DYNAMIC RESPONSE ANALYSIS OF DDMS PLATFORM SUBJECTED TO ACTIONS OF WAVE GROUPS AND CURRENT FOURCES

Coupled dynamic analysis of the Deep Draft Multi-Spar (DDMS) platform and the mooring system under the action of waves and current is carried out in the time domain. Using a geometrically nonlinear finite element method, the mooring-line dynamics is simulated based on the total Lagrangian formulation. Wave groups are obtained by the JONSWAP spectrum and an empirical wave envelope spectrum involving two envelope-based factors Group Height Factor (GFH) and Group Length Factor (GLF). The results show that the wave groups have a significant effect on the motion responses of the platform and the mooring line tensions.