APDL psd error while read the .rst file

- October 17, 2024 at 12:49 pm
  
  Hongtian CHEN
  Subscriber
  
  When I did a random vibration analysis, after using the code below to draw the psd graphic in apdl, it works well:
  ...
  PSDCOM
  PSDRES,DISP,ABS !PSDRES, Lab(DISP/VELO/ACEL), RelKey(REL/ABS/OFF)
  PSDRES,VELO,ABS
  PSDRES,ACEL,ABS
  SOLVE
  FINISH
  /POST26
  STORE,PSD,5
  NSOL,2,NODE0,U,X
  RPSD,3,2,,3,1
  /SHOW,JPEG
  PLVAR,3
  which mean I use /POST26 in the same file, it works well for a spectrum analysis.
  
  However, when I do the part of solution in a file named "Pipe_3A_Transient_Analysis", and use the command "SAVE" to finish the solution part and save the file:
  ...
  PSDCOM
  PSDRES,DISP,ABS !PSDRES, Lab(DISP/VELO/ACEL), RelKey(REL/ABS/OFF)
  PSDRES,VELO,ABS
  PSDRES,ACEL,ABS
  SOLVE
  FINISH
  
  After that, in a new file named "Pipe_4_Post26_TimeHistory", I use the command below to reload the results of Pipe_3A_Transient_Analysis:
  FINISH
  /CLEAR
  /FILNAME,Pipe_4_Post26_TimeHistory,1
  /TITLE,HAHA
  /REPLOT
  /COM,STRUCTURAL
  /UNITS,SI
  *AFUN,RAD
  PI = 3.14159265354
  
  RESUME,'Pipe_3A_Transient_Analysis','db','.'
  
  /POST26
  FILE,'Pipe_3A_Transient_Analysis','rst'
  STORE,PSD,5
  
  the error occurs, in my opinions, it means the .rst file could not be open successfully.
  Because when I do the same operation using the GUI, after clicking on the "TimeHist Postproc", the second GUI occurs, which corresponds to the command "FILE,'Pipe_3A_Transient_Analysis','rst'.
  However, after that, for a spectrum analysis, there is another GUI:
  which has not a corresponding command to make a choice. I think it is a bug, what do you think, and are there any way to solve this question with an APDL command???
  (if I click OK with the GUI method at this moment, it can enter the TimeHist Postproc module, and the command like STORE,PSD/NSOL,.../ESOL,... works well after that, but I want to just use the APDL command, it seems that only the command /POST26 and FILE,'Pipe_3A_Transient_Analysis','rst' could not enter the TimeHist Postproc module correctly for the spectrum analysis case. )
- October 18, 2024 at 1:19 pm
  
  dlooman
  Ansys Employee
  
  Personally, I try to avoid using the APDL gui for anything PSD related. It seems you already know the commands. Just issue them in batch mode and if you want to capture a plot use /show,png. The gui isn't being maintained, so even if there is a bug, it doesn't matter.