The center node of a plate moves in the normal direction. Two other nodes that are neighbors to the center node are constrained such that their displacement in the normal direction is identical.
*CONSTRAINED_LINEAR Linearly Constrained Plate LS-DYNA Manual Section: *CONSTRAINED_LINEAR Additional Sections: BOUNDARY_PRESCRIBED_MOTION_NODE DEFINE_CURVE Example: Linearly Constrained Plate Filename: constrained.linear.plate.k Description: The center node of a plate moves in the normal direction. Two other nodes that are neighbors to the center node are constrained such that their displacement in the normal direction is identical. Model: The plate is made of an elastic material measuring 40 * 40 * 2 mm3 and contains 64 Hughes-Liu shell elements. The center node displacement increases linearly. At the termination time, 0.0005 seconds, the displacement is 15 mm. The degree of freedom in the z-direction for the two nodes is identical. Input: A load curve defines the magnitude of the prescribed displacement of the center node (*BOUNDARY_PRESCRIBED_MOTION_NODE, *DEFINE_CURVE). A linear constraint card defines the coupling of the displacement in the z-direction between the two nodes (*CONSTRAINED_LINEAR). Two equal coefficients with opposite signs control the displacement. Reference: Schweizerhof, K. and Weimar, K.
*BOUNDARY_PRESCRIBED_MOTION_NODE *CONSTRAINED_LINEAR *CONTROL_CONTACT *CONTROL_HOURGLASS *CONTROL_SHELL *CONTROL_TERMINATION *DATABASE_BINARY_D3PLOT *DATABASE_BINARY_D3THDT *DATABASE_EXTENT_BINARY *DATABASE_HISTORY_NODE *DATABASE_NODOUT *DEFINE_CURVE *ELEMENT_SHELL *END *KEYWORD *MAT_ELASTIC *NODE *PART *SECTION_SHELL *TITLE
*KEYWORD
*TITLE
Linear Constraint Equations
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$ LSTC Example
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$ Last Modified: September 3, 1997
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$ Units: mm, s
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$$$$ Control Ouput
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$...>....1....>....2....>....3....>....4....>....5....>....6....>....7....>....8
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*CONTROL_TERMINATION
$ endtim endcyc dtmin endneg endmas
0.0005
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*CONTROL_CONTACT
$ slsfac rwpnal islchk shlthk penopt thkchg orien
0.1 2
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$ usrstr usrfac nsbcs interm xpenen
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*CONTROL_HOURGLASS
$ ihq qh
4
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*CONTROL_SHELL
$ wrpang itrist irnxx istupd theory bwc miter
1
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*DATABASE_BINARY_D3PLOT
$ dt lcdt
0.00002
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*DATABASE_BINARY_D3THDT
$ dt lcdt
0.00001
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*DATABASE_EXTENT_BINARY
$ neiph neips maxint strflg sigflg epsflg rltflg engflg
1
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$ cmpflg ieverp beamip
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*DATABASE_HISTORY_NODE
$ id1 id2 id3 id4 id5 id6 id7 id8
$...>....1....>....2....>....3....>....4....>....5....>....6....>....7....>....8
40 41 42
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*DATABASE_NODOUT
$ dt
0.00001
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$$$$ Constraints and Boundary Conditions
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$...>....1....>....2....>....3....>....4....>....5....>....6....>....7....>....8
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$$$$ nodes 40 and 42 are constrained to have identical z-direction motion
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*CONSTRAINED_LINEAR
$ num
2
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$ nid dofx dofy dofz dofrx dofry dofrz coef
40 1 1.00
42 1 -1.00
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$$$$ node 41 is displaced in the z-direction according to load curve 1
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*BOUNDARY_PRESCRIBED_MOTION_NODE
$ nid dof vad lcid sf vid
41 3 2 1 1.0
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*DEFINE_CURVE
$ lcid sidr scla sclo offa offo
1
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$ abscissa ordinate
0.0 0.0
0.0005 -15.0
0.0015 -15.1
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$$$$ Define Parts and Materials
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*PART
Impacted Material
$ pid sid mid eosid hgid adpopt
1 1 1 0 0 0
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$$$$$$ Materials
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*MAT_ELASTIC
$ mid ro e pr da db k
1 2.00e-8 100000.0 0.300
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$$$$$$ Sections
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*SECTION_SHELL
$ sid elform shrf nip propt qr/irid icomp
1 6 0.83333 2.0 3.0
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$ t1 t2 t3 t4 nloc
2.0 2.0 2.0 2.0
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*END
