Time-Domain Structure Analysis of a Typical Semisubmersible Drilling Rig

This paper evaluates time-domain structure analysis approaches of a semisubmersible drilling rig using a nonlinear finite element method. Hydrodynamic random wave loads are calculated by WVTDUT, which was developed by a research group from the Dalian University of Technology. Time-domain structure analysis of a semisubmersible platform is very time consuming; simplified time-domain analysis approaches are therefore proposed to improve efficiency using equivalent time series. Validity of the approach is tested by a concrete example and simulation results are discussed in detail. The work of this paper can lead to a better understanding of structure behavior of a typical semisubmersible platform under characteristic wave loads. Performing structure analyses in time domain increases the accuracy and reliability of structure performance and the present study may be a benchmark study on time-domain structure analysis of a semisubmersible drilling rig.