A Model for the Equilibrated Co-Cure of Honeycomb Core Sandwich Structures in Autoclave Processing

Abstract

Honeycomb core sandwich structures can be fabricated in the co-cure process by bonding partially cured thermoset prepreg sheets with an adhesive layer to either side of the honeycomb core structure under a selected pressure and temperature cycle in the autoclave. The co-cure of honeycomb core sandwich structures is strongly dependent on many materials and process parameters such as prepreg facesheet consolidation, adhesive bond-line fillet formation, porosity development within facesheets and the adhesive, and the dynamic core pressure. This paper describes the fundamental physics associated with the co-cure process of sandwich structures and present numerical models describing the facesheet consolidation, adhesive bond-line fillet formation, and bond-line porosity during the co-cure process.