Development of Ultra High-Performance Fiber reinforced concrete barge for 5 MW wind turbine

Abstract

Floating wind turbines are gaining more popularity today as one of the effective green energy harvesting systems. In the effort to reduce the cost of construction for floating wind turbines, concrete support structures and concrete barge have been developed. However, due to the concrete low tensile strength and susceptibility to chemical action and freezing temperatures, the concrete barges are designed with very large sections resulting in high energy consumption, high volume of construction materials, weightier structure and more heavy equipment for fabrication and installation. Therefore, in order to overcome these challenges, in this study Ultra High-Performance Fiber Reinforced Concrete (UHPFRC) is proposed for use in casting a barge for a floating offshore wind turbine and compared to a reinforced cement concrete (RCC) barge. The experimental tests conducted on the UHPFRC and RCC barge small sized prototypes, showed less heel on the RCC barge compared to the UHPFRC barge. However, the RCC barge experienced severe green water load which could cause it to capsize. The hydrodynamic analysis results from the finite element analysis showed less pitch motions in the UHPFRC barge in 7 out of the 12 DLCs considered. The roll motions were less than 50 in both barges with insignificant difference between them, while in heave motions, the UHPFRC barge experienced 10% to 20% less motions than the RCC barge in all 12 DLCs. In the structural analysis, the maximum deformation of the UHPFRC barge was 14 mm, which is 129% higher than the deformation of the RCC barge. In overall, the UHPFRC barge proved to be more effective in achieving better hydrodynamic motions for the barge floater in comparison to the RCC barge and can be considered as alternative to the conventional reinforced cement concrete material.