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Indetity pairs should be fixed?

Ciriacos Orphanidis
hello

I am running a static structural mechanics problem on comsol multiphysics 3.5 . I have a building and i want to see the effect of a seismic load on my structure ..

My problem is that the building is an assembly of masonry walls and wooden floors , so i have to set identity pairs between them .... I want to ask , when we create identity pairs , we should set that these pairs are fixed?


1 Reply Last Post Feb 2, 2013, 2:31 PM EST
Posted: 5 years ago Feb 2, 2013, 2:31 PM EST
Hi

the rule is: in Geometry Union mode, all common boundaries are made unique and the fluxes are continuous crossing the "common, unique" boundary (except in latest v4 when some Thin film physics might be added at the boundary layer, hence a boundary up and down definition to distinguish the two domains and the sandwitched layer boundary".

In Geometry Assembly mode, all common boundaries between two domains (that are not already grouped by a specific "union" geometry node, or that are parts of a layer from a primitive geometry shape) are separate and there is no default flux passing through the boundaries. But, one can ask COMSOL to create "Idenity or Contact pairs out of all overlapping boundaries (just as the save "imprints" cuts any common boundary such to make them fully common in shape, with possible some subdivision for single boundaries). Thereafter, you need to select the desired identity pairs, an for ALL related physics (and dependent variables) you must decide if you ant "continuity (the dafault of union mode) or some other combination or local boundary physics.

By the way in v4 we call "domains", what previously in 3.5 was called "sub-domains"

--
Good luck
Ivar
Hi the rule is: in Geometry Union mode, all common boundaries are made unique and the fluxes are continuous crossing the "common, unique" boundary (except in latest v4 when some Thin film physics might be added at the boundary layer, hence a boundary up and down definition to distinguish the two domains and the sandwitched layer boundary". In Geometry Assembly mode, all common boundaries between two domains (that are not already grouped by a specific "union" geometry node, or that are parts of a layer from a primitive geometry shape) are separate and there is no default flux passing through the boundaries. But, one can ask COMSOL to create "Idenity or Contact pairs out of all overlapping boundaries (just as the save "imprints" cuts any common boundary such to make them fully common in shape, with possible some subdivision for single boundaries). Thereafter, you need to select the desired identity pairs, an for ALL related physics (and dependent variables) you must decide if you ant "continuity (the dafault of union mode) or some other combination or local boundary physics. By the way in v4 we call "domains", what previously in 3.5 was called "sub-domains" -- Good luck Ivar

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