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Simulation running very slow in ABAQUS using Dynamic Implicit

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vineetchaturvedi

Mechanical
Dec 2, 2013
3
Hi,

I am running a dynamic implicit simulation of indentation of a cylinder (C3D8H elements) using material properties of a soft tissue.
The next step in this simulation is to set it up for indentation on human finger model in ABAQUS.

I ran the simulation using material properties of rubber and it took me 4 and a half hours to run the simulation of simple indentation with a rigid indentor. I still went ahead and edited the material properties of cylinder to use the soft tissue material parameters ( Hyperelastic and viscoelastic along with elastic parameters) When i submitted the simulation, the simulation runs for hours and reaches a wall time on the server I am using it on ( 30 hours in this case). I know a simple indentation simulation should not be taking this long.

1.I have checked and verified the mesh for the cylinder and there is no problem with the elements.
2.The stable increment time i am using is 1E-5 but even after I increased it to 1E-3, its taking a very long time and not finishing

I would be very thankful if someone could help me with this problem.
I am attaching the input file in case someone needs to see it.

Thanks a lot.

Vineet
 
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your upload was not successful.
Why are you not using the automatic time increment in dynamic implict?
1E-3 is still relatively small
 
Hi Sdebock,

I am really thankful for your response.
I will attach the input file again. Sorry for not checking after submitting.

I tried to give a larger time increment to this simulation, but the error said that "time increment is too large"
I am going to try again and see if it works but I have given it multiple tries and I keep getting the same error.
Also i checked all the possible conditions affecting the simulation time but cant pin point as to why its taking this long.
Again I appreciate your willingness to help me.
Please take a look at the inp file if you get chance, I would be very thankful.

Thanks

Vineet
 

I am pasting a part (assembly onwards) of the input file in case you arent able to ope the file
Thanks again

** ASSEMBLY
**
*Assembly, name=Assembly
**
*Instance, name=cylinder_continuum-1, part=cylinder_continuum
-0.014393, 0.059271, -0.25
*End Instance
**
*Instance, name=base-1, part=base
0., -0.01, -0.01
*Node
1, 0.0399999991, 0.0199999996, 0.25
*Nset, nset=base-1-RefPt_, internal
1,
*Nset, nset=Set-1
1,
*Surface, type=CYLINDER, name=Surf-1
START, -0.06, 0.02
LINE, 0.04, 0.02
LINE, 0.04, 0.
LINE, -0.06, 0.
LINE, -0.06, 0.02
*End Instance
**
*Instance, name=side-1, part=side
-0.08, 0.05, -0.1975
-0.08, 0.05, -0.1975, -0.08, 0.05, -1.19750001268805, 89.9999992730282
*Node
1, 0.0399999991, 0.0199999996, 0.0625
*Nset, nset=side-1-RefPt_, internal
1,
*Nset, nset=Set-1
1,
*Surface, type=CYLINDER, name=Surf-1
START, -0.06, 0.02
LINE, 0.04, 0.02
LINE, 0.04, 0.
LINE, -0.06, 0.
LINE, -0.06, 0.02
*End Instance
**
*Instance, name=side-2, part=side
0.052475, 0.07, -0.1975
0.052475, 0.07, -0.1975, 0.052475, 0.07, 0.802500012688052, 89.9999992730282
*Node
1, 0.0399999991, 0.0199999996, 0.0625
*Nset, nset=side-2-RefPt_, internal
1,
*Nset, nset=Set-1
1,
*Surface, type=CYLINDER, name=Surf-1
START, -0.06, 0.02
LINE, 0.04, 0.02
LINE, 0.04, 0.
LINE, -0.06, 0.
LINE, -0.06, 0.02
*End Instance
**
*Instance, name=side-3, part=side
-0.00749999999999999, 0.05, -0.105
-0.00749999999999999, 0.05, -0.105, -0.584850269189626, 0.627350269189626, -0.682350269189626, 120.
*Node
1, 0.0399999991, 0.0199999996, 0.0625
*Nset, nset=side-3-RefPt_, internal
1,
*Nset, nset=Set-1
1,
*Surface, type=CYLINDER, name=Surf-1
START, -0.06, 0.02
LINE, 0.04, 0.02
LINE, 0.04, 0.
LINE, -0.06, 0.
LINE, -0.06, 0.02
*End Instance
**
*Instance, name=side-4, part=side
0.00247495049504948, 0.0723997240119459, -0.280310697753474
0.00247495049504948, 0.0723997240119459, -0.280310697753474, 1.00247494940574, 0.0723997240119461, -0.280310697753474, 89.7149476336768
*Node
1, 0.0399999991, 0.0199999996, 0.0625
*Nset, nset=side-4-RefPt_, internal
1,
*Nset, nset=Set-1
1,
*Surface, type=CYLINDER, name=Surf-1
START, -0.06, 0.02
LINE, 0.04, 0.02
LINE, 0.04, 0.
LINE, -0.06, 0.
LINE, -0.06, 0.02
*End Instance
**
*Instance, name=indentor1-1, part=indentor1
-0.015025, 0.359252707930565, -0.21289440866557
-0.015025, 0.359252707930565, -0.21289440866557, 0.562325269189626, 0.936602977120191, -0.790244677855195, 120.
*End Instance
**
*Nset, nset=_PickedSet25, internal, instance=side-2
1,
*Nset, nset=_PickedSet27, internal, instance=side-1
1,
*Nset, nset=_PickedSet29, internal, instance=base-1
1,
*Nset, nset=_PickedSet33, internal, instance=side-3
1,
*Nset, nset=_PickedSet35, internal, instance=side-4
1,
*Nset, nset=_PickedSet46, internal, instance=indentor1-1
227,
*Nset, nset=_PickedSet47, internal, instance=indentor1-1, generate
1, 226, 1
*Elset, elset=_PickedSet47, internal, instance=indentor1-1, generate
1, 225, 1
*Nset, nset=_PickedSet55, internal, instance=indentor1-1
227,
*Nset, nset=_PickedSet57, internal, instance=base-1
1,
*Nset, nset=_PickedSet58, internal, instance=side-3
1,
*Nset, nset=_PickedSet59, internal, instance=side-2
1,
*Nset, nset=_PickedSet60, internal, instance=side-1
1,
*Nset, nset=_PickedSet61, internal, instance=side-4
1,
*Nset, nset=_PickedSet63, internal, instance=cylinder_continuum-1, generate
351, 368, 1
*Elset, elset=_PickedSet63, internal, instance=cylinder_continuum-1
241, 242, 245, 251, 254, 255, 256, 257, 258, 259, 260, 262, 272, 273, 274, 275
276, 277
** Constraint: Constraint-1
*Rigid Body, ref node=_PickedSet46, elset=_PickedSet47, tie nset=indentor1-1.Set-1
** Constraint: Constraint-2
*Rigid Body, ref node=_PickedSet25, analytical surface=side-2.Surf-1
** Constraint: Constraint-3
*Rigid Body, ref node=_PickedSet27, analytical surface=side-1.Surf-1
** Constraint: Constraint-4
*Rigid Body, ref node=_PickedSet29, analytical surface=base-1.Surf-1
** Constraint: Constraint-6
*Rigid Body, ref node=_PickedSet33, analytical surface=side-3.Surf-1
** Constraint: Constraint-7
*Rigid Body, ref node=_PickedSet35, analytical surface=side-4.Surf-1
*End Assembly
*Amplitude, name=Amp-1, definition=SMOOTH STEP
0., 0., 1., 50000.
*Amplitude, name=Amp-2, definition=EQUALLY SPACED, fixed interval=1.
0., 0.02
**
** MATERIALS
**
*Material, name=Rubber
*Density
1060.,
*Hyperelastic, n=3, ogden, moduli=LONG TERM
-33500.1, 9.7472, 14975.1, 10.9494, 24865.5, 7.8076, 0., 0.
0.,
*Viscoelastic, time=PRONY
0.219264, 0., 1.9389
0.198434, 0., 8.0788
0.29583, 0., 44.0865
**
** INTERACTION PROPERTIES
**
*Surface Interaction, name=Frictionless
1.,
*Friction
0.,
*Surface Interaction, name="Hard contact"
1.,
*Surface Behavior, pressure-overclosure=HARD
**
** INTERACTIONS
**
** Interaction: frictionlesss
*Contact Pair, interaction=Frictionless, type=SURFACE TO SURFACE
cylinder_continuum-1.Surf-1, indentor1-1.Surf-1
** ----------------------------------------------------------------
**
** STEP: dynamic
**
*Step, name=dynamic, nlgeom=YES, inc=100000
*Dynamic
1e-05,1.,1e-06
**
** BOUNDARY CONDITIONS
**
** Name: BC-7 Type: Displacement/Rotation
*Boundary
cylinder_continuum-1.Set-2, 1, 1
cylinder_continuum-1.Set-2, 2, 2
cylinder_continuum-1.Set-2, 3, 3
cylinder_continuum-1.Set-2, 4, 4
cylinder_continuum-1.Set-2, 5, 5
cylinder_continuum-1.Set-2, 6, 6
** Name: BC-8 Type: Symmetry/Antisymmetry/Encastre
*Boundary
_PickedSet63, PINNED
** Name: base Type: Displacement/Rotation
*Boundary
_PickedSet57, 1, 1
_PickedSet57, 2, 2
_PickedSet57, 3, 3
_PickedSet57, 4, 4
_PickedSet57, 5, 5
_PickedSet57, 6, 6
** Name: bottom Type: Displacement/Rotation
*Boundary
_PickedSet58, 1, 1
_PickedSet58, 2, 2
_PickedSet58, 3, 3
_PickedSet58, 4, 4
_PickedSet58, 5, 5
_PickedSet58, 6, 6
** Name: probe Type: Displacement/Rotation
*Boundary, amplitude=Amp-2
_PickedSet55, 1, 1
_PickedSet55, 2, 2, -1.
_PickedSet55, 3, 3
_PickedSet55, 4, 4
_PickedSet55, 5, 5
_PickedSet55, 6, 6
** Name: side_lefy Type: Displacement/Rotation
*Boundary
_PickedSet60, 1, 1
_PickedSet60, 2, 2
_PickedSet60, 3, 3
_PickedSet60, 4, 4
_PickedSet60, 5, 5
_PickedSet60, 6, 6
** Name: side_rt Type: Displacement/Rotation
*Boundary
_PickedSet59, 1, 1
_PickedSet59, 2, 2
_PickedSet59, 3, 3
_PickedSet59, 4, 4
_PickedSet59, 5, 5
_PickedSet59, 6, 6
** Name: top Type: Displacement/Rotation
*Boundary
_PickedSet61, 1, 1
_PickedSet61, 2, 2
_PickedSet61, 3, 3
_PickedSet61, 4, 4
_PickedSet61, 5, 5
_PickedSet61, 6, 6
**
** OUTPUT REQUESTS
**
*Restart, write, number interval=1, time marks=NO
**
** FIELD OUTPUT: F-Output-1
**
*Output, field, number interval=20, time marks=NO
*Node Output
A, RF, U, V
*Element Output, directions=YES
E, MISES, S
*Contact Output
CSTRESS,
**
** HISTORY OUTPUT: force
**
*Output, history, frequency=1
*Contact Output, master=indentor1-1.Surf-1, slave=cylinder_continuum-1.Surf-1
CFN2, CFNM
**
** HISTORY OUTPUT: H-Output-1
**
*Output, history, time interval=0.05, time marks=NO
*Energy Output
ALLAE, ALLCD, ALLDMD, ALLEE, ALLFD, ALLIE, ALLJD, ALLKE, ALLKL, ALLPD, ALLQB, ALLSD, ALLSE, ALLVD, ALLWK, ETOTAL
*Contact Output
CSTRESS,
*End Step
 
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