In this study, a comprehensive investigation is conducted to improve a surface film resin formulation for advanced composite applications. This surface film is designed to be co-cured with a base substrate made of carbon fiber/epoxy-based prepregs. The curing behavior of an epoxy resin formulation for a prepreg with a high glass transition temperature and a surface film formulation containing a high percentage of glass microspheres were characterized by isothermal and dynamic Differential Scanning Calorimetry, and rheometry; and the cure kinetics profiles were modeled. The effects of the curing system, glass microspheres, and accelerator on cure kinetics and rheological behavior were thoroughly investigated to assess the compatibility of these two resin systems to be used in a composite lay-up. Initial trials resulted in excessive bleeding of the surface film resin, and specific improvements have been made to accelerate the reaction so that the system co-cures without bleeding.

A numerical model is developed to predict the process induced deformations of continuous fibre reinforced plastic plates which is made of AS4/8552 (Carbon fibre/epoxy) prepregs. In this way, Manufacturing costs can be reduced with elimination of trial and error approach. Sources of the process induced residual stress are clarified with the help of literature and implemented in 3D numerical model. In addition to the literature review to examine separate sources for residual stresses, an experimental measurement is conducted to observe tool part interaction which is quantified with strain gage which is embedded in prepreg. Numerical model is modified and verified with respect to overall deformation field of manufactured parts. Individual contribution of different mechanisms on overall deformation is discussed with the help of the numerical model. Moreover anisotropic friction between tool and the part is proposed to enhance the predictions of 3-D numerical model.