 Jun '15

Dear Robert Cimrman, I am trying to implement elastic inclusion problem. It is a 2D mesh with an inclusion(and therefore eigenstrain) at mesh centre. I developed my codes(as attached) based on following two previous issues. https://groups.google.com/forum/#!searchin/sfepy-devel/Ronghai/sfepy-devel/… https://groups.google.com/forum/#!searchin/sfepy-devel/elastic$20periodic$2… But I have troubles with the boundary conditions. I would like to try two kinds of boundary conditions: (1) Top and bottom boundaries: uniaxial loading(or surface traction). Left and Right boundaries: periodic. I used "dw_tl_surface_traction" but some errors come out. (2) Periodic at all boundaries. I think there must be a easy way for this, but failed to find out in SfePy documentation and mailing list. Could you please give me some help. Thanks. Regards Ronghai

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ANN: SfePy 2015.2
by Robert Cimrman 29 May '15

29 May '15

I am pleased to announce release 2015.2 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 (preliminary 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, wiki: http://github.com/sfepy Highlights of this release -------------------------- - major code simplification (removed element groups) - time stepping solvers updated for interactive use - improved finding of reference element coordinates of physical points - reorganized examples - reorganized installation on POSIX systems (sfepy-run script) 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): Lubos Kejzlar, Vladimir Lukes, Anton Gladky, Matyas Novak

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Re: [sfepy-devel] Transform coordinates stress tensor
by Robert Cimrman 27 May '15

27 May '15

Hi Patricia, check sfepy.mechanics.tensors.transform_data(). You will need to prepare the transformation matrices for the spheroid yourself - take inspiration in prepare_cylindrical_transform() in the same module . r. ----- Reply message ----- From: "Patricia Garcia Cañadilla" <patricia.gar...(a)gmail.com> To: <sfepy...(a)googlegroups.com> Subject: [sfepy-devel] Transform coordinates stress tensor Date: Wed, May 27, 2015 13:06 Hi all, I have a 3D ellipsoid and I will need to transform the stress tensor (9 components) from cartesian to cylindrical / prolate spheroid coordinates. Is there any function in Sfepy to do it? Thanks a lot! -- You received this message because you are subscribed to the Google Groups "sfepy-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sfepy-devel...(a)googlegroups.com. To post to this group, send email to sfepy...(a)googlegroups.com. Visit this group at http://groups.google.com/group/sfepy-devel.

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Transform coordinates stress tensor
by Patricia Garcia Cañadilla 27 May '15

27 May '15

Hi all, I have a 3D ellipsoid and I will need to transform the stress tensor (9 components) from cartesian to cylindrical / prolate spheroid coordinates. Is there any function in Sfepy to do it? Thanks a lot!

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Setup field-dependent boundary condition
by YTC 13 May '15

13 May '15

Hi, I am trying to simulate an electrostatic problem with the boundary condition (electric potential) not fixed but dependent on local charge density. I am very new to SfePy and after learning from the online examples, I was able to set up the simulation with a fixed boundary condition, which works well. Next I tried to set up a function for the field-dependent boundary condition as the following. Example function taken from poisson_field_dependent_material example <http://sfepy.org/doc-devel/examples/diffusion/poisson_field_dependent_mater…> def set_potential(ts, coors, problem, equations=None, mode=None, **kwargs): # this function updates the potential at region: Electrode if mode=='qp': E_values = problem.evaluate('ev_grad.i.Electrode(v)', mode='qp', verbose=False) # calculating the electric field (potential gradient) at the electrode (a short straight line) return UpdatedPotential(E_values) # the potential on this electrode depends on the local charge density (which is proportional to the local electric field calculated above) else: return np.zeros(len(coors)) # for the initial step ebcs = { 'v1' : ('Boundary', {'v.all' : 1}), # this is one edge of the square box 'v2' : ('Electrode', {'v.all' : 'set_potential'}), # this is one short straight line inside the square. In the fixed ebcs case, it is set to 0 } functions = { 'set_potential' : (set_potential,), } However, it looks like it doesn't really update the boundary condition during runtime. The set_potential function is only called once at the beginning. Any ideas what is wrong here? Thanks a lot. YT

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operators in spherical coordinates
by Sergey Osipov 07 May '15

07 May '15

Hi! I'm currently solving equations on the sphere. Is there are any way to get terms, lets say laplacian, in spherical coordinates? So far it seems I have to add new term myself. PS: sfepy is a great library and I loved it immediately. Thank you guys for your hard work!

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