Load combination

I used the load combination task to input the combination rules and factors as i found it to be quicker than teddy input. But when i did a simple comparison of a load comb with pz value at a support , the sofistik value was much higher that manual summation of pz values of individual load cases with factors. I would like to know how Sofistik does the combining of forces when we assign to “use the most unfavorable case” etc in load case type…

image

Check the report output.
In a text version I include “Echo Opt Fact Val Yes”
Then you can see the included loadcases and used factors

Hello,

with your description it is not clear which task (program) you have used.
SOFiSTiK offers in the SSD the task ‘Combine loads’. Here the program SOFiLOAD is used. For the load case combination it is necessary to input each load case with its factor which should be used in the load combination.

Or do you have used the task ‘Superpositioning’ in combination with the task ‘Define combinations’. Here results from initial load cases are superimposed with action combinations. The program is MAXIMA. For these action combination MAXIMA calculates the used load cases and its used final factors automatically according to the given design code.

For more information please see our the Online Tutorials. The link you can find in the SSD:
Help → Online Help → Tutorials
than under Tutorials → Superpositions

Regards
Sabine Fahrendholz
Productmanagement

Hi Sabine ,

Thanks for the clarity. It seems i had given a dead load factor of 1.0 for settlement load defined in load case manager in Sofiplus. Also i had considered the settlement load as add always (G perm) in combination definition . It seems the two settlement loads that were defined added up rather than take the most unfavorable. Now its is sorted . Thank you.

Also , If i define combination and use MAXIMA , can i get using ‘REPORTS’ the exact load cases and factors considered for the results ?

Hi,

thank you for the information.

The program MAXIMA has a load case tracer in version 2020. More information about the tracer can you find in the MAXIMA manual record TRAC or in the Online Tutorial ‘Superposition of Load Groups’ which has example files.

Another way to check the resulting factors is to use the ECHO option of MAXIMA:

  • ECHO CHCK prints the most relevant max and min values with the determined factors
  • ECHO LOAD,FACT in addition with the selection of an element or node in record SUPP … FROM TO INC prints the determination of the factors for the selected elements or nodes.

Regards
Sabine Fahrendholz
Product Managment