Current trends in wind turbine blade manufacturing aim at increasing the fibre deposit rate by placing stacks of binder-stabilised non-crimp fabrics directly in the main casting mould. However, fibre wrinkles may arise at geometric transitions. Fibre wrinkling is one of the most severe manufacturing defects in fibre-reinforced polymer composite structures. For large offshore wind turbine blades, even a small wrinkle in the fibre reinforcement fabrics of a few centimetres in size can severely decrease the load-carrying capabilities and lead to premature failure of the blade. The amount of wrinkling arising in composite structures during manufacturing can be limited by using process simulations to find the right configuration of material and process parameters. However, no predictive models currently exist for predicting wrinkles in thick binder-stabilised preforms used for blade manufacturing.

In this PhD project, a new advanced mechanical model of a preform that can describe the response before, during, and after wrinkling has been developed. Furthermore, a complete experimental framework for accurately characterising the preform material has been developed. This simulation framework has been used to generate new knowledge on how to avoid wrinkles during the manufacturing of wind turbine blades with preforms.