Response Control of TLP Using Tuned Mass Dampers

Offshore tension leg platform (TLP) is a compliant type offshore structure where the tendons are deployed under initial pretension to counteract the excessive buoyancy. TLPs show large amplitude response under environmental loads due to their compliancy, which poses threat under extreme loads. Use of passive dampers like Tuned Mass Damper (TMD) is common to control such large amplitude motion, however their deployment in offshore structures is relatively new. Response control of a scaled model of TLP is attempted using tuned mass damper of pendulum type under regular waves. Based on the experimental studies carried out, it is seen that there is a significant reduction in the surge response under the folded pendulum type damper. Results also show that there is a reduction in the heave response due to the control envisaged in the surge motion. The discussed method of response control is one of the effective methods of retrofitting offshore platforms whose operability at rough sea states is a serious concern.