*heading
 Test of 3-D slip ring connectors 
(nonlinear elastic + friction) behavior
*preprint, model=yes, echo=yes, history=yes
*parameter
** User input data defining the pulley properties
 stiff = 1500.
 Tp    = 1.2E-6
 R1    = 1.0
 R2    = 1.0
 R3    = 1.0
 xmu   = 0.1
 pi    = 3.141592653589
 alpha = pi/2.0
 zero  = 0.0
*node, nset=nall3d
 1,    0.,   0.
 2,    0.,   2.
 3,    3.,   2.
 4,    3.,   0.
*****************************************
*ELEMENT, TYPE=CONN3D2, elset=belt1
 101, 1,2
*CONNECTOR SECTION,ELSET=BELT1,BEHAVIOR=BELT_FRIC
slipring,

 <Tp>, <alpha>, <R1>, <R2>
*ELEMENT, TYPE=CONN3D2, elset=belt2
 102, 2,3
*CONNECTOR SECTION,ELSET=BELT2,BEHAVIOR=BELT_FRIC
slipring,

 <Tp>, <alpha>,<R2>, <R3>
*ELEMENT, TYPE=CONN3D2, elset=belt3
 103, 3,4
*CONNECTOR SECTION,ELSET=BELT3,BEHAVIOR=BELT_FRIC
slipring,

 <Tp>, <pi>,<R2>, <R3>
*CONNECTOR BEHAVIOR,NAME=BELT_FRIC
*CONNECTOR ELASTICITY,NONLINEAR,COMPONENT=1
0.0,0.0
40.0,0.2
220.0,0.4
340.0,0.6
380.0,0.8
440.0,1.0
*connector friction, predefined, stickstiffness=10000.0
*friction
<xmu>,
*elset, elset=belt
belt1,belt2,belt3
*****************************************
*ELEMENT, TYPE=MASS, ELSET=MASS
4001, 1
4002, 2
4003, 3
4004, 4
*MASS, ELSET=MASS
0.01,
*boundary
 1, 1,1
 1, 3,3
 1, 10,10
**
 2, 1,3
 3, 1,3
**
 4, 1,1
 4, 3,3
 4, 10,10
**
*amplitude, name=amp, definition=smooth
0.0,0.0,0.25,1.0,0.5,0.5,0.75,0.5,1.0,1.0
*amplitude, name=amp1, definition=smooth
0.0,0.0,0.5,1.0,0.75,1.0,1.0,0.0
*NSET, NSET=QA_TEST
1,4
*step, nlgeom=yes
*dynamic, explicit, direct user control
 0.001, 1.0
**------------------------------------------------
***boundary,type=velocity
** 3, 1,1, 1.0
*cload,amp=amp1
1,2,-1.0
*cload,amp=amp
4,2,-1.0
*output,field, num = 10
*node output, nset=nall3d
 u,
*output,history, time interval=1.0e-03
*node output, nset=nall3d
 u, rf
*element output, elset=belt
CTF,CEF,CU,CSF,CNF,CASU,CP
*energy output, var=all
*OUTPUT,HISTORY,VARIABLE=PRESELECT,TIMEINT=1.0E-3
*********** QA **********
*OUTPUT,FIELD,NUM=10
*NODE OUTPUT,NSET=QA_TEST
U,
*end step