Experimental Testing and Numerical Analysis of a GFRP BladePole Prototype Repurposed from a Decommissioned GE37 Wind Turbine Blade

Abstract

Glass fiber–reinforced polymer (GFRP) composites are the main constituents of wind turbine blades. Due to the large numbers of wind turbine blades deployed around the globe and their limited life span of 20–25 years, millions of tons of GFRP composites are expected to be disposed of in the next 20–30 years. Economic and environmentally friendly solutions are preferable over landfilling, incineration, or physical and chemical recycling. Structural repurposing is currently the main objective for several research teams across Europe and the United States. The Re-Wind Network is focused on developing strategies and methodologies to implement decommissioned wind turbine blades in civil infrastructure. This paper is focused on testing a high-voltage transmission pole called BladePole. A 5.5-m segment cut from a GE37 wind blade equipped with connectors and with standard braced line posts was tested under gravity loading. Structural performance of the loaded prototype segment of the BladePole was studied and compared to analytical and numerical predictions to assess its efficacy for a proposed second-life application. The experimental results revealed that the current BladePole design can carry an ultimate vertical load at the braced line conductor connection location of 57.8 kN achieving a minimum safety margin of 2.5 for the proposed application. The failure mode was due to a weld fracture of the custom designed universal connector and suggests that the wind blade’s body can sustain a higher load for a larger BladePole rating or a higher safety factor.