Damage tolerant cork based composites for aerospace applications

Abstract

AbstractThis work aims at improving the resilience and damage tolerant properties of CFRP by using cork, which is a natural material with good energy absorption capacity and thermal insulating and vibration damping characteristics. Two types of materials were considered: a sandwich formed by carbon-epoxy facesheets with a cork-epoxy core and a carbon-epoxy laminate with embedded cork granulates. The damage tolerant properties were evaluated by low velocity impact tests according to the type of material. Additionally, this work intends to evaluate the feasibility of using a cork agglomerate combined with CFRP in a sandwich configuration in order to improve the aeroelastic properties of certain types of aerospace components aiming at preventing the occurrence of damage due to flutter. A computational analysis was used to determine the critical flutter speed of a cork based sandwich plate and other conventional materials, such as aluminium alloy and CFRP.Results are clear about the benefits of using cork based composites either by improving the damage tolerant properties under impact loading or by extending the flight envelope without weight penalty by increasing the flutter critical speed.