Mailman 3 July 2014 - SfePy

Neumann BCs at an interface
by Joseph Batley 23 Jul '14

23 Jul '14

Hello, I have been using sfepy to simulate charge currents with Poisson's equation and I would like to add in spin dependence using Valet-Fert theory. The strong form of the continuity equations are charge: \Delta(\sigma_{up} \mu{up} + \sigma_{down} \mu{down} ) = 0 spin: \Delta(\mu{up} - \mu{down} ) = (\mu{up} - \mu{down}) / \lambda where \mu_{up} and \mu_{down} are the chemical potentials for spin up and spin down electrons, \sigma_{up} and \sigma_{down} are the spin dependent conductivities and \lambda is a material constant. The problem I am looking at is a charge current being driven from a magnetic metal to a non-magnetic metal. My issue is with the Neumann BCs, the spin current is defined as Js = \sigma_{up} grad \mu_{up} - \sigma_{down} grad \mu_{down} which has to be continuous across the interface. I do not know how to implement this in sfepy as I do not know what the fluxes at the interface will be before running the simulation in order to add them as material parameters as in the examples. Should I define the continuity of spin fluxes at the interface as a separate equation? is this something achievable in sfepy? Many thanks, Joe

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a point loaded block
by Ouyang 18 Jul '14

18 Jul '14

Hi there, I follow the point loaded disk example: its2D and simulate the 3d point loaded block as show in the attached figure. Here are my questions: 1. When I use "vertex <id>", the <id> seems not the node id in mesh and looks like an index in a list. My node id is 5 and I have to put 4 there. 2. Are there any way to customize contour bands? Since the point loaded rock block could fails at the center point (0,0,0), I want to see the stress or strain details at the point (0,0,0) and would like to add more contour bands in. 3. How to output a contour map for stress or strain components, \sigma_{ij} or \epsilon_{ij}, on any cross section in sfepy? The following script can give me stress components but I am still looking for their corresponding coordinates out['cauchy_stress'] = Struct(name='output_data', mode='cell', data=stress, dofs=None) print out['cauchy_stress'].data any suggestions would be appreciated very much. Thanks ouyang <https://lh4.googleusercontent.com/-lukMCkvX0FQ/U8Cj5RiaBhI/AAAAAAAAC4M/9PZy…>

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Mac installation instructions
by Robert Cimrman 07 Jul '14

07 Jul '14

Hi, any Mac users here able to help with [1]? r. [1] https://github.com/sfepy/sfepy/issues/264

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how to add gravity body force, b_i, into biot.py
by Ouyang 04 Jul '14

04 Jul '14

Hi all, I would like to add gravity body force, b_i, into biot.py: http://sfepy.org/doc-devel/examples/biot/biot.html I could find any examples. The body force, b_i, in balance equation can be expressed by (\sigma_{ij} - p \delta_{ij}),j + \rho b_i = 0 where \sigma_{ij} is stress, p is pore pressure and \rho is the density of solid phase. \delta_{ij} is Kronecker delta. Should I add a new term from scratch? Thanks in advance. ouyang

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test instance creation failed
by Stuart Cook 02 Jul '14

02 Jul '14

I'm having issues with the initial installation. I'm running windows 8 and using anaconda. After following the Windows 7 installation instructions all the tests fail and debugging gives the same error on each. The output from running it with --debug is below: $ ./run_tests.py --debug <<< directory: tests, test files: 79 <<< tests\test_assembling.py --- test instance creation failed Traceback (most recent call last): File "./run_tests.py", line 225, in <module> main() File "./run_tests.py", line 219, in main op.walk( options.test_dir, run_tests, stats ) File "c:\Anaconda\lib\ntpath.py", line 231, in walk func(arg, top, names) File "./run_tests.py", line 148, in run_tests n_fail, n_total, test_time = run_test( conf_name, options ) File "./run_tests.py", line 94, in run_test conf = ProblemConf.from_file( conf_name, required, _required + other ) File "C:\sfepy\sfepy\base\conf.py", line 325, in from_file funmod = import_file(filename) File "C:\sfepy\sfepy\base\base.py", line 143, in import_file mod = __import__('.'.join((package_name, name)), fromlist=[name]) ImportError: No module named test_assembling Any idea what the issue is?

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