Study of the ultrasonic compaction process of composite laminates - part I: process modeling

Recent advances in out-of-autoclave manufacturing processes for composite materials may require the compaction of the pre-preg plies just after placing them. Ultrasonic compactors are a good solution for this task. The quality of the compaction will depend on the frequency and amplitude of the ultrasonic vibration, which produces a viscous heating in the resin. The increase in temperature liquefies the resin, thus helping the air bubbles to escape. The study of how this heat is generated and distributed is fundamental to better understand and optimize the compaction process. In this work, the formulation of a thermomechanical model for the viscous heating of an uncured laminate of pre-preg plies due to ultrasonic vibrations is presented. In addition, a thermal model for the heat transfers to obtain the temperature distribution during the compaction process of composite layers will be shown.