Effect of stretch mooring line on the dynamic response of the semi-submersible platform

The types of floating platforms are all need to be moored when they are working as production platforms. mooring cables are typically used to maintain a floating offshore platform in position in a sea environment. Extensive research has been carried out in the past concerning semisubmersible motion response. In the present work، firstly، Amirkabir semi-submersible platform modeling in AQWA-ANSYS software and then the effect of stretch mooring line on the motion responses of platform are investigated through frequency domain and time domain simulation. Aqwa employs a hybrid method to model the large-volume components of a structure by diffracting panels and the small cross sectional components by Morison elements. Also this software uses the three-dimensional radiation/diffraction theory. Each dynamic mooring line is modeled as a chain of Morison-type elements subjected to various external forces. The obtained result shows that increasing Stretch mooring line، could reduce motions of the platform but instead could increase the mooring line tension.

Keywords:

semisubmersible platform , radiation/diffraction theory , mooring cable , frequency domain , time domain