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Error 6170 in modelling stress-strain with contact pairs

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Dear all,

I try to calculate temperature distribution (and later stresses) in 2D axial symmetrical ladle with contact pairs. When trying to solve T I get the following error:

Error: 6170
Failed to evaluate variable.
- Variable: auglagiter
- Geometry: 1
- Boundary: 79
Failed to evaluate variable.
- Variable: pn_cp1_smaxi
- Defined as: ((E_smaxi*min((0.001*(5^auglagiter)),1))/hmin_cp1_smaxi)
Failed to evaluate operator Jacobian
- Operator: if
- Geometry: 1
- Boundary: 79

I think that there is some problem with contact pair no.1 (includes boundaries 78 and 79), but I don't understand what variable pn is and why it has problems with smaxi while I'm only in htgh mode. What can I do to solve the problem?

Thanks for suggestions and helps,
Birgit

2 Replies Last Post 2011/11/02 11:32 GMT-4
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago 2011/11/02 11:12 GMT-4
Hi

definitively its related with your penalty function of your contact pair, seems that it is not derivable, do you have step functions defined in some of those variables mentioned there ?

It's not easy to debug like that I agree

--
Good luck
Ivar
Hi definitively its related with your penalty function of your contact pair, seems that it is not derivable, do you have step functions defined in some of those variables mentioned there ? It's not easy to debug like that I agree -- Good luck Ivar

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Posted: 1 decade ago 2011/11/02 11:32 GMT-4
Hi Ivar,

the only functions I have defined are not valid for the contact pairs - T(inf) and heat transfer coefficient at the boundary facing the inside of the ladle, contact pairs were defined between bricks of bottom and wall with symmetry defined. The functions are not step functions, but analytic functions with arguments and an expression (Boolean functions) for T and h. They should not have an influence on the contact pairs, should they?

Helpless greetings,
Birgit
Hi Ivar, the only functions I have defined are not valid for the contact pairs - T(inf) and heat transfer coefficient at the boundary facing the inside of the ladle, contact pairs were defined between bricks of bottom and wall with symmetry defined. The functions are not step functions, but analytic functions with arguments and an expression (Boolean functions) for T and h. They should not have an influence on the contact pairs, should they? Helpless greetings, Birgit

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