Shell 1

A fuse plate is used to connect a cut in a wide flange beam. The beam is loaded at an end, putting the fuse plate in tension. In this loading condition, the fuse plate exhibits a great deal of hourglassing.

*SECTION_SHELL
 Fuse Plate in Tension Exhibits Hourglassing
 LS-DYNA Manual Section: *SECTION_SHELL

Additional Sections:
*CONSTRAINED_SPOTWELD
*LOAD_NODE_POINT

Example: Fuse Plate in Tension Exhibits Hourglassing

Filename: section_shell.hourglassing.k

Description:
A fuse plate is used to connect a cut in a wide flange beam. The beam is loaded
at an end, putting the fuse plate in tension. In this loading condition, the
fuse plate exhibits a great deal of hourglassing.

Model:
The fuse plate and beam are constructed with shell elements and a piecewise
linear plasticity material model with failure. The fuse plate is connected to
the beam using spot welds (*CONSTRAINED_SPOTWELD). One end of the beam is
fixed with SPC's, while the other end has several nodal point loads
(*B OUNDARY_SPC_NODE, *LOAD_NODE_POINT). Multiple point loads are used to
better distribute the input loads.

Results:
One look at the figures explains why it's called "hour glassing". To fix the
hourglassing problem the fuse plate could be re-meshed or a fully integrated
shell element formulation could be used.

$     ===> *SECTION_SHELL - ELFORM
*BOUNDARY_SPC_NODE
*CONSTRAINED_SPOTWELD
*CONTROL_ENERGY
*CONTROL_OUTPUT
*CONTROL_TERMINATION 
*DATABASE_BINARY_D3PLOT
*DATABASE_BINARY_D3THDT
*DATABASE_GLSTAT
*DATABASE_MATSUM
*DATABASE_SWFORC
*DEFINE_CURVE
*ELEMENT_SHELL
*END
*KEYWORD
*LOAD_NODE_POINT
*MAT_PIECEWISE_LINEAR_PLASTICITY
*NODE
*PART
*SECTION_SHELL
*TITLE

*KEYWORD
*TITLE
Fuse plate being pulled a part exhibits hourglassing troubles.
$
$  LSTC Example
$
$  Last Modified: October 14, 1997
$
$  Really good hourglassing on fuse plate - part 3
$
$  Switch to shell formulation S/R Hughes-Liu (6) - eliminates HG
$     ===> *SECTION_SHELL - ELFORM
$
$
$  Units: mm, kg, ms, kN, GPa, kN-mm
$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$
$$$$  Control Ouput
$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$
$...>....1....>....2....>....3....>....4....>....5....>....6....>....7....>....8
$
*CONTROL_TERMINATION 
$   endtim    endcyc     dtmin    endneg    endmas
     10.01
$
*CONTROL_ENERGY
$     HGEN      RWEN    SLNTEN     RYLEN
         2         2         1         1
$
*CONTROL_OUTPUT
$    NPOPT    NEECHO    NREFUP    IACCOP     OPIFS    IPNINT    IKEDIT
         1         3
$
$
*DATABASE_BINARY_D3PLOT
$       dt      lcdt
       1.0
$
*DATABASE_BINARY_D3THDT
$       dt      lcdt
    999999
$
*DATABASE_GLSTAT
$       dt
       0.1
$
*DATABASE_MATSUM
$       dt
       0.1
$
*DATABASE_SWFORC
$       dt
       0.1
$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$
$$$$  Constrain the Plates Together
$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$
$$$  Spotweld the fuse plate to the post flanges.
$
*CONSTRAINED_SPOTWELD
$       n1        n2        sn        sf         n         m
       284       511
       247       512
       428       527
       417       517
$
$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$
$$$$  Boundary and Loading Conditions
$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$
$...>....1....>....2....>....3....>....4....>....5....>....6....>....7....>....8
$
*BOUNDARY_SPC_NODE
$      nid       cid         x         y         z        rx        ry        rz
       150         0         1         1         1         1         1         1
       151         0         1         1         1         1         1         1
       152         0         1         1         1         1         1         1
       179         0         1         1         1         1         1         1
       180         0         1         1         1         1         1         1
       181         0         1         1         1         1         1         1
       204         0         1         1         1         1         1         1
       205         0         1         1         1         1         1         1
$
*LOAD_NODE_POINT
$      nid       dof      lcid        sf       cid        m1        m2        m3
        17         1         2 2.000E+03         0
        18         1         2 2.000E+03         0
        19         1         2 2.000E+03         0
        61         1         2 2.000E+03         0
        62         1         2 2.000E+03         0
        63         1         2 2.000E+03         0
       100         1         2 2.000E+03         0
       101         1         2 2.000E+03         0
$
*DEFINE_CURVE
$     lcid      sidr      scla      sclo      offa      offo
         2
$           abscissa            ordinate
0.00000000000000E+00 1.0000000000000E+00
1.00000000000000E+04 1.0000000000000E+04
$
$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$
$$$$  Define Parts and Materials
$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$
$...>....1....>....2....>....3....>....4....>....5....>....6....>....7....>....8
$
*PART
$      pid       sid       mid     eosid      hgid      grav    adpopt
pstflang
         1         1         1
postweb
         2         2         1
fuseplat
         3         3         1
$
$
$$$$  Materials
$
$
*MAT_PIECEWISE_LINEAR_PLASTICITY
$...>....1....>....2....>....3....>....4....>....5....>....6....>....7....>....8
$      mid        ro         e        pr      sigy      etan      eppf      tdel
         1 0.783E-05 2.000E+02       0.3 2.070E-01           7.500E-01
$  Cowper/Symonds Strain Rate Parameters
$        c         p      lcss      lcsr
        40         5
$  Plastic stress/strain curve
 0.000E+00 8.000E-02 1.600E-01 4.000E-01 9.900E+01
 2.070E-01 2.500E-01 2.750E-01 2.899E-01 3.000E-01
$
$
$$$$  Sections
$
*SECTION_SHELL
$      sid    elform      shrf       nip     propt   qr/irid     icomp
         1         6
$       t1        t2        t3        t4      nloc
5.4600E+00 5.460E+00 5.460E+00 5.460E+00
$
*SECTION_SHELL
$      sid    elform      shrf       nip     propt   qr/irid     icomp
         2         6
$       t1        t2        t3        t4      nloc
4.3200E+00 4.320E+00 4.320E+00 4.320E+00
$
$
*SECTION_SHELL
$      sid    elform      shrf       nip     propt   qr/irid     icomp
         3         2
$         3         6
$       t1        t2        t3        t4      nloc
4.7625E+00 4.762E+00 4.762E+00 4.762E+00
$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$
$$$$  Define Nodes and Elements
$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$
$...>....1....>....2....>....3....>....4....>....5....>....6....>....7....>....8
$
$
*END