Linear
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. Download is available in the download section of this document.
Introduction
*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 * 4 0* 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 ma gnitude of the prescribed displacement of the center node (*BOUNDARY_PRESCRIBED_MOTION_NODE, *DE FINE_CURVE). A linear constraint card defines the coupling of the displacement in the z -direction between the two nodes (*CONSTRA INED_LINEAR). Two equal coefficients with opposite signs control the displacement. Reference: Schweizerhof, K. and Weimar, K.
Keywords
*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
Reduced Input
*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
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