Structural responses of offshore multi-body floating photovoltaic array under different connection conditions

• The outer floats and connectors formed the outer-frame integrity phenomenon that plays a critical role in maintaining the array stability. • Floats interconnected by rigid connectors are most significantly influenced by the surrounding floats, which will increase the axial stress on the connectors, thereby increasing the potential for fracture. • Flexible connections experience the highest axial forces due to the sudden straightening of ropes. • For the second row of floats, which experienced the less mooring restraints, the closer a float is positioned at the centre, the smaller its roll motion. • The fatigue cycles experienced by the connectors attached to corner modules exhibited an increased sensitivity to the incident wave angle. The connector design plays a pivotal role in ensuring the structural integrity and operational efficiency of offshore floating photovoltaic (FPV) systems. This study aims to systematically investigate the impact of various connection types (rigid, rubber, hinged, and flexible) on the hydrodynamic response of offshore FPV arrays, as well as on the structural responses of their connectors. Firstly, a single-float model was developed, and the hydrodynamic coefficients necessary for the time-domain analysis were meticulously derived using frequency-domain methods. Subsequently, a 3 × 3 FPV array model was constructed, including the connectors with specifications tailored to the stiffness and constraints of the four distinct connection types. Finally, a comparative analysis was conducted on the motion responses of the three representative modules (central, edge, and corner), along with the corresponding connectors’ responses. This study demonstrates that floats interconnected by rigid connectors are most significantly influenced by the surrounding floats. The outer floats, in conjunction with their connectors, constitute an outer-frame integrity phenomenon that plays a critical role in maintaining the array stability. Furthermore, the fatigue cycles experienced by the connectors attached to corner modules exhibited an increased sensitivity to the incident wave angle, highlighting the importance of precise wave direction considerations.