*HEADING
: LINEAR BEHAVIOR OF SPRING AND DASHPOT ELEMENTS
[SPRING1, SPRING2, SPRINGA, DASHPOT1, DASHPOT2, DASHPOTA] 
*********************************************
** Define three spring/dashpot 
** systems to be analyzed simultaneously
*********************************************
*NODE,NSET=NALL
3,10.,0.
11,0.,10.
12,10.,10.
13,20.,10.
*NODE,NSET=TRANS
101,0.,20.
102,10.,30.
103,20.,40.
*NSET,NSET=NALL
TRANS, 
*TRANSFORM,NSET=TRANS,TYPE=R
1.,1.,0.,-1.,1.,0.
**
** Spring Definitions
**
*ELEMENT,TYPE=SPRING1,ELSET=SPR1
1,3
*ELEMENT,TYPE=SPRING2,ELSET=SPR2
2,12,11
3,13,12
*ELEMENT,TYPE=SPRINGA,ELSET=SPRA
4,102,101
5,103,102
**
** Dashpot Definitions
**
*ELEMENT,TYPE=DASHPOT1,ELSET=DSH1
6,3
*ELEMENT,TYPE=DASHPOT2,ELSET=DSH2
7,13,12
*ELEMENT,TYPE=DASHPOTA,ELSET=DSHA
8,103,102
**
** Point Masses
**
*ELEMENT,TYPE=MASS,ELSET=MA
9,3
10,12
11,13
12,102
13,103
*NSET,NSET=MASSES
3,12,13,102,103
**
** Property Definitions
**
*ORIENTATION,NAME=TRANS,DEFINITION=COORDINATES
1.,1.,0.,-1.,1.,0.
*SPRING,ELSET=SPR1
1, 
30.0, 
*SPRING,ELSET=SPR2
1,1
30.0, 
*SPRING,ELSET=SPRA,ORIENTATION=TRANS

30.0, 
*DASHPOT,ELSET=DSH1
1, 
0.12, 
*DASHPOT,ELSET=DSH2
1,1
0.12, 
*DASHPOT,ELSET=DSHA, ORIENTATION=TRANS

0.12, 
*MASS,ELSET=MA
0.02588, 
**
****************************
** Analysis
****************************
**
****************************
** Test Elements
** 	SPRING1,DASHPOT1
**	SPRING2,DASHPOT2
** 	SPRINGA,DASHPOTA
** under equal conditions.
** Results should match.
****************************
**
** ---------------- STEP 1
**
*STEP,NLGEOM
  STRETCH OUT
*STATIC
1.E2,1.E2
*BOUNDARY
**
** First fix spring to walls and prevent the top
** spring2/A masses from moving (cfr. drawing)
** Results from this step should
** match for all three spring/dashpot systems.
**
11,1,6,0.
101,1,6,0.
12,1,6,0.
102,1,6,0.
**
** Apply a positive displacement to nodes (masses) 2, 13 and 103
**
3,1,1,1.
13,1,1,1.
103,1,1,1.
3,2,6,0.
13,2,6,0.
103,2,6,0.
*EL PRINT, FREQ=2,SUMMARY=NO
S, 
E, 
*NODE PRINT,FREQ=2,SUMMARY=NO,GLOBAL=NO
U, 
V, 
A, 
CF, 
RF, 
*NODE FILE,NSET=NALL,FREQ=10,GLOBAL=NO
U , V , A
*OUTPUT,FIELD,FREQ=10
*NODE OUTPUT,NSET=NALL
U,V,A
*EL FILE,FREQUENCY=10
S,E
*OUTPUT,FIELD,FREQ=10
*ELEMENT OUTPUT
S,E
*END STEP
**
*****************************
** Release Stretched System
*****************************
**
** ---------------- STEP 2
**
*STEP,INC=200
 RELEASE
*DYNAMIC,HAFTOL=0.1
5.E-4,0.7,,0.7
*BOUNDARY,OP=NEW
**
** Removed previous BC's.  Now we add all but
** those belonging to the mass nodes, so they
** are free to move.
**
11,1,6,0.
101,1,6,0.
12,1,6,0.
102,1,6,0.
**
** let nodes (masses) 2, 13 and 103 free to move
**
3,2,6,0.
13,2,6,0.
103,2,6,0.
*MONITOR,NODE=3,DOF=1
*NODE FILE,NSET=NALL,FREQ=1,GLOBAL=NO
U,V,A
*OUTPUT,FIELD,FREQ=1
*NODE OUTPUT,NSET=NALL
U,V,A
*EL FILE,FREQ=50
S,E
*OUTPUT,FIELD,FREQ=50
*ELEMENT OUTPUT
S,E
*END STEP