Hybrid fabrication route - Cost efficient CFRP primary airframe structures

Abstract

This paper presents a new production method for carbon fibre reinforced airframe structures (CFRP). The manufacturing process of CFRP structures is the basic element to control the success and cost of a composite component. Unfortunately highest structural performance will often not be achieved along with low manufacturing costs producing a CFRP assembly in a single manufacturing system (pure Prepreg or pure liquid Resin Infusion LRI). In large assemblies such as stringer stiffened panels geometric simple but heavy loaded components may be preferably layed up by automated Prepreg tape laying systems. More complex components such as stringers or frames can be cost efficiently manufactured in LRI processes. Due to similar infusion cycles and/or cure cycles of prepreg and LRI processes the next step for reducing the production costs is to use an integral process for integral structures, the so called hybrid fabrication route. This hybrid fabrication route is based on the combination of the two industrially well established production methods: the Prepreg- and the LRI Technology. This technology comprises both, maximum structural performance and low manufacturing cost for large integral airframe structures. For a fundamental assessment of this new procedure numerous experimental investigations were carried out referring mainly to the characterisation of the contact zone which is formed in the considered case of two-matrix materials.