*HEADING
 SUBSTRUCTURE ANALYSIS WITH UNSORTED NSET AND RETAINED DOFS  
Requires substructure generation file 
hertzcontact_2d_unsorted_gen1.inp
*NODE
 201, 0.,-10.
*NODE,SYSTEM=C
 209,10.,-78.
*NGEN,LINE=C
 201,209
*NSET,NSET=DBODY,GENERATE
201,209,1
*surface,type=node,NAME=DSURF
DBODY, 
*NODE,NSET=FIX
 301, 0.     ,-10.
 302, 0.26177,-10.
 303, 0.52336,-10.
 304, 0.78459,-10.
 305, 1.04528,-10.
 306, 1.30526,-10.
 307, 1.56434,-10.
 308, 1.82236,-10.
 309, 2.07912,-10.
*NODE,NSET=REF
999,1.,-11.
*ELEMENT,TYPE=R2D2,ELSET=SURFACE
101,301,302
*ELGEN,ELSET=SURFACE
101,8,1,1
*RIGID BODY,ELSET=SURFACE,REFNODE=999
*surface,NAME=RSURF
SURFACE,SPOS
*ELEMENT,TYPE=Z1001,ELSET=SUPER, FILE=hertzcontact_2d_unsorted_gen1
 99,  201,202,203,204,205,206,207,208,209,1
*SUBSTRUCTURE PROPERTY,ELSET=SUPER,POSITION TOL=0.
*CONTACT PAIR,INTERACTION=RDINT1,SMALL SLIDING
DSURF,RSURF
*SURFACE INTERACTION,NAME=RDINT1
1., 
*BOUNDARY
 REF,1,2
 REF,6,6 
 201,1
*STEP
*STATIC,DIRECT
 1., 
*BOUNDARY
 1,2,2,-.4
*EL FILE,ELSET=SURFACE
S,E
*PRINT,CONTACT=YES,SOLVE=YES
*CONTACT FILE,SECONDARY=DSURF,FREQ=999
*CONTACT PRINT,SECONDARY=DSURF,FREQ=999
*NODE PRINT
U,
*OUTPUT,VAR=PRESELECT,FIELD
*SUBSTRUCTURE PATH,ENTER ELEMENT=99
*OUTPUT,VAR=PRESELECT,FIELD
*EL PRINT
 S ,
*NODE PRINT
 U,
*SUBSTRUCTURE PATH,LEAVE
*SUBSTRUCTURE PATH,ENTER ELEMENT=99
*OUTPUT,VAR=PRESELECT,FIELD
*EL PRINT,ELSET=TOP
E,
*EL FILE,ELSET=BOT
S,E
*NODE PRINT,NSET=CYLSURF
RF, 
*SUBSTRUCTURE PATH,LEAVE
*END STEP