Robot Structural Analysis - load combinations types and load factor

[chrismcc]

Hello,
I am working to Euro code. I am interested to know what RSA does with the factors for characteristic, frequent and quasi permanent load cases - the factors which vary dependent on the category of the live load. Do I have to apply these factors manually or does RSA apply them internally?

I have set up several SLS loadcases and ascribed them to SLS:CHR and SLS:QPR all with 1.0 load factors. When I go to RC slab design do I add all of the SLS load combinations to the SLS list? Will RSA then automatically choose the correct combination to check deflection then creep? I believe that SLS:QPR should be used in the creep calculation, but I may be wrong.

Thank you for any replies.

Regards

Cmcc

[Artur.Kosakowski]

I am working to Euro code. I am interested to know what RSA does with the factors for characteristic, frequent and quasi permanent load cases - the factors which vary dependent on the category of the live load. Do I have to apply these factors manually or does RSA apply them internally?

If you generate automatic code combinations or load combinations with wizard (oads > Automatic combinations) then the factors are applied automatically. If you use Loads > Manual combinations you are supposed to define them yourself.

I have set up several SLS loadcases and ascribed them to SLS:CHR and SLS:QPR all with 1.0 load factors. When I go to RC slab design do I add all of the SLS load combinations to the SLS list? Will RSA then automatically choose the correct combination to check deflection then creep? I believe that SLS:QPR should be used in the creep calculation, but I may be wrong.

You can type all of them and Robot will use them as required by the code based on their types.

If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.

[DennisVDijk]

Hello Chris,

Maybe a usefull tip if you have a lot of loadcases and even more combinations, like in my case of an footbridge (500 combinations).

You can make a combination tabel in Excel manualy and paste it in ROBOT!

Hereby you can multiply and loadcases with a coefficent.

ULS --> Pg x yg + Pq x yq x psi0

SLS-chr --> Pg x yg,serv + Pq x yq,serv x psi0 + Pq x yq,serv x psi1

ect...

First you have to make the same columnstructure from Robot into Excel.

Than you can put in you combinations in excel manualy.

Copy, past in Combination table in Robot -->Edit mode... 

See attachment.....

[Rafal.Gaweda]

This can help:
http://forums.autodesk.com/t5/Robot-Structural-Analysis/Editing-load-cases-in-excel-API/m-p/3929901#...

[chrismcc]

Thank you for the link

[chrismcc]

Thank you. Please see my reply to Artur. I have only used manual combinations before, normally generated in excel and then copied into Robot. I find it quicker and easier to check. I have just started looking at automatic combinations, but there are lots of options. Pawel has intorduced me to another drop down menu so that is more to decipher and learn....
Thanks again.