*heading
normal impact of two identical spheres
**
*preprint, model=yes, history=yes
**
**NODES
**
*node,nset=qa_test
1, -0.010005, 0.0, -0.05
2, 0.010005, 0.0, -0.05
3, -0.010005, 0.0, 0.05
4, 0.010005, 0.0, 0.05
**
**NODE SETS
**
*nset, nset=glass
1, 2
*nset, nset=limestone
3, 4
*nset, nset=dem
1, 2, 3, 4
**
**ELEMENTS and ELEMENT SETS
**
*element, type=pd3d, elset=glass
1, 1
2, 2
*element, type=pd3d, elset=limestone
3, 3
4, 4
*elset, elset=dem
1, 2, 3, 4
**
**SECTION DEFINITIONS 
**
*discrete section, elset=glass,shape=sphere,density=2800
0.01
*discrete elasticity
48E9, 0.2
*discrete section, elset=limestone,shape=sphere,density=2500
0.01
*discrete elasticity
20E9, 0.2
*section control, name=autodem




**<fStability>,<fTracking>,<fCollision>,<fRayleigh>,<fSepDist>,<fRotation>
 0.1, 0.1, 0.1, 0.1, 0.1, 0.1 
**
**SURFACES
**
*surface, type=element, name=glass_surf
glass,
*surface, type=element, name=limestone_surf
limestone,
**
**SURFACE INTERACTION 
**
*surface interaction, name=glass_int
*friction
0.35
*surface behavior, pressure-overclosure=Hertz
1E10
*contact damping, definition=damping coefficient
0.0
*surface interaction, name=limestone_int
*friction
0.35
*surface behavior, pressure-overclosure=Hertz
1E10
*contact damping, definition=damping coefficient
0.0
**
**INITIAL CONDITIONS
**
*initial conditions, type=velocity
1, 1, 10
2, 1, -10
3, 1, 10
4, 1, -10
**
**STEP
**
*step
*dynamic, explicit, element by element
 , 6e-5
**
**CONTACT DEFINITIONS
**
*contact
*contact inclusions
glass_surf, glass_surf
limestone_surf, limestone_surf
*contact property assignment
glass_surf, glass_surf, glass_int
limestone_surf, limestone_surf, limestone_int
**
**HISTORY OUTPUT
**
*output, history, freq=1
*node output, nset=qa_test
V,
*node output, nset=glass
V,
*node output, nset=limestone
V,
*energy output, variable=all
*INCREMENTATION OUTPUT,var=all
**
**FIELD OUTPUT
**
*output, field, timeinterval=2e-5
*node output, nset=dem
U,V,A
*contact output
CFORCE
*end step