*HEADING
 TEST WITH TWO LEVELS OF SUBSTRUCTURES   
 SUBSTRUCTURE GENERATION FILES substrframe_2level_gen1.inp 
 substrframe_2level_gen2.inp, substrframe_2level_gen3.inp AND
 substrframe_2level_gen4.inp SHOULD BE RUN FIRST (in the given order).
**                
** Build up the frame with two column elements and one beam element
*ELEMENT,TYPE=Z101,ELSET=ZUPER2, FILE=substrframe_2level_gen3
61 , 1,11
63 ,31,21
*SUBSTRUCTURE PROPERTY,ELSET=ZUPER2
*ELEMENT,TYPE=Z201,ELSET=ZUPER3, FILE=substrframe_2level_gen4
62 ,11,21
*SUBSTRUCTURE PROPERTY,ELSET=ZUPER3
*BOUNDARY
1,1,6
31,1,6
*RESTART, WRITE
*STEP
*STATIC     
*SLOAD
62 , SNOW, -235.
*SUBSTRUCTURE PATH, ENTER ELEMENT=61
*NODE PRINT
U, 
*SUBSTRUCTURE PATH, ENTER ELEMENT=1
*NODE PRINT
U, 
*EL PRINT
S, 
*NODE FILE 
U,
*EL FILE  
S,
*SUBSTRUCTURE PATH, LEAVE, ENTER ELEMENT=2
*NODE PRINT
U, 
*SUBSTRUCTURE PATH, LEAVE
*SUBSTRUCTURE PATH, LEAVE, ENTER ELEMENT=62
*NODE PRINT
U, 
*SUBSTRUCTURE PATH, ENTER ELEMENT=2
*EL PRINT
E, 
*SUBSTRUCTURE PATH, LEAVE
*SUBSTRUCTURE PATH, LEAVE
*NODE PRINT
U,RF
*NODE FILE
U,RF
*OUTPUT,FIELD,VAR=PRESELECT
*END STEP
*STEP
*FREQUENCY, eigensolver=lanczos
10, , 
*MODAL FILE
*NODE FILE,FREQUENCY=0
*END STEP