Experimental study on mitigation of ice-induced vibration for offshore platforms with a tuned mass damper

Abstract

Experimental studies have been conducted on the tuned mass damper (TMD) – a passive control device. These studies investigate the feasibility that the TMD can mitigate the vibrations induced by ice forces on offshore steel jacket platforms. A TMD device was designed and manufactured with respect to an offshore oil platform. Large-scale testing is expensive and the requirements for model similarity in model-scale testing are hard to meet. Thus, an experimental technique that focuses on the control device itself and emulates the behaviour of the structure with a simulator is presented. This novel experimental system consists of a virtual part and an actual part called the semi-experimental testing system. The virtual parts include scaled external load and a scaled simplified platform model. The actual parts include the TMD device and a moving table, which is controlled by a hydraulic actuator. By introducing the interaction between the ice sheet and the structure, the performance of the device is investigated and reasons of effectiveness reduction are explained. The results show that an optimally tuned TMD can reduce the amplified response significantly under ice load action. Finally, the application possibilities of vibration absorption using TMD to other arctic offshore structures are discussed.