Advances in aircraft and spacecraft science

Techno-Press (테크노프레스)
권호 표지
DOI QR코드

DOI QR Code

Numerical comparison between lattice and honeycomb core by using detailed FEM modelling

  • Giuseppe, Pavano (Stress Analyst and Independent Researcher, Aerospace Sector)
  • Received : 2021.12.24
  • Accepted : 2022.06.13
  • Published : 2022.09.25
⟨ Previous Next ⟩

Abstract

The aim of this work is a numerical comparison (FEM) between lattice pyramidal-core panel and honeycomb core panel for different core thicknesses. By evaluating the mid-span deflection, the shear rigidity and the shear modulus for both core types and different core thicknesses, it is possible to define which core type has got the best mechanical behaviour for each thickness and the evolution of that behaviour as far as the thickness increases. Since a specific base geometry has been used for the lattice pyramidal core, the comparison gives us the opportunity to investigate the unit cell strut angle giving the higher mechanical properties. The presented work considers a detailed FEM modelling of a standard 3-point bending test (ASTM C393/C393M Standard Practice). Detailed FEM modelling addresses to detailed discretization of cores by means of beam elements for lattice core and shell elements for honeycomb core. Facings, instead, have been modelled by using shell elements for both sandwich panels. On lattice core structure, elements of core and facings are directly connected, to better simulate the additive manufacturing process. Otherwise, an MPC-based constraint between facings and core has been used for honeycomb core structure. Both sandwich panels are entirely built of Aluminium alloy. Prior to compare the two models, the FEM sandwich panel model with lattice pyramidal core needs to be validated with 3-point bending test experimental results, in order to ensure a good reliability of the FEM approach and of the comparison. Furthermore, the analytical validation has been performed according to Allen's theory. The FEM analysis is linear static with an increasing midspan load ranging from 50N up to 500N.

Keywords

References

  1. Allen, H.G. (2013), Analysis and Design of Structural Sandwich Panels, Pergamon, London.
  2. ASTM C393/C393M (2012), Standard Test Method for Core Shear Properties of Sandwich Constructions by Beam Flexure, ASTM International.
  3. ASTM D7250/D7250M (2016), Standard Test Method for Determining Sandwich Beam Flexural and Shear Stiffness, ASTM International.
  4. Bhate, D. (2019), "Four questions in cellular material design", Mater., 12, 1060. https://doi.org/10.3390/ma12071060
  5. Buhring, J., Nuno, M. and Schroder, K.U. (2021), "Additive manufactured sandwich structures: Mechanical characterization and usage potential in small aircraft", Aerosp. Sci. Technol., 111, 106548. https://doi.org/10.1016/j.ast.2021.106548.
  6. DIN 53293 (1982), Testing of Sandwiches; Bending Test, Standard by Deutsches Institut Fur Normung E.V.
  7. DOT/FAA/AR-MMPDS-01 (2003), Metallic Materials Properties Development and Standardization (MMPDS), U.S. Department of Transportation, FAA.
  8. Gibson, L.J. and Ashby, M.F. (1997), Cellular Solids: Structure and Properties, 2nd Edition, Cambridge University Press, Cambridge, UK.
  9. Hexcel Composites (2000), HexWeb Honeycomb Sandwich Design Technology.
  10. Tao, W. and Leu, M.C. (2016), "Design of lattice structure for additive manufacturing", Cleveland, OH, USA.
  11. Wesolowski, M., Ludewicz, J., Domski, J. and Zakrzewski, M. (2017), "Shear properties evaluation of a truss core of sandwich beams", IOP Conf. Ser.: Mater. Sci. Eng., 251(1), 012085. https://doi.org/10.1088/1757-899X/251/1/012085
  12. Wicks, N. and Hutchinson, J.W. (2001), "Optimal truss plates", Int. J. Solid. Struct., 38, 5165-5183. https://doi.org/10.1016/S0020-7683(00)00315-2.
  13. Wicks, N. and Hutchinson, J.W. (2004), "Performance of sandwich plates with truss cores", Mech. Mater., 36, 739-751. https://doi.org/10.1016/j.mechmat.2003.05.003.