TIME HISTORY FATIGUE ANALYSIS IN SACS

Hello All,

Greetings.

I have to perform TIME HISTORY FATIGUE ANALYSIS IN SACS, for some project as per the client requirement. I have experience in doing deterministic and spectral fatigue analysis, but time history domain is completely new to me. I have gone through the sacs wave response module and some other papers dealing with time history fatigue and got some insight regarding that but still very vague in how to perform the analysis in sacs (Procedures).

1) how to decide the time increment?

2) what is the number of frequencies to be considered & where it is going as the input in the analysis?

3) what is seed means and how to decide the number of seeds?

4) what is the time duration to be considered? ( for fixed offshore well head jacket structures)

5) How sacs will perform the Rain flow counting process?

6) What is the Return period (like 1-yr or 10-yr or 100-yr) to be considered for the Significant wave height and Dominant period?

Kindly provide me a sample time history fatigue sacs file with procedure so that I can complete my task within stipulated time. Also if permits provide me the step by step procedure write up (denoting how the input flows and the corresponding output) and some theoretical backup calculation references.

Thanks & Regards,

Vasudevan V

Structural Engineer - Offshore.