Learning Forum

[longt8]

Hello,

I have a Johnson Cook Model which has the function to transfer the visoplastic work to heat. Currently, I only want to see the temper due to the viscosity effect from Johnson Cook model. Also, I want to set initial temperature for my part.  I want to ignore the heat transfer effect and only want to see the current temperature(initial temperature + temperature by viscosity)

1: To initialize the initial temperature, do I only need to use the Initial_temperatue_set keyword by creating a node-set that includes the nodes of the whole part?

2: Would you let me know what i need to change from my database settings for example database_extent_binary? I think I need to give NEIPH as 14. Do I need to add the control solution and thermal solver?

 

3: How can I check the temperature contour result in LS Prepost?

 

Thank you so much!

 

Best,

 

Teng

 

 

[Armin]

Hi Teng,

I’m not very familiar with the thermal solver but if you’re using material type 224 (*MAT_TABULATED_JOHNSON_COOK), you don’t need a thermal solver as the generated plastic work is simply converted to heat and is controlled by the BETA variable in the card.

The initial temperature is provided to the model as an input in the card and the temperature contours can be accessed via history variables (history variable #10 or #14 depending on whether shells or solids elements are used) in the Fringe Component window of LS-PrePost.

[Atul Verma]

I was just watching

, I have seen that radiation is not modelled on capsule outer surface. Please let me know why it is so? As every body having some temperature more than absolute zero will radiated some energy.

[longt8]

 

Hello Everyone,

Currently, I am not going to involve the thermal-mechanical solver. My current MAT 224 has specific heat. That means the temperature can transfer to energy. 

To see how temperature affects the energy, I go to ASCII to check glstat or matsum, but I can only see the internal energy, kinetic energy, hourglass energy, etc. I can not find the thermal energy. Also, I can not see the thermal stress under FriComp.

Would you let me know where I can find to plot the thermal energy and thermal stress?

Is the thermal energy included in internal energy and we can not separate it?

Thank you!

Best,

Teng

 

[Armin]

Hi Teng,

From my understanding, it might not be possible to properly determine thermal stresses without employing a thermal solver. The MAT 224 model provides a simplified technique to calculate temperature rise without a full thermal analysis by assuming a portion of plastic work at each element is converted to heat (using the BETA variable). While it alleviates the need for fully coupled thermo-mechanical analysis, it is best suited for modeling deformation at dynamic strain rates where adiabatic or semi-adiabatic condition prevails and an estimate of temperature rise is needed.