Timestep
A rod of steel is forged between two dies. The billet upset problem is a measure of friction under forming conditions.
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Timestep
A rod of steel is forged between two dies. The billet upset problem is a measure of friction under forming conditions.
*CONTROL_TIMESTEP Billet Upset LS-DYNA Manual Section: *CONTROL_TIMESTEP Example: Billet Upset Filename: control_timestep.billet-forge.k Description: A rod of steel is forged between two dies. The billet upset problem is a measure of friction under forming conditions. Model: The billet material is isotropic elastic-plastic, and the model has 1 * 8 symmetry. The billet measures 2.25 inches in height and 1.26 inches in radius. The die compresses the billet 1.60 inches. The relationship between the shear friction and the normal pressure is bilinear. Input: The mass scaling time step size is set to 12 microseconds (*CONTRO L_TIMESTEP). The billet nodes contact the die surfaces (*CONTACT_NODES_TO_SURFACE). The Coulomb frictional constant is 0.10 and the constant shear is 2,055 psi. A half sine wave defines the velocity of the die (*BOUNDARY_PRESCRIBED_MOTION). Results: The results show that effective plastic strains with and without time-step control are the same. CPU savings is approximately 33% on the cray J90 using 1 cpu.. Reference: Avitzur, B., Lee, C. H. and Altan, T.
*BOUNDARY_PRESCRIBED_MOTION_RIGID *CONTACT_NODES_TO_SURFACE *CONTROL_ENERGY *CONTROL_OUTPUT *CONTROL_TERMINATION *CONTROL_TIMESTEP *DATABASE_BINARY_D3PLOT *DATABASE_BINARY_D3THDT *DATABASE_EXTENT_BINARY *DATABASE_GLSTAT *DATABASE_MATSUM *DATABASE_RBDOUT *DATABASE_RCFORC *DEFINE_CURVE *ELEMENT_SHELL *ELEMENT_SOLID *END *KEYWORD *MAT_PIECEWISE_LINEAR_PLASTICITY *MAT_RIGID *NODE *PART *SECTION_SHELL *SECTION_SOLID *TITLE
*KEYWORD
*TITLE
BILLET UPSET
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$ LSTC Example
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$ Last Modified: September 16, 1997
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$ Units: lbf-s2/in, in, s, lbf, psi, lbf-in
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$$$$ Control Ouput
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*CONTROL_TERMINATION
$ endtim endcyc dtmin endneg endmas
0.0015
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*CONTROL_TIMESTEP
$ dtinit scft isdo tslimt dtms lctm erode ms1st
-1.200E-07
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*CONTROL_ENERGY
$ hgen rwen slnten rylen
2 2
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*CONTROL_OUTPUT
$ npopt neecho nrefup iaccop opifs ipnint ikedit
1 3
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*DATABASE_BINARY_D3PLOT
$ dt lcdt
0.0001
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*DATABASE_EXTENT_BINARY
$ neiph neips maxint strflg sigflg epsflg rltflg engflg
$ cmpflg ieverp beamip
1
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*DATABASE_BINARY_D3THDT
$ dt lcdt
999999
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*DATABASE_GLSTAT
$ dt
0.00001
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*DATABASE_MATSUM
$ dt
0.00001
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*DATABASE_RBDOUT
$ dt
0.00001
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*DATABASE_RCFORC
$ dt
0.00001
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$$$$ Loading - PRESCRIBED_MOTION_RIGID
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*BOUNDARY_PRESCRIBED_MOTION_RIGID
$ mid dof vad lcid sf vid
2 3 0 1 1.000E+00
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*DEFINE_CURVE
$ lcid sidr scla sclo offa offo
1
$ abscissa ordinate
0.000E+00 0.000E+00
5.000E-05 -4.931E+00
1.000E-04 -1.960E+01
1.500E-04 -4.365E+01
2.000E-04 -7.649E+01
2.500E-04 -1.173E+02
3.000E-04 -1.651E+02
3.500E-04 -2.187E+02
4.000E-04 -2.767E+02
4.500E-04 -3.378E+02
5.000E-04 -4.005E+02
5.500E-04 -4.632E+02
6.000E-04 -5.243E+02
6.500E-04 -5.823E+02
7.000E-04 -6.359E+02
7.500E-04 -6.837E+02
8.000E-04 -7.245E+02
8.500E-04 -7.573E+02
9.000E-04 -7.814E+02
9.500E-04 -7.961E+02
1.000E-03 -8.010E+02
1.050E-03 -7.961E+02
1.100E-03 -7.814E+02
1.150E-03 -7.573E+02
1.200E-03 -7.245E+02
1.250E-03 -6.837E+02
1.300E-03 -6.359E+02
1.350E-03 -5.823E+02
1.400E-03 -5.243E+02
1.450E-03 -4.632E+02
1.500E-03 -4.005E+02
1.550E-03 -3.378E+02
1.600E-03 -2.767E+02
1.650E-03 -2.187E+02
1.700E-03 -1.651E+02
1.750E-03 -1.173E+02
1.800E-03 -7.649E+01
1.850E-03 -4.365E+01
1.900E-03 -1.960E+01
1.950E-03 -4.931E+00
2.000E-03 0.000E+00
2.200E-03 0.000E+00
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$$$$ Define Contacts
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$...>....1....>....2....>....3....>....4....>....5....>....6....>....7....>....8
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*CONTACT_NODES_TO_SURFACE
$ ssid msid sstyp mstyp sboxid mboxid spr mpr
1 2 3 3
$ fs fd dc vc vdc penchk bt dt
0.1 0.1 2.055E+03
$ sfs sfm sst mst sfst sfmt fsf vsf
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$$$$ Define Parts and Materials
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$$$ Part 1 solid: Billet - Aluminum
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$$$ Part 2 shell: Press - Aluminum - rigid
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*PART
$ pid sid mid eosid hgid adpopt
Billet - Aluminum
1 1 1
Press - Aluminum
2 2 2
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$$$$ materials
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*MAT_PIECEWISE_LINEAR_PLASTICITY
$ mid ro e pr sigy etan eppf tdel
1 2.50e-4 10.00e+6 0.33
$ c p lcss lcsr
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$ eps1 eps2 eps3 eps4 eps5 eps6 eps7 eps8
0.000E+00 5.000E-03 1.000E-02 5.000E-02 1.000E-01 2.000E-01 7.000E-01 4.000E+00
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$ es1 es2 es3 es4 es5 es6 es7 es8
4.785E+03 6.505E+03 7.423E+03 1.063E+04 1.254E+04 1.482E+04 2.010E+04 3.081E+04
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*MAT_RIGID
$ mid ro e pr n couple m alias
2 2.50e-4 10.00e+6 0.33
$ cmo con1 con2
-1.0 0.0 110111
$ lco/a1 a2 a3 v1 v2 v3
0.0
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$$$$ sections
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*SECTION_SOLID
$ sid elform
1 0
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*SECTION_SHELL
$ sid elform shrf nip propt qr/irid icomp
2
$ t1 t2 t3 t4 nloc
1.000E-02 1.000E-02 1.000E-02 1.000E-02
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$$$$ Define Nodes and Elements
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$$$$ Many nodes have boundary conditions in order to simulate symmetry.
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*END