Airbag
An airbag inflates below a rigid cylinder, causing the cylinder to fly into the air.
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Airbag
An airbag inflates below a rigid cylinder, causing the cylinder to fly into the air.
*AIRBAG_SIMPLE_AIRBAG_MODEL Airbag Deploys into Cylinder LS-DYNA Manual Section: *AIRBAG_SIMPLE_AIRBAG_MODEL Additional Sections: *CONTACT_NODES_TO_SURFACE *RIGIDWALL_PLANAR Example: Airbag Deploys into Cylinder Filename: airbag.deploy.k Description: An airbag inflates below a rigid cylinder, causing the cylinder to fly into the air. Model: The volume pressure relationships is defined by the Simple Airbag Model for control volumes. The bag inflates through the flow of mass into the bag. Input: The control volume defines the thermodynamic relationship for the gas in terms of parameters such as heat capacity, gas temperature, incoming mass, and out going m ass (*AIRBAG_SIMPLE_AIRBAG_MODEL). A rigidwall is used below the airbag to act as ground (*RIGIDWALL_PLANAR). A ground is displayed using rigid shell elements, but is used only for visualization purposes. The contact between the airbag and the cylinder is automatically generated by part id (*CONTACT_NODES_TO_SURFACE). Results: The plots show the bag expanding. The ASCII file abstat contains information on the computed pressure, volume, mass flow and internal energy of the control volume (*DATABASE_ABSTAT).
*AIRBAG_SIMPLE_AIRBAG_MODEL *CONTACT_NODES_TO_SURFACE *CONTROL_ENERGY *CONTROL_OUTPUT *CONTROL_TERMINATION *DATABASE_ABSTAT *DATABASE_BINARY_D3PLOT *DATABASE_BINARY_D3THDT *DATABASE_EXTENT_BINARY *DATABASE_GLSTAT *DATABASE_MATSUM *DATABASE_RBDOUT *DATABASE_RCFORC *DATABASE_RWFORC *DEFINE_CURVE *ELEMENT_SHELL *END *KEYWORD *MAT_FABRIC *MAT_RIGID *NODE *PART *RIGIDWALL_PLANAR *SECTION_SHELL *SET_PART_LIST *TITLE
*KEYWORD
*TITLE
Airbag and Structure
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$ LSTC Example
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$ Last Modified: August 29, 1997
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$ Airbag with a cylinder on top, deploys and pushes the cylinder into the air.
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$ Airbag is approximately 19 x 25 inches, with 0.015 in thickness
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$
$ Units: lbf-s^2/in, in, s, lbf, psi, lbf-in
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$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
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$$$$ Control Ouput
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$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
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$...>....1....>....2....>....3....>....4....>....5....>....6....>....7....>....8
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*CONTROL_TERMINATION
$ endtim endcyc dtmin endneg endmas
3.000E-02
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*CONTROL_ENERGY
$ hgen rwen slnten rylen
2 2 2
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*CONTROL_OUTPUT
$ npopt neecho nrefup iaccop opifs ipnint ikedit
1 3
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*DATABASE_BINARY_D3PLOT
$ dt lcdt
5.000E-04
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*DATABASE_EXTENT_BINARY
$ neiph neips maxint strflg sigflg epsflg rltflg engflg
$ cmpflg ieverp beamip
1
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*DATABASE_BINARY_D3THDT
$ dt lcdt
999999
$
$
*DATABASE_ABSTAT
$ dt
2.000E-04
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*DATABASE_GLSTAT
$ dt
2.000E-04
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$
*DATABASE_MATSUM
$ dt
2.000E-04
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*DATABASE_RCFORC
$ dt
2.000E-04
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*DATABASE_RBDOUT
$ dt
2.000E-04
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*DATABASE_RWFORC
$ dt
2.000E-04
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$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
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$$$$ Airbag
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$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
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$...>....1....>....2....>....3....>....4....>....5....>....6....>....7....>....8
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*AIRBAG_SIMPLE_AIRBAG_MODEL
$ sid sidtyp rbid vsca psca vini mwd spsf
1 1
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$ cv cp t lcid mu a pe ro
1.736E+03 2.430E+03 1.200E+03 1 7.000E-01 0.000E+00 1.470E+01 3.821E-06
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$ lou
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*SET_PART_LIST
$ sid da1 da2 da3 da4
1
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$ pid1 pid2 pid3 pid4 pid5 pid6 pid7 pid8
3
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*DEFINE_CURVE
$ lcid sidr scla sclo offa offo
1
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$ abscissa ordinate
0.000E+00 0.000E+00
3.200E-02 2.600E+01
4.500E-02 6.000E-01
8.000E-02 1.000E-01
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$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
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$$$$ Rigid Walls
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$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
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$$$$ Ground
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*RIGIDWALL_PLANAR
$...>....1....>....2....>....3....>....4....>....5....>....6....>....7....>....8
$ nsid nsidex boxid
0 0 0
$ xt yt zt xh yh zh fric
0.0 0.0 0.0 0.0 1.0 0.0 0.5
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$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
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$$$$ Define Contacts - Sliding Interfaces
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$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
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$...>....1....>....2....>....3....>....4....>....5....>....6....>....7....>....8
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$$$$ Contact between the airbag and the cylinder.
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*CONTACT_NODES_TO_SURFACE
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$ ssid msid sstyp mstyp sboxid mboxid spr mpr
3 2 3 3 1 1
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$ fs fd dc vc vdc penchk bt dt
0.5 0.5
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$ sfs sfm sst mst sfst sfmt fsf vsf
1.0000 0.06667
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$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
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$$$$ Define Parts and Materials
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$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
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*PART
Plate - Rigid - Fixed (for viewing)
$ pid sid mid eosid hgid adpopt
1 1 1 0 0 0
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*PART
Cylinder - Rigid
$ pid sid mid eosid hgid adpopt
2 1 2 0 0 0
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*PART
Airbag - Fabric
$ pid sid mid eosid hgid adpopt
3 2 3 0 0 0
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$
$$$$$$ Materials
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$
*MAT_RIGID
$ mid ro e pr n couple m alias
1 7.84e-4 30.00e+6 0.30
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$ cmo con1 con2
1 7 7
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$ lco/a1 a2 a3 v1 v2 v3
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$
*MAT_RIGID
$ mid ro e pr n couple m alias
2 1.96e-4 30.00e+6 0.30
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$ cmo con1 con2
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$ lco/a1 a2 a3 v1 v2 v3
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*MAT_FABRIC
$ mid ro ea eb ec prba prca prcb
3 1.00e-4 2.00e+6 2.00e+6 2.00e+6 0.35 0.35 0.35
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$ gab gbc gca gse el prl lratio damp
1.53e+6 1.53e+6 1.53e+6
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$ aopt
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$ xp yp zp a1 a2 a3
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$ v1 v2 v3 d1 d2 d3
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$$$$$$ Sections
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*SECTION_SHELL
$ sid elform shrf nip propt qr/irid icomp
1 0
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$ t1 t2 t3 t4 nloc
0.500 0.500 0.500 0.500
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$
*SECTION_SHELL
$ sid elform shrf nip propt qr/irid icomp
2 9 4 1
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$ t1 t2 t3 t4 nloc
0.015 0.015 0.015 0.015
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$ b1 b2 b3 b4 b5 b6 b7 b8
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$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
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$$$$ Define Nodes and Elements
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$...>....1....>....2....>....3....>....4....>....5....>....6....>....7....>....8
$ nid x y z tc rc
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*END