Continous output in .op2 file 2

[Regretful]

Hello people!

I wish for nastran to update the .op2 file for every completed increment so i can check in my postprocessor that the model is not misbehaving, does anyone know of a way to do this?

Kind Regards,
Regretful

 

[Zadrobu]

Could you clarify what you mean exactly by 'every completed increment'?

 

[Regretful]

Sure, I mean if the model has fixed stepping of 5 steps, as soon as one of those are completed it should update the op2 file.

 

[nlgyro]

set the 9th field on the NLPARM card to "YES". this should do the job.

 

[Regretful]

Yeah, maybe i should have mentioned im using SOL400 so im using NLSTEP instead of NLPARM! However this lead me to the NLPARM, INTOUT option where i can define intermediate output, this should produce what i am looking for! Thanks a lot for the responses

Its not so easy to find stuff when you dont know where to look!

Edit: I am using "FIXED" time stepping, this is probably not the solution that i am looking for, but i cant be sure until i have tested. Since i had to input the ADAPT keyword to get the INTOUT keyword.

Kind Regards

 

[dmapguru]

One of the issues with the "standard" op2 output (written by PARAM,POST,-1/+1) is that you don't get data recovery until all steps are finished. Even if you did, the op2 might not be readable by a post processor due to buffered output not finishing a write, as well as the EOF marker not being written at the end of the op2 until the job terminates.

Take a look at the NLOPRM case control command; there is an option called OUTCTRL=INTERM. If you requests intermediate output on NLSTEP, then for each converged load increment, you get a separate op2 file containing the solution at the end of that increment. These "increment" op2 files are additional to the standard op2 file, and as soon as the increment has converged, the op2 files are sync'd (buffers emptied) and the EOF written. At that point you can read the op2 file (while MSC Nastran is still running), and even move the op2 file elsewhere or delete it.

 

[Regretful]

Thank you dmapguru, this is exactly what i was looking for!