Abstract: A sandwich structure including a core having opposing top and bottom surfaces, a plurality of discrete pins disposed through the core and extending beyond the top and bottom surfaces of the core, a face sheet on the top core surface, and a face sheet on the bottom core surface. The ends of each pin are bent over and lie between the respective core surfaces and the face sheets to secure the face sheets to the core, improve the strength of the core, and to provide a physical connection between the two face sheets. Also disclosed is a reinforced core for a sandwich structure which does not yet have the face sheets assembled to it. Also disclosed is a method of making such a reinforced core and completed sandwich structures including such a core.

Abstract: A method of making a perforated laminate wherein a pliable perforation device having plurality of holes and plurality of perforation pins in the holes is assembled on a laminate; the pins are driven through the uncured laminate to perforate the laminate; the laminate is then staged or cured with pins in place; and the pins are then removed from the cured laminate and pushed back into the perforation device for reuse thereof.

Abstract: An ultrasonic fastening system wherein an ultrasonic transducer is used to insert a plurality of fasteners supported by a compressible member into two components to be joined or a single composite part to be reinforced.