Structural performance validation of a glass fibre-reinforced composite demonstrator for wind turbine blades

Abstract

As the world moves towards a more sustainable way of life, Ireland must invest significantly in creating a carbon-free energy system. Currently, in Ireland, the largest source of renewable energy is wind. According to the Irish governmentﾒs Climate Action Plan 2021, the development of offshore wind will be facilitated, including connecting at least 5 GW of offshore wind, based on competitive auctions, to the grid by 2030. The typical life span of a wind turbine is 20 years but it can be extended to 25 years or longer depending on environmental factors and the maintenance procedures. Therefore, the structural performance of rotor blades is vital to ensure a safe operation of a wind turbine during its life span. As the wind turbine blade can be considered as a slender structure, which mainly suffers flexural loading, its strength at the root region is critical in structural design.

This research focuses on validating the structural performance of a 5 metre composite demonstrator, which represents the spar cap at the root region of a 13 metre wind turbine blade. The demonstrator has a hollow rectangular cross-section and is made of glass fibre-reinforced polymer. Physical tests are carried out to investigate the demonstratorﾒs structural performance. A hydraulic actuator is used to simulate the extreme loadings that act on the wind turbine blade. During testing, both the tip deflection, strain on the external surfaces and the structural integrity are monitored to ensure the blade root region can withstand the extreme wind loadings during operation. Besides de-risking the demonstrator, test results will be used to validate a finite-element model for wind turbine blades. The model can be utilised to assist future blade design iterations and structural performance optimisation.