Ultrasonic consolidation of thermoplastic composite prepreg for automated fiber placement

Abstract

To address the industrial need for manufacturing advanced thermoplastic composite parts with less energy, waste, and time and at lower cost, the feasibility of automated fiber placement using ultrasonic consolidation (UC) is investigated as an alternative to hot gas torch, laser, and infrared (IR) heating. The flexural stiffness and strength of simple flat parts made using UC and also thermal pressing per manufacturer’s specifications are measured by three-point bending and compared. Whereas UC proved to be more effective in welding polyethylene terephthalate/carbon prepreg tape than thermal pressing for both unidirectional and quasi-isotropic layups, the opposite was true for high-density polyethylene/glass, although optimal welding process parameters may not have been used. Finally, a simple transient conduction model is used to predict temperature rise in the thickening laminate and is compared to experimental measurements.