FSI: change material parameters before restart

Lance · September 29, 2010, 10:31

I made a restart on my FSI simulation and at the same time changed the Youngs modulus and stiffness of the solid domain (just edited the .mf file and added the new MP,DENS and MP,EX commands).
However, I got a warning that it is a "non-standard behaviour" to change material parameters between load steps. Is there a "standard behaviour" to do this, or arent you supposed to make a restart with new material parameters?

stumpy · September 30, 2010, 09:32

I'm guessing that some of the transient terms may not be accurate for the first timestep when changing material properties (this really is just a guess). I think support would have to answer that - or is there an ANSYS FEA forum somewhere? Maybe we should add one here and rename the site to CAE Online :-)

Lance · September 30, 2010, 09:38

I've been in contact with the support but so far no answer. Anyway, the results seem reasonable, so I guess it works. The warning message looks as follow:
*** WARNING *** CP = 53.720 TIME= 16:50:06
Changing material properties (MP commands) between load steps is a
non-standard use of the program

As long as it's just a warning and the program accepts the new material, Im fine with it.

Yeah, maybe a new forum, or at least a FSI subforum would be great :-)

September 29, 2010, 10:31	FSI: change material parameters before restart	#1
Lance Senior Member Lance Join Date: Mar 2009 Posts: 669 Rep Power: 22	I made a restart on my FSI simulation and at the same time changed the Youngs modulus and stiffness of the solid domain (just edited the .mf file and added the new MP,DENS and MP,EX commands). However, I got a warning that it is a "non-standard behaviour" to change material parameters between load steps. Is there a "standard behaviour" to do this, or arent you supposed to make a restart with new material parameters?

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September 30, 2010, 09:32		#2
stumpy Senior Member Join Date: Apr 2009 Posts: 531 Rep Power: 21	I'm guessing that some of the transient terms may not be accurate for the first timestep when changing material properties (this really is just a guess). I think support would have to answer that - or is there an ANSYS FEA forum somewhere? Maybe we should add one here and rename the site to CAE Online :-)

September 30, 2010, 09:38		#3
Lance Senior Member Lance Join Date: Mar 2009 Posts: 669 Rep Power: 22	I've been in contact with the support but so far no answer. Anyway, the results seem reasonable, so I guess it works. The warning message looks as follow: * WARNING * CP = 53.720 TIME= 16:50:06 Changing material properties (MP commands) between load steps is a non-standard use of the program As long as it's just a warning and the program accepts the new material, Im fine with it. Yeah, maybe a new forum, or at least a FSI subforum would be great :-)