Adaptive 2

A square cross section of a crush tube uses adaptivity to re-fine the mesh as needed to improve accuracy.

CONTROL_ADAPTIVE
Square Crush Tube with Adaptivity
LS-DYNA Manual Section: *CONTROL_ADAPTIVE

Additional Sections:
*CONTROL_SUBCYCLE

Example: Square Crush Tube with Adaptivity

Filename: control_adaptive.square-beam.k

Description:
A square cross section of a crush tube uses adaptivity to re-fine the mesh as
needed to improve accuracy.

Model:
Only 1/4 of the tube is modeled because of symmetry. The nodes on top of the
crush tube are assigned extra mass with *EL EMENT_MASS and given an initial
velocity in the y direction of -5,646 mm/s. The nodes on the bottom of the
tube are fixed in y-translation. Automatic single surface contact is defined
to prevent penetration when the folds of the crush tube start to form.
The model has sub-cycling defined.

Results:
The mesh at the fold location in the crush tube is automatically re-fined as
the crush progresses.

*CONSTRAINED_NODE_SET
*CONTACT_AUTOMATIC_SINGLE_SURFACE
*CONTROL_ADAPTIVE
*CONTROL_ENERGY
*CONTROL_OUTPUT
*CONTROL_SUBCYCLE
*CONTROL_TERMINATION
*DATABASE_BINARY_D3PLOT
*DATABASE_GLSTAT
*DATABASE_MATSUM
*ELEMENT_MASS
*ELEMENT_SHELL
*END
*INITIAL_VELOCITY_NODE
*KEYWORD
*MAT_PLASTIC_KINEMATIC
*NODE
*PART
*SECTION_SHELL
*SET_NODE
*SET_PART
*TITLE

  *KEYWORD
  *TITLE
  square cross section for single surface contact and adaptivity test
  $
  $  LSTC Example
  $
  $  Last Modified: October 15, 1997
  $
  $  Units: ton, mm, s, N, MPa, N-mm
  $
  $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
  $
  $$$$  Control Ouput
  $
  $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
  $
  $...>....1....>....2....>....3....>....4....>....5....>....6....>....7....>....8
  $
  *CONTROL_TERMINATION
  $   endtim    endcyc     dtmin    endneg    endmas
   3.000E-03
  $
  *CONTROL_ENERGY
  $     hgen      rwen    slnten     rylen
           2         2         2
  $
  *CONTROL_OUTPUT
  $    npopt    neecho    nrefup    iaccop     opifs    ipnint    ikedit
           1         3
  $
  $
  *DATABASE_BINARY_D3PLOT
  $       dt       lcdt 
    0.999e-4
  $
  *DATABASE_GLSTAT
  $       dt
     0.00002
  $
  *DATABASE_MATSUM
  $       dt
     0.00002
  $
  $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
  $
  $$$$  Adaptivity
  $
  $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
  $
  $...>....1....>....2....>....3....>....4....>....5....>....6....>....7....>....8
  $
  *CONTROL_ADAPTIVE
  $  adpfreq    adptol    adpopt    maxlvl    tbirth    tdeath     lcadp    ioflag
      1.0e-4       5.0         2         2       0.0       0.0         0
  $
  $
  *CONTROL_SUBCYCLE
  $
  $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
  $
  $$$$  Initial Conditions
  $
  $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
  $
  $...>....1....>....2....>....3....>....4....>....5....>....6....>....7....>....8
  $
  *INITIAL_VELOCITY_NODE
  $      nid        vx        vy        vz       vxr       vyr       vzr
          650.0000E+00-0.5646E+40.0000E+00
          660.0000E+00-0.5646E+40.0000E+00
          990.0000E+00-0.5646E+40.0000E+00
         1320.0000E+00-0.5646E+40.0000E+00
         1650.0000E+00-0.5646E+40.0000E+00
         1980.0000E+00-0.5646E+40.0000E+00
         4230.0000E+00-0.5646E+40.0000E+00
         4560.0000E+00-0.5646E+40.0000E+00
         4890.0000E+00-0.5646E+40.0000E+00
         5220.0000E+00-0.5646E+40.0000E+00
         5550.0000E+00-0.5646E+40.0000E+00
  $
  $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
  $
  $$$$  Constraints
  $
  $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
  $
  $...>....1....>....2....>....3....>....4....>....5....>....6....>....7....>....8
  $
  *CONSTRAINED_NODE_SET
  $     nsid       dof
          11         2
  $
  *SET_NODE
  $      sid       da1
          11        11
  $     nid1      nid2      nid3      nid4      nid5      nid6      nid7      nid8
          65        66        99       132       165       198       423       456
         489       522       555
  $
  $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
  $
  $$$$  Define Contacts - sliding interface definitions
  $
  $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
  $
  $...>....1....>....2....>....3....>....4....>....5....>....6....>....7....>....8
  $
  *CONTACT_AUTOMATIC_SINGLE_SURFACE
  $     ssid      msid     sstyp     mstyp    sboxid    mboxid       spr       mpr
           1         0         2         0
  $       fs        fd        dc        vc       vdc    penchk        bt        dt
  
  $      sfs       sfm       sst       mst      sfst      sfmt       fsf       vsf
  
  $
  $
  *SET_PART
  $      sid       da1
           1         1
  $      pid
           1
  $
  $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
  $
  $$$$  Define Parts and Materials
  $
  $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
  $
  $...>....1....>....2....>....3....>....4....>....5....>....6....>....7....>....8
  $
  *PART
  $      pid       sid       mid     eosid      hgid      grav    adpopt
  square-tube
           1         1         1         0         0         0         1
  $
  $
  *MAT_PLASTIC_KINEMATIC
  $      mid        ro         e        pr      sigy      etan      beta
           1 7.850E-09 1.994E+05 3.000E-01 3.366E+02 1.000E+00 1.000E+00 0.000E+00
  $      src       srp        fs
  
  $
  $
  *SECTION_SHELL
  $      sid    elform      shrf       nip     propt   qr/irid     icomp
           1         2        1.        3.        0.        0.         0
  $       t1        t2        t3        t4      nloc
         1.2       1.2       1.2       1.2
  $
  $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
  $
  $$$$  Define Nodes and Elements
  $
  $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
  $
  $...>....1....>....2....>....3....>....4....>....5....>....6....>....7....>....8
  $
  $
  $...>....1....>....2....>....3....>....4....>....5....>....6....>....7....>....8
  $
  $$$$$  Elements - Discrete Masses
  $
  *ELEMENT_MASS
  $    eid     nid            mass
        65      65       1.000E-02
        66      66       1.000E-02
        99      99       1.000E-02
       132     132       1.000E-02
       165     165       1.000E-02
       198     198       5.000E-03
       423     423       1.000E-02
       456     456       1.000E-02
       489     489       1.000E-02
       522     522       1.000E-02
       555     555       5.000E-03
  $
  *END