ANSYS - Transient modal superposition method 1

[Piew]

Hello everybody,

I have a question regarding transient modal superposition method in seismic analysis.
Here is the problem :

The model is a building. I want to load the base with two different accelerograms at two different points of the base. For that, I have defined two rigid regions. Each regions have 6 springs for the six dofs.
With the ACEL command I can't choose where I want to apply the accelerations. I have tried to use the CMACEL command on these two regions but it didn't worked. I've seen that for this kind of analysis method, CMACEL must be called where the modes are calculate and, after, use the LVSCALE command. But I don't know how to use this. Does anyone can help me ?

Thanks a lot !

Hereafter the part of the code for the MODE calculation and the transiant modal modal superposition method

! MODE CALCULATION

/solu   

outres, all,none
outres,nsol,all 

antype,modal			! MODAL ANALYSIS TYPE
    
modo   ,lanb,M_MAX,0,F_MAX

mxpand  
eqslv,sparce
BCSOPTION,,incore,  
check,,
 
solve   
    
fini


! TRANSIENT MODAL TIME HISTORY

*dim,accx,table,4096,1		! First array
*dim,acc_cor,table,4096,1	! Second array

*tread,accx,acc_x,txt		! Read the first accelerogram
*tread,acc_cor,sig_cor1,txt	! Read the second accelerogram


/solu
antype,trans
trnopt,msup		    	! Mode Superposition method msup
deltim,Step			! Time step
outpr,erase
outres,all,all
time,.01			! Static step
check,,
solve  		               	! static step
cmacel,base1,%accx%		! Support acceleration for the first rigid region
cmacel,base2,%acc_cor%		! Support acceleration for the second rigid region
time,20               		! transient step
check,,
solve