Foam

This problem contains a single element with one degree of freedom on a side. The element compresses and expands.

*MAT_SOIL_AND_FOAM
Soil and Foam Single Element
LS-DYNA Manual Section: *MAT_SOIL_AND_FOAM

Example: Soil and Foam Single Element

Filename: mat_soil_foam.element.k

Description:
This problem contains a single element with one degree of freedom on a side.
The element compresses and expands.

Model:
The element measures 100 cubic inches. One side follows a velocity curve which
results in a range of relative volume (V/Vo) 1.000 to 0.0091 to 1.441.

Input:
The foam follows a pressure volumetric strain relationship (*MAT_SOIL_AND_FOAM).
The unloading behavior may follow either the unloading bulk modulus or the
loading curve. The unloading in the first case follows the bulk modulus,
while the unloading in the second case follows the loading curve. The material
has a cutoff pressure of 0.5.

Results:
The plots show the element pressure versus time.

*BOUNDARY_PRESCRIBED_MOTION_SET
*CONTROL_ENERGY
*CONTROL_TERMINATION
*DATABASE_BINARY_D3PLOT
*DATABASE_BINARY_D3THDT
*DATABASE_ELOUT
*DATABASE_GLSTAT
*DATABASE_HISTORY_SOLID
*DEFINE_CURVE
*ELEMENT_SOLID
*END
*KEYWORD
*MAT_SOIL_AND_FOAM
*NODE
*PART
*SECTION_SOLID
*SET_NODE_LIST
*TITLE

  *KEYWORD
  *TITLE
  Foam Material Model for a Single Element
  $
  $  LSTC Example
  $
  $  Last Modified: September 18, 1997
  $
  $    This problem contains a single element with one degree of
  $    freedom on a single side.  The element compresses and expands
  $    following a prescribed velocity motion.
  $
  $    The material is a foam which follows a pressure volumetric
  $    strain relationship.  The foam block is compressed and
  $    expanded in a range of relative volume (V/Vo) from 1.0
  $    to 0.0091 to 1.441.
  $
  $    Two types of unloading are explored:
  $      1. Unloading follows the loading curve
  $      2. Bulk unloading modulus is used - volumetric crushing
  $
  $    The foam has a tensile fracture pressure cutoff of 0.5
  $
  $  Units: lbf-s2/in, in, s, lbf, psi, lbf-in
  $
  $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
  $
  $$$$  Control Ouput
  $
  $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
  $
  $...>....1....>....2....>....3....>....4....>....5....>....6....>....7....>....8
  $
  *CONTROL_TERMINATION
  $   endtim    endcyc     dtmin    endneg    endmas
       0.250
  $
  *CONTROL_ENERGY
  $     hgen      rwen    slnten     rylen
           2         2
  $
  $
  *DATABASE_BINARY_D3PLOT
  $  dt/cycl      lcdt
       0.005
  $
  *DATABASE_BINARY_D3THDT
  $  dt/cycl      lcdt
       0.001
  $
  *DATABASE_GLSTAT
  $  dt/cycl      lcdt
       0.005
  $
  *DATABASE_ELOUT
  $  dt/cycl      lcdt
       0.005
  $
  *DATABASE_HISTORY_SOLID
           1
  $
  $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
  $
  $$$$  Boundary Motion Conditions
  $
  $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
  $
  $...>....1....>....2....>....3....>....4....>....5....>....6....>....7....>....8
  $
  *BOUNDARY_PRESCRIBED_MOTION_SET
  $      nid       dof       vad      lcid        sf       vid
           1         3         0         1       1.0         0
  $
  *DEFINE_CURVE
  $     lcid      sidr      scla      sclo      offa      offo
           1
  $           abscissa            ordinate
             0.000E+00          -9.000E+02
             1.000E-01          -9.000E+02
             1.010E-01           9.000E+02
             2.500E-01           9.000E+02
  $
  *SET_NODE_LIST
  $      sid
           1
  $     nid1      nid2      nid3      nid4      nid5      nid6      nid7      nid8
           5         6         7         8
  $
  $
  $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
  $
  $$$$  Define Parts and Materials
  $
  $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
  $
  $...>....1....>....2....>....3....>....4....>....5....>....6....>....7....>....8
  $
  *PART
  $      pid       sid       mid     eosid      hgid    adpopt
  foam block
           1         1         1
  $
  $
  *MAT_SOIL_AND_FOAM
  $      mid        ro         g      bulk        a0        a1        a2        pc
           1 6.740E-11 5.760E+01 1.794E+01 1.200E-01 0.000E+00 0.000E+00-5.000E-01
  $        f         f
  $      vcr       dun
  $
  $ Unloading follows the loading curve
  $ 1.000E+00 0.000E+00
  $
  $ Bulk unloading modulus is used - volumetric crushing
   0.000E+00 0.000E+00
  $
  $     eps1      eps2      eps3      eps4      eps5      eps6      eps7      eps8
  -2.500E-02-5.000E-02-1.050E-01-3.570E-01-6.930E-01-9.160E-01-1.200E+00-1.610E+00
  $
  $     eps9     eps10
   0.000E+00 0.000E+00
  $
  $       p1        p2        p3        p4        p5        p6        p7        p8
   3.450E-01 5.170E-01 6.890E-01 8.070E-01 1.110E+00 1.240E+00 1.300E+00 1.500E+00
  $
  $       p9       p10
   0.000E+00 0.000E+00
  $
  $
  *SECTION_SOLID
  $      sid    elform 
           1    
  $
  $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
  $
  $$$$  Define Nodes and Elements
  $
  $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
  $
  $...>....1....>....2....>....3....>....4....>....5....>....6....>....7....>....8
  $
  $
  *END