Error in look-up table generation: which dataline entries to add? 1

[barlume]

I am playing a bit with subroutines in Abaqus 6.13 to understand how they work.
At the moment I am using a VUSDFLD to variate the stiffness/density/conductivity in a model (I defined the field variable) depending on Temperature and Position.

It seems that there are not particular errors in the .dat file for the inp file and the for files, but I got this error in the .sta file for more (180) times:

***ERROR: Internal error in look-up table generation. Check that dataline
entries are sufficient to describe the dependence in all independent
variables.

I understand that I have to correct the tables and the fields, but I am not sure what I have to add/change.
Can you help me out, please?

Thank you very much!

This is the table I used for stiffness, for instance. The data are in this order to have increasing values. E_fin is the stiffness at the final temperature (T_fin), while E_in is at the initial T (T_in). B0, B1, etc are the level in the structure, from the base to the top.

*Elastic, dependencies=2
<E_fin_B0>, 0.3,<T_fin>, , <E_fin_B0>
<E_fin_B1>, 0.3,<T_fin>, , <E_fin_B1>
<E_in_B0>, 0.3,<T_in>, , <E_in_B0>
<E_fin_B2>, 0.3,<T_fin>, , <E_fin_B2>
<E_in_B1>, 0.3,<T_in>, , <E_in_B1>
<E_in_B2>, 0.3,<T_in>, , <E_in_B2>
<E_fin_B3>, 0.3,<T_fin>, , <E_fin_B3>
<E_in_B3>, 0.3,<T_in>, , <E_in_B3>
<E_fin_B4>, 0.3,<T_fin>, , <E_fin_B4>
<E_in_B4>, 0.3,<T_in>, , <E_in_B4>
<E_fin_B5>, 0.3,<T_fin>, , <E_fin_B5>
<E_in_B5>, 0.3,<T_in>, , <E_in_B5>

 

[akabarten]

Hi,

Check and post the table after parameter substitution.
You can find it in *.pes file.

Regards,
Bartosz

 

[barlume]

Hi Bartosz,

thank you for the info about the .pes file.
Here you are the table (in Pa):

*Elastic, dependencies=2
185775736440.0, 0.3,650.0, , 185775736440.0
191678923675.0, 0.3,650.0, , 191678923675.0
207787706560.0, 0.3,300.0, , 207787706560.0
209388485381.0, 0.3,650.0, , 209388485381.0
213698948549.0, 0.3,300.0, , 213698948549.0
231432674517.0, 0.3,300.0, , 231432674517.0
238904421557.0, 0.3,650.0, , 238904421557.0
260988884463.0, 0.3,300.0, , 260988884463.0
280226732203.0, 0.3,650.0, , 280226732203.0
302367578387.0, 0.3,300.0, , 302367578387.0
333355417320.0, 0.3,650.0, , 333355417320.0
355568756289.0, 0.3,300.0, , 355568756289.0

I have 3 more tables similar to this one (for density, conductivity and thermal expansion coefficient).
What do you think I should modify/add?

Thank you very much for your help

 

[akabarten]

Hi,

Abaqus Analysis User's Manual, 21.1.2 Material data definition, Specifying material data as functions of temperature and independent field variables:

the variation of the properties with respect to the first variable must be given at fixed values of the other variables, in ascending values of the second variable, then of the third variable, and so on.

In different words material properties can go down, up or be constant.
With independent variables is different, they must increase in specific order.

In your definition of *ELASTIC we have:
- E - material properties
- v - material properties
- T - 1st independent variable
- FV1 - 2nd independent variable
- FV2 - 3rd independent variable

It means correct definition is:

**
**  E,   v,   T,  FV1,   FV2
**----------100-------------
**--------10---------
 10.0, 0.3, 1.0, 10.0, 100.0
 10.0, 0.3, 2.0, 10.0, 100.0
 10.0, 0.3, 3.0, 10.0, 100.0
 10.0, 0.3, 4.0, 10.0, 100.0
**--------20---------
 10.0, 0.3, 1.0, 20.0, 100.0
 10.0, 0.3, 2.0, 20.0, 100.0
 10.0, 0.3, 3.0, 20.0, 100.0
 10.0, 0.3, 4.0, 20.0, 100.0
**--------30---------
 10.0, 0.3, 1.0, 30.0, 100.0
 10.0, 0.3, 2.0, 30.0, 100.0
 10.0, 0.3, 3.0, 30.0, 100.0
 10.0, 0.3, 4.0, 30.0, 100.0
**----------200-------------
**--------10---------
 10.0, 0.3, 1.0, 10.0, 200.0
 10.0, 0.3, 2.0, 10.0, 200.0
 10.0, 0.3, 3.0, 10.0, 200.0
 10.0, 0.3, 4.0, 10.0, 200.0
**--------20---------
 10.0, 0.3, 1.0, 20.0, 200.0
 10.0, 0.3, 2.0, 20.0, 200.0
 10.0, 0.3, 3.0, 20.0, 200.0
 10.0, 0.3, 4.0, 20.0, 200.0
**--------30---------
 10.0, 0.3, 1.0, 30.0, 200.0
 10.0, 0.3, 2.0, 30.0, 200.0
 10.0, 0.3, 3.0, 30.0, 200.0
 10.0, 0.3, 4.0, 30.0, 200.0
**----------300-------------
**--------10---------
 10.0, 0.3, 1.0, 10.0, 300.0
 10.0, 0.3, 2.0, 10.0, 300.0
 10.0, 0.3, 3.0, 10.0, 300.0
 10.0, 0.3, 4.0, 10.0, 300.0
**--------20---------
 10.0, 0.3, 1.0, 20.0, 300.0
 10.0, 0.3, 2.0, 20.0, 300.0
 10.0, 0.3, 3.0, 20.0, 300.0
 10.0, 0.3, 4.0, 20.0, 300.0
**--------30---------
 10.0, 0.3, 1.0, 30.0, 300.0
 10.0, 0.3, 2.0, 30.0, 300.0
 10.0, 0.3, 3.0, 30.0, 300.0
 10.0, 0.3, 4.0, 30.0, 300.0
**

As you can see 1st independent variable (T) is increasing for whole range you want to use (1-4)
next 2nd independent variable is increasing for his range (10-30)
and next 3rd independent variable is increasing in his range (100-300).

Since you do not use 2nd independent variable the definition is shorter:

**
**  E,   v,   T,  FV1,   FV2
**----------100-------------
 10.0, 0.3, 1.0,     , 100.0
 10.0, 0.3, 2.0,     , 100.0
 10.0, 0.3, 3.0,     , 100.0
 10.0, 0.3, 4.0,     , 100.0
**----------200-------------
 10.0, 0.3, 1.0,     , 200.0
 10.0, 0.3, 2.0,     , 200.0
 10.0, 0.3, 3.0,     , 200.0
 10.0, 0.3, 4.0,     , 200.0
**----------300-------------
 10.0, 0.3, 1.0,     , 300.0
 10.0, 0.3, 2.0,     , 300.0
 10.0, 0.3, 3.0,     , 300.0
 10.0, 0.3, 4.0,     , 300.0
**

I hope you see now that your definition does not follow this rule and you have to rearrange your table.

Regards,
Bartosz

 

[barlume]

Hi Bartosz,

thank you very much.
It is really clear and I got which was my mistake.
One of my independent variables (the last one) was indeed a dependent variable from Temperature (the stiffness itself in this case).
Now I changed it, using a completely independent variable (Z in my case) and adopted the structure you showed me and it seems that everything is working fine.
It is even more elegant.

Thank you very much again!

Cheers

Gabriele