Purpose of maxima comb numbers

SOFiSTiK Teddy
1

Hi

Can someone explain to me, the purpose of the combination rule number? As per the maxima manual 3.6 it must be assigned 1-999, but to me it seems that It can just be an arbitrary number between 1 and 999 as long as the same number i not repeated?

See snippet below:

+prog Maxima $ LM1 Envelope
head
COMB no 3 base 6300 extr 'DESI' type 'pr' titl 'LM1 Envelope'
ACT type 't1' sup 'excl'
ACT type 't2' sup 'excl'
SUPP comb 3 extr 'mami' etyp 'node' type p,ux,uy,uz titl 'LM1 Envelope'
SUPP comb 3 extr 'mami' etyp 'quad' type m,vx,vy,n titl 'LM1 Envelope'
SUPP comb 3 extr 'mami' etyp 'qnod' type m,vx,vy,n titl 'LM1 Envelope'
end

Is this number (3) used anywhere else than in SUPP? Is anything stopping me from just generating a random number which is inserted into COMB and SUPP, so I don’t have to type in a new number each time I create a maxima envelope?

2

Hello,

the number of the combination rule for actions have to be between 1 – 999 and can be freely selected. A number should not be used more than once, as otherwise the information in the database will be overwritten. This is important if you want to use the tracing of the determined load case combinations with TRAC.
Default combination numbers for the selected design code which are available in SSD task Combination Rules start with 100. The combination number is used for the superpositions SUPP and in the SSD task Combine Loads and Combine Results in the case of the automatic determination of the load case combinations using a specific action combination.

With kind regards
Sabine Fahrendholz
Senior Product Manager

3

This is exactly what I discovered after leaving the number undefined (i.e. = 1).

But that means that there’s nothing stopping me from simply adding an increasing number each time COMB is called?

Thank you very much for your reply!

4

As long as you are within the same Maxima program, you can do whatever you want.

If you need traceability between runs/programs you need unique numbers, i.e.:

  • Defining the Comb in one maxima Supp later
  • Using tracing (Trac )
5

Hello,

without an input for number 1 is used for the combinations. Different combinations should be defined with arbitrary different numbers between 1 – 999.
The tracing has to be in an own MAXIMA definition. The combinations COMB with the actions and the superpositions with SUPP can be in different MAXIMA definitions.
SOFiSTiK offers workflows where only the combinations are necessary, e.g. design of steel structures. Here the action combinations are used for the automatic determination of the resulting load case combinations.

Regards
Sabine Fahrendholz
Senior Product Manager