SfePy June 2017

sfepy@python.org

4 participants
6 discussions

Calculate total force from cauchy stress

by Patricia Garcia Cañadilla

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), }

2 years, 9 months

Re: Torque

by Robert Cimrman

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.

3 years, 7 months

Re: ImportError: No module named crcm

by Robert Cimrman

The error looks like some permission problem - could you try removing the build/ directory completely, and also running python setup.py clean - the above should succeed. If not, try removing the whole sfepy/ directory, and start from a new one, that you unpack as you, not as a root or another user... r. On 06/19/2017 04:11 AM, Deepak Pawar wrote: > Hello Robert > > I tried the python setup.py build_ext --inplace > > But things doesn't work out. > I know i am doing some stupid mistake but couldn't figure out. > > Need ur comments > > PFA > > Thanks > > On Mon, Jun 19, 2017 at 3:15 AM, Robert Cimrman <cimrman3(a)ntc.zcu.cz> wrote: > >> Hi! >> >> it looks that you did not build the extension modules of sfepy - try >> running >> >> python setup.py build_ext --inplace >> >> before running simple.py. >> >> r. >> >> On 06/18/2017 08:15 AM, deepakpawar.2310(a)gmail.com wrote: >> >>> Hii >>> >>> New user at sfepy >>> >>> Any comment on the following error ? >>> >>> >>> >>> pawar@pawar:~/sfepy$ ./simple.py >>> Traceback (most recent call last): >>> File "./simple.py", line 21, in <module> >>> from sfepy.applications import PDESolverApp >>> File "/home/pawar/sfepy/sfepy/applications/__init__.py", line 3, in >>> <module> >>> from .pde_solver_app import PDESolverApp, solve_pde, >>> assign_standard_hooks >>> File "/home/pawar/sfepy/sfepy/applications/pde_solver_app.py", line >>> 7, in <module> >>> from sfepy.discrete import Problem >>> File "/home/pawar/sfepy/sfepy/discrete/__init__.py", line 9, in >>> <module> >>> from .variables import Variables, Variable, FieldVariable, >>> create_adof_conns >>> File "/home/pawar/sfepy/sfepy/discrete/variables.py", line 14, in >>> <module> >>> import sfepy.linalg as la >>> File "/home/pawar/sfepy/sfepy/linalg/__init__.py", line 2, in <module> >>> from .extmods.crcm import rcm, permute_in_place >>> ImportError: No module named crcm >>> _______________________________________________ >>> SfePy mailing list >>> sfepy(a)python.org >>> https://mail.python.org/mm3/mailman3/lists/sfepy.python.org/ >>> >>> >> > >

4 years, 4 months

ImportError: No module named crcm

by deepakpawar.2310＠gmail.com

Hii New user at sfepy Any comment on the following error ? pawar@pawar:~/sfepy$ ./simple.py Traceback (most recent call last): File "./simple.py", line 21, in <module> from sfepy.applications import PDESolverApp File "/home/pawar/sfepy/sfepy/applications/__init__.py", line 3, in <module> from .pde_solver_app import PDESolverApp, solve_pde, assign_standard_hooks File "/home/pawar/sfepy/sfepy/applications/pde_solver_app.py", line 7, in <module> from sfepy.discrete import Problem File "/home/pawar/sfepy/sfepy/discrete/__init__.py", line 9, in <module> from .variables import Variables, Variable, FieldVariable, create_adof_conns File "/home/pawar/sfepy/sfepy/discrete/variables.py", line 14, in <module> import sfepy.linalg as la File "/home/pawar/sfepy/sfepy/linalg/__init__.py", line 2, in <module> from .extmods.crcm import rcm, permute_in_place ImportError: No module named crcm

4 years, 4 months

Please unsubscribe me !

by Tú Bùi Khắc

Sent from Mail for Windows 10

4 years, 4 months

setting Dirichlet boundary conditions by a function - change of behaviour for vector variables

by Robert Cimrman

Hi, currently, when setting the Dirichlet boundary conditions (ebcs) by a function, the function should return a 1D array with all values of the first component, then of the second one etc. concatenated together (= DOF-by-DOF ordering). Passing a 2D array has been silently ignored, but now with numpy 1.13 out, this lead to #404 [1]. It is not a hard-to-fix bug, but I would also like to make the behaviour of the boundary conditions setting functions consistent with the material parameters setting functions, and change the ordering from DOF-by-DOF to node-by-node, e.g. all components in the first node, all components in the second node, etc. Example: having in 3 nodes the values (2 DOFs per node) [[1, 2], [3, 4], [5, 6]] the old behaviour required the function to return [1, 3, 5, 2, 4, 6], while the new version will require either [1, 2, 3, 4, 5, 6], or directly [[1, 2], [3, 4], [5, 6]] that will be ravelled automatically. So, with the new behaviour, the returned vector values would have the same shape as the `coors` argument (the coordinates) that are passed into the setting functions. IMHO this is much easier to get right for users. Any thoughts? Cheers, r. [1] https://github.com/sfepy/sfepy/issues/404

4 years, 4 months

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SfePy June 2017