Hollow pyramidal lattice truss structures

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.

[1]  Frank W. Zok,et al.  Design of metallic textile core sandwich panels , 2003 .

[2]  Vikram Deshpande,et al.  Energy absorption of an egg-box material , 2003 .

[3]  Hilary Bart-Smith,et al.  Imperfection sensitivity of pyramidal core sandwich structures , 2007 .

[4]  Vikram Deshpande,et al.  The compressive and shear responses of corrugated and diamond lattice materials , 2006 .

[5]  Frank W. Zok,et al.  A protocol for characterizing the structural performance of metallic sandwich panels: application to pyramidal truss cores , 2004 .

[6]  H. Wadley.  Cellular Metals Manufacturing , 2002 .

[7]  M. Ashby,et al.  The topological design of multifunctional cellular metals , 2001 .

[8]  M. Ashby.  The properties of foams and lattices , 2006, Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences.

[9]  N. Fleck,et al.  The out-of-plane compressive behavior of metallic honeycombs , 2004 .

[10]  H. Wadley.  Multifunctional periodic cellular metals , 2006, Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences.

[11]  Haydn N. G. Wadley,et al.  Lattice truss structures from expanded metal sheet , 2007 .

[12]  S. Reid,et al.  METALLIC ENERGY DISSIPATING SYSTEMS. , 1978 .

[13]  M. Ashby,et al.  Effective properties of the octet-truss lattice material , 2001 .

[14]  Abdulmalik A. Alghamdi,et al.  Collapsible impact energy absorbers: an overview , 2001 .

[15]  Michael F. Ashby,et al.  Multifunctionality of cellular metal systems , 1998 .

[16]  Michael F. Ashby,et al.  Material limits for shape efficiency , 1997 .

[17]  A. Evans,et al.  Measurement and Simulation of the Performance of a Lightweight Metallic Sandwich Structure With a Tetrahedral Truss Core , 2004 .

[18]  Lorenzo Valdevit,et al.  Structural performance of near-optimal sandwich panels with corrugated cores , 2006 .

[19]  Douglas T. Queheillalt,et al.  Pyramidal lattice truss structures with hollow trusses , 2005 .

[20]  Norman A. Fleck,et al.  Fabrication and structural performance of periodic cellular metal sandwich structures , 2003 .

[21]  Anthony G. Evans,et al.  Strength optimization of metallic sandwich panels subject to bending , 2005 .

[22]  N. Fleck,et al.  The out-of-plane compressive behaviour of woven-core sandwich plates , 2004 .

[23]  N. Jones.  Several phenomena in structural impact and structural crashworthiness , 2003 .

[24]  H. G. Allen.  Analysis and design of structural sandwich panels , 1969 .

[25]  Douglas T. Queheillalt,et al.  Shear behavior of aluminum lattice truss sandwich panel structures , 2008 .

[26]  N. Fleck,et al.  Collapse of truss core sandwich beams in 3-point bending , 2001 .

[27]  Zhenyu Xue,et al.  Constitutive model for quasi‐static deformation of metallic sandwich cores , 2004 .

[28]  Haydn N. G. Wadley,et al.  Cellular metal lattices with hollow trusses , 2005 .

[29]  Norman A. Fleck,et al.  The plastic collapse and energy absorption capacity of egg-box panels , 2003 .

[30]  H. Wadley,et al.  Compressive behavior of age hardenable tetrahedral lattice truss structures made from aluminium , 2004, Acta Materialia.

[31]  Haydn N. G. Wadley,et al.  Titanium alloy lattice truss structures , 2009 .

[32]  A. G. Evans,et al.  Structural performance of metallic sandwich panels with square honeycomb cores , 2005 .

[33]  Douglas T. Queheillalt,et al.  Structural performance of metallic sandwich beams with hollow truss cores , 2006 .

[34]  H. Wadley,et al.  The compressive response of carbon fiber composite pyramidal truss sandwich cores , 2007, International Journal of Materials Research.