AUTODYN automatically replaces an area of air with void

- September 25, 2021 at 10:07 am
  
  DavideGiuliano
  Subscriber
  
  Good morning,
  I'm doing a 2D simulation on AUTODYN in which a TNT explosion occurs, and I want to measure the pressure in a certain point by using a gauge. The problem is that as soon as I start the simulation AUTODYN replaces an area of air with void (see image) and this changes the results.
- September 30, 2021 at 2:14 pm
  
  Chris Quan
  Ansys Employee
  
  I noticed that the system of units - m/kg/s is used in the model setup while the descriptions say the element size is in mm.
  Can you change the system of units to the default system of units, mm/mg/ms, then retrieve both TNT and Air from the material library to update their material parameter to the new units?
  Check if the mesh is still valid in the new system of units. If yes, run the model again to see if the problem persists. Otherwise, re-build the mesh and run the model.
- October 5, 2021 at 2:37 pm
  
  DavideGiuliano
  Subscriber
  
  I tried to re-build the model using mm/mg/ms units since it takes only a couple of minutes and I noticed this problem occurs no more, thank you very much Can you please tell me how to mark your answer as the best one and close the discussion?