When running an analysis and then checking the output, I have noticed that for some reason the allowable stress in the code check is changing. The allowable stress box has not been ticked and hence as it is 'distributive' the allowable stress should remain the same as previous elements. This is not the case though, can anyone advice where I am going wrong? Thanks

Which code are you using, which load case type (OPE/SUS/EXP) are you refering to and does it change once, or for almost every element?

thanks for replying corne.it is the pd8010 part two code check. it is an operating load case. it's only two elements as far as i can tell, one of them is a weldolet connection, it doesnt seem to happen if i take off the SIF on that element, however i have several other SIF's in he model that arent affected.

The offshore Codes supported by CAESAR II all have multiple "code stress" and "code allowable" equations to check. For a number of reasons (page size and the ability to use multiple Codes in the same job) CAESAR II only reports one Code stress and one Code allowable.

In the case of PD-8010-2 there is a hoop stress requirement and an equivalent stress requirement. Both checks are made by CAESAR II. Then the ratio of "code stress / code allowable" is determined for both the hoop and equivalent conditions. Which ever ratio is larger determines which Code and Allowable stress appears in the output. You can determine which stress you're looking at (either hoop or equivalent) by comparing the allowable to Sy to obtain the multiplier from Table 2 of PD-8010-2.

thanks richard, that makes sense as there is change in od at the weldolet. i had entered a different value of allowable stress factor from those in pd8010 as the piping is duplex (both equivalent and hoop stress design factor is 0.8), do you know what value it assumes for equivalent stress design factor if a value that is not in Table 2 is entered for the hoop? Thanks