Help running abaqus explicit dynamic analysis

[Hajakala]

Hello. Can someone check my model and see what I am doing wrong?

I basically have a rigid body at the top, liquid like material in the middle and a deformable body subjected to bending in the z direction.
The model is simple but it just won't run at all and is stuck at time 0.
I get errors saying:

***WARNING: THE ANALYSIS NEEDS AN EXTREMELY LARGE NUMBER OF INCREMENTS (MORE
THAN 2,000,000). CHECK THE PROPERTIES OF THE MOST CRITICAL
ELEMENTS AND THE DATA FILE FOR WARNING MESSAGES.


***WARNING: The ratio of maximum SPH particle velocity to sound speed for a
EOS USUP material in element set WarnElemSoundSpeedExccedRatio
exceeds the warning ratio 0.1. Either increase the sound speed or
decrease the SPH particle velocity to have more accurate results.
This message is printed in the first applicable increment, but
will not be printed during subsequent increments for the remainder
of the step.

***WARNING: Mass scaling is ignored for the elements associated with EOS
materials.

Thanks for your help.

 

[Hajakala]

-------------------------------------------------------------------------------
SOLUTION PROGRESS
-------------------------------------------------------------------------------

STEP 1 ORIGIN 0.0000

Total memory used for step 1 is approximately 116.4 megabytes.
Global time estimation algorithm will be used.
Scaling factor: 1.0000
Variable mass scaling factor at zero increment: 1.0000
STEP TOTAL CPU STABLE CRITICAL KINETIC TOTAL
INCREMENT TIME TIME TIME INCREMENT ELEMENT ENERGY ENERGY
0 0.000E+00 0.000E+00 00:00:00 8.622E-11 12116 1.294E-12 1.294E-12
INSTANCE WITH CRITICAL ELEMENT: TIM
ODB Field Frame Number 0 of 20 requested intervals at increment zero.

***WARNING: THE ANALYSIS NEEDS AN EXTREMELY LARGE NUMBER OF INCREMENTS (MORE
THAN 2,000,000). CHECK THE PROPERTIES OF THE MOST CRITICAL
ELEMENTS AND THE DATA FILE FOR WARNING MESSAGES.


***WARNING: The ratio of maximum SPH particle velocity to sound speed for a
EOS USUP material in element set WarnElemSoundSpeedExccedRatio
exceeds the warning ratio 0.1. Either increase the sound speed or
decrease the SPH particle velocity to have more accurate results.
This message is printed in the first applicable increment, but
will not be printed during subsequent increments for the remainder
of the step.


***WARNING: The ratio of maximum SPH particle velocity to sound speed for a
EOS USUP material in element set WarnElemSoundSpeedExccedRatio
exceeds the warning ratio 0.1. Either increase the sound speed or
decrease the SPH particle velocity to have more accurate results.
This message is printed in the first applicable increment, but
will not be printed during subsequent increments for the remainder
of the step.


***WARNING: The ratio of maximum SPH particle velocity to sound speed for a
EOS USUP material in element set WarnElemSoundSpeedExccedRatio
exceeds the warning ratio 0.1. Either increase the sound speed or
decrease the SPH particle velocity to have more accurate results.
This message is printed in the first applicable increment, but
will not be printed during subsequent increments for the remainder
of the step.


***WARNING: The ratio of maximum SPH particle velocity to sound speed for a
EOS USUP material in element set WarnElemSoundSpeedExccedRatio
exceeds the warning ratio 0.1. Either increase the sound speed or
decrease the SPH particle velocity to have more accurate results.
This message is printed in the first applicable increment, but
will not be printed during subsequent increments for the remainder
of the step.

2587 3.614E-07 3.614E-07 00:02:00 1.399E-10 5891 2.528E-12 -5.462E+02
INSTANCE WITH CRITICAL ELEMENT: TIM
5214 7.288E-07 7.288E-07 00:04:00 1.399E-10 6134 4.869E-12 -5.462E+02
INSTANCE WITH CRITICAL ELEMENT: TIM
7928 1.108E-06 1.108E-06 00:06:00 1.399E-10 6134 5.747E-12 -5.462E+02
INSTANCE WITH CRITICAL ELEMENT: TIM
10358 1.448E-06 1.448E-06 00:08:00 1.399E-10 6134 5.192E-12 -5.462E+02
INSTANCE WITH CRITICAL ELEMENT: TIM
12985 1.816E-06 1.816E-06 00:10:00 1.399E-10 6134 4.688E-12 -5.462E+02
INSTANCE WITH CRITICAL ELEMENT: TIM
15456 2.161E-06 2.161E-06 00:12:00 1.399E-10 6134 4.814E-12 -5.462E+02
INSTANCE WITH CRITICAL ELEMENT: TIM

 

[FEA way]

Can you attach a picture showing your model along with mesh and boundary conditions ?

 

[Hajakala]

 

[Hajakala]

 

[FEA way]

You should check which elements have the lowest stable time increment. Tyis can be done in the Mesh module. Apart from that make sure that all values (including velocity, loads and material properties) are correct and defined with consistent units.

 

[Hajakala]

Thanks for your help FEA way, would you be able to check my input file please? I am using SPH to model the liquid like substance.
Could it be that there are too many spheres? The elements have similar time increment.


*Material, name=DIE
*Density
2.3e-09,
*Elastic
131000., 0.3
*Expansion
2.7e-06,
*Material, name=PCB
*Density
1.9e-09,
*Elastic
18000., 0.2
*Expansion
1.7e-05,
*Material, name=TIM
*Density
2.7e-09,
*Eos, type=USUP
1.482e+06,0.,0.
*VISCOSITY, DEFINITION=HERSCHEL-BULKLEY
1.0, 103e-6, 192.022e-6, 0.64

Most critical elements:
Element number Rank Time increment Increment ratio
(Instance name)
----------------------------------------------------------
11207 1 8.105169E-11 1.000000E+00
TIM
11215 2 8.105169E-11 1.000000E+00
TIM
11216 3 8.105169E-11 1.000000E+00
TIM
11217 4 8.105169E-11 1.000000E+00
TIM
12295 5 8.105169E-11 1.000000E+00
TIM
12297 6 8.105169E-11 1.000000E+00
TIM
12304 7 8.105169E-11 1.000000E+00
TIM
12305 8 8.105169E-11 1.000000E+00
TIM
12306 9 8.105169E-11 1.000000E+00
TIM
13375 10 8.105169E-11 1.000000E+00
TIM

 

[Hajakala]

I forgot to attach the input file in the first thread..

 

[Mustaine3]

You stable time increment is extremely small. Check what the reason is.

 

[Hajakala]

Is it possible to view the sph in visualization like a smooth contour (CEL) or extrapolate between spheres to make it look like a contour map?

 

[FEA way]

No, in Abaqus particles are visualized as spheres and there’s no other form of display for these elements.