Optistruct

Hi @Mahantesh

Add Control Cards>>PARAM>>LFREQ  hereby modes with frequencies less than LFREQ are not used in Modal Frequency Response and Modal Transient Analysis.  

Hi @Prakash Pagadala,

When I use this card, I have another message :

Mode eliminated by:
  M - Modeselect card for at least one subcase.
  L - PARAM, LFREQ/FL when MODESELECT card is not active.
  H - PARAM, HFREQ/FL when MODESELECT card is not active.
  S - LFREQ/FL, HFREQ/FL, or MODESELECT depending on the subcase.

Should I add another card?

Thank you!

Hi @Alina

Can you share the entire .out file please?

When you add LFREQ card, you need to specify the frequency within which modes are removed. 

@Prakash Pagadala,

There are my .out file and my .fem file.

Unable to find an attachment - read this blog

Hi @Alina

Is there a reason for having LFREQ?

Since you set V1 from 0 which is lower bound on EIGRL card, you don't need a LFREQ. 

If the lower bound is set to a non zero value, in this case you can use this card. 

The message you see is just for information on which modes are removed and by what means. 

Yes, I'm sorry if it was not clear. I have a rigid body mode below 1Hz and I dont want to have it and when I try to change the lower limit in the EIGRL card I have an error message. I do a Squeak analysis after and this rigid body mode is not welcome.

@Alina

OK, so you have used LFREQ to skip the rigid mode. 

Anyways, the message provides information and nothing to do with the results. 

Hi @Alina

 

Is there a reason for having LFREQ?

 

Since you set V1 from 0 which is lower bound on EIGRL card, you don't need a LFREQ. 

 

If the lower bound is set to a non zero value, in this case you can use this card. 

 

The message you see is just for information on which modes are removed and by what means.