Experimental motion and load comparison of rigidly and hinged connected very large floating platforms

Very large floating structures (VLFS) could provide a new approach to floating wind foundations due to their capacity to host multiple wind turbines into a single platform. Nonetheless, further evidence of their motion and loading performance is needed. Among the existing options, very large hydroelastic platforms or hinged connected platforms with multiple pontoons can be deployed. However, a comparative experimental assessment of both type of platforms is missing in the literature. To this aim, we test the response of a laboratory scale rigidly and hinged connected VLFS subject to different regular wave conditions. The rigidly connected VLFS emulates a hydroelastic platform, whilst the hinged connected VLFS is built with two hinges. We demonstrate experimentally, an improved load alleviation of the hinged connected VLFS compared to the rigidly connected VLFS. Results are modelled numerically through a Discrete-Module-Beam (DMB) method. Our findings suggest that although both type of platforms can contribute to offshore survivability, hinged connected VLFS could have an edge due to an improved load alleviation. This work aims to contribute to the development of novel floating foundations and provides a benchmark experimental database for hydroelastic and hinged connected VLFS. • Experimental campaign to compare rigidly and hinged connected VLFS. • VLFS 1:100th prototype built with three pontoons and two connectors. • VLFS tested in regular waves at the Kelvin Hydrodynamics Laboratory. • Load alleviation of hinged connected VLFS demonstrated experimentally. • Discussion in the context of VLFS for offshore renewables.