# Pendulum — Welcome to LS-DYNA Examples

A pendulum with two colliding spheres is calculated. The pendulum is modelled with beam elements of elastic behaviour. The spheres are modelled with shell elements of plastic behaviour and one of it is given an initial velocity. The *DEFORMABLE_TO_RIGID option is used to decrease execution time before impact.

## Keywords

```*BOUNDARY_SPC_NODE
*CONTACT_AUTOMATIC_SINGLE_SURFACE
*CONTROL_CONTACT
*CONTROL_ENERGY
*CONTROL_OUTPUT
*CONTROL_SHELL
*CONTROL_TERMINATION
*DATABASE_BINARY_D3PLOT
*DATABASE_BINARY_D3THDT
*DATABASE_EXTENT_BINARY
*DATABASE_GLSTAT
*DATABASE_HISTORY_NODE
*DATABASE_MATSUM
*DATABASE_NODOUT
*DATABASE_RBDOUT
*DATABASE_RCFORC
*DEFINE_BOX
*DEFINE_CURVE
*DEFORMABLE_TO_RIGID
*ELEMENT_BEAM
*ELEMENT_SHELL
*END
*INITIAL_VELOCITY
*KEYWORD
*MAT_ELASTIC
*MAT_PLASTIC_KINEMATIC
*NODE
*PART
*SECTION_BEAM
*SECTION_SHELL
*TITLE```

## Reduced Input

```  *KEYWORD
*TITLE
Pendulum with 2 spheres colliding
\$
\$  J.D. Reid    6/22/95, 4/7/98
\$
\$  Units: mm, kg, ms, kN, GPa, kN-mm
\$
\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$
\$
\$\$\$\$  Control Ouput
\$
\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$
\$
\$...>....1....>....2....>....3....>....4....>....5....>....6....>....7....>....8
\$
*CONTROL_TERMINATION
\$   endtim    endcyc     dtmin    endeng    endmas
11.0
\$
*CONTROL_ENERGY
\$     hgen      rwen    slnten     rylen
2         2
\$
*CONTROL_OUTPUT
\$    npopt    neecho    nrefup    iaccop     opifs    ipnint    ikedit
1         3
\$
*CONTROL_SHELL
\$   wrpang    itrist     irnxx    istupd    theory       bwc     miter
1         2
\$
*DATABASE_BINARY_D3PLOT
\$       dt      lcdt
1.00
\$      0.1
\$
*DATABASE_EXTENT_BINARY
\$    neiph     neips    maxint    strflg    sigflg    epsflg    rltflg    engflg

\$   cmpflg    ieverp    beamip
1
\$
*DATABASE_BINARY_D3THDT
\$       dt      lcdt
999999
\$
\$
*DATABASE_GLSTAT
\$       dt
0.10
\$
*DATABASE_MATSUM
\$       dt
0.10
\$
*DATABASE_NODOUT
\$       dt
0.10
\$
*DATABASE_HISTORY_NODE
\$   define nodes that output into nodout
\$      id1       id2       id3       id4       id5       id6       id7       id8
350       374       678       713
\$
*DATABASE_RBDOUT
\$       dt
0.10
\$
*DATABASE_RCFORC
\$       dt
0.10
\$
\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$
\$
\$\$\$\$  Define Contacts - Sliding Interfaces
\$
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\$
\$...>....1....>....2....>....3....>....4....>....5....>....6....>....7....>....8
\$
*CONTACT_AUTOMATIC_SINGLE_SURFACE
\$     ssid      msid     sstyp     mstyp    sboxid    mboxid       spr       mpr
0
\$  Equating ssid to zero means that all segments are included in the contact
\$
\$       fs        fd        dc        vc       vdc    penchk        bt        dt
0.08      0.08
\$      sfs       sfm       sst       mst      sfst      sfmt       fsf       vsf

\$
\$
\$ Add Flag to insure that thickness is checked during surface/surface contact
\$
\$
*CONTROL_CONTACT
\$   slsfac    rwpnal    islchk    shlthk    penopt    thkchg     orien
2
\$   usrstr    usrfrc     nsbcs    interm     xpene     ssthk      ecdt   tiedprj

\$
\$
\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$
\$
\$\$\$\$  Gravity
\$
\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$
\$
\$...>....1....>....2....>....3....>....4....>....5....>....6....>....7....>....8
\$
\$     lcid        sf    lciddr        xc        yc        zc
1   0.00981
\$
*DEFINE_CURVE
\$     lcid      sidr      scla      sclo      offa      offo
1
\$
\$           abscissa            ordinate
\$
0.00               1.000
10000.00               1.000
\$
\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$
\$
\$\$\$\$  Boundary and Initial Conditions
\$
\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$
\$
\$...>....1....>....2....>....3....>....4....>....5....>....6....>....7....>....8
\$
\$\$\$\$  Constrain translation of end points of beams
\$
*BOUNDARY_SPC_NODE
\$      nid       cid      dofx      dofy      dofz     dofrx     dofry     dofrz
45004         0         1         1         1         0         0         0
45005         0         1         1         1         0         0         0
45010         0         1         1         1         0         0         0
45011         0         1         1         1         0         0         0
\$
\$
*INITIAL_VELOCITY
\$     nsid    nsidex     boxid
5
\$
\$       vx        vy        vz        wx        wy        wz
0.0     -12.0       0.0
\$
*DEFINE_BOX
\$    boxid       xmm       xmx       ymn       ymx       zmn       zmx
5    -120.0     -80.0      80.0     120.0     -30.0      30.0
\$
\$
\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$
\$
\$\$\$\$  Define Parts and Materials
\$
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\$
\$...>....1....>....2....>....3....>....4....>....5....>....6....>....7....>....8
\$
*PART
\$      pid       sid       mid     eosid      hgid      grav    adpopt
sphere1
1         1         1
sphere2
2         2         1
\$
\$
\$\$\$\$ Materials
\$
\$  Aluminum
\$
*MAT_PLASTIC_KINEMATIC
\$      mid        ro         e        pr      sigy      etan      beta
1   2.70e-6      68.9     0.330     0.286   0.00689
\$
\$      src       srp        fs

\$
\$\$\$\$ Sections
\$
\$
*SECTION_SHELL
\$      sid    elform      shrf       nip     propt   qr/irid     icomp
1         2
\$
\$       t1        t2        t3        t4      nloc
1.0       1.0       1.0       1.0
\$
*SECTION_SHELL
\$      sid    elform      shrf       nip     propt   qr/irid     icomp
2         2
\$
1.0       1.0       1.0       1.0
\$
\$
\$\$\$\$\$   PENDULUM WIRES - ELASTIC BEAMS
\$
*PART
Pendulum Wires - Elastic Beams
\$      pid       sid       mid     eosid      hgid      grav    adpopt
45        45        45
\$
\$
*SECTION_BEAM
\$      sid    elform      shrf   qr/irid       cst
45         3   1.00000       1.0
\$
\$ int: ts1       ts2       tt1       tt2     nsloc     ntloc
\$
\$ res:   a       iss       itt       irr        sa
10.0
\$
\$ disc:vol      iner       cid        ca    offset
\$
\$       t1        t2        t3        t4      nloc
\$
\$
*MAT_ELASTIC
\$      mid        ro         e        pr        da        db         k
45   7.86e-6     210.0      0.30
\$
\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$
\$
\$\$\$\$  Deformable Switching
\$
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\$
\$...>....1....>....2....>....3....>....4....>....5....>....6....>....7....>....8
\$
*DEFORMABLE_TO_RIGID
\$      pid       mrb
1
\$
*DEFORMABLE_TO_RIGID
\$      pid       mrb
2
\$
\$
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\$
\$\$\$\$  Define Nodes and Elements
\$
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\$
\$...>....1....>....2....>....3....>....4....>....5....>....6....>....7....>....8
\$
*END```