Abstract
Offshore platforms are extensively used to explore, drill, produce, storage, and transport ocean oil and/or gas resources in different depths. There are several types of offshore platforms, such as self-elevating platforms, gravity platforms, steel jacket platforms, tension leg platforms (TLPs), articulated leg platforms, guyed tower platforms, spar platforms, floating production systems, and very large floating structures. These platforms can be divided into fixed-bottom platforms and buoyant platforms, which have their own particular purposes and different configurations. To meet an increasing demand for marine sources of energy and minerals, in the past several decades, a lot of research effort has been made on offshore platforms. The related investigations are focused mainly on structure design and monitoring, damage detection, fatigue analysis and reliability assessment, mathematical modeling, and analysis of structures. Specifically, offshore platforms, which are located in a very tough ocean environment over a long period of time, are inevitably affected by environmental loading, such as waves, winds, ice, currents, flow, and earthquakes [1, 2]. The environmental loading may lead to excessive vibration of offshore platforms, thereby causing failure of deck facilities, fatigue failure of structures, inefficiency of operation, and even discomfort of crews. Note that reduction of vibration amplitude of an offshore platform by 15% can extend service life over two times and can result in decreasing expenditure on maintenance and inspection of structures [3]. Therefore, it is of great significance to explore proper ways to reduce different types of vibrations of offshore platforms, and comprehensive surveys of vibration control for offshore structures are provided by Kandasamy et al. [4] and Zhang et al. [5].