Learning Forum

[helen.durand]

Hello,

I am currently running a transient structural simulation where I create a linear material (material 25) and two nonlinear materials (material 30 and 50) using an APDL command object in the prep phase. I am trying to switch from the linear material to one of the nonlinear materials, but I am getting warnings saying that material 25 is nonlinear:

 *** FATAL ***                           CP =     385.078   TIME= 20:27:25
 Change a nonlinear material model, 25, to another nonlinear material   
 model, 50, is not allowed for element type 186.                        

 ************************************************************************
 The above error is non-recoverable by ANSYS                            
  ANSYS run terminated by the indicated error                           
  Current data base saved if possible.                                  
 ************************************************************************

For the linear material, I am using the following APDL inserted into a command block in transient structural:

MP,KXX,25,15,
MP,DENS,25,5e3,
MP,EX,25,5e10,
MP,C,25,300,
MP,ENTH,25,5e9,
MP,NUXY,25,0.3,

I am aware that it is not possible to switch betweeen nonlinear materials, but I do not understand why it is saying material 25 is nonlinear. Why might material 25 become nonlinear?

Thank you!

[peteroznewman]

Hello Helen,

I can't answer your question, but I have some questions for you. Are you trying to switch materials in the middle of the simulation? Why do you need to switch from a linear material to a nonlinear material during the simulation? Why not begin the simulation with the nonlinear material?

I have used temperature dependent properties for a material. That single material definition then works over a wide temperature range and Ansys automatically interpolates the correct value from the table at each time step in the simulation.

Regards,

Peter