Method of forming a composite structure of expandable matrix and a reinforcing medium

Abstract

A composite structure having first and second layers which are wrapped about one another to form a cylinder. The first layer is formed from an expandable film or foaming adhesive. The second layer is formed from a reinforcing member. The second layer is overlaid onto the first layer. The first and second layers are then rolled together in a jelly roll fashion. The roll is then cured to expand the film. The structure may thereafter be incorporated into a panel and drilled to receive a fastener. The composite structure is generally lightweight having a high compressive strength-to-density ratio. The physical properties of the composite structure may be tailored to a particular application. For example, the physical properties of the composite structure may be tailored to provide improved energy absorption or a reduced initial peak compressive strength. A method for forming a composite structure from an expandable film member and a reinforcing member is also provided.

Dependencies are inferred from the claim text.