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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.
Introduction
*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
(*BOUNDARY_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 "hourglassing". To fix the
hourglassing problem the fuse plate could be re-meshed or a fully integrated
shell element formulation could be used.
Keywords
$ ===> *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 apart 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
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