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Error 7111: Singular matrix
Posted 24 apr 2010, 06:38 GMT-4 1 Reply
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Hi all,
I'm trying to solve a simple hyperelastic cube (Neo-Hookean) that contains two hyperelastic fibers.
I'm using a 3D Structural mechanics - Solid, Stress-Strain module.
1) At first,
a) I applied one set of periodic boundary conditions from one face of the cube to the opposite face.
b) Then I added constraints on 3 points (using "point settings").
c) and I added constraints on the all remaining boundaries (using "boundary settings").
This one worked!
2) However, when I chose two more (opposite) faces and applied one more set of periodic boundary conditions on them (instead of the boundary constraints that were applied on them in the last case), I received the following error:
Error 7111: Singular matrix
Details:
Exception:
com.femlab.jni.FlNativeException: Singular matrix
Messages:
Singular matrix
Stack trace:
at umfpack.cpp, row 597, ()
at com.femlab.solver.FlSolver.femStatic(Native Method)
at com.femlab.solver.FemStatic.run(Unknown Source)
at com.femlab.server.FlRunner.run(Unknown Source)
at com.femlab.util.i.run(Unknown Source)
at com.femlab.util.aa.run(Unknown Source)
3) The periodic boundary conditions are supposed to be correct - I'll explain: When I used a simple cube- without the fibers and applied both sets of periodic boundary conditions on 4 faces plus adding constraints on 3 points - this was solved! The error occurs only when adding the fibers... Is this a meshing problem?
What do you suggest I should do in this case?
Thank you in advance,
Tal
I'm trying to solve a simple hyperelastic cube (Neo-Hookean) that contains two hyperelastic fibers.
I'm using a 3D Structural mechanics - Solid, Stress-Strain module.
1) At first,
a) I applied one set of periodic boundary conditions from one face of the cube to the opposite face.
b) Then I added constraints on 3 points (using "point settings").
c) and I added constraints on the all remaining boundaries (using "boundary settings").
This one worked!
2) However, when I chose two more (opposite) faces and applied one more set of periodic boundary conditions on them (instead of the boundary constraints that were applied on them in the last case), I received the following error:
Error 7111: Singular matrix
Details:
Exception:
com.femlab.jni.FlNativeException: Singular matrix
Messages:
Singular matrix
Stack trace:
at umfpack.cpp, row 597, ()
at com.femlab.solver.FlSolver.femStatic(Native Method)
at com.femlab.solver.FemStatic.run(Unknown Source)
at com.femlab.server.FlRunner.run(Unknown Source)
at com.femlab.util.i.run(Unknown Source)
at com.femlab.util.aa.run(Unknown Source)
3) The periodic boundary conditions are supposed to be correct - I'll explain: When I used a simple cube- without the fibers and applied both sets of periodic boundary conditions on 4 faces plus adding constraints on 3 points - this was solved! The error occurs only when adding the fibers... Is this a meshing problem?
What do you suggest I should do in this case?
Thank you in advance,
Tal
1 Reply Last Post 24 apr 2010, 07:56 GMT-4
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Posted:
1 decade ago
I don't know if it helps, but for periodic boundary conditions you should have an exact mesh of the source on the clone boundary, and you can acheive this by copying the meshes between the boundaries.