Experimental analysis of high and steep wave impacts and related hydroelastic effects relevant for offshore structures in steel

An experimental strategy to investigate high and steep wave impacts and related hydroelastic effects relevant for offshore structures in steel is proposed. A physical model was shaped as a vertical rectangular surface-piercing column mimicking a semi-submersible leg at the scale of 1:40 and studied in irregular waves with two different setups, respectively, a rectangular A) rigid and a B) flexible panel installed in the impact zone. The measurements at discrete locations of the rigid and flexible panels are pressure and strain, respectively, synchronized with wave measurements and high-speed videos. The steps of the analysis involve preliminary hammer tests in dry flexible panel and the wave tests with setup A) and B) and their comparative analysis so to identify the features of the critical wave-impact scenarios, and those of the excited modes and involved added-mass effects. These steps are described using one of the most critical wave-impact scenarios observed in the tests.