a1 Mechanical and Aerospace Engineering Department, University of California at Irvine, Irvine, California 92697
a2 Computer Science Department, University of California at Irvine, Irvine, California 92697
a3 Sensors and Materials Lab, HRL Laboratories, LLC, Malibu, California 90265
Recent advances in multiscale manufacturing enable fabrication of hollow-truss based lattices with dimensional control spanning seven orders of magnitude in length scale (from ∼50 nm to ∼10 cm), thus enabling the exploitation of nano-scale strengthening mechanisms in a macroscale cellular material. This article develops mechanical models for the compressive strength of hollow microlattices and validates them with a selection of experimental measurements on nickel microlattices over a wide relative density range (0.01–10%). The limitations of beam-theory-based analytical approaches for ultralight designs are emphasized, and suitable numerical (finite elements) models are presented. Subsequently, a novel computational platform is utilized to efficiently scan the entire design space and produce maps for optimally strong designs. The results indicate that a strong compressive response can be obtained by stubby lattice designs at relatively high densities (∼10%) or by selectively thickening the nodes at ultra-low densities.
(Received February 04 2013)
(Accepted May 16 2013)