Experimental and numerical studies on dynamic performances of the hybrid modular floating structure system

The present work mainly reports experimental and numerical studies on dynamic performances of the chain-type hybrid multi-module floating structure (HMFS) system under typical wave conditions. For the HMFS system, box-type modules are arranged outermost with functions of floating breakwaters for better anti-wave effect, and semi-sub modules are arranged internally for functions of production and living due to superior hydrodynamic performance. The outermost module is hinged with its adjacent module with an additional Wave Energy Converter (WEC), and semi-sub modules are mutually connected by hinges with torsional stiffness. Numerical analysis has been conducted through ANSYS AQWA based on potential flow theory and structural dynamic method, and scaled physical model tests have been conducted in a wave-current flume laboratory. WECs driven by parallel-shaft gears and hinge connectors with additional linear torsional stiffness are specially designed. The effect of the WEC on the main dynamic performances of the chain-type HMFS system has been studied, and results reveal that it is reasonable and feasible to attach a WEC to the outermost connector for reducing module motion responses and generating wave energy. In addition, the main experimental and numerical results have been compared systematically, which verifies the effectiveness of the coupling dynamic numerical method to a certain extent. Test results of dynamic responses under the survival sea condition demonstrate good motion performance of the system, and the extremum of connector loads can provide an experimental data basis for the design of connectors.