Simulation and monitoring of the infusion of thick composites with thermoplastic acrylic resin

Abstract

Abstract. The ZEBRA project aims to advance the circular economy by creating wind turbine blades that can be completely recycled. Currently, Wind turbine blades are fabricated through Vacuum-Assisted Resin Infusion (VARI) using thermoset resins. In this endeavor, the recyclable thermoplastic resin Elium® from Arkema is utilized as a sustainable alternative to traditional thermoset resins. The production of thick and sizable components using reactive resins presents various intertwined physical aspects and difficulties, notably concerning potential overheating during the Elium® radical polymerization process. The optimization of this process necessitates the use of simulation to save the expensive time and effort caused by the experiments. However, to be reliable, these numerical methods must be validated to allow accurate predictions for potential defects with thick and complex parts. The challenge lies in flow front detection in the through-thickness direction. In this work, infusion tests were conducted for thick parts in a testing bench instrumented with a robust monitoring system. QRS sensors are placed through the part thickness to detect the front arrival instantaneously. The simulations are compared and validated to the signals of the QRS sensors for validation. Then the model was used to predict the flow behavior for more complex parts. A 3D flow is observed by the differences in permeability between the flow medium and the fabric, which induces a high difference in resin arrival times to the sensors depending on the position of sensors through the part thickness. The flow simulations showed a good approximation of the experimental results. However, deviations are observed in the flow front position, caused by the disturbance induced by the presence of the sensors.