High-fidelity multiaxial testing of composite substructures

This paper outlines a facility and general methodology for high-fidelity experimental characterization of complex composite substructures subjected to complex multiaxial loading conditions. The load response and failure behaviour of 'grid-scored' sandwich panels used in wind turbine blades have been investigated. A full-scale structural experimental and numerical characterization of a composite wind turbine blade has been conducted. The development of a full-scale numerical model is detailed, and the necessary experimental setup is described. Further, the numerical and experimental results obtained are compared, and an idealised set of boundary conditions for a chosen blade substructure is presented. From this, the development of a test rig suitable for representing the established loading and boundary conditions is presented, and selected experimental results are discussed. Moreover, simple failure criteria for the prediction of the onset of failure of the grid-score sandwich core have been proposed based on the experimental findings. Finally, a generic methodology for high-fidelity testing of composite substructures subjected to realistic multiaxial loading conditions has been proposed.