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Undefined value found.

Posted Feb 5, 2013, 9:27 p.m. EST Version 4.3a 4 Replies

Quan Gao
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I am using poroelasticity module to simulate soil behavior of porous materials, the error information is as follows:

Undefined value found.
- Detail: Undefined value found in the stiffness matrix.
There are 892 equations giving NaN/Inf in the matrix rows for the variable mod1.poro.pw.
at coordinates: (0,0), (0,0.00192308), (0.00125682,0.00130079), (0.00192308,0), (0,0.00384615), ...
There are 3437 equations giving NaN/Inf in the matrix rows for the variable mod1.u.
at coordinates: (0,0), (0,0.000961538), (0,0.00192308), (0.000628409,0.00161194), (0.00125682,0.00130079), ...
There are 3437 equations giving NaN/Inf in the matrix rows for the variable mod1.w.
at coordinates: (0,0), (0,0.000961538), (0,0.00192308), (0.000628409,0.00161194), (0.00125682,0.00130079), ...
and similarly for the degrees of freedom, NaN/Inf in the matrix columns.

Anyone can tell me how should I cope with this error? from what kind of aspects? thanks
4 Replies Last Post Feb 6, 2013, 2:25 p.m. EST
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)
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Posted: 1 decade ago Feb 6, 2013, 12:55 a.m. EST
Hi

it can come from missing BC, particularly in muiltiphysics cases you need to define ALL the BC for ALL the dependent variables, sometimes these BC appears as duplicates

--
Good luck
Ivar
Hi it can come from missing BC, particularly in muiltiphysics cases you need to define ALL the BC for ALL the dependent variables, sometimes these BC appears as duplicates -- Good luck Ivar
Pu Zhang
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Posted: 1 decade ago Feb 6, 2013, 9:46 a.m. EST
Then the duplicates will introduce linear dependent equations?
Then the duplicates will introduce linear dependent equations?
Quan Gao
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Posted: 1 decade ago Feb 6, 2013, 10:23 a.m. EST
I have checked the BC for all variables. I dont think some mistake in BC, any other possibilities? thanks
I have checked the BC for all variables. I dont think some mistake in BC, any other possibilities? thanks
Quan Gao
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Posted: 1 decade ago Feb 6, 2013, 2:25 p.m. EST
poisson's ratio should not be 0.5
poisson's ratio should not be 0.5

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