http://www-mech.eng.cam.ac.uk/profiles/fleck/papers/163.pdf

Fabrication and structural performance of periodic cellular metal sandwich structures

The elastic moduli of single layer graphene sheet (SLGS) have been a subject of intensive research in recent years. Calculations of these effective properties range from molecular dynamic simulations to use of structural mechanical models. On the basis of mathematical models and calculation methods, several different results have been obtained and these are available in the literature. Existing mechanical models employ Euler-Bernoulli beams rigidly jointed to the lattice atoms. In this paper we propose truss-type analytical models and an approach based on cellular material mechanics theory to describe the in-plane linear elastic properties of the single layer graphene sheets. In the cellular material model, the C-C bonds are represented by equivalent mechanical beams having full stretching, hinging, bending and deep shear beam deformation mechanisms. Closed form expressions for Young's modulus, the shear modulus and Poisson's ratio for the graphene sheets are derived in terms of the equivalent mechanical C-C bond properties. The models presented provide not only quantitative information about the mechanical properties of SLGS, but also insight into the equivalent mechanical deformation mechanisms when the SLGS undergoes small strain uniaxial and pure shear loading. The analytical and numerical results from finite element simulations show good agreement with existing numerical values in the open literature. A peculiar marked auxetic behaviour for the C-C bonds is identified for single graphene sheets under pure shear loading.

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Effective elastic mechanical properties of single layer graphene sheets.

Bioinspired engineering of honeycomb structure – Using nature to inspire human innovation

Mechanical response of Ti–6Al–4V octet-truss lattice structures

A new type of cellular material named Shellular, in which cells are composed of a continuous, smooth-curved shell according to the minimal surface theory, is proposed. Shellular specimens are fabricated using 3D lithography with negative templates and hard coating, and exhibit superb strength and stiffness at densities lower than 10(-2) Mg m(-3), incorporating benefits from hierarchical structures and constituent materials with nanosized grains.

A New Type of Low Density Material: Shellular.

Introduction. Honeycomb core. Sandwich design. Honeycomb processes. Sandwich fabrication. Structural applications. Other honeycomb applications. Honeycomb and sandwich testing. Sandwich panel repair. Appendix. Index.

Tom Bitzer

Papers

Honeycomb Technology: Materials, Design, Manufacturing, Applications and Testing