*HEADING 
 MULTI-FRAME STRUCTURE WITH BASE MOTION
*NODE
1,0.,0.
41,1000.,0.
101,0.,8.
141,1000.,8
*NGEN,NSET=BASE
1,41,2
*NGEN,NSET=DECK
101,141,1
*NSET, GENERATE, NSET=MID_DECK
102, 140, 2
*NSET, NSET=NODE_OUT
102, 108, 114, 120
*ELEMENT, TYPE=B23
1,1,101
101,101,102
*ELGEN,ELSET=FRAME
1,21,2,2
101,40,1,1
*BEAM GENERAL SECTION, SECTION=GENERAL, DENSITY=7800., ELSET=FRAME
.0362,.00233,0,.0001878,.00001
0,0,-1.
2.1E11,.8E11
*DAMPING, ALPHA=0.02, BETA=0.02
*BOUNDARY
BASE,ENCASTRE
*AMPLITUDE,NAME=SPECTRUM,VALUE=ABSOLUTE
1.4,0.,1.5,1.,1.8,5.,2.0,2.
2.1,0.
**
** STEP 1 - EIGENFREQUENCY EXTRACTION 
**
*STEP 
 EIGENFREQUENCY EXTRACTION USING LANCZOS
*FREQUENCY, EIGENSOLVER=LANCZOS, NORMALIZATION=MASS
25, -1., 1000.0
*END STEP
**
** STEP 2 - SSD WITH MATERIAL VISCOUS DAMPING
**
*STEP 
 HARMONIC VERTICAL BASE MOTION EXCITATION WITH MATERIAL VISCOUS DAMPING
*STEADY STATE DYNAMICS, SUBSPACE PROJECTION, INTERVAL=RANGE, FREQUENCY SCALE=LINEAR
1.4, 2.1, 40
*SELECT EIGENMODES, GENERATE
1,25,1
*BASE MOTION, DOF=2, AMPLITUDE=SPECTRUM, TYPE=ACCELERATION
**
** OUTPUT REQUESTS
**
*NODE PRINT, NSET=NODE_OUT, FREQ=4
U,V,A
*OUTPUT, FIELD
*NODE OUTPUT, NSET=NODE_OUT
U, V, A,
*OUTPUT, HISTORY
*NODE OUTPUT, NSET=NODE_OUT
U, V, A,
*END STEP