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Yield vs Temperature Function

Dear All,

 

I define a function Yield stress vs temperature in Femap and setting this function in a non linear material definition Card (setting initial yield stress = 1) but when I run the analysis I obtain an error.

The solver consider yield stress = 1 and not considered the predefined function.

How I can properly define this analysis?

 

Best Regards

Stefano

6 REPLIES

Re: Yield vs Temperature Function

Phenom
Phenom
What sort of analysis? Are you using Advanced Non-linear?
If you are using Advanced Non-linear, you need to define a stress strain function for each temperature value. Then you need to define another Femap function, which is Type 5: Function vs Temp. This function will have as many data points as you have stress strain curves. Each data point will be the temperature value (X), and the Function ID (Y) of the function used to define the stress strain curve at that temp.

Re: Yield vs Temperature Function

Hi,

 

I don't used Advanced non linear analysis but the classic non linear analysis (SOL 106).

This procedure is applied also with this solver? 

 

Best regards

Stefano

 

Re: Yield vs Temperature Function

Phenom
Phenom

Unfortunately, I don't recall if thermal plasticity works the same way in SOL106.

 

I know SOL106 has thermal elasticity, and it also has creep plasticity including thermal effects, but don't recall if it can do direct thermal plasticity without using a creep method.

 

I suggest you look at Chapter 6 of the "Handbook of Nonlinear Analysis (SOL106)" via the Femap menu: Help -> NX Nastran.

Re: Yield vs Temperature Function

Hi,

 

I contacted Nastran support and I resolve the problem by manually entering MATST1card and associated TABLEM1 function (as reported in the attached figure).

 

Best regards

 

Stefano

Re: Yield vs Temperature Function

Phenom
Phenom

Interesting. My copy of the docs (Quick Ref Guide) doesn't even have an entry for MATST1.
I will respectfully urge caution... GTAC may have advised how to produce temp dependent Nastran entries, but I suggest you check very carefully that those entries are producing the intended effect on plasticity if you are using SOL106.
Perhaps its a new feature not documented yet, which would be exciting, as SOL106 has not changed a great deal over the years.
And interesting that it does not use exactly the same entries as SOL601 (adv NL) for the same purpose.

Re: Yield vs Temperature Function

Siemens Phenom Siemens Phenom
Siemens Phenom

That input is unique to Autodesk Nastran, that option is not available in NX Nastran. It always helps to identify the solver when questions come up on advanced features.