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how to set model temperature

how to set model temperature

how to set model temperature

(OP)
I have one small question. I'm trying to demonstrate material non linearity due to temperature.
In other words, I want to show that for the same force, the stresses in the material may be different due to the temperature of the object. Now, I figured the commands for the material property part, but what I can't figure out is how I set my model to have a specific temperature. I tried using the da command (eg: da,1,TEMP,50) but it showed no effects whatsoever.

Do you have any tips for me?
Thank you and every help is much appreciated.

RE: how to set model temperature

What version of Ansys are you using? I'm pretty sure that you can vary the temperature by load step in 12.1 and 13 within the GUI. If not, perhaps you need to apply temperatures at body forces (BF command) or run a thermal model beforehand and read in the results.

RE: how to set model temperature

(OP)
I'm using version 12.

What I was planning to do is this: First I set the material property commands:


MPTEMP,1,0,400        
MP,EX,1,12E6,-8E3    
TB,BKIN,1,2        
TBTEMP,0.0        
TBDATA,1,44E3,1.2E6    
TBTEMP,400        
TBDATA,1,29.33E3,0.8E6    
/XRANGE,0,0.02        
TBPLOT,BKIN,1    

What I'm trying to achieve by this is set 2 material properties for different temperatures, and every temperature in between solves itself out due to the -8E3 tangent.

I didn't consider your body force idea, will delve into the help file to see if i could apply this for the area of the model, give it a set temperature and demonstrate  that when I vary this temperature the stress varies according to the material property table.

thank you for the tip, much appreciated
 

RE: how to set model temperature

In a structural model, temperatures are imposed as body forces. That should get you what you want.

RE: how to set model temperature

(OP)
thank you pal for the tip, worked perfectly. much appreciated.

If I may, I've got another small question. As you probably noticed by now my assignment is about material non-linearity, and I thought a good example would be a circlip being pulled apart.
My problem in this case is how I can simulate the boundary conditions effectively, as in real case there's nothing fixed when pulling the circlip from around the tube or pipe.

I included a picture of the circlip should you require it. Thank you.

http://img3.imageshack.us/img3/1746/eg000.png

RE: how to set model temperature

Your model is unconstrained. Even though the forces balance, without a displacement constraint, the part will fly away due to the numerical nature of the solution. Replace one of the loads with a cylindrical support (i.e. constrain the hole radially) and your solution will converge.

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