Comments

• Victor

  April 2020

  That sounds like it should work. Is there any strain or displacement or is it completely ignoring the thermal load? Perhaps post the model.
  
  If it's completely ignored, some things to check:

  • That the material has a thermal expansion coefficient.
    
  • That the temperatures really were transferred from the solution - select the node temperature item it created and make sure the numbers shown in the graphics area are reasonable. Beware that for transient analysis, it takes temperature from the current time step, which is the initial one by default, where they might be all at the initial value.
    
• Stoyan

  April 2020

  I do a fair bit of thermal work with Mecway, if you upload a test case I'd be happy to take a look for you
• gemada

  April 2020

  Thanks a lot for the replies.
  Victor, I've checked everything but it doesn't generate thermal stresses.
  Stoyan, I'm uploading the simple test case (thermal and static files). Thanks a lot.
  

  beam-thermal-transient.liml 344K

  beam-thermal-stress-120min.liml 349K
• Victor

  April 2020

  Add stress to the solution with Solution -> New stress and strain -> stress.
• gemada

  April 2020

  Thanks a lot Victor. That worked!
• gemada

  April 2020

  I'm attaching another example: simply supported beam exposed to ISO 834 fire only at the bottom surface: 1 file with thermal transient analisys for conduction, convection and/or radiation, 1 file with thermal stresses just for heat conduction and 1 file with temperature comparison. In the file with temperature comparison case A is convection and radiation and case B is only heat conduction and (usually this is the combination used in scientific papers).
  
  My doubts above hehehe:
  1) Temperature values in case A are strange because of the mesh and transient analysis parameters? (I believe they should be more refined).
  2) I'm not sure about the stress values...they seem to high. Are these the expected results?
  3) Is there any thermal validation cases in here for beams or slabs or columns (transient temperatures x thermal stresses)?

  beam-thermal-transient-120min-example.liml 434.6K

  beam-thermal-stress-120min-example.liml 642.7K

  compare-conduction-vs-convection-and-radiation.jpg 79.3K
• Victor

  April 2020

  1) Yes, those wiggles look like a typical result of time steps or elements being too big.
  
  2) What makes them seem high? Check for mesh convergence. That might go very slowly with linear elements. Quadratic ones are much better on thermal stress problems with non-constant temperature fields.
  
  3) I don't know, sorry. You could get some confirmation by using the CCX solver too.
  
• gemada

  April 2020

  Thanks a lot once again Victor.
  I must learn a bit more about mesh convergence.
  I'll try all your tips.