Continuous Curing and Induced Thermal Stresses of a Thick Filament Wound Composite Cylinder

Abstract

A new composite manufacturing technique called continuous curing is discussed and analyzed. This method is especially suited to the manufacture of thick composite materials in which thermal spiking is a common problem. Thermal and cure fronts are propagated in the thickness direction as material is accreted on the outer surface. An experimental apparatus was designed and built for use with a filament winder to continuously cure thick composite cylinders. A demonstration experiment was carried out using IM6/3501-6 graphite/epoxy prepreg tow. A hoop-wound composite cylinder with 152 mm wall thickness was manufactured and embedded thermocouples and strain gages were monitored throughout the cure process. Results indicate that very thick and good quality composite cylinders can be fabricated without long manufacturing time, material degradation due to thermal spiking, and high level of thermally induced residual stresses.