Shell 1

A spherical shell is subjected to outward point loads on the x-axis and inward point loads on the z-axis.

*CONTROL_SHELL
Hemispherical Load
LS-DYNA Manual Section: *CONTROL_SHELL

Example: Hemispherical Load

Filename: control_shell.hemi-load.k

Description:
A spherical shell is subjected to outward point loads on the x-axis and inward
point loads on the z-axis.

Model:
The 1/8 symmetry model of a sphere measures 10 inches in radius with a
thickness of 0.04 inches. The model contains 48 shell elements. A force of one
pound is applied in the positive x -direction to the node on the x -axis.
A force of one pound is applied in the negative z-direction to the node on the
y-axis.

Input:
The element formulation is the Hughes-Liu shell with four integration points
through the thickness. Note: If B-T element formulation is used the solution
would be incorrect. To fix it, the Belytschko-Tsay shell requires the
Belytschko-Wang-Chiang warpage stiffness modification (*CONTRO L_SHELL).
The concentrated loads are applied to two nodes (*DEFINE_CURVE,
*LOAD_NODE_POINT).

Results:
The oscillation of the node on the z-axis shows a regular oscillatory behavior.
Since there is no specified damping, oscillations would be expected.

Reference:
Belytschko, T., Wang and Chiang.

*CONTROL_ENERGY
*CONTROL_HOURGLASS
*CONTROL_SHELL
*CONTROL_TERMINATION
*DATABASE_BINARY_D3PLOT
*DEFINE_CURVE
*ELEMENT_SHELL
*END
*KEYWORD
*LOAD_NODE_POINT
*MAT_PLASTIC_KINEMATIC
*NODE
*PART
*SECTION_SHELL
*TITLE

  *KEYWORD
  *TITLE
  Hemispherical Shell
  $
  $  LSTC Example
  $
  $  Last Modified: September 12, 1997
  $
  $  Units: lbf-s2/in, in, s, lbf, psi, lbf-in
  $
  $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
  $
  $$$$  Control Ouput
  $
  $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
  $
  $...>....1....>....2....>....3....>....4....>....5....>....6....>....7....>....8
  $
  *CONTROL_TERMINATION
  $   endtim    endcyc     dtmin    endneg    endmas
   6.000E-02
  $
  *CONTROL_ENERGY
  $     hgen      rwen    slnten     rylen
           2         2
  $
  *CONTROL_HOURGLASS
  $      ihq        qh
           4
  $
  *CONTROL_SHELL
  $   wrpang    itrist     irnxx    istupd    theory       bwc     miter
                              -2                   1
  $
  $
  *DATABASE_BINARY_D3PLOT
  $       dt      lcdt
   6.000E-04
  $
  $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
  $
  $$$$  Loading
  $
  $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
  $
  $$$$  Load node  1 in the positive x-direction.
  $
  *LOAD_NODE_POINT
  $      nid       dof      lcid        sf       cid        m1        m2        m3
           1         3         1       1.0
  $
  $$$$  Load node 46 in the negative z-direction.
  $
  *LOAD_NODE_POINT
  $      nid       dof      lcid        sf       cid        m1        m2        m3
          46         1         1      -1.0
  $
  $
  *DEFINE_CURVE
  $     lcid      sidr      scla      sclo      offa      offo
           1
  $           abscissa            ordinate
             0.000E+00           1.000E+00
             1.000E+00           1.000E+00
  $
  $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
  $
  $$$$  Define Parts and Materials
  $
  $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
  $
  $...>....1....>....2....>....3....>....4....>....5....>....6....>....7....>....8
  $
  *PART
  $      pid       sid       mid     eosid      hgid    adpopt
  Hemisphere
           1         1         1
  $
  $
  *MAT_PLASTIC_KINEMATIC
  $      mid        ro         e        pr      sigy      etan      beta
           1 1.000E-03 6.825E+07       0.3 600000.00 0.000E+00 0.000E+00
  $      src       srp        fs
   0.000E+00 0.000E+00 0.000E+00
  $
  $
  *SECTION_SHELL
  $      sid    elform      shrf       nip     propt   qr/irid     icomp
           1                             5
  $       t1        t2        t3        t4      nloc
   4.000E-02 4.000E-02 4.000E-02 4.000E-02
  $
  $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
  $
  $$$$  Define Nodes and Elements
  $
  $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
  $
  $$$$  Multiple nodes have boundary conditions to simulate symmetry.
  $
  $
  *END