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How I can add data for a solution to a new study?

Posted 23.12.2012, 17:54 GMT-5 Low-Frequency Electromagnetics, Heat Transfer & Phase Change, Structural Mechanics Version 4.1, Version 4.3a 8 Replies

Jorge Zaragoza
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I'm working on the simulation of an iron foundry, I made a transient thermal study, and I exported data solution in time 200seg temperatures. I would like to know how I can add the output exported to a structural study, in order to meet the thermal expansion at that time.

Kind Regards.
8 Replies Last Post 08.01.2013, 11:42 GMT-5
Josh Thomas Certified Consultant
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Posted: 1 decade ago 24.12.2012, 08:51 GMT-5
Jorge,

No need to export the solution data from your transient thermal study. Just add a solid mechanics physics interface and a new study to the same model file (mph file). Do the following:

Right-click on Model 1 and select Add Physics
Add Solid Mechanics
Add the appropriate study type (I am assuming Stationary)
Right-cllick on Linear Elastic Material 1 and add Thermal Expansion
Expand Model Inputs and type "T" in the User defined list for Temperature (this couples the thermal expansion with the Temperature solved for by the Heat Transfer interface)
Apply boundary conditions to solid mechanics domains
Click on Study 2>Step 1: Stationary
In the Settings window, expand Values of Dependent Variables
Click check box for Values of variables not solved for
Change method to Solution
Change Study to Study 1, Time Dependent (your transient thermal study)
Change Time to 200 sec (or whatever time you want)

Best regards,
Josh Thomas
AltaSim Technologies
Jorge, No need to export the solution data from your transient thermal study. Just add a solid mechanics physics interface and a new study to the same model file (mph file). Do the following: Right-click on Model 1 and select Add Physics Add Solid Mechanics Add the appropriate study type (I am assuming Stationary) Right-cllick on Linear Elastic Material 1 and add Thermal Expansion Expand Model Inputs and type "T" in the User defined list for Temperature (this couples the thermal expansion with the Temperature solved for by the Heat Transfer interface) Apply boundary conditions to solid mechanics domains Click on Study 2>Step 1: Stationary In the Settings window, expand Values of Dependent Variables Click check box for Values of variables not solved for Change method to Solution Change Study to Study 1, Time Dependent (your transient thermal study) Change Time to 200 sec (or whatever time you want) Best regards, Josh Thomas AltaSim Technologies
Zhifang Wang
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Posted: 1 decade ago 25.12.2012, 03:19 GMT-5
I have modeled it similar to your guide ,but i found the heating result isnot equal to the cooling one(t=0s),what's the reason?
i pasted my temperature graph as follow, in the picture solution 3 is temperature field of heating,solution1 express
the cooling initial, why they are difference??

could you give me some advice


thank you and merry christmas
I have modeled it similar to your guide ,but i found the heating result isnot equal to the cooling one(t=0s),what's the reason? i pasted my temperature graph as follow, in the picture solution 3 is temperature field of heating,solution1 express the cooling initial, why they are difference?? could you give me some advice thank you and merry christmas
Josh Thomas Certified Consultant
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Posted: 1 decade ago 26.12.2012, 08:36 GMT-5
Zhifang-

From looking at your screenshots, it's not clear to me exactly what your study set-up is. What do you mean by heating result and cooling result?

Would you be able to post your mph and give more explanation?

Regards,
Josh Thomas
AltaSim Technologies
Zhifang- From looking at your screenshots, it's not clear to me exactly what your study set-up is. What do you mean by heating result and cooling result? Would you be able to post your mph and give more explanation? Regards, Josh Thomas AltaSim Technologies
Jorge Zaragoza
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Posted: 1 decade ago 26.12.2012, 15:06 GMT-5
Thanks a lot, another cuestion. when I want to invest mathematically the result and type "1 / T" instead of "T" I changed the lyrics to red, you can enter the mathematical inverse of a thermal solution prior model of thermal input expansion module, put only "1 / T "?
Thanks a lot, another cuestion. when I want to invest mathematically the result and type "1 / T" instead of "T" I changed the lyrics to red, you can enter the mathematical inverse of a thermal solution prior model of thermal input expansion module, put only "1 / T "?
Zhifang Wang
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Posted: 1 decade ago 07.01.2013, 07:33 GMT-5
thanks for your reply and sorry for my Delayed reply

after modeling the induction heating,I would like to use the known temperature distribution to simulate a natural cooling or water cooling process. the cooling initial and the known temperature field should be same theoretically

my model is too big to paste,so could you give me your mail?

thanks a lot
thanks for your reply and sorry for my Delayed reply after modeling the induction heating,I would like to use the known temperature distribution to simulate a natural cooling or water cooling process. the cooling initial and the known temperature field should be same theoretically my model is too big to paste,so could you give me your mail? thanks a lot
Josh Thomas Certified Consultant
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Posted: 1 decade ago 07.01.2013, 08:39 GMT-5
Zhifang-

To reduce mph file size, try clicking Edit>Clear All Meshes and Edit>Clear All Solutions. Then save.

Regards,
Josh Thomas
AltaSim Technologies

Zhifang- To reduce mph file size, try clicking Edit>Clear All Meshes and Edit>Clear All Solutions. Then save. Regards, Josh Thomas AltaSim Technologies
Zhifang Wang
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Posted: 1 decade ago 08.01.2013, 02:07 GMT-5


thanks for your advice


my model is to big,so i paste a simplified 2D model with a similar Physical process,my actual model is a moving 3D one,the inductor move upon the plate



appreciate to your reply
thanks for your advice my model is to big,so i paste a simplified 2D model with a similar Physical process,my actual model is a moving 3D one,the inductor move upon the plate appreciate to your reply
Josh Thomas Certified Consultant
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Posted: 1 decade ago 08.01.2013, 11:42 GMT-5
Zhifang,

I see what you are talking about and the reason is because when you divide your analysis into mutliple steps/studies the initial conditions for the cooling process must be "calculated" based on the input. For this reason, there is a slight difference due to the solver initializing the input conditions. This initialization step is important for some analyses where the initial field contiions need to be made consistent with the boundary conditions. In this case, it just makes a slight change to the values.

To avoid this, consider performing your analysis in one step. You can turn off the magnetic heat source by defining a step function that is smoothed and drops from 1 to 0. Right-click on Defintions and select Functions>Step. Then multiply your heating term by an appropriate step function so that it drops off after 10 seconds. Then run your simulation for 11 seconds. This will be a more realistic simulation of what's going on anyway.

See this thread for more info on using step functions:

www.comsol.com/community/forums/general/thread/29498/

Regards,
Josh Thomas
AltaSim Technologies
Zhifang, I see what you are talking about and the reason is because when you divide your analysis into mutliple steps/studies the initial conditions for the cooling process must be "calculated" based on the input. For this reason, there is a slight difference due to the solver initializing the input conditions. This initialization step is important for some analyses where the initial field contiions need to be made consistent with the boundary conditions. In this case, it just makes a slight change to the values. To avoid this, consider performing your analysis in one step. You can turn off the magnetic heat source by defining a step function that is smoothed and drops from 1 to 0. Right-click on Defintions and select Functions>Step. Then multiply your heating term by an appropriate step function so that it drops off after 10 seconds. Then run your simulation for 11 seconds. This will be a more realistic simulation of what's going on anyway. See this thread for more info on using step functions: http://www.comsol.com/community/forums/general/thread/29498/ Regards, Josh Thomas AltaSim Technologies

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