Deformation modelling of quasi-isotropic aerodynamic components with life cycle predictions

Abstract

The aim of this thesis is to investigate the performance of wind turbine blades during normal operational loading cases to aid the prediction of life cycles. The main aim of this work is to critically evaluate if these devices are over-engineered to withstand extreme conditions. It is already known that these systems have a number of replacements during their whole life. The rationale for this work is to develop knowledge of the mechanical material properties used for these devices and how applying normal operating loads introduce fatigue within the materials. Using analytic theories such as Classical Lamination, bending, and Runge-Kutta techniques; along with numerical simulations via ANSYS APDL & Workbench to develop representative models and simulations to draw logical conclusions to the proposed scientific hypothesis. The key findings relating to both how wind turbine blade design, materials and behaviour responses to the loading conditions imposed. The findings will enable a deeper knowledge to the wider community, outside of engineering as well as monetary reductions unless extreme events affect the devices structure. The thesis concludes that Classical Lamination Theory can be used for orthotropic models, aerospace token test pieces can be used to determine composite material properties, layup sequencing of composites yields similar results to orthotropic equivalents, the application of twisted sections within the blade geometry increases the structural stiffness of these devices, and stress calculations can be employed irrespective of modelling software.