hi Stress Engineers

i consider a load case for occasional and same case for sustain. result are same.what purpose to mention the case in load case window.

W+P1+U1+U2+U3+WIN1+WIN3(OCC)
W+P1+U1+U2+U3+WIN1+WIN3(SUS)
In above case results are same.

The stress type (EXP, SUS, OCC, etc.) sets the formula for calculating stress and also the limit for this stress. This stress and its limit are defined by the piping code and can be modified in your CAESAR II Configuration.
Since you are looking at sustained and occasional loads here, I would expect the same formula for stress but different allowed limits.
(Another difference in CAESAR II would be that occasional load cases automatically activate snubbers, this might change the calculated forces and moments even though the stress formulae are the same.)

SUS Allowable= SH
OCC Allowable= SH*OCC Factor

Check your OCC Factor. Maybe you used zero thats why results are the same.

Hi shabeer
I guess you check restraint summery only for the load case mention.
Sus, OCC & exp have different criteria for stress checking as mr Dave already mention. Restraint load is not affected by load case selection for static analysis.


Jr park
You are talking about OCC factor one ? If occ factor is zero then allowable stress also zero & there will not be any stress checking by caesar.

Even though the occasional load factor is set to zero in the CAESAR II Configuration file, CAESAR II will not produce zero as the allowable limit for sustained and occcasional stresses. A zero for this parameter in CAESAR II indicates that the "default" value for the associated piping code be used.

How are the occasional factor
by eartquake OPE and SSE ASME B31.1 ?

For B31.1, I figure the allowed stress for sustained stress plus earthquake stress should be k*Sh where k=1.2.

You can set k=1.2 in the Config file.

thanks for all.now i undershoot.

Hi everybody, I am trying to change the Occasional Load Factor which is highlighted in the image I attached, then I exit with save, run the analysis but the allowable doesn't change, I always obtain the default ratio Occ/Sus 1.33 . The strange thing is that when I go back to the configuration window the Load Factor isn't 1.33 but the one I choosed. Is it possible I checked some options that conflicts with this parameter?
Many thanks

The occasional load factor set in the Configuration module (screen shot above) is used as a "seed value" when initializing new load cases. Once the load cases are defined, changing the Configuration has no effect.

To change the occasional load factor, on a "per load case" basis, use the "Load Case Options" tab of the "Static Load Case Editor".