*HEADING
rbd_3d_sm_xybc:  same as rbd_3d_i_xybc, except that the inertia is
provided for the rigid body by the masses distribued on its surface nodes
instead of inertia specified at the reference node.
**In this analysis the mass, m2, in Figure 2, is not divided among the 2
**nodes initially at x=1.5 (nodes 5 and 95), instead this mass is entirely
**lumped at node 95. This should not affect the solution because the rigid
**body is constrainted to only rotate about the z-axis. This is done to
**provide additional verification of the rigid body dynamics code, because
**with this distribution of mass the z-axis is not a principal direction
**of the rotary inertia of the rigid body.
*RESTART,TIMEMARKS=NO,WRITE,NUM=4
**
** Definition of the nodes
**
*NODE, NSET=QA_TEST_ALLNODES
1, -0.5,0.,1.5 
2,-0.5,1.,1.5
3,0.,0.
4,0.,1.
5, 1.5,1.,1.5
92,-0.5,1.,-0.5
95, 1.5,1.,-0.5
101, 2.0,1.,0.5
*NSET,NSET=REFND
101, 
*NSET,NSET=NOUT
4,2,101
**
** Definition of the elements
**
*ELEMENT,ELSET=SPRNGONE,TYPE=SPRINGA
1,1,2
*ELEMENT,ELSET=SPRNGTWO,TYPE=SPRINGA
2,3,4
*ELEMENT,ELSET=MASS_SP1,TYPE=MASS
3,1
*ELEMENT,ELSET=MASS_SP2,TYPE=MASS
4,4
*ELEMENT,ELSET=RIGID,TYPE=R3D4
5,92,95,5,2
*ELEMENT,ELSET=SM_RGD1,TYPE=MASS
8, 2
78, 92 
*ELEMENT,ELSET=SM_RGD2,TYPE=MASS
79, 95
**
** Definition of element properties
**
*SPRING,ELSET=SPRNGONE

1.E6, 
*SPRING,ELSET=SPRNGTWO

1.E6, 
*MASS,ELSET=MASS_SP1
5.,
*MASS,ELSET=MASS_SP2
5.,
*MASS,ELSET=SM_RGD1
5., 
*MASS,ELSET=SM_RGD2
10., 
** Initial and boundary conditions
**
*INITIAL CONDITION,TYPE=VELOCITY
101,6,10.
4,2,-20
*BOUNDARY
1,1,3 
3,1,3
4,1,1
4,3,3
101,1,2
101,3,5
**
** Definition of the dummy element used for controlling the time 
** increment size.
**
*NODE,NSET=DUMMY
10001,.1,-0.2
10002,.2,-0.2
10003,.1,0.8
10004,.2,0.8
10005,.1,-0.2,1.
10006,.2,-0.2,1.
10007,.1,0.8,1.
10008,.2,0.8,1.
*ELEMENT,ELSET=DUMMY,TYPE=C3D8R
10001,10001,10002,10004,10003,10005,10006,10008,10007
*SOLID SECTION,ELSET=DUMMY,MATERIAL=MAT
*MATERIAL,NAME=MAT
*ELASTIC
1.E7,0.2
*DENSITY
100., 
*BOUNDARY
10001,1,3
10002,2,3
10005,1,3
10006,2,3
**
*SURFACE,TYPE=NODE,NAME=DEFBLE
4,
*SURFACE,TYPE=ELEMENT,NAME=RIGID
RIGID,SPOS
*RIGID BODY,ELSET=RIGID,REF NODE=101
**
*NSET, NSET=QA_TEST_ALLNODES
QA_TEST_ALLNODES, REFND, NOUT, DUMMY
**
*NSET,NSET=QA_TEST_REFND
REFND,
**
*STEP
*DYNAMIC,EXPLICIT
,0.013
*CONTACT PAIR
RIGID,DEFBLE
*CLOAD
5, 2, 100000.0
*FILE OUTPUT,NUMBER INTERVAL=4,TIMEMARKS=YES
*NODE FILE
U,
*NODE FILE, NSET=REFND
RF,
***OUTPUT,HISTORY,TIME INTERVAL=0.0
***NODE OUTPUT,NSET=NOUT
**U,V,A
***NODE OUTPUT,NSET=REFND
**UR3,VR3,AR3
***ENERGY OUTPUT
**ALLKE,ALLIE,ALLAE,ALLWK,ETOTAL,DT
*OUTPUT, FIELD, NUMBER INTERVAL=4, TIMEMARKS=YES
*NODE OUTPUT, NSET=QA_TEST_ALLNODES
U,
*NODE OUTPUT, NSET=QA_TEST_REFND
RF,
*OUTPUT,FIELD,VARIABLE=PRESELECT
*OUTPUT,HISTORY,VARIABLE=PRESELECT,TIMEINT=0.00325
*END STEP