The continuous curing process for thick filament wound composite structures

In this thesis a new manufacturing process for thick thermosetting matrix composites, called continuous curing, is studied. In this process cure proceeds at the same time as material is supplied, for instance by tape laying or filament winding. The cure is initiated from one side by an external heat source after a small initial thickness has been built up. A cure front, which is the idealization of a thin reaction region, forms and propagates outwards as material lay-up proceeds. With proper control the cure front speed matches the material accretion rate, leaving an uncured layer of fixed thickness near the surface where consolidation can take place.Thermo-chemical and consolidation models have been developed to study this process. The thermo-chemical model is based on coupled energy and cure reaction equations. A finite difference method is used to solve the equations. An asymptotic method is also used for the n-th order and autocatalytic cure kinetics. The consolidation model uses a rate form constitutive equation that relates the total stresses to the fiber bundle deformation and resin pressure, with the resin flow governed by Darcy's law. The stiffness and permeability of the fiber bundles are functions of the fiber volume fraction. A finite difference method is used to simulate the consolidation process.Through steady propagation of a thin reaction front, the continuous curing process is a unique technique of processing thick thermoset composites. It not only eliminates problems with conventional processing methods, but also increases production rates by combining material lay-up and curing into one single process. The models developed here provide a way to select suitable processing parameters without expensive trial-and-error experimentation.U of I OnlyETDs are only available to UIUC Users without author permissio