Material damping affects the vibrational response of composite wind turbine blades, which in turn has an impact on the structural stability and fatigue life of the entire system. Understanding material-level structural damping is crucial for improving the performance and reliability of wind turbines. The present work aims to develop an increased understanding of material-level structural damping and focuses on the development of a rig to reliably quantify energy dissipation properties of candidate wind turbine materials. The novel test rig employs Experimental Modal Analysis (EMA) in a vacuum to improve experimental structural damping characterization of high-modulus materials. The test rig allows for a non-constrained, free-free suspension of a sample which minimizes energy loss mechanisms that can lead to unrepresentative results. Sample excitation methods were also compared, and an automated excitation method was devised. The capabilities of the test rig are presented by the damping extraction of aluminum specimens. The results presented also quantify the component of aerodynamic damping present by comparing EMA with and without the presence of air, for several tests, allowing for the characterization of structural damping.
|Proceedings of ASME 2023 Aerospace Structures, Structural Dynamics, and Materials Conference, SSDM 2023
|ASME 2023 Aerospace Structures, Structural Dynamics, and Materials Conference
|19/06/23 → 21/06/23
- structural damping
- dynamic mechanical analysis (DMA)
- experimental modal analysis (EMA)