The in-plane linear elastic constants and out-of-plane bending of 3-coordinated ligament and cylinder-ligament honeycombs

• Published in: Composites science and technology Vol. 70; no. 7; pp. 1034 - 1041
• Main Authors: Alderson, A., Alderson, K.L., Chirima, G., Ravirala, N., Zied, K.M.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.07.2010; Elsevier
• Subjects: A. Smart materials; Applied sciences; B. Mechanical properties; Bending; C. Deformation; C. Elastic properties; C. Finite element analysis (FEA); Curvature; Cylinders; Exact sciences and technology; Forms of application and semi-finished materials; Honeycomb; Honeycomb construction; Ligaments; Mathematical analysis; Miscellaneous; Poissons ratio; Polymer industry, paints, wood; Technology of polymers; B. Mechanical properties; C. Finite element analysis (FEA); C. Deformation; A. Smart materials; C. Elastic properties; Elastic constant; Structure effect; Mechanical properties; Compressive strength; Experimental study; Modeling; Finite element method; Bending strength; Honeycomb structure; Poisson ratio; Numerical simulation; Acrylic polymer
• ISSN: 0266-3538; 1879-1050
• DOI: 10.1016/j.compscitech.2009.07.010

Four novel cylinder-ligament honeycombs are described, where each cylinder has 3 tangentially-attached ligaments to form either a hexagonal or re-entrant hexagonal cellular network. The re-entrant cylinder-ligament honeycombs are reported for the first time. The in-plane linear elastic constants and out-of-plane bending response of these honeycombs are predicted using finite element (FE) modelling and comparison made with hexagonal and re-entrant hexagonal honeycombs without cylinders. A laser-crafted re-entrant cylinder-ligament honeycomb is manufactured and characterized to verify the FE model. The re-entrant honeycombs display negative Poisson’s ratios and synclastic curvature upon out-of-plane bending. The hexagonal and ‘trichiral’ honeycombs possess positive Poisson’s ratios and anticlastic curvature. The ‘anti-trichiral’ honeycomb (short ligament limit) displays negative Poisson’s ratios when loaded in the plane of the honeycomb, but positive Poisson’s ratio behaviour (anticlastic curvature) under out-of-plane bending. These responses are understood qualitatively through considering deformation occurs via direct ligament flexure and cylinder rotation-induced ligament flexure.