In a hybrid simulation, the OWT system is divided into subsystems, some modeled numerically (i.e., analytical substructure) and others experimentally tested in the laboratory (i.e., experimental substructure). These subsystems are kinematically linked in the spatial and time domains to ensure that the interaction between the subsystems is properly captured which enables accurate understanding of the response of the complete OWT structure.
The proposed coupled aero-hydro-mechanical hybrid simulation method for OWTs will enable understanding the response of the whole structure. This approach differs from the sequential iterative process currently used by design engineers. The proposed concept allows for: (1) generating real data from large-scale tests; (2) simulating the coupled aero-hydro-mechanical interaction of the whole OWT structure as opposed to the sequential iterative process currently used by design engineers; (3) applying loads to model operational conditions and extreme events; (4) investigating different soil and foundation conditions, simulating their installation in the laboratory and evaluating the response of new concepts, such as bio-inspired foundations; (5) testing new designs to identify flaws before field deployment; and (6) evaluating the response of different designs, foundation systems and investigating the effects of snap loads and anchor uplift for floating OWTs. It is also important to note that the proposed SFI facility upgrade and hybrid simulation approach can be used to simulate conditions in the five US offshore regions (North Atlantic, Mid Atlantic, Gulf of Mexico, Pacific, and Great Lakes). It is worth noting that Lehigh capabilities allow for geographically-distributed hybrid simulation where experimental tests and numerical simulations are performed at different facilities.
The project allows for understanding the behavior of OWT structures for U.S.-specific loading and geotechnical conditions and for reducing the levelized cost of energy (LCOE). The proposed concept is expected to lead to economically-competitive and resilient OWTs, development of new design standards and practices, advancing research and development, and providing validation of high-risk innovative technologies leading to a reduction of cost and risk, increased market competition, and a high pace of technical innovation.