*HEADING
 STEADY STATE  DYNAMICS PROCEDURES FOR 3D CONNECTORS WITH VISCOUS DAMPING
**
*NODE, NSET=NALL
 1,0.0,0.0,
 2,1.0,0.0,
 3,2.0,0.0,
 4,3.0,0.0,
*NSET, NSET=FIXED
 1,4
*NSET, NSET=NODE2
 2,3
*PARAMETER
 C=1.0
 CS=0.002
 KAXIAL1=1.0E3
 U1=1.0E-3
 KAXIAL2=KAXIAL1/10
 U2=100*U1
 F1=KAXIAL1*U1
 F2=F1+KAXIAL2*(U2-U1)
 mF1=-F1
 mF2=-F2
 mU1=-U1
 mU2=-U2
**
** CONNECTOR ELEMENTS
**
*ELEMENT, TYPE=CONN3D2, ELSET=AXIAL
 1,1,2
 2,2,3
*ELEMENT, TYPE=CONN3D2, ELSET=ACTUATOR 
 3,3,4
*ELSET, ELSET=CONNECTORS
 AXIAL,ACTUATOR 
**
** MASS ELEMENTS
**
*ELEMENT, TYPE=MASS, ELSET=MASS
 1001,1
 1002,2
 1003,3
 1004,4
**
** SECTION DEFINITIONS
**
*MASS, ELSET=MASS
 1.0,
*CONNECTOR SECTION, ELSET=AXIAL, BEHAVIOR= CB_AXIAL
 CARTESIAN
*CONNECTOR SECTION, ELSET=ACTUATOR
 CARTESIAN
**
** CONNECTOR BEHAVIOR DEFINITIONS
**
*CONNECTOR BEHAVIOR, NAME= CB_AXIAL
*CONNECTOR ELASTICITY, COMPONENT=1, NONLINEAR
 <mF2>,<mU2>
 <mF1>,<mU1>
 <F1>,<U1>
 <F2>,<U2>
*CONNECTOR DAMPING, COMPONENT=1
 <C>,
*CONNECTOR DAMPING, COMPONENT=1, TYPE=STRUCTURAL
 <CS>
**
** BOUNDARY CONSTRAINTS (BASE STATE)
**
*CONNECTOR MOTION
 AXIAL,2
 AXIAL,3
*BOUNDARY
 NALL,4,6
 FIXED,1,3
***
** STEP 1 - FREQUENCY EXTRACTION
***
*STEP
 STEP-1: EXTRACT EIGENMODE USING LANCZOS
**
*FREQUENCY, EIGENSOLVER=LANCZOS, NORM=MASS
 2, ,30, 
**
*OUTPUT, FIELD
*NODE OUTPUT
 U,
*END STEP
***
** STEP 2 - MODE-BASED SSD
***
*STEP
 STEP-2: SUBSPACE-BASED STEADY STATE DYNAMIC RESPONSE 
**
*STEADY STATE DYNAMICS, SUBSPACE PROJECTION, FREQUENCY SCALE=LINEAR, INTERVAL=RANGE
 1, 20, 20
**
*damping controls, structural=none
*CONNECTOR LOAD, LOAD CASE=1
 ACTUATOR,1,-1.0
*CONNECTOR LOAD, LOAD CASE=2
 ACTUATOR,1,-1.0
**
** OUTPUT REQUEST
**
*OUTPUT, FIELD
*NODE OUTPUT
 U, V, A,
*OUTPUT, HISTORY
*NODE OUTPUT, NSET=NODE2
 U, V, A,
*NODE PRINT, NSET=NODE2
 U1, V1, A1,
*END STEP
** STEP 3 - MODE-BASED SSD
***
*STEP
 STEP-3: SUBSPACE-BASED STEADY STATE DYNAMIC RESPONSE 
**
*STEADY STATE DYNAMICS, SUBSPACE PROJECTION, FREQUENCY SCALE=LINEAR, INTERVAL=RANGE
 1, 20, 20
**
*damping controls, structural=none,viscous=factor
*global damping,beta=0.001
*CONNECTOR LOAD, LOAD CASE=1
 ACTUATOR,1,-1.0
*CONNECTOR LOAD, LOAD CASE=2
 ACTUATOR,1,-1.0
**
** OUTPUT REQUEST
**
*OUTPUT, FIELD
*NODE OUTPUT
 U, V, A,
*OUTPUT, HISTORY
*NODE OUTPUT, NSET=NODE2
 U, V, A,
*NODE PRINT, NSET=NODE2
 U1, V1, A1,
*END STEP
*STEP
 STEP-4: SUBSPACE-BASED STEADY STATE DYNAMIC RESPONSE 
**
*STEADY STATE DYNAMICS, SUBSPACE PROJECTION, FREQUENCY SCALE=LINEAR, INTERVAL=RANGE
 1, 20, 20
**
*damping controls, structural=element,viscous=none
*CONNECTOR LOAD, LOAD CASE=1
 ACTUATOR,1,-1.0
*CONNECTOR LOAD, LOAD CASE=2
 ACTUATOR,1,-1.0
**
** OUTPUT REQUEST
**
*OUTPUT, FIELD
*NODE OUTPUT
 U, V, A,
*OUTPUT, HISTORY
*NODE OUTPUT, NSET=NODE2
 U, V, A,
*NODE PRINT, NSET=NODE2
 U1, V1, A1,
*END STEP
*STEP
 STEP-5: SUBSPACE-BASED STEADY STATE DYNAMIC RESPONSE 
**
*STEADY STATE DYNAMICS, SUBSPACE PROJECTION, FREQUENCY SCALE=LINEAR, INTERVAL=RANGE
 1, 20, 20
**
*damping controls, structural=factor,viscous=none
*global damping,structural=0.002
*CONNECTOR LOAD, LOAD CASE=1
 ACTUATOR,1,-1.0
*CONNECTOR LOAD, LOAD CASE=2
 ACTUATOR,1,-1.0
**
** OUTPUT REQUEST
**
*OUTPUT, FIELD
*NODE OUTPUT
 U, V, A,
*OUTPUT, HISTORY
*NODE OUTPUT, NSET=NODE2
 U, V, A,
*NODE PRINT, NSET=NODE2
 U1, V1, A1,
*END STEP