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heat conduction issue in imported assembly

Posted Jun 6, 2011, 3:56 a.m. EDT Geometry, Mesh, Modeling Tools & Definitions, Parameters, Variables, & Functions, Studies & Solvers, Structural Mechanics Version 4.1 3 Replies

a k
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Hey guys,
I have an assembly made of two partial tubes and a flexure (bridge) connecting them. the connection is normally via pressing or welding and makes the whole assembly a one part.
I use manual meshing (quad on the surfaces and sweep along each volume) and for that I need to import the CAD model as an assembly, now the problem is that even after definning contact pairs and involving them in my Solid or Heat Transfer physics, the parts are have no interaction at contact interfaces.
I need to fix the geometry on one side and rotate the other end and get the stress values while the fixed end and the rotating end are in different constant temperatures.
I cant even do a simple steady state structural analysis let alone a coupled thermal-structural.
the only way I get the results is by chaging the Assembly to Union and use auto meshing but that is not working for me as Later on i will have 40 of this structures in one bigger assembly and using auto mesh would make the model way complicated.
can some one please tell me how to bound the contact faces in a way that moving or heating one will affect the other one?

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3 Replies Last Post Jun 7, 2011, 4:10 a.m. EDT
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)
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Posted: 1 decade ago Jun 6, 2011, 11:01 a.m. EDT
Hi

if they are press-fit it's like a continuity, you can then use "union" and not necesarily "assembly". It its the total flexing contact you want, then you can group most of your volumes into an explicit geometrical "union" first (with continuity for these internal boundaries) and keep the last boundaries in contact as "assembly"

--
Good luck
Ivar
Hi if they are press-fit it's like a continuity, you can then use "union" and not necesarily "assembly". It its the total flexing contact you want, then you can group most of your volumes into an explicit geometrical "union" first (with continuity for these internal boundaries) and keep the last boundaries in contact as "assembly" -- Good luck Ivar
a k
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Posted: 1 decade ago Jun 7, 2011, 3:14 a.m. EDT

Hi

if they are press-fit it's like a continuity, you can then use "union" and not necesarily "assembly". ...



Thanks for your reply Ivan, Like I mentioned in the first post, I will be having around 20 of these in another bigger assembly and using a Union means I can not simply quad mesh and sweep my geometry like i can in Assembly.
Union requires tethrahydral elements and they increase the number of totall elements by a factor of at least 25.
I have tried the Union with an auto coarse mesh and the model works flawlessly, i was wondering if i could keep it as an assembly and yet maintain the whole unity of the structure.
lets say i am trying to do the "glue" command in ANSYS where simply by glueing two contact faces they interact although they belong to different domains in an assembly.
Any Ideas?
thanks again.

Ali
[QUOTE] Hi if they are press-fit it's like a continuity, you can then use "union" and not necesarily "assembly". ... [/QUOTE] Thanks for your reply Ivan, Like I mentioned in the first post, I will be having around 20 of these in another bigger assembly and using a Union means I can not simply quad mesh and sweep my geometry like i can in Assembly. Union requires tethrahydral elements and they increase the number of totall elements by a factor of at least 25. I have tried the Union with an auto coarse mesh and the model works flawlessly, i was wondering if i could keep it as an assembly and yet maintain the whole unity of the structure. lets say i am trying to do the "glue" command in ANSYS where simply by glueing two contact faces they interact although they belong to different domains in an assembly. Any Ideas? thanks again. Ali
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)
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Posted: 1 decade ago Jun 7, 2011, 4:10 a.m. EDT
Hi

from what I understand the Ansys "glue" is the COMSOL assembly + "identity pair". In v4.2 these are (again, as for 3.5) "automatically" generated, so you do not need to click select them all manually.

--
Good luck
Ivar
Hi from what I understand the Ansys "glue" is the COMSOL assembly + "identity pair". In v4.2 these are (again, as for 3.5) "automatically" generated, so you do not need to click select them all manually. -- Good luck Ivar

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