Ansys Workbench 9---Thermal Expansion?
Ansys Workbench 9---Thermal Expansion?
(OP)
Hi There,
For thermal analysis, I got the result of temperatures distribution on 3D model, from there, How can I find thermal expansion on model? I use workbench 9.0
best regards,
av
For thermal analysis, I got the result of temperatures distribution on 3D model, from there, How can I find thermal expansion on model? I use workbench 9.0
best regards,
av





RE: Ansys Workbench 9---Thermal Expansion?
RE: Ansys Workbench 9---Thermal Expansion?
Eth = alpha(T-Tref)
alpha = linear coefficient of thermal expansion (a material property)
Tref = some reference temperature (e.g. ambient)
T = the unknown temperature to be found
Hence to find the expansion you can do a thermal stress analysis in workbench, and from this you can find the thermal strains and the expansion of the model.
Use the results from your thermal analysis to start a thermal-stress analysis (search for "filters" in the help file). Either that or do the thermal in WB and then transfer to ANSYS and issue the command LDREAD for the thermal results.
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RE: Ansys Workbench 9---Thermal Expansion?
<Eth=alpha(T-Tref)>
Yes, but my collegues who use Workbench told me that T must be constant over the application target, so if there is a variable T distribution over a surface, for example, either you slice the surface within the CAD and "discretize" the T gradient, or you must switch to ANSYS classical.
Is there something we are missing?
RE: Ansys Workbench 9---Thermal Expansion?
The problem appears to me to be very simple, but perhaps the OP could clear it up, or perhaps I am also missing something. You need a differential T over a surface (say) in order to get the thermal expansion (if the T was constant, there would be no thermal strain/expansion). You can apply this T either by transient or static means to obtain the thermal distribution. Once you have this, you can obtain the thermal stress, which implicitly contains the thermal expansion through the alpha constant.
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RE: Ansys Workbench 9---Thermal Expansion?
The fact is: OK, to have thermal expansion there must be a DELTA-Temperature. But this DELTA can be constant over the, say, surface, or not (=be dependent on the spatial coordinate).
I mean:
If the T is constant over the surface, it will be
T=f(x;y)=const
This can obviously be handled by WB. In this case, if T.ne.Tref, there is thermal expansion but not necessarily thermal stress (it depends on the restraints).
If the T is a gradient in the x direction, it will be:
T=f(x;y)=a*x+b
Let's generalize to an arbitrary T distrib (polynomial in this case):
T=f(x;y)=a*x^2+b*y^2+c*xy+d*x+e*y+f
For these cases, my collegues said that WB can not be used (that's why they shift to Clasical). Are we missing something?
You may note that this has nothing to do with time-dependency.
Discretization:
of course, when you have T=f(x;y), you can slice the surface in the x and y directions with sufficiently small pitch in order for you to consider T=const over the slice. The error with respect to the continuous distrib function can be very easily calculated.
RE: Ansys Workbench 9---Thermal Expansion?
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RE: Ansys Workbench 9---Thermal Expansion?
(You too have to make your answer clearer)
Refer to what? Must I understand that WB does handle gradiented BC?
Or, simply, did I get confused by reading "...for a thermal analysis, I got..." instead of "...from a thermal analysis, I got..."?
RE: Ansys Workbench 9---Thermal Expansion?
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RE: Ansys Workbench 9---Thermal Expansion?
But, by the way, are gradiented BC possible in WB9, or not? I never used it until now except for some simple tasks, always used Classical, but as my company is pushing on CAD/FEM interoperation, WB would be great in conjunction with our CAD...
RE: Ansys Workbench 9---Thermal Expansion?
Best regards,
a.v