Plotting Strength ratio of composite with param SRCOMPS 3

[Onda]

Using MSC Nastran 2007. With the PARAM,SRCOMPS,YES I could have the strength ratio written on F06 file but I didn't arrive to have the same result on the OP2 file.
I would like to plot the Strength ratio, so there is anybody that know how to have this result in the OP2?
Thanks

 

[babajv]

I had the same problem, come to find out the following:

Strength ratios are not supported in Patran.

Extended Description Avoidance: With the following alter, the strength ratios (SRs) can be written to the op2 file and displayed in Patran. This is because the Nastran failure index datablock (OEFIT) has the same format as the SR datablock. However, with this alter, Patran will still think the values are failure indices, so titles in Patran will indicate failure indices while the values are SRs:

compile sedrcvr
$
$ ***This DMAP works with only param,post,-1
$
$ DMAP alter to replace Failure Index data block with
$ the Strength Ratio data block. The f06 will have both
$ Failure Index and Strength Ratio values printed as
$ usual; however, the op2 file has the Failure Index
$ data replaced with the Stregth Ratio data.
$
$ by Dean Bellinger, 7Jul2006
$
$ WARNING: Tested with only one test case using two elements,
$ and two subcases on version 2005.5.0 and 2005.0.0.
$
alter 'output2.*oes1c,oefit,oesrt' (1,-1) $
copy oesrt/oefitz/always/-1 $
type parm,,i,n,reclpoef $
reclpoef=1 $
do while ( reclpoef>=0 ) $
paraml oefitz/oefitzz/'tabrepi'/s,n,reclpoef/2//25 $
reclpoef = reclpoef + 2 $
paraml oefit//'dti'/s,n,reclpoef/2//s,n,junkit $
equivx oefitzz/oefitz/always $
enddo $ reclpoef
equivx oefitzz/oefit/always $
endalter

Anyone know how to alter a dmap file?

 

[Onda]

Babajv!

I've run your alter on a 100k elements and the result displayed match with F06 file.
Also, because no one was replying to my post, I've write a excel macro that read the F06 and write a *.els file with the Strength ratio.
The result obtained with your alter match the result imported from F06 with the macro.
Thank you for your help! It allow me to make a lighter F06 file and speed up the work.

Onda

 

[babajv]

Hey Onda,

where did you physically use the alter code? BDF? PCL? Please let me know, since I have the answer but not sure where to use it. I was gonna try putting it into the BDF, but I am not really sure if that will work yet.

Thanks

 

[Onda]

You must put the DMAP routine in the executive control section
in the bdf file.

If you don't have the file management section you could just put it in the top of your bdf.

Or to be more sure you could put it after the SOL xxx statement and before the CEND statement.

Try and ask me if you have any trouble.

regards

Stefano

 

[babajv]

I did exactly what you have said. However, towards the end of my run, my nastran run hangs and never finishes. When I look in the f06 file it basically never says end of job. Did you change anything when you used the alter code to make it work?

 

[Onda]

I'm running SOL 101.
I just have put the alter in the file management section
and used the following parameters:
PARAM POST -1
PARAM SRCOMPS YES

I've all ready done several checks versus F06 and personal calculation and results are correct.


Which Nastran version are you using??
I think you should try a very little model as begin to see if it work on your PC.
Also you need to have all failure data in your materials, and a congruent Failure theory for each material.
Onda

 

[babajv]

Yea, I am running a solution 106 and have failure criteria defined that should be correct. Maybe this code does not work in non-linear solution sequence eventhough I dont see why it wouldnt. I am using 2005 R2. What are you using?

 

[Onda]

I'm using 2007.0.0 and running 101, I suggest to try first with SOL 101 and then try with different solutions.
On the alter is write that as been developed and tested with version 2005.0.0 and 2005.5.0.

Do you have correct FI and SR on F06 if you run without alter?
try the simplest problem with sol 101, and then step by step move toward biggest more complex models and sol 106 in way to understand why is not working.

 

[babajv]

I just got off the phone with MSC support and I am basically told that the alter code is for a Linear Solution (Sol 101) ONLY.
JOY

 

[Onda]

Just as turnaround.. If the non linearity are geometric and large deformation but you don't have material non linearity.

load result from nonlinear analysis in Patran, create a field of displacement and apply the field on ALL nodes less one as enforced displacement.
solve with SOL 101 and the alter on.
In this way you have imposed on all nodes the correct displacement/strain and you can get the correct Strength Ratio on op2 file.

hope this help!

regards

Stefano

 

[fpelizza]

Hi onda
I happened to have the same problem and did as you suggested.
Very very clever. thanks a lot. You have a lot of Nastran experience.

Regards
Francesco

 

[Onda]

Grazie Francesco.