Böcker av Nikolaos I. Xiros

As pointed out by other researchers, hybrid structures in ocean engineering are based on flat concrete foundations. Due to wave action these foundations are exposed to different pressure distributions on the top and bottom sides. As a result, the bottom side is exposed to a saddle type pressure distribution leading to huge forces on the foundation. Indeed, such huge forces have been observed at a number of offshore platforms installed in the North Sea.In an attempt to turn a problem into an advantage, the concept in this work aims to develop an integrated system to harness and harvest ocean wave energy right at the seabed. The long-term interest is to develop integrated devices that can be used as actuators or sensors, which, due to low manufacturing cost, can be employed in large quantities for control of ocean engineering systems, e.g., maritime renewable power-plants, or monitoring of marine processes, e.g., oceanographic sensing.A key element to the proposed system is the nonlinear coupled electromechanical oscillator unit, the dynamics of which are investigated with a novel approach in this work. The fundamental nature of the oscillator at hand makes it an excellent choice for applications involving oceanic transducers consisting of a dry driving electrical stator physically separated from a wet-driven payload mechanism. Without such units available at a low cost and a large number, harvesting the energy of a vibrating plate at seabed may prove impractical.