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how to select boundary condition for 2 or 3 different material those are not sholdered or not firmly joined but attach by pressure, for example pressure contact IGBT.
Posted Mar 1, 2011, 11:52 a.m. EST Version 3.5a 2 Replies
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Hi All,
I want to draw and simulate IGBT chip + DBC + Base plate those are in contact by an external pressure from top towards bottom direction. in this case, i splitted different materials connecting layers but i am facing difficulties to mention the boundary condition of the additioal layers due to splititng into the coupling place for the Heat transfer due to conduction(ht). without splitting, it autometically shown the option 'contunity' but after splitting what can i select. by splitting, i need to observe the mechanical stress and to compare it with firlmy joined IGBT. i also facing difficulties to select boundary condition for conductive media DC (emdc).
please give me some idea.
Thanks.
Best Regards,
Rony
I want to draw and simulate IGBT chip + DBC + Base plate those are in contact by an external pressure from top towards bottom direction. in this case, i splitted different materials connecting layers but i am facing difficulties to mention the boundary condition of the additioal layers due to splititng into the coupling place for the Heat transfer due to conduction(ht). without splitting, it autometically shown the option 'contunity' but after splitting what can i select. by splitting, i need to observe the mechanical stress and to compare it with firlmy joined IGBT. i also facing difficulties to select boundary condition for conductive media DC (emdc).
please give me some idea.
Thanks.
Best Regards,
Rony
2 Replies Last Post Mar 2, 2011, 9:14 a.m. EST
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Posted:
1 decade ago
Hi
indeed when you have multiphysics models sometimes the same boundary should be continuity for one physics and act as a "assembly" type boundary for another. I havent really trid this out, but it seems rather logic to me then to use "assembly" mode on every boundary that has at least one non-continuous flux link. And then make a lot of "pairs" and add continuity pairs for the physics that require this, and contact or thermal isolation, or thin boundry thermal or electrical impedance for others.
It takes some time, but I do not see how else to do it. Unfortunately in v4.1 all non-composed boundaries are flagged as assembly boundaries, and you must relink them all by hand, in v3.5 they were (almost) all predefined automaticaly as identity pairs with continuity as these are often the majority
--
Good luck
Ivar
indeed when you have multiphysics models sometimes the same boundary should be continuity for one physics and act as a "assembly" type boundary for another. I havent really trid this out, but it seems rather logic to me then to use "assembly" mode on every boundary that has at least one non-continuous flux link. And then make a lot of "pairs" and add continuity pairs for the physics that require this, and contact or thermal isolation, or thin boundry thermal or electrical impedance for others.
It takes some time, but I do not see how else to do it. Unfortunately in v4.1 all non-composed boundaries are flagged as assembly boundaries, and you must relink them all by hand, in v3.5 they were (almost) all predefined automaticaly as identity pairs with continuity as these are often the majority
--
Good luck
Ivar
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Posted:
1 decade ago
Hello Lvar,
Thanks for your reply. yes, to split, i used 'Assembly' to get 2 layers in the contact place of two materials. but when i go for solving then i couldn't get any solution. i am trying. thanks for your reply.
Regards,
Rony
Thanks for your reply. yes, to split, i used 'Assembly' to get 2 layers in the contact place of two materials. but when i go for solving then i couldn't get any solution. i am trying. thanks for your reply.
Regards,
Rony