Learning Forum

[John Miller]

Hello,

I'm facing some troubles with a AM simulation.

The Modell is shown below and consists of a heated base plate and a circular extruded volume

The script of the AM process with ekill and subsequent ealive so that a volume is constantly generated is not difficult. My problem is an embedded restart analysis. I have to enter /post1 in every substep and create a component that includes all contact elements (targe169-conta178) for further processing.

The component should be used to apply convection bc the nodes on the base plate are not covered by extruded material.

The APDL snippet is this:

tintp,,,,1.0
lnsrch,on
nropt,full
thopt,full

...

*do,i,1,k,1
/GOPR
rescontrol,define,2,k 
 
  cmsel,s,path,node
  cm,Tload,node
  ddele,Tload,temp
  esel,...
  cm,alive,elem
  ealive,alive
 
  cmsel,s,path,node  
  nsel,...
  cm,load,node

  D,load,temp,TL
  
  nsel,...
  cmsel,...
  cmsel,...
  cm,external,node
  sfdele,external,conv
  
  *DIM,Rad_Conv,TABLE,7,15,1,,,,11
  ...
  sf,external,conv,%Rad_Conv%,Talpha
  
  allsel,all
  outres,all,all

  Time,...
  solve 

  finish
  /post1
  /GOPR
  set,last

  esel,s,enam,,169,178
  nsle,s,active
  !etab,contact_elem,nmis,41
  cm,interface_nodes_bed_contact,node

  finish
  
  /solu
  /GOPR
  nropt,full
  thopt,full
  antype,,rest

  nsel,...
  cmsel,...
  cmsel,...
  cm,bed_ring_nodes_conv,node

  sfdele,bed_ring_nodes_conv,conv
  sf,bed_ring_nodes_conv,conv,hc,Talpha

*enddo

Unfortunately, the simulation is crashing in the first substep of the 2^nd load step (1^st load step is only for bed heating). The script without /post1 and restart is working just fine.

The sig$segv is crashing the simulation.

I guess it has something do to with the database because of all elements of the AM path death and subsequently activated (via ealive).

Some information is missing regarding the active elements.

Maybe someone has a clue about how to fix this problem

 

With Best Regards

John Miller

[Ashish Khemka]

Hi John,

SIG$SEGV is short for signal segment violation. Technically, it is described as an incorrect use of pointer or a buffer overflow (memory problems). It is a bug, whenever it happens, but it is difficult to relate the cause to any one particular issue. Based on previous call records, it has happened in the past with distributed solver and rezoning, but is not limited to these applications.

If you are using a distributed solver then please uncheck that option and then run the analysis.

Regards,

Ashish Khemka

[John Miller]

 

 

 

Hello Ashish,

I was able to get rid of the sig$segv error via removal of the thopt,full line.

 

! tintp,,,,1.0
!lnsrch,on
!nropt,full
!thopt,full

…

*do,i,1,k,1
/GOPR
rescontrol,define,2,k 

The command rescontrol is generating the necessary .rnnn file, but I’m not able to generate the .rdb file within the script. In thermal analysis “restart control” isn’t available via GUI (only in mechanical).

Below is the error message attached

Is there a way to perform a restart analysis in thermal transient (with script based .rdb file generation)?

Best regards

John

 

 

 

[John Miller]

Hi Ashish,

 

Unfortunately, I knew the issues of distributed solver and tried to run the simulation with only one core aka undistributed solver. The issue is not caused by solver distribution.

 

I guess the reason is the element status at the beginning of the first substep of the second step. During the first, heating step, the workpiece elements are all deactivated (via ekill at the beginning of the first load step). In the second load step, the former deactivated elements are activated via ealive.

 

  finish
  /post1
  /GOPR
  set,last

  esel,s,enam,,169,178
  nsle,s,active
  !etab,contact_elem,nmis,41
  cm,interface_nodes_bed_contact,node

  finish
  
  /solu
  /GOPR
  nropt,full
  thopt,full
  antype,,rest

  nsel,...
  cmsel,...
  cmsel,...
  cm,bed_ring_nodes_conv,node

  sfdele,bed_ring_nodes_conv,conv
  sf,bed_ring_nodes_conv,conv,hc,Talpha

Unfortunately, the simulation is not running anymore without the /post1 trip in every substep (on Ansys WB R2021 R2 Teaching) a few weeks before the model without /post1 script was running just fine.

Other simulations are running without error.

I don't understand whats happening here, seems the file is corrupted.

 

Best Regards

John

 

 

[John Miller]

 

 

Hello together,

I was able to get rid of the sig$segv error via removal of the thopt,full line.

 

! tintp,,,,1.0
!lnsrch,on
!nropt,full
!thopt,full

…

*do,i,1,k,1
/GOPR
rescontrol,define,2,k 

The command rescontrol is generating the necessary .rnnn file, but I’m not able to generate the .rdb file within the script. In thermal analysis “restart control” isn’t available via GUI (only in mechanical).

Below is the error message attached

Is there a way to perform a restart analysis in thermal transient (with script based .rdb file generation)?

Best regards

John