*HEADING
 EARTHQUAKE ANALYSIS (B23) VIA MULTIPLE BASE MOTION  
 MODAL DYNAMICS MODEL WITH PRIMARY BASE AND SECONDARY BASE (NODE21)
*NODE
1 ,300.
21, 
*NSET,NSET=ENDS
1,21
*NSET,NSET=NOUT
1,11,21
*NGEN
 1,21
*ELSET,ELSET=PR
10, 
*ELEMENT,TYPE=B23
1,1,2
*ELGEN,ELSET=EALL
1,20
*MATERIAL,NAME=A1
*ELASTIC
30.E6, 
*DENSITY
 .000728, 
*BEAM SECTION,SECTION=RECT,MATERIAL=A1,ELSET=EALL
1. , 2.
*BOUNDARY
 1, 1, 6
21, 1 
21, 6
** THIS INPUT ASSUMES THAT bmk/multibasemotion_quake.inp 
** HAS BEEN COPIED TO QUAKE01.AMP 
*AMPLITUDE,VALUE=RELATIVE,INPUT=QUAKE01.AMP,NAME=EQ
*RESTART,WRITE,FREQUENCY=100
*STEP
*FREQUENCY,EIGENSOLVER=LANCZOS, SIM=NO
10,,,-10000.,
*EL PRINT,FREQUENCY=0
*BOUNDARY,BASE NAME=NODE21
21,2
*NODE PRINT
U,
*MODAL FILE
*OUTPUT,FIELD
*END STEP
*STEP
 EARTHQUAKE INPUT
*MODAL DYNAMIC
 .01 , 2.
*SELECT EIGENMODES,GENERATE
1,7,1
*BASE MOTION,DOF=2,AMPLITUDE=EQ,SCALE=386.09
*BASE MOTION,DOF=2,AMPLITUDE=EQ,SCALE=386.09,BASE NAME=NODE21
*PRINT,FREQUENCY=50
*EL PRINT,ELSET=PR,FREQUENCY=500
S,E
*NODE PRINT,FREQUENCY=100
U,TU,
V,TV,
A,TA,
*MODAL PRINT,FREQUENCY=100
GU,GV,GA,
BM, 
*NODE FILE,NSET=NOUT
U,V,A,TU,TV,TA
*MODAL FILE,FREQUENCY=10
GU,GV,GA,BM
*OUTPUT,HIST,FREQ=10
*MODAL OUTPUT
GU,GV,GA,BM
*OUTPUT,HIST
*NODE OUTPUT,NSET=NOUT
U,V,A,TU,TV,TA
*OUTPUT,FIELD,FREQ=5
*NODE OUTPUT
U, 
*END STEP