*HEADING
TEST FOR CONNECTOR UNIAXIAL BEHAVIOR (Permanent Deformation)
The force-displacement curves shows the loading/unloading behavior. 
*preprint, model=yes
*restart, write, number=20
*NODE,NSET=NALL3D
1,0.,0.,0.
2,1.,0.,0.
11,0.,1.,0.
12,1.,1.,0.
21,0.,2.,0.
22,1.,2.,0.
31,0.,3.,0.
32,1.,3.,0.
*ORIENTATION,SYS=RECT,NAME=ORIGLOB
1.,0.,0.,0.,1.,0.
3,0.
*ELEMENT,TYPE=CONN3D2,ELSET=quadratic
1,1,2
*CONNECTOR SECTION,ELSET=quadratic,BEHAVIOR=quadratic
AXIAL,
ORIGLOB,
*ELEMENT,TYPE=CONN3D2,ELSET=exponential
10,11,12
*CONNECTOR SECTION,ELSET=exponential,BEHAVIOR=exponential
AXIAL,
ORIGLOB,
*ELEMENT,TYPE=CONN3D2,ELSET=shiftedcurve
20,21,22
*CONNECTOR SECTION,ELSET=shiftedcurve,BEHAVIOR=shiftedcurve
AXIAL,
ORIGLOB,
*ELEMENT,TYPE=CONN3D2,ELSET=interpcurve
30,31,32
*CONNECTOR SECTION,ELSET=interpcurve,BEHAVIOR=interpcurve
AXIAL,
ORIGLOB,
**
*CONNECTOR BEHAVIOR,NAME=quadratic
**, integration=explicit
**
**  QUADRATIC UNLOADING
**
*connector uniaxial behavior, component=1
*loading data, direction=tension, type=Permanent Deform, extrapolation=linear, yield onset=0.0
0,  0  
10, 0.1
20, 0.2
30, 0.3
40, 0.4
50, 0.5
*unloading data, definition=quadratic
0.5, 0.4
**
*CONNECTOR BEHAVIOR,NAME=exponential
**, integration=explicit
**
**  EXPONENTIAL UNLOADING
**
*connector uniaxial behavior, component=1
*loading data, direction=tension, type=Permanent Deform, extrapolation=linear, yield onset=0.0
0,  0  
10, 0.1
20, 0.2
30, 0.3
40, 0.4
50, 0.5
*unloading data, definition=exponential
0.5, 0.4
**
*CONNECTOR BEHAVIOR,NAME=shiftedcurve
**, integration=explicit
**
**  SHIFTED CURVE UNLOADING
**
*connector uniaxial behavior, component=1
*loading data, direction=tension, type=Permanent Deform, extrapolation=linear, yield onset=0.0
0,  0  
10, 0.1
20, 0.2
30, 0.3
40, 0.4
50, 0.5
*unloading data, definition=shifted curve
0,  0  
166.6667, 1.0
**
*CONNECTOR BEHAVIOR,NAME=interpcurve
**, integration=explicit
**
**  INTERPOLATED CURVE UNLOADING
**
*connector uniaxial behavior, component=1
*loading data, direction=tension, type=Permanent Deform, extrapolation=linear, yield onset=0.0
0,  0  
10, 0.1
20, 0.2
30, 0.3
40, 0.4
50, 0.5
*unloading data, definition=interpolated curve
0,  0.4  
166.6667, 1.4
*unloading data, definition=interpolated curve
0,  0.8  
166.6667, 1.8
*unloading data, definition=interpolated curve
0,  1.2  
166.6667, 2.2
*unloading data, definition=interpolated curve
0,  1.6  
166.6667, 2.6
**
*BOUNDARY
1,1,6
2,2,6
11,1,6
12,2,6
21,1,6
22,2,6
31,1,6
32,2,6
*ELEMENT, TYPE=MASS, ELSET=MASS
4001, 1
4002, 2
4011, 11
4012, 12
4021, 21
4022, 22
4031, 31
4032, 32
*MASS, ELSET=MASS
1.E-3
*NSET,NSET=QA_TEST_NALL3D
NALL3D,
*ELSET, ELSET=QA_TEST_UNI
quadratic, exponential, shiftedcurve, interpcurve
*NSET, NSET=LOAD
2,12,22,32
**------------------------------------------------
*STEP,NLGEOM=YES
*DYNAMIC, EXP, DIRECT USER CONTROL
0.005,100.0
*amplitude, name=ramp1, definition=smooth
0,0,100,1
*cload, amplitude=ramp1
LOAD,1,100.
*OUTPUT,HISTORY, TIME INTERVAL=0.1
*ELEMENT OUTPUT,ELSET=QA_TEST_UNI
CTF1,CUF1,CU1
*ENERGY OUTPUT, VARIABLE=ALL
*OUTPUT, FIELD
*NODE OUTPUT, NSET=QA_TEST_NALL3D
U,
*ENDSTEP
*STEP,NLGEOM=YES
*DYNAMIC, EXP, DIRECT USER CONTROL
0.005,100.0
*amplitude, name=ramp2, definition=smooth
0,1,100,0
*cload, amplitude=ramp2
LOAD,1,100.
*END STEP
*STEP,NLGEOM=YES
*DYNAMIC, EXP, DIRECT USER CONTROL
0.005,100.0
*amplitude, name=ramp3, definition=smooth
0,0,100,1
*cload, amplitude=ramp3
LOAD,1,125.
*END STEP
*STEP,NLGEOM=YES
*DYNAMIC, EXP, DIRECT USER CONTROL
0.005,100.0
*amplitude, name=ramp4, definition=smooth
0,1,100,0
*cload, amplitude=ramp4
LOAD,1,125.
*END STEP
*STEP,NLGEOM=YES
*DYNAMIC, EXP, DIRECT USER CONTROL
0.005,100.0
*amplitude, name=ramp5, definition=smooth
0,0,100,1
*cload, amplitude=ramp5
LOAD,1,150.
*END STEP