Why does Risa run each load combination rather than running the load cases and then superimposing them. I know that you need to run each load combination for a P-Delta analysis, but if you're not using P-Delta then why can't you superimpose the load cases? Is there a reason for this because its much quicker and RAM does is.
Tek-Tips is the largest IT community on the Internet today!
Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!
-
Congratulations TugboatEng on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!
Running Load Combo's and Cases
- Thread starter Stazz
- Start date
JoshPlumSE
Structural
RISA used load combinations because that is more accurate.
That's because of various non-linear effects (P-Delta, Tension only members, compression only springs, Direct Analysis Method's stiffness adjustmenst...et cetera,).
Technically, it would be possible for us to use one solution strategy (Load Cases) whenever non-linear effects should not be present and a seperate solution method when those effects are present. However, we have not chosen to do this at this time.
By the way, when are you allowed to solve without P-Delta these days? Wood design? It seems to me that all the new codes are really emphasizing these types of second order analysis requirements in their analysis requirements.
Josh
That's because of various non-linear effects (P-Delta, Tension only members, compression only springs, Direct Analysis Method's stiffness adjustmenst...et cetera,).
Technically, it would be possible for us to use one solution strategy (Load Cases) whenever non-linear effects should not be present and a seperate solution method when those effects are present. However, we have not chosen to do this at this time.
By the way, when are you allowed to solve without P-Delta these days? Wood design? It seems to me that all the new codes are really emphasizing these types of second order analysis requirements in their analysis requirements.
Josh
- Status
Similar threads
- Locked
- Question
- Locked
- Question