SPC sets in modal transient analysis

Hi,

 

I'm a bit lost with the SPC sets.

I have to apply a time dependent displacement on a node (802 035 in my model). As I understand, the HM has to create a constraint on the same node  to make the solver work. So in my model I have the general boundary conditions (embedded nodes including the excitation node) and this specific constraint due to the displacement excitation on the excitation node. My model .fem file thus contains :

 

SPC            1    7948  123456     0.0    $BC
SPC            1    7949  123456     0.0    $BC
SPC            1    7950  123456     0.0    $BC
SPC            1    7951  123456     0.0    $BC
SPC            1    7952  123456     0.0    $BC
SPC            1    7953  123456     0.0    $BC
SPC            1    7954  123456     0.0    $BC
SPC            1  802035  123456     0.0   $excitation node  

 

I have another fem file tu run the study :

$$------------------------------------------------------------------------------$
$$                            I/O Option
$$------------------------------------------------------------------------------$
TITLE=p21-pdb-slush_MTR_S2_11
METHOD(STRUCTURE)=1
SDISP(SORT2,PUNCH)=1
SPC=7
CPU=6
SCREEN OUT
output,HM,NONE
$$------------------------------------------------------------------------------$
$$                      Case Control Cards                                      $
$$------------------------------------------------------------------------------$
SUBCASE       1
  LABEL NM_200hz
ANALYSIS MODES
  DISPLACEMENT(H3D,MODAL,,,) =1
$$
$$
SUBCASE       2
  LABEL MTR_S2
ANALYSIS MTRAN
  RESVEC(APPLOAD)=YES
  DLOAD=9
  TSTEP=11
  SDAMPING(STRUCTURE)=999
  DISPLACEMENT(PUNCH,,,)=1
$$------------------------------------------------------------------------------$
$$                      Bulk Data                                      
$$------------------------------------------------------------------------------$
$$
$$
BEGIN BULK  
PARAM,AUTOSPC,YES     
PARAM,CHECKEL,NO      
$PARAM,G,0.08     
$$
$$
$-------2-------3-------4-------5-------6-------7-------8-------9------X
SPCADD,7,1
DLOAD,9,1.0,1.0,23,1.0,24,1.0,25
EIGRL,1,0.0,200.0,,,,,MASS
TSTEP,11,10000,0.001,2
TABDMP1,999,G
+,1.0,0.03,500.0,0.03,ENDT
$$
$$
$$
$-------2-------3-------4-------5-------6-------7-------8-------9------X
SPCD,20,802035,1,1.0
TLOAD1,23,20,,DISP,904043  
$$
$$
$$
$-------2-------3-------4-------5-------6-------7-------8-------9------X
SPCD,21,802035,2,1.0
TLOAD1,24,21,,DISP,904044
$$
$$
$$
$-------2-------3-------4-------5-------6-------7-------8-------9------X
SPCD,22,802035,3,1.0
TLOAD1,25,22,,DISP,904045
$$
$$  
INCLUDE 'signal_S2.dat'           $excitation signal
INCLUDE 'mesh_Squeak.fem'  $model file
ENDDATA

 

Do you think it's correct? Or I have to create 2 SPC sets in my model : general boundary conditions and constraint due to the excitation?

I hope I was clear,

Thank you