A Numerical Study Into the Use of Auxectic Structures for Structural Damping in Composite Sandwich Core Panels for Wind Turbine Blades

The ever-increasing demand for energy necessitates the use of renewable energy sources such as wind energy. Wind turbines are widely used to convert wind energy into electrical and mechanical energy, with designs constantly being improved to increase efficiency and power. The turbine blades are considered as long cantilever structures, which are susceptible to vibrations that reduce the performance of the turbine. Honeycomb and closed cell foam sandwich structures have been previously used for turbine blade planking. In this research work, the use of an auxetic core instead of a honeycomb core is proposed for use in wind turbine blades to reduce structural vibrations. Different auxetic topologies are investigated and compared with the half-power method, and their vibration and damping behavior is analyzed in comparison with the conventional honeycomb core. It has been shown through finite element analysis simulations that both the damping ratios are higher and the vibration amplitudes are lower for the auxetic as compared with conventional closed celled structures like honeycombs.