*heading
verification test normal displacement controlled contct
two identical spheres (ADHESION: JKR and JKR shifted)
**
*preprint, model=yes, history=yes
**
**NODES
**
*node
1, -5.000, 0.0, -5.5
2, 5.00, 0.0, -5.5
3, -5.00, 0.0, 5.0
4, 5.000, 0.0, 5.0
**
**NODE SETS
**
*nset, nset=JKR
1, 2
*nset, nset=JKR_SHIFTED
3, 4
*nset, nset=dem
1, 2
3, 4
**
**ELEMENTS and ELEMENT SETS
**
*element, type=pd3d, elset=JKR
1, 1
2, 2
*element, type=pd3d, elset=JKR_SHIFTED
3, 3
4, 4
*elset, elset=dem
1, 2
3, 4
**
**SECTION DEFINITIONS 
**
*discrete section, elset=JKR,shape=sphere,density=distDens,control=box
distRad
*discrete elasticity
1.0e+03,0.3
*discrete section, elset=JKR_SHIFTED,shape=sphere,density=distDens1,control=box
distRad1
*discrete elasticity
1.0e+03,0.3
*section control, name = box


-10.0,-10.0,-10.0,10.0,10.0,10.0,1
*distribution table, name=distDensTable
density
*distribution, name=distDens, table=distDensTable, location=element
 ,1.0
1, 1.4e-09
2, 1.4e-09
*distribution, name=distDens1, table=distDensTable, location=element
 ,1.0
3, 1.4e-09
4, 1.4e-09
*distribution table, name=distRadTable
length
*distribution, name=distRad, table=distRadTable, location=element
 ,1.0
1, 5.0
2, 5.0
*distribution, name=distRad1, table=distRadTable, location=element
 ,1.0
3, 5.0
4, 5.0
**
**SURFACES
**
*surface, type=element, name=JKR_surf
JKR,
*surface, type=element, name=JKR_SHIFTED_surf
JKR_SHIFTED,
**
**SURFACE INTERACTION 
**
*surface interaction, name=JKR_int
*friction
0.0
*surface behavior, pressure-overclosure=JKR
5.0e-02, 170.0
*contact damping, definition=damping coefficient
0.0
*surface interaction, name=JKR_SHIFTED_int
*friction
0.0
*surface behavior, pressure-overclosure=JKR
5.0e-02, 170.0,SHIFTED
*contact damping, definition=damping coefficient
0.0
**
** displacement controlled test
**
*boundary
1,2,6
2,1,6
3,2,6
4,1,6
*amplitude, name=disp,definition=smooth
0.0,0.0,2.5e-03,0.01,10.0e-03,-0.01
**
**STEP
**
*step
*dynamic, explicit, direct
2.5e-8, 10.0e-03
**
*boundary, amp=disp
1,1,1,1.0
3,1,1,1.0
**
**CONTACT DEFINITIONS
**
*contact
*contact inclusions
JKR_surf, JKR_surf
JKR_SHIFTED_surf, JKR_SHIFTED_surf
*contact property assignment
JKR_surf, JKR_surf, JKR_int
JKR_SHIFTED_surf, JKR_SHIFTED_surf, JKR_SHIFTED_int
**
**HISTORY OUTPUT
**
*output, history, freq=1
*node output, nset=JKR
U1,RF1
*node output, nset=JKR_SHIFTED
U1,RF1
**
**FIELD OUTPUT
**
*output, field, timeinterval=1e-3
*node output, nset=dem
U
*contact output
CFORCE
*end step