Abstract: A composite fastener, preferably in the form of a rivet, which comprises a shank having a first head integrally formed on one end thereof, the shank and head formed of a high temperature thermoplastic matrix material selected from the group consisting of a polyether ether ketone resin and a polyamide imide resin, and having continuous reinforcing fibers, such as graphite fibers, axially oriented in substantially parallel relation throughout the shank, the fibers being flared and extending continuously into the head and substantially evenly flared and swaged therein, thereby forming a fastener having high shear and high tensile characteristics.

Abstract: A novel method of forming complex structures by using an accordion expansion process is disclosed. The process involves a plurality of flat workpieces of predesigned shapes and sizes that are positioned in such a manner, that after the workpieces have been first joined together, they are expanded to form high strength structural members of complex design.

Abstract: A method of making sandwich structures from a plurality of workpieces is disclosed. The method comprises providing a plurality of workpieces, each having principal opposed surfaces. The workpieces comprise first and second outer workpieces and at least two core workpieces. Each of the core workpieces have cutout portions defining at least one strip. The workpieces are treated at selected locations to inhibit joining at said locations. The treated workpieces are positioned in a stack contacting at their principal surfaces. The workpieces are joined, preferably by diffusion bonding, at their untreated contacting surfaces such that alternate longitudinal edges of superimposed strips are joined together and to the outer workpieces. Preferably, at least one chamber is enclosed by positioning the stacked workpieces relative to a plurality of shaping members.