*HEADING
 SUBSTRUCTURE GENERATION FILE FOR psupfre2.inp
*NODE,NSET=NALL
  1, 0.0, 0.0
 11, 1.0, 0.0
*NGEN,NSET=NALL
 1,11,1
*NSET,NSET=NTRA
 1,2,4,5,7,8,9,10
*TRANSFORM,NSET=NTRA
 0.,-1.,0.,1.,0.,0.
**
*ELEMENT,TYPE=B21,ELSET=BEAM
 1,1,2
*ELGEN,ELSET=BEAM
 1,10,1,1
*BEAMSECTION,ELSET=BEAM,SECT=RECT,MAT=STEEL
 0.1,0.1
*MATERIAL,NAME=STEEL
*ELASTIC
 2.1E11,0.3
*DENSITY
 7800., 
**
*NSET,NSET=RETNODES
3, 6, 11
**
**
*STEP
*FREQUENCY
6,
*BOUNDARY
  1,1,2
  1,6,6
  RETNODES,1,2
*END STEP
**
**
*STEP
*SUBSTRUCTURE GENERATE,TYPE=Z1,RECOVERYMATRIX=YES,MASSMATRIX=YES,OVERWRITE
*RETAINED NODAL DOFS
  RETNODES,1,2
*SELECT EIGENMODES,GENERATE
1,6
*BOUNDARY
 1,1,2
 1,6,6
*END STEP