[QUESTION] Offshore structure H beam CODE check practice

[offshorejhlee]

Hello off-str-engineers,

As to the Rolled H section and Built-up H section, I have very basic questions about offshore topside structure design code check.

1. Is there any difference in the aspect of Code check? Especially AISC code.
There might be some differences in code check between Built-up and Rolled.

2. Is there any SACS options for Built-up and rolled beam?
In actual situation, I have never seen anyone who applies the built-up or rolled H beam.

3. Is "this sentence" correct?
"the most offshore topside structural design codes are based on AISC for H beams and API for tubulars."
I have designed about 6 offshore steel structures such as FPSO and Jackets which are installed in Africa, Asia and North Sea for 8 years. However, I have never seen other topside design codes. (Except only one Eurocode design for Aluminum structure)
Is this a normal practice? or are there any other practices?

4. Any difference for Fatigue check between Rolled and Built-up H section?

Thank you for your help in advance.

 

[Crannog]

4. Any difference for Fatigue check between Rolled and Built-up H section?

Easy answer for this one, yes. There are significant differences between rolled and built H's for fatigue. Having a look through Appendix A of DNV RP-C203 (or similar) will tell you a lot of what you need to know. Disregarding the geometry differences the addition of welds (and weld defects) plays a major part in fatigue analysis.

 

[Jason8zhu]

"the most offshore topside structural design codes are based on AISC for H beams and API for tubulars."
-- Totally agree.

 

[andriver]

I know SACS has a built-up-member option, but I don't think this addresses your question. I am not sure if it is doing any different code check for the built-up vs the catalog of standard rolled shapes.