Hollow pyramidal lattice truss structures

Abstract

Abstract Pyramidal lattice core sandwich structures with millimeter scale hollow trusses have been assembled from 304 stainless steel tubes and bilayer face sheets, and bonded using a vacuum brazing approach. Rigid, large interfacial area nodes between the trusses and face sheets could be made by this approach. The through-thickness compression and transverse shear stiffness and strengths of these structures have been measured and compared with analytical predictions based upon plastic yielding and the various modes of lattice strut buckling. The compressive and shear strengths of hollow pyramidal lattices with relative densities of 1 to 6 % were 3 to 5 times those of solid pyramidal lattices of equivalent relative density and were accompanied by significant strength retention of the post buckled structures resulting in very high specific energy absorption.