Learning Forum

[Sebastien ARRIVET]

Hi,

 

I'm trying to export results in .csv format, from a static simulation.

I've struggled to understand how to achieve that, but after looking around in various forum I came up with that bit of code:

!--------------------------------------------------------------------------

/POST1

RSYS,0

SET,1,LAST

csv_name = 'out_node_U_s_1_LAST_post.csv'

*cfopen,csv_name

*cfwrite,'node_num',S11,S22,S33,S12,S13,S23,SEQV

/POST1

allsel

cmsel,s,N_POST,NODE

 

*vget,nodeIds_sel,NODE,,NLIST

*get,nNodes,NODE,0,COUNT

*do,i_noeud,1,nNodes,1

    no_node=nodeIds_sel(i_noeud)

    nsel,s,node,,no_node

    *get,variable_S11,NODE,no_node,S,X

    *get,variable_S22,NODE,no_node,S,Y

    *get,variable_S33,NODE,no_node,S,Z

    *get,variable_S12,NODE,no_node,S,XY

    *get,variable_S13,NODE,no_node,S,XZ

    *get,variable_S23,NODE,no_node,S,YZ

    *get,variable_SEQV,NODE,no_node,S,EQV

 

    *cfwrite, %no_node%,variable_S11,variable_S22,variable_S33,variable_S12,variable_S13,variable_S23,variable_SEQV

 

*enddo

*cfclos

!--------------------------------------------------------------------------

 

The simulation in itself takes less than a second, as the model is very light (around 12k nodes, shell181 elements, one step and simple load), but the export (the selection has around 10k nodes) takes more than 15min on a cluster with loads of ram and cpus.

I have a large amount of such simulation to carry, and I can't understand how outputing 10k nodes can take that much time when the simulation itself wrote it in the .rst file in less than a second.

If you know a better way for outputs I'm listening, as I'm kinda stucked.

Sebastien

[Govindan Nagappan]

HI Sebastien,

You have a do loop that goes through 10k times(once for each node). 

A much more efficient way to read data into arrays is to use the *VGET command. *VGET is much like *GET , except instead of returning a scalar parameter, *VGET fills arrays with data. 

You do not need a do loop. Here is an example:

cmsel, s, N_POST  
*vget,NMASK,node,,nsel
*vmask,NMASK(1)
*vget,array_S11,node,,S,X   !component stress in X

Check help doc for more details: *VGET (ansys.com)

 

[Sebastien ARRIVET]

Thanks for your answer. I've tried the following based on what I understood:

*cfopen,csv_name
*cfwrite,'node_num',S11,S22,S33
/PREP7
allsel
cmsel,s,N_POST,NODE
*vget,NMASK,node,,nsel
*vmask,NMASK(1)
*vget,node_list,node,,NLIST
/POST1
*vmask,NMASK(1)
*vget,array_S11,node,,S,X
*vget,array_S22,node,,S,Y
*vget,array_S33,node,,S,Z
*vwrite, node_list,array_S11,array_S22,array_S33
(I,ES2.3,ES2.3,ES2.3)
*cfclos

 

And I get the following warning: "Some entities requested in the *VGET were underfined". It happens for the request of S,X; S,Y and S,Z. 

I'm not familiar with array like variable in ANSYS APDL, so I'm not sure how to solve that.

[Govindan Nagappan]

select the result set in post prcessor. For example:

/post1

set,last  !select last result set

[Sebastien ARRIVET]

I selected it just before the code I pasted:

/POST1
RSYS,0
SET,1,LAST
csv_name = 'out_node_U_s_1_LAST_post.csv'

[Sebastien ARRIVET]

Also: i've tried without the /PREP7 but the doc seems to indicate that NLIST or NSEL only works in /PREP7 for *VGET