in the static analysis, I have always combined the PSV reaction force with the sustained case directly (W+P+F) and have checked it as an occasional case. recently I have recieved a recommandation from the client to change it as per what it is normally done for a static seismic or wind load case:
L1 W+P+T+F
L2 W+P+T
L3 W+P
L4 L1-L2 (ALGEBRIC)
L5 L3+L4 (SCALAR)
my question is; is it not really overkill for a PSV reaction force to make its load case as mentioned above? if not, why should we not make such load case for spring hanger load? (both are constant point force on the system)

regards

spring hanger load is sustained load.

Regards,

See this file. Is simple, but maybe will answer to your questions. Things become more complex for non-linear systems.

Regards,

Danb,

thanks for the file, I compared the cases combined directly with those scalarly combined. it was obvious that the results from the second group of cases would be higher than the first. I think I already found my answer; the reaction force should be taken as a scalarly combination because it happens later for the system (occasionaly)and not simultaneously with other sustained load types. could you confirm?

thanks

A

I think "what" and not "when" is important.

Also see:

http://65.57.255.42/ubbthreads/ubbthreads.php?ubb=showflat&Main=8497&Number=38534#Post38534

http://65.57.255.42/ubbthreads/ubbthreads.php?ubb=showflat&Main=8848&Number=40185#Post40185

Regards,