*HEADING
rbd_2d_sm_xybc:  same as rbd_2d_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.  
*RESTART,TIMEMARKS=NO,WRITE,NUM=4
**
** Definition of the nodes 
**
*NODE, NSET=QA_TEST_ALLNODES
1, -0.5, 0.
2,-0.5,1.
3, 0., 0.
4, 0., 1.
5, 1.5,1.
101, 2.0,1.
*NSET,NSET=REFND
101, 
*NSET,NSET=NOUT
2, 4, 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=R2D2
5, 2,5
*ELEMENT,ELSET=SM_RGD1, TYPE=MASS
8, 2
*ELEMENT,ELSET=SM_RGD2, TYPE=MASS
9, 5
**
** 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
10.0, 
*MASS, ELSET=SM_RGD2
10.0, 
**
** Initial and boundary conditions 
**
*INITIAL CONDITION,TYPE=VELOCITY
101,6,10.
4,2,-20.
*BOUNDARY
1,1,3
3,1,3
4,1,1
101,1,5
**
** 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
*ELEMENT,ELSET=DUMMY,TYPE=CPS4R
10001,10001,10002,10004,10003
*SOLID SECTION,ELSET=DUMMY,MATERIAL=MAT
*MATERIAL,NAME=MAT
*ELASTIC
1.E7,0.2
*DENSITY
100., 
*BOUNDARY
10001,1,2
10002,2,2
10003,1,1
10004,1,1
**
*SURFACE,TYPE=NODE,NAME=DEFBLE
4,
*SURFACE,TYPE=ELEMENT,NAME=RIGID
RIGID,SNEG
*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